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Case presentations and discussion
Case
Presentdoy John
A. Kastor,
and Discussion MD (Moderator)
John A. Kastor, MD (Baltimore, Maryland): We
give a proper response, I would need to know how repetitive this event was, using Holter monitoring. Michael R. Gold, MD (Baltimore, Maryland): She had one previous Holter monitoring, off P-blocker therapy, showing nonsustained polymorphic VT. We don’t know the number of episodes, as it was done CASE 1 at an outside hospital, but we have the present one GR was a 29-year-old woman with mitral valve prolapse and a 2-year history of palpitations and with a 24-hour Holter monitor, showing about 20 weakness. She recently fainted for about 5 seconds. episodes of VT up to 12 beats in duration. tachycardia worShe was given metoprolol, 100 mg a day. Later she Dr. Myerburg: The polymorphic ries me as I indicated in my presentation. I think this again lost consciousness at work while sitting in a chair. She was found unresponsive by fellow work- is a high-risk marker, particularly, when the cycle ers, but then awoke without any intervention. She lengths are that short. And, the question now is, had no chest ‘pain or palpitations. She is a social where do we go from here. worker, works at a hospital, is married, and wants to Dr. Kastor: Dr. Calkins, what do you think? become pregnant. The physical exam revealed a Hugh G. CalMns, M (Baltimore, Maryland): I agree with the commen ? ‘s that have been made so far. midsystolic click. Echocardiography showed mitral There are 2 main points: One was that during the tilt valve prolapse with mild mitral regurgitation. Left table test her symptoms were not reproduced. I think ventricular size and systolic function were normal. that’s important because a tilt table test may be a Holter monitoring revealed many episodes (Figure false positive and reproduction of symptoms is im1) of a rapid polymorphic ventricular tachycardia portant. So, I think that, to a large degree, it is a red (VT) with as many as 12 beats per episode-clearly, herring, and if anything, pregnancy would be thera polymorphic ventricular arrhythmia, She had a vasodepressor response to a,tilt table study without iso- apeutic for that condition. But that’s not the main proterenol and almost fainted after 15 minutes of up- problem here. In terms of the polymorphic VT, we’re right tilt; she had a prodrome of diaphoresis and all concerned about long QT syndrome, or some variant of that, that could kill her. I would be interested nausea that was different from any of her clinical to know if she had a stress test and what the test episodes. An electrophysiology study was normal showed. Also, we have yet to see a 12-lead electrowith no inducible supraventricular or ventricular arcardiogram (ECG). These missing pieces of inforrhythmias. We have two questions. How would you treat this mation would be useful. patient? and, What recommendations would you Dr. Kastor: Dr. Calkins, please follow up on that give to her about pregnancy? Dr. Myerburg, do you interesting observation that pregnancy would be therapeutic for the condition. have a lead-off observation? Robert J. Myerburg, MD (Miami, Florida): There Dr. Calkins: Well, pregnancy is a high-volume state and, in general, if you ask women with neurocardiare 3 factors to consider in this patient. First, mitral ogenic syncope who have had children how they felt valve prolapse; second, nonsustained polymorphic during pregnancy, they say they felt the best they VT, and third, what appears to be real neurocardiogenic syncope, assuming the syndrome is real. I do ever have, which is, I think, related to the pregnancy itself. So, the point is that pregnancy is not contranot believe that it relates directly to polymorphic indicated, indeed may even be recommended. tachycardia. And, the mitral valve prolapse, as I indicated during my earlier discussion, at least as de- Dr. Myerburg: I would not brush off the response scribed in this patient, is not a high-risk marker. So, to the tilt test, even though it didn’t reproduce the I see only one thing to worry about in regard to this clinical syndrome; the clinical syndrome may not be patient, the polymorphic tachycardia. First, I would related to that. I think that’s enough of a positive test without isoproterenol to indicate that she’s at risk for treat the neurocardiogenic syncope with a P-blocker neurocardiogenic syncope. trial and repeat the test. The drug is not contraindiArthur J. Moss, MD (Rochester, New York): I must cated during pregnancy. I don’t make much of the say I am very impressed by the syncopal episodes, mitral valve prolapse. The question is how seriously to take the short run of polymorphic tachycardia. To especially the one that occurred while she was sitting. And I have to differ with Dr. Myerburg in that I don’t put much stock in the tilt table test. I think From the Deportment of Medicine, University of Maryland Medical that has been one of the more misleading tests; it School and University of Maryland Hospital, Baltimore, Maryland. doesn’t account for people dying and it doesn’t acAddress for reprints: John A. Kastor, MD, Department of Medicine, count for syncope while sitting in a chair. That’s not University of Maryland Medical School and University of Maryland Hospital, Baltimore, Maryland 2 1201, a neurogenic syncope tilt table equivalent, and I have four cases for discussion. We will present each case, with the appropriate figures, followed by a discussion with our panelists and the audience.
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0002.9149/97/$17.00 PII SOOO2-9149(97)001’17-3
Fiiura 1 (Cow 1). One of maqy opisedu d rapid pdymwphic vwricular fuchycardiifromq Hoher monitor.
both conditions. Therefore, the neurocardiogenic part of her physiology is irrelevant to the decision making we are talking about now. I believe that for many patients with polymorphic VT, even high-risk forms, p blockers are quite good as therapy. The well’publicized case of the sudden death of the basketball player, Hank Gathers, is an example of an individual with good documentation of suppression of arrhythmia with @ blockers, who then failed to take the drug. The problem is that our present patient was on a B blocker-and I realize that adequacy of dosage is an issue-and still had as many episodes as she was having. Thus I am afraid that p blockers are not going to be adequate. Would I go further in testing with a nonselective p blocker and higher dosages? Probably. Am I optimistic that that is going to work for her? No.
think that the specificity of tilt table testing leaves a lot to be desired. Here we have a young person who has had unexplained $yncope and polymorphous nonsustained VT. I think this patient is at exceedingly high risk, despite the electrophysiologic study. Resolution: I too would like to see; a 1Zlead ECG, but I think Dr. Gold: We were very concerned about the drathis patient has a very thigh ,probability of winding matic episode of syncope that she had on ,B blockers. up with an implanted defibrillator. After much discussion, we decided to implant a deRobert G. Hauser, MC) (Minneapolis, Minnesota): fibrillator. She subsequently became pregnant, but Do we know anything about her family history? Dr. Gold: Her family history was negative. There after 4 months, had another similar episode of syncope, found herself on the floor and came to the hoswas no history of any sudden cardiac death, atrhythmia, or syncope in the family. Her, ECG WPS essen- pital. We interrogated her defibrillator (Figure 2) and tially unremarkable. She had normal corrected QT found this episode of rapid ventricular fibrillation on the stored electrogram, which was appropriately terintervals on multiple ECGs. There were, at most, I& minated by the defibrillator. She is doing well and is nor ST-T wave variations, but essentially it was a due to deliver in about 3 weeks. normal ECG. On stress’ testing, she had no arrhythDr. Kastor: The device worked, and as far as we mia and the QT intervals were shortened somewhat. know the fetus is fine. Dk-.Hauser: Any drugsk recreational or unusual? Dr. Moss: I would like to reemphasize the imporDr. Gold: No. She’s a social worker so we know that tance of unexplained syncope. That is a red flag of she doesn’t take drugs. extreme note; we all know the mistakes that were Dr. Hauser: Of course.: recently made with two athletes. You don’t get neuJoseph M. Reilly, MD [Baltimore, Maryland): I’m not anxious to treat her at all. I’m really not sure rogenic syncope running on the basketball court. You don’t get neurogenic syncope sitting in a chair. what causes her symptoms. She’s had palpitations for 2 years. She’s been treated by p blockade. I So, when you have syncope and runs of polymorphic would first try to make ,the diagnosis. It think that a VT together, you have to assume they are related. Audience question: Dr. Myerburg, in the initial prereasonable thing to give her is an event recorder. nonEven though some peoble would say that she is at sentation you said that benign monomorphic sustained VT is less threatening than polymorphic high risk for a life-threatening arrhythmia, I’m not sure what we are treating yet. So, I agree with Dr. rapid VT. How polymorphic is too polymorphic and Calkins, I would certainly put her on treadmill and how rapid is too rapid, and when do you start to worry about it? see if we couldn’t stir up something. Dr. Myerburg: You’re talking about a setting of norAudience question: I think a /? blocker seems like an appropriate approach, at least to begin with. If mal or near-normal hearts, with minimal structural there are no numbers to you are concerned about the polymorphic VT, what disease. Unfortunately, does the panel think would be an adequate dosage? guide us and my remarks were intended to give a general overview. Polymorphic VTs tend to be rapid And would a less selective p blocker than metoprolol and benign, monomorphic VTs tend to be slower. be more appropriate? Or is the panel thinking of imCertainly, when the cycle lengths are ~300 msec planting a defibrillator iquickly because this patient may be at high risk of sudden death? Dr. Kastor: Remember, the exercise test was negative. Dr. Myerburg: I have do clarify something with Dr. Moss. What I said was that I think she has the physiology of neurocardiogenic syncope. I did not say, and do not believe, that the polymorphic VT, which I think is the much more relevant clinical presenta- Figure 2 (Case 1). Syncopal ack aborted by shock from imtion, is in some way related to that. I think she has pkankde. THE MIROWSKI SYMPOSIUM
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with rates >200 beats/mm, you begin to worry. On the first tracing for this patient, there were cycle lengths down to 200 msec. At that range, and with a polymorphic pattern like that, I would worry. I will concede that there are some forms of polymorphic tachycardia that are rather better tolerated, but they tend to be the slower ones. To answer your question, I would use a range of 180-200 beats/mm with a definite polymorphic pattern as a guideline for when to be seriously concerned. Audience question: Dr. Gold, how did you know how to program her device, given the episodes of nonsustained VT. How many inappropriate shocks did she receive from her device? Dr. Gold: Actually this was her first shock. We used a device that did not provide antitachycardia pacing; it was simply a device that was to give her shocks. We programmed it so that it would only give her shocks for prolonged episodes of VT. We were concerned about the nonsustained VT. She had had several detections previously. So, of course, we use a noncommitted device that continued to senseand reconfirm during the episode. We also programmed it so that the first shock would be delayed. By using these two features, about 1% 18 set elapsed until therapy, although we didn’t have an exact time scale. In addition, because of her relatively young age and only rapid VTs, we set her rate cut-off high and gave /3 blockers. I agree with Dr. Moss that unexplained syncope is really worrisome, even in some patients without documented arrhythmia. What I do after electrophysiology studies, is infuse epinephrine to detect any form of repolarization abnormality. Dr. Myerburg: We do a fair amount of that. We studied a group of patients with ventricular tachyarrhythmia documented alinically, who had normal or near-normal hearts, and who were not inducible at baseline or with isoproterenol. We then found among them a subgroup that was inducible with epinephrine, and one of the twists in this protocol was that once we knew they were inducible with epinephrine, we did a simultaneous infusion with isoproterenol and phenylephrine to give them both (Y and p stimulation, and they again became noninducible. It was very specific for epinephrine. But, this was a very small group.1 Some of them presented with polymorphic tachycardia, some were monomorphic. But you do tind a few patients who will react this way, and I think it’s worth doing. I wouldn’t skip the isoproterenol phase to get there, but I would do it. Dr. Calkins: Dr. Moss, if her 1Zlead ECG had shown QT prolongation consistent with long QT syndrome, would you have managed this patient differently? Since the metoprolol had failed, would you have recommended a defibrillator or a higher dosage of nonselective ,8 blocker? With a long QT patient, how concerned would you be about syncope without stress,as when sitting in a chair? Dr. Moss: That was exactly the question that recently concerned Eric Prystowsky. It was almost exactly 22
THE AMERICAN JOURNAL OF CARDIOLOGY”
that kind of case-a patient with long QT syndrome-and he wanted to know what our experience was with the implanted defibrillator. Fortunately, we had just looked that up: we have 32 patients in our registry of over 2,000 patients with long QT syndrome who have had defibrillators implanted. I think that if apatient has failed p blockade, we would go with stellectomy; if it’s a chromosome 3 abnormality, we might go with tocainide or mexiletine, but I have developed a very low threshold now for putting defibrillators into these patients. If it happened once, it’s going to happen again, and there is no question but that defibrillators are effective. So, if the patient has long QT syndrome and has had a syncopal episode on @blockers, it’s surely going to happen again; I would have very little reservation about putting in a permanent implantable defibrillator in a person of this relatively young age group. So, I don’t think I would change my thinking much, particularly, since this patient was already on a moderate dosage-100 mg of metoprolol is not a low dose; One could possibly go higher, but 100 mg is not piddling. CASE2 AJ was a 26-year-old-woman in the 28th week of pregnancy with no past cardiac history. She suddenly fainted while walking to her car. There was no prodrome and she was unconscious for about 30 sec. When the paramedics arrived, she was awake and alert. While being transported to the hospital she developed a wide-complex tachycardia that degenerated into ventricular fibrillation (VF). She was cardioverted with 2 countershocks and an infusion of lidocaine was started. She denied that chest pain or dyspnea preceded either episode of syncope, but reported mild substemal chest pain on arriving at the hospital A 12-lead ECG was obtained. There was sinus rhythm and the T waves were inverted in III (Figure 3). Dr. Gold: Figure 3 was during the ambulance ride to the hospital, after she went into VF. Figure 4 was obtained sometime within 0.5 hour of that event. She had some subtle ST elevations in the inferior leads and in leads Vl and V2 on some ECGs. In some rhythm strips the ST elevations were more marked than this. Dr. K&or: She was admitted to the hospital and myocardial infarction was ruled out. The fetal ultrasound and echocardiogram were normal. The question at this point is, how would you manage her without further information? Dr. Hauser: I noticed she was treated with nifedipine. Is that correct? Dr. K&or: Yes, but we’re not supposed to know that yet. So, let’s assume at this point that this is all you know: A woman was defibrillated, has this ECG, and is pregnant. What are you going to do? Dr. Hauser: We have an echocardiogram that is normal and an ECG that has been described. We need a diagnosis before letting this patient go home. I would prefer to avoid invasion, but I am
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very concerned: she is inow 28 weeks pregnant and I do not know what her tachycardia was due to. I’ve never had an electrophysiology study done in a pregnant patient, and I would consult our electrophysiologist to determine how I might better clarify her arrhythmia. Dr. Calkins: I probably wouldn’t send her home from the hospital. I would wait until she has the baby and then sort it out. She’s 28 weeks pregnant, she has another 8 weeks to go. I think there’s no way to put in a defibrillator without risk. You can’t even do an electrophysiology study without some risk. If it were my wife, I’d keep! her in the hospital. After the baby’s born, I’d do an selectrophysiology study and then figure out how to get her home safely. Is she an HMO patient? (Laughter.) Dr. Kastor: A very relevant point. Dr. Myerburg? Dr. Myerburg: I fully agree. I think that she should be confined for the duration of the pregnancy and then worked up after delivery. Can I use nifedipine yet? Dr. Gold: Yes, that’s the next step. She stayed in the hospital, was given niffedipine, and was monitored for the remainder of her pregnancy. She stayed in the hospital. Although she was indeed an HMO patient, the HMO agreed to let’ her stay in the hospital, because no one was comfortable with sending her home. Dr. Kastor: Wonderful! For 8 weeks she was in a university hospital-among the most expensive treatment around! Dr. Gold: They wanted her transferred to a local hospital, but no one would accept that. So, we kept her in a monitor ward throughout her hospitalization and gave her the nifedipine as mentioned. Of course, she had an uneventful labor and delivery. Coronary arteriography was then performed, which was normal, A challenge with methylergonovine produced no coronary vasospasm. Now that’s where we are. The baby’s delivered. Angiogram normal. No spasm produced. Dr. Myerburg: The problem is that a negative ergonovine or methylergbnovine study 7 weeks after the event does not tell you what the state of the endothelium was at the time of the event and whether or not she might have been spasm inducible at that point. If you delay ergonovine provocation studies that long in patients in whom you suspect spasm is a mechanism, you are, going to miss, because the endothelium is only in the active state near the time the spasm occurs. Unfortunately, you are now in a situation where I don’t~think you’re going to get an answer. Dr. Kastor: I take it the physicians were. worried about the possibility of spasm, so they kept her in the hospital and put her on nifedipine, just on the basis of that ECG? Dr. Gold: Yes, basedon this ECG and her presentation. The difficulty was performing the challenge 2 months after the episode because we did not feel we could perform the ahallenge at the time.
Fiire lance.
3 (Case 2). Wdacomplex
Fiire
4 (Case 2). l l-bad
k&yccwdia
ECG on arrival
recorded
in ambu-
at hospital.
Dr. Calkius: I would definitely have done an electrophysiology study and also a stress test, and maybe based on that, an MRI scan. Dr. Gold: Her evaluation was negative. We did an electrophysiology study, which revealed nothing. Catheterization showed normal coronary arteries. A challenge showed nothing. She did not have a formal stress test but, immediately postpartum, was actively walking around the wards. She has shown no further arrhythmia. Now we were faced with a decision about what to do with her. Dr. Myerburg: If you have acetylcholine available you can get around the ergonovine issue. You can even do this during pregnancy; but it is hard to get acetylcholine. Dr. Kastor: Dr. Myerburg, tell us more about that, in case some of the audience isn’t familiar with it. Dr. Myerburg: Acetylcholine normally dilates the coronary vasculature. If the endothelium is abnormal, however, you may get a paradoxical response and induce focal spasms. Dr. Kastor: Even though the ergonovine is not positive? Dr. Myerburg: At this point you’re looking for shades of gray; acetylcholine would certainly have been safer for the fetus than ergonovine. Any evidence of spasm would lead you in the proper therapeutic direction. Dr. Gold: Well, we were unable to come up with a clear diagnosis; after much discussion, we ended up implanting a defibrillator in this woman and left her on nifedipine. It is now several months after her disTHE MIROWSKI SYMPOSIUM
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charge and she has had no further episodes; whether she will in the future, we of course don’t know. Dr. Myerburg: In our series of patients with proven spasm-related cardiac arrest, we have treated all of them save one with calcium antagonists. The exception received a defibrillator; I’ll mention her again in a moment. These patients have to be spasm inducible at baseline. That’s the problem. But if they are inducible, we can titrate spasm inducibility against the calcium antagpnist in repeated studies. If they become spasm noninducible, we let them go; we have not had any recurrent cardiac arrest in those patients. This patient, not being inducible, really creates a dilemma. Dr. Calkins: What struck me about this case is that there is really nothing to, suggest spasm, except the slight ST abnormalities after cardiac arrest, and I’m not sure what that means after some sort of rapid arrhythmia. She didn’t have any preceding chest pain. Do you usually see that? Doesn’t one usually have chest pain and then an arrest, as opposed to just showing up with VT and, then an arrest? Dr. Myerburg: Most of ‘them have chest pain. It’s the unusual cases that have truly silent ischemia, but they do occur. Dr. Gold: Our plan had been to demonstrate spasm with a challenge, even if late, and then using that to titrate therapy. We ended up in a situation where we had no endpoint for therapy. Audience question: Just a little clarification. Although we have the strip you see here, there was another one from the paramedics, which, unfortunately, was lost. There was a normal QRS interval with a normal ST segment going into fairly marked ST-segment elevation, then going right into the VF; this happened in the ambulance. This also gave us a very high suspicion of spasm. Question: Assuming there are no discharges, will you replace the device when it becomes depleted? Dr. Gold: We discussed that with the patient. Defibrillators now have life expectancies of 5-7 years, and since we think she is probably at relatively low risk, this is likely a one-shot deal. If after 5-7 years she shows no further arrhythmia, we would feel comfortable not replacing this defibrillator. Dr. Kastor: Do you think there is any relation between the tachycardia and the pregnancy? Would you advise her against becoming pregnant again? Dr. Moss: I know it sounds kind of old-fashioned, but the 1Zlead ECG had the so called Sl -Q3 inverted T pattern that is sometimes seen with acute pulmonary embolus. Pregnant women do get venostasis. Can I assume that that was excluded? Dr. Gold: She had Doppler studies, yes; she did not have an MRI Dr. Hauser: What is considered adequate prophylactic treatment for patients who have spasm-induced tachycardia? We see one or two cases a year and we always argue about whether they should be on one calcium antagonist or two. What’s your practice? Dr. Myerburg: As I mentioned a moment ago, what we have been doing is, if we can induce a spasm in 24
THE AMERICAN JOURNAL OF CARDIOLOGY”
the lab, we give calcium antagonists. If we can make them spasm noninducible, we let them go home on medical therapy, and that has worked consistently, but admittedly, only for a small group of patients. If that fails, then we would put in a defibrillator. Dr. Kastor: What about further pregnancy? Dr. Myerberg: She has a defibrillator now. There’s no reason why she shouldn’t undertake a further pregnancy.
CASE 3 A 44-year-old woman taking amitriptyline 50 mg once a day for the last year for depression had a wide-complex tachycardia. Over the past 2 months there were several episodes of rapid heart action and dizziness without chest pain, diaphoresis, or nausea. She came to the emergency department because of a prolonged episode lasting 45 minutes. On arrival, she had an unremarkable physical exam and was in normal sinus rhythm. A sustained wide-complex tachycardia then developed (Figure 5), which had an axis of about +lOO” and left bundle branch block form. The heart rate was close to 200 beats/mm; the QRScomplex interval was about 0.14 sec. She was admitted to the hospital and acute myocardial infarction ruled out. The echocardiogram was normal. What is your diagnosis of the arrhythmia, and how would you treat this patient? Dr.‘Reilly: Well, she has left bundle branch, inferior right axis tachycardia, suggesting that the origin is the right ventricular outflow tract. This would lead me to look very closely at the right ventricle to see if there was any evidence of dysplasia. I would do an electrophysiology study and see if she has more than one inducible tachycardia. If this is a right ventricular outflow tract tachycardia, then there’s good success with ablation. I think I would go in that direction first. Dr. Kastor: What do you think about the amitriptyline? Red herring or related? Dr. Reilly: Unrelated. But I would certainly like to see other data on her, such as from a 12-lead ECG. Dr. Moss: We should be suspicious that this could be a wide-complex tachycardia due to Wolff-Parkinson-White Syndrome,, and we would certainly want to look at the 1Zlead ECG in this age group. Dr. Kastor: The resting ECG was normal.
Figure
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5 (Case 3). Widecamplex
MARCH 20, 1997
tachycardia
developing
in ER.
Dr. Calkins: I agree with Dr. Reilly. It looks like idiopathic left bundle branch inferior right axis VT. With a relatively slow iachycardia the history is certainly compatible with that, so I agree that an electrophysiology study wOuld be helpful. Dr. Kastor: Do you think there is a relation to catecholamines and exercise here? Dr. Calkins: Yes, you ‘could do a stress test as part of her workup prior to the electrophysiology study, and you may or may nvt be able to induce. Dr. Kastor: But aren’t! these the patients who may ,be catecholamine depehdent?
Dr. Calkius: Yes. Question: We haven’t’ heard about termination
of this tachycardia. Did ‘it terminate spontaneously, which would be more suggestive of an outflow tract cause, or was it sustained, requiring cardioversion, which I think would be more in favor of a reentry mechanism? Dr. Gold: She actually had a second episode on the ward; both times it was sustained for several minutes, and both times it self-terminated. There were occasional periods in which she had isolated premature ventricular Complexes of the same morphology as this, but did not have any nonsustained runs. Dr. Myerburg: This sits on the borderline of what would worry me as a ri&ht ventricular dysplasia type of tachycardia. So, I ylould work her up for right ventricular dysplasia as well, but I suspect it’s going to be a benign outflow tract tachycardia. Dr. Gold: She had ain electrophysiology study, which was unrevealing, despite multiple different stimulations; and despite catecholamine infusions with both isoproterenol and epinephrine we were unable to induce tachycardia. From the electrophysiology study, however, we were able to rule out an accessory pathway, There was no evidence of any aberration or any supraventricular tachycardias. Audience question: Shouldn’t the study really be about amitriptyline? Dr. Gold: The amitrippyline had been stopped for several days, since she :had entered the hospital. Dr. Kastor: You are spggesting that a stress study with the amitriptyline on board might have been fruitful. Dr. Myerburg: How high did you go with the epinephrine in the infusion? Dr. Gold: I don’t remember the dose of epinephrine; but we pushed her resting heart rate to 1 lo-120 beats/min. Dr. Myerburg: You went over 0.3 p/kg per min?
Dr. Gold: Yes. Dr. Kastor: Dr. Myerbbrg, what is your point? Dr. Myerburg: Many protocols don’t go over 0.20.3 @kg per min of epinephrine infusion, but you can go up to 0.4,0.5, or even 0.6 and see some effect in terms of inducing the tachycardia. Dr. Gold: She was a relatively small woman, so the concentration had to be at least at 0.5.
Dr. Calkins: As far as right ventricular
dysplasia goes, I’d be reassured since she was not ,inducible. Most such patients are inducible. Dr. Myerburg: Many are inducible, but some aren’t. I would definitely get an MRI scan. Dr. Moss: Since she was depressed, did you measure blood levels, to make sure she wasn’t taking an excessive amount of amitriptyline. Also, did you make sure she did not have some acute intercurrent illness? Dr. Gold: She had had a toxic screen done when she initially presented and showed therapeutic or low therapeutic levels of amitriptyline. She was actually on quite a low dose, 25 or 50 mg. An MRI scan to rule out right ventricular dysplasia was negative and we elected to treat her with verapamil; she has done well with no further episodes. Dr. Kastor: What about the amitriptyline? Dr. Gold: She was taken off of that. The psychiatrist agreed there were many other drugs she could take, Just an anecdotal comment. We’ve had several patients who were unresponsive to provocation and upper extremity bicycle ergometry sometimes would precipitate VT. Dr. Myerburg: Because upper extremity isometrics is a powerful sympathetic stimulus, much more powerful than lower body isometrics or isotonics. Dr. K&or: That’s a good point.
CASE 4 BH was a 51-year-old former police officer with dilated cardiomyopathy first recognized in 1990, when he fainted because of spontaneous VT-i.e., this was a patient with real heart disease. Catheterization revealed normal epicardial coronary arteries and left ventricular global hypokinesis with injection fraction of 0.30. Electrophysiology studies demonstrated easily inducible sustained monomorphic VT, resistant to many class I and class III antiarrhythmic drugs, including amiodarone. A first-generation Ventak 1550 ICD was implanted. The patient had appropriate shocks every few months. At times, he received multiple shocks, which was particularly troubling to him and for which he was hospitalized repeatedly. He was treated with procainamide, mexiletine, sotalol, and amiodarone over the next 3 years. When the ICD pulse generator reached the end of its life, it was replaced with a third-generation device with antitachycardia pacing capabilities. Bouts of VT became more frequent, however, and the dose of amiodarone was increased to 600 mg/day. However, the episodes continued and he remained highly symptomatic, even with successful antitachycardia pacing and low energy shocks. Subsequently, he complained of weakness and fatigue that had lasted 2 days. On presentation to the emergency room (Figure 6) he had a slow VT at about 115 beats/min, fusing and competing with a sinus rhythm that was below the cutoff. The device was reprogrammed and the arrhythmia terminated with pacing. Audience question: Did all these VTs have the same morphology? THE MIROWSKI SYMPOSIUM
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think you’ve met this patient. What thoughts do you have? Dr. Hauser: I’d be interested in the original electrophysiology findings. We recently reviewed our implant records and found several patients who, at the time of their original electrophysiology study, had evidence for bundle branch reentry. Dr. Gold: The electrophysiology study performed by Dr. Reilly on this patient at the University pf Maryland showed multiple morphologies of sustained VT of various rates that were poorly tolerated at the time. The patient went through serial drug testing before he had\ his first defibrillator implantation. Although Figure 6 (Case 4). Ventricular iuthycardii on presentation to ER. he had multiple VTs, this was at a time when antitachycardia pacing devices were not available; this is why he received a simple device with shock-only Dr. Gold: The VTs he presented with on this ad- capabilities. mission all had the same morphology. In fact, this Dr. Hauser: Well, I’d go for the electrophysiology was after lidocaine was given to him in the emerstudy and, hopefully, an ablation. gency room. This is why it’s repetitively monomorDr. Myerburg: I agree. The use of ablation as adphic and not sustained. But he did present with sus- junctive, not as primary therapy in VT of any etioltained monomorphic VT, and the subsequent ogy can be very useful. In this situation, I would do episodes that he had spontaneously on the wards two things: go in and look for bundle branch reentry, were of similar morphology. He was also known to even accepting the former data as correct, because have had many VTs of other morphology. Over the the substrate may be changing and he may have a years, we’ve collected ECGs from most of the emer- bundle branch reentry now, and if that’s what this is, gency rooms in Baltimore on this patient and they then ablate the right bundle branch. If that’s not what have various morphologies. it is, I would map the LV and try to find an ablation Dr. Moss: He had an ejection fraction of 0.30 when site so we can get rid of this as ancillary therapy to he had the Ventak 1550 put in. It’s now 4 years later, the defibrillator as the primary backup. he’s 55, and the ejection fraction is probably lower. Dr. Kastor: The point being made is that the patient I think he’s a candidate for cardiac transplant. has a cardiomyopathy, and that’s the group in which Dr. Call&w: One other option at this stage would be we especially see bundle branch reentry. The probcatheter ablation of the slow VT. He has multiple lem, of course, is that these patients have very bad morphologies, but you can target the slow VT that ventricles and often there is more than one arrhythis causing a lot of his symptoms and then use anti- mia going on; you can cure the bundle branch reentry tachycardia pacing for the other ones that are symp- but you are then left with another reentry. What’s the tomatic. I think medical therapy certainly has failed ejection fraction now? at this point. Dr. Gold: About 0.25. Dr. Kastor: What are the chances of a cardiomyDr. Kastor: Myocardium-wise, he’s done pretty opathy like this having a successful outcome? well, as a matter of fact. Dr. Calkins: If you can induce the slow VT it’s probResolution: ably 70-80%. Dr. Gold: We all agreed that ablation was a good Dr. Reilly: One thing to consider in dilated cardio- palliative therapy for him. We went in and mapped myopathy is bundle branch reentry tachycardia, the site to the free wall of the left ventricle, and he which is curable. A lot of times patients do not need underwent successful ablation of this focus. Afterto have a defibrillator. I don’t think that’s the case ward, he still had multiple inducible VT morpholohere, because it’s such a slow VT, but he’s on a huge gies, which we did not treat, but he’s done remarkamount of amiodarone. It’s something I would con- ably well over 3 months. He’s had no emergency sider. room visits, which is a record for him. We’ve reDr. Gold: Dr. Reilly, you implanted this defibrillator. cently been able to decrease his amiodarone dose from 600 to 200 mg. So, palliatively, he’s had a very (Laughter.) Dr. Reilly: Well then, we, can assume he didn’t have good response to ablation. Dr. Kastor: It’s time to devote one of these Mibundle branch reentry after all! rowski sessions to advances in ablation. What has Dr. Kastor: We like to spring these little surprises! been going on recently is really very exciting. Now, Dr. Hauser, you live in the Midwest so I don’t
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John A. Kastor, MD (Baltimore, Maryland): We
give a proper response, I would need to know how repetitive this event was, using Holter monitoring. Michael R. Gold, MD (Baltimore, Maryland): She had one previous Holter monitoring, off P-blocker therapy, showing nonsustained polymorphic VT. We don’t know the number of episodes, as it was done CASE 1 at an outside hospital, but we have the present one GR was a 29-year-old woman with mitral valve prolapse and a 2-year history of palpitations and with a 24-hour Holter monitor, showing about 20 weakness. She recently fainted for about 5 seconds. episodes of VT up to 12 beats in duration. tachycardia worShe was given metoprolol, 100 mg a day. Later she Dr. Myerburg: The polymorphic ries me as I indicated in my presentation. I think this again lost consciousness at work while sitting in a chair. She was found unresponsive by fellow work- is a high-risk marker, particularly, when the cycle ers, but then awoke without any intervention. She lengths are that short. And, the question now is, had no chest ‘pain or palpitations. She is a social where do we go from here. worker, works at a hospital, is married, and wants to Dr. Kastor: Dr. Calkins, what do you think? become pregnant. The physical exam revealed a Hugh G. CalMns, M (Baltimore, Maryland): I agree with the commen ? ‘s that have been made so far. midsystolic click. Echocardiography showed mitral There are 2 main points: One was that during the tilt valve prolapse with mild mitral regurgitation. Left table test her symptoms were not reproduced. I think ventricular size and systolic function were normal. that’s important because a tilt table test may be a Holter monitoring revealed many episodes (Figure false positive and reproduction of symptoms is im1) of a rapid polymorphic ventricular tachycardia portant. So, I think that, to a large degree, it is a red (VT) with as many as 12 beats per episode-clearly, herring, and if anything, pregnancy would be thera polymorphic ventricular arrhythmia, She had a vasodepressor response to a,tilt table study without iso- apeutic for that condition. But that’s not the main proterenol and almost fainted after 15 minutes of up- problem here. In terms of the polymorphic VT, we’re right tilt; she had a prodrome of diaphoresis and all concerned about long QT syndrome, or some variant of that, that could kill her. I would be interested nausea that was different from any of her clinical to know if she had a stress test and what the test episodes. An electrophysiology study was normal showed. Also, we have yet to see a 12-lead electrowith no inducible supraventricular or ventricular arcardiogram (ECG). These missing pieces of inforrhythmias. We have two questions. How would you treat this mation would be useful. patient? and, What recommendations would you Dr. Kastor: Dr. Calkins, please follow up on that give to her about pregnancy? Dr. Myerburg, do you interesting observation that pregnancy would be therapeutic for the condition. have a lead-off observation? Robert J. Myerburg, MD (Miami, Florida): There Dr. Calkins: Well, pregnancy is a high-volume state and, in general, if you ask women with neurocardiare 3 factors to consider in this patient. First, mitral ogenic syncope who have had children how they felt valve prolapse; second, nonsustained polymorphic during pregnancy, they say they felt the best they VT, and third, what appears to be real neurocardiogenic syncope, assuming the syndrome is real. I do ever have, which is, I think, related to the pregnancy itself. So, the point is that pregnancy is not contranot believe that it relates directly to polymorphic indicated, indeed may even be recommended. tachycardia. And, the mitral valve prolapse, as I indicated during my earlier discussion, at least as de- Dr. Myerburg: I would not brush off the response scribed in this patient, is not a high-risk marker. So, to the tilt test, even though it didn’t reproduce the I see only one thing to worry about in regard to this clinical syndrome; the clinical syndrome may not be patient, the polymorphic tachycardia. First, I would related to that. I think that’s enough of a positive test without isoproterenol to indicate that she’s at risk for treat the neurocardiogenic syncope with a P-blocker neurocardiogenic syncope. trial and repeat the test. The drug is not contraindiArthur J. Moss, MD (Rochester, New York): I must cated during pregnancy. I don’t make much of the say I am very impressed by the syncopal episodes, mitral valve prolapse. The question is how seriously to take the short run of polymorphic tachycardia. To especially the one that occurred while she was sitting. And I have to differ with Dr. Myerburg in that I don’t put much stock in the tilt table test. I think From the Deportment of Medicine, University of Maryland Medical that has been one of the more misleading tests; it School and University of Maryland Hospital, Baltimore, Maryland. doesn’t account for people dying and it doesn’t acAddress for reprints: John A. Kastor, MD, Department of Medicine, count for syncope while sitting in a chair. That’s not University of Maryland Medical School and University of Maryland Hospital, Baltimore, Maryland 2 1201, a neurogenic syncope tilt table equivalent, and I have four cases for discussion. We will present each case, with the appropriate figures, followed by a discussion with our panelists and the audience.
20
0 1997 by Excerpta All rights reserved.
Medico,
Inc.
0002.9149/97/$17.00 PII SOOO2-9149(97)001’17-3
Fiiura 1 (Cow 1). One of maqy opisedu d rapid pdymwphic vwricular fuchycardiifromq Hoher monitor.
both conditions. Therefore, the neurocardiogenic part of her physiology is irrelevant to the decision making we are talking about now. I believe that for many patients with polymorphic VT, even high-risk forms, p blockers are quite good as therapy. The well’publicized case of the sudden death of the basketball player, Hank Gathers, is an example of an individual with good documentation of suppression of arrhythmia with @ blockers, who then failed to take the drug. The problem is that our present patient was on a B blocker-and I realize that adequacy of dosage is an issue-and still had as many episodes as she was having. Thus I am afraid that p blockers are not going to be adequate. Would I go further in testing with a nonselective p blocker and higher dosages? Probably. Am I optimistic that that is going to work for her? No.
think that the specificity of tilt table testing leaves a lot to be desired. Here we have a young person who has had unexplained $yncope and polymorphous nonsustained VT. I think this patient is at exceedingly high risk, despite the electrophysiologic study. Resolution: I too would like to see; a 1Zlead ECG, but I think Dr. Gold: We were very concerned about the drathis patient has a very thigh ,probability of winding matic episode of syncope that she had on ,B blockers. up with an implanted defibrillator. After much discussion, we decided to implant a deRobert G. Hauser, MC) (Minneapolis, Minnesota): fibrillator. She subsequently became pregnant, but Do we know anything about her family history? Dr. Gold: Her family history was negative. There after 4 months, had another similar episode of syncope, found herself on the floor and came to the hoswas no history of any sudden cardiac death, atrhythmia, or syncope in the family. Her, ECG WPS essen- pital. We interrogated her defibrillator (Figure 2) and tially unremarkable. She had normal corrected QT found this episode of rapid ventricular fibrillation on the stored electrogram, which was appropriately terintervals on multiple ECGs. There were, at most, I& minated by the defibrillator. She is doing well and is nor ST-T wave variations, but essentially it was a due to deliver in about 3 weeks. normal ECG. On stress’ testing, she had no arrhythDr. Kastor: The device worked, and as far as we mia and the QT intervals were shortened somewhat. know the fetus is fine. Dk-.Hauser: Any drugsk recreational or unusual? Dr. Moss: I would like to reemphasize the imporDr. Gold: No. She’s a social worker so we know that tance of unexplained syncope. That is a red flag of she doesn’t take drugs. extreme note; we all know the mistakes that were Dr. Hauser: Of course.: recently made with two athletes. You don’t get neuJoseph M. Reilly, MD [Baltimore, Maryland): I’m not anxious to treat her at all. I’m really not sure rogenic syncope running on the basketball court. You don’t get neurogenic syncope sitting in a chair. what causes her symptoms. She’s had palpitations for 2 years. She’s been treated by p blockade. I So, when you have syncope and runs of polymorphic would first try to make ,the diagnosis. It think that a VT together, you have to assume they are related. Audience question: Dr. Myerburg, in the initial prereasonable thing to give her is an event recorder. nonEven though some peoble would say that she is at sentation you said that benign monomorphic sustained VT is less threatening than polymorphic high risk for a life-threatening arrhythmia, I’m not sure what we are treating yet. So, I agree with Dr. rapid VT. How polymorphic is too polymorphic and Calkins, I would certainly put her on treadmill and how rapid is too rapid, and when do you start to worry about it? see if we couldn’t stir up something. Dr. Myerburg: You’re talking about a setting of norAudience question: I think a /? blocker seems like an appropriate approach, at least to begin with. If mal or near-normal hearts, with minimal structural there are no numbers to you are concerned about the polymorphic VT, what disease. Unfortunately, does the panel think would be an adequate dosage? guide us and my remarks were intended to give a general overview. Polymorphic VTs tend to be rapid And would a less selective p blocker than metoprolol and benign, monomorphic VTs tend to be slower. be more appropriate? Or is the panel thinking of imCertainly, when the cycle lengths are ~300 msec planting a defibrillator iquickly because this patient may be at high risk of sudden death? Dr. Kastor: Remember, the exercise test was negative. Dr. Myerburg: I have do clarify something with Dr. Moss. What I said was that I think she has the physiology of neurocardiogenic syncope. I did not say, and do not believe, that the polymorphic VT, which I think is the much more relevant clinical presenta- Figure 2 (Case 1). Syncopal ack aborted by shock from imtion, is in some way related to that. I think she has pkankde. THE MIROWSKI SYMPOSIUM
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with rates >200 beats/mm, you begin to worry. On the first tracing for this patient, there were cycle lengths down to 200 msec. At that range, and with a polymorphic pattern like that, I would worry. I will concede that there are some forms of polymorphic tachycardia that are rather better tolerated, but they tend to be the slower ones. To answer your question, I would use a range of 180-200 beats/mm with a definite polymorphic pattern as a guideline for when to be seriously concerned. Audience question: Dr. Gold, how did you know how to program her device, given the episodes of nonsustained VT. How many inappropriate shocks did she receive from her device? Dr. Gold: Actually this was her first shock. We used a device that did not provide antitachycardia pacing; it was simply a device that was to give her shocks. We programmed it so that it would only give her shocks for prolonged episodes of VT. We were concerned about the nonsustained VT. She had had several detections previously. So, of course, we use a noncommitted device that continued to senseand reconfirm during the episode. We also programmed it so that the first shock would be delayed. By using these two features, about 1% 18 set elapsed until therapy, although we didn’t have an exact time scale. In addition, because of her relatively young age and only rapid VTs, we set her rate cut-off high and gave /3 blockers. I agree with Dr. Moss that unexplained syncope is really worrisome, even in some patients without documented arrhythmia. What I do after electrophysiology studies, is infuse epinephrine to detect any form of repolarization abnormality. Dr. Myerburg: We do a fair amount of that. We studied a group of patients with ventricular tachyarrhythmia documented alinically, who had normal or near-normal hearts, and who were not inducible at baseline or with isoproterenol. We then found among them a subgroup that was inducible with epinephrine, and one of the twists in this protocol was that once we knew they were inducible with epinephrine, we did a simultaneous infusion with isoproterenol and phenylephrine to give them both (Y and p stimulation, and they again became noninducible. It was very specific for epinephrine. But, this was a very small group.1 Some of them presented with polymorphic tachycardia, some were monomorphic. But you do tind a few patients who will react this way, and I think it’s worth doing. I wouldn’t skip the isoproterenol phase to get there, but I would do it. Dr. Calkins: Dr. Moss, if her 1Zlead ECG had shown QT prolongation consistent with long QT syndrome, would you have managed this patient differently? Since the metoprolol had failed, would you have recommended a defibrillator or a higher dosage of nonselective ,8 blocker? With a long QT patient, how concerned would you be about syncope without stress,as when sitting in a chair? Dr. Moss: That was exactly the question that recently concerned Eric Prystowsky. It was almost exactly 22
THE AMERICAN JOURNAL OF CARDIOLOGY”
that kind of case-a patient with long QT syndrome-and he wanted to know what our experience was with the implanted defibrillator. Fortunately, we had just looked that up: we have 32 patients in our registry of over 2,000 patients with long QT syndrome who have had defibrillators implanted. I think that if apatient has failed p blockade, we would go with stellectomy; if it’s a chromosome 3 abnormality, we might go with tocainide or mexiletine, but I have developed a very low threshold now for putting defibrillators into these patients. If it happened once, it’s going to happen again, and there is no question but that defibrillators are effective. So, if the patient has long QT syndrome and has had a syncopal episode on @blockers, it’s surely going to happen again; I would have very little reservation about putting in a permanent implantable defibrillator in a person of this relatively young age group. So, I don’t think I would change my thinking much, particularly, since this patient was already on a moderate dosage-100 mg of metoprolol is not a low dose; One could possibly go higher, but 100 mg is not piddling. CASE2 AJ was a 26-year-old-woman in the 28th week of pregnancy with no past cardiac history. She suddenly fainted while walking to her car. There was no prodrome and she was unconscious for about 30 sec. When the paramedics arrived, she was awake and alert. While being transported to the hospital she developed a wide-complex tachycardia that degenerated into ventricular fibrillation (VF). She was cardioverted with 2 countershocks and an infusion of lidocaine was started. She denied that chest pain or dyspnea preceded either episode of syncope, but reported mild substemal chest pain on arriving at the hospital A 12-lead ECG was obtained. There was sinus rhythm and the T waves were inverted in III (Figure 3). Dr. Gold: Figure 3 was during the ambulance ride to the hospital, after she went into VF. Figure 4 was obtained sometime within 0.5 hour of that event. She had some subtle ST elevations in the inferior leads and in leads Vl and V2 on some ECGs. In some rhythm strips the ST elevations were more marked than this. Dr. K&or: She was admitted to the hospital and myocardial infarction was ruled out. The fetal ultrasound and echocardiogram were normal. The question at this point is, how would you manage her without further information? Dr. Hauser: I noticed she was treated with nifedipine. Is that correct? Dr. K&or: Yes, but we’re not supposed to know that yet. So, let’s assume at this point that this is all you know: A woman was defibrillated, has this ECG, and is pregnant. What are you going to do? Dr. Hauser: We have an echocardiogram that is normal and an ECG that has been described. We need a diagnosis before letting this patient go home. I would prefer to avoid invasion, but I am
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very concerned: she is inow 28 weeks pregnant and I do not know what her tachycardia was due to. I’ve never had an electrophysiology study done in a pregnant patient, and I would consult our electrophysiologist to determine how I might better clarify her arrhythmia. Dr. Calkins: I probably wouldn’t send her home from the hospital. I would wait until she has the baby and then sort it out. She’s 28 weeks pregnant, she has another 8 weeks to go. I think there’s no way to put in a defibrillator without risk. You can’t even do an electrophysiology study without some risk. If it were my wife, I’d keep! her in the hospital. After the baby’s born, I’d do an selectrophysiology study and then figure out how to get her home safely. Is she an HMO patient? (Laughter.) Dr. Kastor: A very relevant point. Dr. Myerburg? Dr. Myerburg: I fully agree. I think that she should be confined for the duration of the pregnancy and then worked up after delivery. Can I use nifedipine yet? Dr. Gold: Yes, that’s the next step. She stayed in the hospital, was given niffedipine, and was monitored for the remainder of her pregnancy. She stayed in the hospital. Although she was indeed an HMO patient, the HMO agreed to let’ her stay in the hospital, because no one was comfortable with sending her home. Dr. Kastor: Wonderful! For 8 weeks she was in a university hospital-among the most expensive treatment around! Dr. Gold: They wanted her transferred to a local hospital, but no one would accept that. So, we kept her in a monitor ward throughout her hospitalization and gave her the nifedipine as mentioned. Of course, she had an uneventful labor and delivery. Coronary arteriography was then performed, which was normal, A challenge with methylergonovine produced no coronary vasospasm. Now that’s where we are. The baby’s delivered. Angiogram normal. No spasm produced. Dr. Myerburg: The problem is that a negative ergonovine or methylergbnovine study 7 weeks after the event does not tell you what the state of the endothelium was at the time of the event and whether or not she might have been spasm inducible at that point. If you delay ergonovine provocation studies that long in patients in whom you suspect spasm is a mechanism, you are, going to miss, because the endothelium is only in the active state near the time the spasm occurs. Unfortunately, you are now in a situation where I don’t~think you’re going to get an answer. Dr. Kastor: I take it the physicians were. worried about the possibility of spasm, so they kept her in the hospital and put her on nifedipine, just on the basis of that ECG? Dr. Gold: Yes, basedon this ECG and her presentation. The difficulty was performing the challenge 2 months after the episode because we did not feel we could perform the ahallenge at the time.
Fiire lance.
3 (Case 2). Wdacomplex
Fiire
4 (Case 2). l l-bad
k&yccwdia
ECG on arrival
recorded
in ambu-
at hospital.
Dr. Calkius: I would definitely have done an electrophysiology study and also a stress test, and maybe based on that, an MRI scan. Dr. Gold: Her evaluation was negative. We did an electrophysiology study, which revealed nothing. Catheterization showed normal coronary arteries. A challenge showed nothing. She did not have a formal stress test but, immediately postpartum, was actively walking around the wards. She has shown no further arrhythmia. Now we were faced with a decision about what to do with her. Dr. Myerburg: If you have acetylcholine available you can get around the ergonovine issue. You can even do this during pregnancy; but it is hard to get acetylcholine. Dr. Kastor: Dr. Myerburg, tell us more about that, in case some of the audience isn’t familiar with it. Dr. Myerburg: Acetylcholine normally dilates the coronary vasculature. If the endothelium is abnormal, however, you may get a paradoxical response and induce focal spasms. Dr. Kastor: Even though the ergonovine is not positive? Dr. Myerburg: At this point you’re looking for shades of gray; acetylcholine would certainly have been safer for the fetus than ergonovine. Any evidence of spasm would lead you in the proper therapeutic direction. Dr. Gold: Well, we were unable to come up with a clear diagnosis; after much discussion, we ended up implanting a defibrillator in this woman and left her on nifedipine. It is now several months after her disTHE MIROWSKI SYMPOSIUM
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charge and she has had no further episodes; whether she will in the future, we of course don’t know. Dr. Myerburg: In our series of patients with proven spasm-related cardiac arrest, we have treated all of them save one with calcium antagonists. The exception received a defibrillator; I’ll mention her again in a moment. These patients have to be spasm inducible at baseline. That’s the problem. But if they are inducible, we can titrate spasm inducibility against the calcium antagpnist in repeated studies. If they become spasm noninducible, we let them go; we have not had any recurrent cardiac arrest in those patients. This patient, not being inducible, really creates a dilemma. Dr. Calkins: What struck me about this case is that there is really nothing to, suggest spasm, except the slight ST abnormalities after cardiac arrest, and I’m not sure what that means after some sort of rapid arrhythmia. She didn’t have any preceding chest pain. Do you usually see that? Doesn’t one usually have chest pain and then an arrest, as opposed to just showing up with VT and, then an arrest? Dr. Myerburg: Most of ‘them have chest pain. It’s the unusual cases that have truly silent ischemia, but they do occur. Dr. Gold: Our plan had been to demonstrate spasm with a challenge, even if late, and then using that to titrate therapy. We ended up in a situation where we had no endpoint for therapy. Audience question: Just a little clarification. Although we have the strip you see here, there was another one from the paramedics, which, unfortunately, was lost. There was a normal QRS interval with a normal ST segment going into fairly marked ST-segment elevation, then going right into the VF; this happened in the ambulance. This also gave us a very high suspicion of spasm. Question: Assuming there are no discharges, will you replace the device when it becomes depleted? Dr. Gold: We discussed that with the patient. Defibrillators now have life expectancies of 5-7 years, and since we think she is probably at relatively low risk, this is likely a one-shot deal. If after 5-7 years she shows no further arrhythmia, we would feel comfortable not replacing this defibrillator. Dr. Kastor: Do you think there is any relation between the tachycardia and the pregnancy? Would you advise her against becoming pregnant again? Dr. Moss: I know it sounds kind of old-fashioned, but the 1Zlead ECG had the so called Sl -Q3 inverted T pattern that is sometimes seen with acute pulmonary embolus. Pregnant women do get venostasis. Can I assume that that was excluded? Dr. Gold: She had Doppler studies, yes; she did not have an MRI Dr. Hauser: What is considered adequate prophylactic treatment for patients who have spasm-induced tachycardia? We see one or two cases a year and we always argue about whether they should be on one calcium antagonist or two. What’s your practice? Dr. Myerburg: As I mentioned a moment ago, what we have been doing is, if we can induce a spasm in 24
THE AMERICAN JOURNAL OF CARDIOLOGY”
the lab, we give calcium antagonists. If we can make them spasm noninducible, we let them go home on medical therapy, and that has worked consistently, but admittedly, only for a small group of patients. If that fails, then we would put in a defibrillator. Dr. Kastor: What about further pregnancy? Dr. Myerberg: She has a defibrillator now. There’s no reason why she shouldn’t undertake a further pregnancy.
CASE 3 A 44-year-old woman taking amitriptyline 50 mg once a day for the last year for depression had a wide-complex tachycardia. Over the past 2 months there were several episodes of rapid heart action and dizziness without chest pain, diaphoresis, or nausea. She came to the emergency department because of a prolonged episode lasting 45 minutes. On arrival, she had an unremarkable physical exam and was in normal sinus rhythm. A sustained wide-complex tachycardia then developed (Figure 5), which had an axis of about +lOO” and left bundle branch block form. The heart rate was close to 200 beats/mm; the QRScomplex interval was about 0.14 sec. She was admitted to the hospital and acute myocardial infarction ruled out. The echocardiogram was normal. What is your diagnosis of the arrhythmia, and how would you treat this patient? Dr.‘Reilly: Well, she has left bundle branch, inferior right axis tachycardia, suggesting that the origin is the right ventricular outflow tract. This would lead me to look very closely at the right ventricle to see if there was any evidence of dysplasia. I would do an electrophysiology study and see if she has more than one inducible tachycardia. If this is a right ventricular outflow tract tachycardia, then there’s good success with ablation. I think I would go in that direction first. Dr. Kastor: What do you think about the amitriptyline? Red herring or related? Dr. Reilly: Unrelated. But I would certainly like to see other data on her, such as from a 12-lead ECG. Dr. Moss: We should be suspicious that this could be a wide-complex tachycardia due to Wolff-Parkinson-White Syndrome,, and we would certainly want to look at the 1Zlead ECG in this age group. Dr. Kastor: The resting ECG was normal.
Figure
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MARCH 20, 1997
tachycardia
developing
in ER.
Dr. Calkins: I agree with Dr. Reilly. It looks like idiopathic left bundle branch inferior right axis VT. With a relatively slow iachycardia the history is certainly compatible with that, so I agree that an electrophysiology study wOuld be helpful. Dr. Kastor: Do you think there is a relation to catecholamines and exercise here? Dr. Calkins: Yes, you ‘could do a stress test as part of her workup prior to the electrophysiology study, and you may or may nvt be able to induce. Dr. Kastor: But aren’t! these the patients who may ,be catecholamine depehdent?
Dr. Calkius: Yes. Question: We haven’t’ heard about termination
of this tachycardia. Did ‘it terminate spontaneously, which would be more suggestive of an outflow tract cause, or was it sustained, requiring cardioversion, which I think would be more in favor of a reentry mechanism? Dr. Gold: She actually had a second episode on the ward; both times it was sustained for several minutes, and both times it self-terminated. There were occasional periods in which she had isolated premature ventricular Complexes of the same morphology as this, but did not have any nonsustained runs. Dr. Myerburg: This sits on the borderline of what would worry me as a ri&ht ventricular dysplasia type of tachycardia. So, I ylould work her up for right ventricular dysplasia as well, but I suspect it’s going to be a benign outflow tract tachycardia. Dr. Gold: She had ain electrophysiology study, which was unrevealing, despite multiple different stimulations; and despite catecholamine infusions with both isoproterenol and epinephrine we were unable to induce tachycardia. From the electrophysiology study, however, we were able to rule out an accessory pathway, There was no evidence of any aberration or any supraventricular tachycardias. Audience question: Shouldn’t the study really be about amitriptyline? Dr. Gold: The amitrippyline had been stopped for several days, since she :had entered the hospital. Dr. Kastor: You are spggesting that a stress study with the amitriptyline on board might have been fruitful. Dr. Myerburg: How high did you go with the epinephrine in the infusion? Dr. Gold: I don’t remember the dose of epinephrine; but we pushed her resting heart rate to 1 lo-120 beats/min. Dr. Myerburg: You went over 0.3 p/kg per min?
Dr. Gold: Yes. Dr. Kastor: Dr. Myerbbrg, what is your point? Dr. Myerburg: Many protocols don’t go over 0.20.3 @kg per min of epinephrine infusion, but you can go up to 0.4,0.5, or even 0.6 and see some effect in terms of inducing the tachycardia. Dr. Gold: She was a relatively small woman, so the concentration had to be at least at 0.5.
Dr. Calkins: As far as right ventricular
dysplasia goes, I’d be reassured since she was not ,inducible. Most such patients are inducible. Dr. Myerburg: Many are inducible, but some aren’t. I would definitely get an MRI scan. Dr. Moss: Since she was depressed, did you measure blood levels, to make sure she wasn’t taking an excessive amount of amitriptyline. Also, did you make sure she did not have some acute intercurrent illness? Dr. Gold: She had had a toxic screen done when she initially presented and showed therapeutic or low therapeutic levels of amitriptyline. She was actually on quite a low dose, 25 or 50 mg. An MRI scan to rule out right ventricular dysplasia was negative and we elected to treat her with verapamil; she has done well with no further episodes. Dr. Kastor: What about the amitriptyline? Dr. Gold: She was taken off of that. The psychiatrist agreed there were many other drugs she could take, Just an anecdotal comment. We’ve had several patients who were unresponsive to provocation and upper extremity bicycle ergometry sometimes would precipitate VT. Dr. Myerburg: Because upper extremity isometrics is a powerful sympathetic stimulus, much more powerful than lower body isometrics or isotonics. Dr. K&or: That’s a good point.
CASE 4 BH was a 51-year-old former police officer with dilated cardiomyopathy first recognized in 1990, when he fainted because of spontaneous VT-i.e., this was a patient with real heart disease. Catheterization revealed normal epicardial coronary arteries and left ventricular global hypokinesis with injection fraction of 0.30. Electrophysiology studies demonstrated easily inducible sustained monomorphic VT, resistant to many class I and class III antiarrhythmic drugs, including amiodarone. A first-generation Ventak 1550 ICD was implanted. The patient had appropriate shocks every few months. At times, he received multiple shocks, which was particularly troubling to him and for which he was hospitalized repeatedly. He was treated with procainamide, mexiletine, sotalol, and amiodarone over the next 3 years. When the ICD pulse generator reached the end of its life, it was replaced with a third-generation device with antitachycardia pacing capabilities. Bouts of VT became more frequent, however, and the dose of amiodarone was increased to 600 mg/day. However, the episodes continued and he remained highly symptomatic, even with successful antitachycardia pacing and low energy shocks. Subsequently, he complained of weakness and fatigue that had lasted 2 days. On presentation to the emergency room (Figure 6) he had a slow VT at about 115 beats/min, fusing and competing with a sinus rhythm that was below the cutoff. The device was reprogrammed and the arrhythmia terminated with pacing. Audience question: Did all these VTs have the same morphology? THE MIROWSKI SYMPOSIUM
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think you’ve met this patient. What thoughts do you have? Dr. Hauser: I’d be interested in the original electrophysiology findings. We recently reviewed our implant records and found several patients who, at the time of their original electrophysiology study, had evidence for bundle branch reentry. Dr. Gold: The electrophysiology study performed by Dr. Reilly on this patient at the University pf Maryland showed multiple morphologies of sustained VT of various rates that were poorly tolerated at the time. The patient went through serial drug testing before he had\ his first defibrillator implantation. Although Figure 6 (Case 4). Ventricular iuthycardii on presentation to ER. he had multiple VTs, this was at a time when antitachycardia pacing devices were not available; this is why he received a simple device with shock-only Dr. Gold: The VTs he presented with on this ad- capabilities. mission all had the same morphology. In fact, this Dr. Hauser: Well, I’d go for the electrophysiology was after lidocaine was given to him in the emerstudy and, hopefully, an ablation. gency room. This is why it’s repetitively monomorDr. Myerburg: I agree. The use of ablation as adphic and not sustained. But he did present with sus- junctive, not as primary therapy in VT of any etioltained monomorphic VT, and the subsequent ogy can be very useful. In this situation, I would do episodes that he had spontaneously on the wards two things: go in and look for bundle branch reentry, were of similar morphology. He was also known to even accepting the former data as correct, because have had many VTs of other morphology. Over the the substrate may be changing and he may have a years, we’ve collected ECGs from most of the emer- bundle branch reentry now, and if that’s what this is, gency rooms in Baltimore on this patient and they then ablate the right bundle branch. If that’s not what have various morphologies. it is, I would map the LV and try to find an ablation Dr. Moss: He had an ejection fraction of 0.30 when site so we can get rid of this as ancillary therapy to he had the Ventak 1550 put in. It’s now 4 years later, the defibrillator as the primary backup. he’s 55, and the ejection fraction is probably lower. Dr. Kastor: The point being made is that the patient I think he’s a candidate for cardiac transplant. has a cardiomyopathy, and that’s the group in which Dr. Call&w: One other option at this stage would be we especially see bundle branch reentry. The probcatheter ablation of the slow VT. He has multiple lem, of course, is that these patients have very bad morphologies, but you can target the slow VT that ventricles and often there is more than one arrhythis causing a lot of his symptoms and then use anti- mia going on; you can cure the bundle branch reentry tachycardia pacing for the other ones that are symp- but you are then left with another reentry. What’s the tomatic. I think medical therapy certainly has failed ejection fraction now? at this point. Dr. Gold: About 0.25. Dr. Kastor: What are the chances of a cardiomyDr. Kastor: Myocardium-wise, he’s done pretty opathy like this having a successful outcome? well, as a matter of fact. Dr. Calkins: If you can induce the slow VT it’s probResolution: ably 70-80%. Dr. Gold: We all agreed that ablation was a good Dr. Reilly: One thing to consider in dilated cardio- palliative therapy for him. We went in and mapped myopathy is bundle branch reentry tachycardia, the site to the free wall of the left ventricle, and he which is curable. A lot of times patients do not need underwent successful ablation of this focus. Afterto have a defibrillator. I don’t think that’s the case ward, he still had multiple inducible VT morpholohere, because it’s such a slow VT, but he’s on a huge gies, which we did not treat, but he’s done remarkamount of amiodarone. It’s something I would con- ably well over 3 months. He’s had no emergency sider. room visits, which is a record for him. We’ve reDr. Gold: Dr. Reilly, you implanted this defibrillator. cently been able to decrease his amiodarone dose from 600 to 200 mg. So, palliatively, he’s had a very (Laughter.) Dr. Reilly: Well then, we, can assume he didn’t have good response to ablation. Dr. Kastor: It’s time to devote one of these Mibundle branch reentry after all! rowski sessions to advances in ablation. What has Dr. Kastor: We like to spring these little surprises! been going on recently is really very exciting. Now, Dr. Hauser, you live in the Midwest so I don’t
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THE AMERICAN
JOURNAL
OF CARDIOLOGY@
VOL.
79 (6A)
MARCH
20,
1997