Direct Current Countershock: Long Term Follow-up*

Direct Current Countershock: Long Term Follow-up* BERNARD L. CHARMS, M.D., F.C.C.P., JOSEF EDELSTEIN, M.D., ALAN KAMEN, M.D. AND ALBERTO GoLDBARG, M.D.

Cleveland, Ohio

T

H E WORK OF LoWN DEMONSTRATING

the ease, safety, and high rate of success in the treatment of arrhythmias by direct current countershock has been confirmed by numerous investigators'?' This, together with the knowledge that cardiac output is decreased when arrhythmias are present," justifies the wide use of this procedure. Little has been reported concerning the longer range results in cardioverted arrhythmias-infonnation that might be of value in predicting long-term benefit in these patients. It is the purpose of this paper to review our experience and analyze long-term follow-up in patients treated by this method. MATERIALS AND METHODS

Sixty-six adult patients underwent direct current countershock during the period of January, 1963 to March, 1965. Their ages ranged from the second to the eighth decade of life. They were generally in an older age group, 34 being over 60 years of age. Fifty-six had one, four had two, and six had three separate cardioversions for a total of 82 treatments. Twenty-eight had coronary artery disease, 27 rheumatic heart disease, and the remainder had other pathology or heart disease of undetermined etiology. When the procedure was performed electively, it was carried out in the recovery room. The patients were in a fasting state and pre-medicated one hour before with an intramuscular barbiturate. Light general anesthesia, using a rapid-acting intravenous barbiturate, was preferred. Occasionally, because of the serious life-threatening nature of the arrhythmia, cardioversion was done as an emergency. It was carried out *From the Cardio-Pulmonary Laboratory, Mount Sinai Hospital of Cleveland.

in the emergency room, or at the bedside with intravenous narcotics or barbiturates." Several patients were discharged only hours after conversion to normal sinus rhythm. A 12 lead electrocardiogram was taken prior to, and shortly after cardioversion. The patients were monitored on an oscilloscope throughout the procedure. The Lawn Direct Current Cardioverter was used with the technique described elsewhere." The earlier conversions employed 3.5 inch electrodes placed at the base and apex of the heart. However, most of the cardioversions were done with five inch anterior-posterior paddles. The energy initially used varied from 50 to 100 watts/ second and was gradually increased until success or inability to convert at 400 watts/ second. At first those patients with atrial fibrillation were given quinidine for at least a day before cardioversion; more recently, patients were only given quinidine starting at the time of conversion with 0.16 gm. of quinidine gluconate intramuscularly and thereafter orally as maintenance sufficient to produce an adequate blood level and avoid some of the complications reported in those cardioverted while on quinidine therapy." Anticoagulants were used in 45 patients. The indication used was chronic atrial fibrillation. Acute arrhythmias were not routinely anticoagulated. Conversion was considered successful in this series if normal sinus rhythm was restored for at least six hours after electrical countershock was applied. If the original arrhythmia recurred before this time, it was considered unsuccessful. RESULTS

Eighty-two arrhythmias were treated in 66 patients with 68 reversions to normal sinus rhythm (83 per cent). Eighty-seven 232

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per cent of those undergoing a single cardioversion converted; however, only 73 per cent subjected to multiple treatments changed to normal sinus rhythm. Tables 1 and 2 outline the type and duration of arrhythmias. There was no apparent relationship of successful conversions to the patient's age, arrhythmia, or etiology of heart disease (Table 3). Those with arrhythmias lasting over one year had a lower rate of successful conversions. Thirteen of the 34 with rheumatic heart disease had combined valvular lesions. All were successfully converted compared with 71 per cent when only the mitral valve W;lS involved, this being contrary to previous observations," (Table 4 ). One patient could not be successfully converted for any length of time from ventricular tachycardia because of a ventricular aneurysm. Subsequent to its removal, the patient maintained a normal sinus rhythm. Two attempts in another patient with the small paddles were failures, but a third countershock five months later with the larger anterior-posterior paddles was successful. CoMPUCATlONS AND ASSOCIATED ARRHYTHMIAS

There was no fatality or serious complication in our experience. Three patients had first degree chest wall burns which healed without sequela. One with an unsuccessful cardioversion developed a transient current of injury and another had a right bundle branch block after the procedure. Two had embolic phenomena associated with the procedure; one had a cerebrovascular accident 24 hours later

despite anticoagulant therapy; the other, who maintained a normal sinus rhythm only 12 hours after countershock and then relapsed to atrial fibrillation, subsequently had a cerebral embolism. Both had a satisfactory recovery. Twelve had temporary arrhythmias postconversion including first degree A-V block, premature beats (atrial, ventricular, nodal), nodal rhythm, paroxysmal atrial tachycardia with 2: 1 block, and A-V dissociation. None was of serious consequence. Most were felt to be due to digitalis which apparently is required in higher dosage for control of atrial fibrillation than it is for a heart in normal sinus rhythm.'•.1f FOLLOW-UP

The period of follow-up ranged from three to 26 months. Thirty-one patients (47 per cent) remained in normal sinus rhythm. Thirty-two (48 per cent) had reverted to the previous arrhythmia; three were lost to follow-up. With two exceptions, all patients unable to maintain a normal mechanism reverted to their original arrhythmias within three months. Those with rheumatic heart disease (64 per cent) and hypertensive cardiovascular disease (56 per cent) had a higher incidence of reversion to their arrhythmias than those with coronary artery disease (38 per cent) . DISCUSSION

This study confirms previous work in demonstrating the ease and safety of cardioversion. However, our success rate of 83 per cent was somewhat less than reported by Lawn and associates' and Morris and co-workers' who had 91 per cent and 94 per cent in their series. It is not clear why our results are poorer-s-our cri-

TABLE I-RESULTS OF CAamOVEaSION IN DIFFERENT ARRHYTHMIAS

Type of Arrhythmia

Atrial flutter Atrial fibrillation Atrial tachycardia Ventricular tachycardia

Number of Cases

13 61 4

4 82

Converted to Normal (Per Cent) 10 (77) 53 (87) 3 (75)

~ 68 (83)

TABLE 2-DuRATlON OF AaaHYTRMIA AND RESULTS OF CAIlDIOVERSION

Number Duration of Arrhythmia of Cues

1 week 1 week-l year 1 year Unknown

36 23 19 4

Successful Convenion (Per Cent) 29 (81)

23 (100) 12 (63) 4 (100)

CHARMS,

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TABLE 3-RELATIONSHIP BETWEEN ETIOLOGY OF HEART DISEASE AND SUCCESSFUL CONVERSION

Type of Heart Disease

Number of Patients

Number of Cardiovenions

Successful Convenion

17 4 9 25 2 2 2 5

23 4 10 34 2 2 2 5 82

19 2 9

Coronary artery disease Coronary artery disease with acute myocardial infarction Hypertensive cardiovascular disease Rheumatic heart disease Myocardopathy No known heart disease Heart disease of unknown etiology Miscellaneous

66

teria for success, requiring at least six hours of normal sinus rhythm after conversion, may be one factor. Several patients converted for shorter periods and were considered failures. Another reason for poorer results may be the difference in patient population. Our patients were older, had more hypertensive cardiovascular disease and coronary artery disease. However, neither our study nor previous data can correlate prognosis for successful conversion to age or type of heart disease. Eleven patients in this series did not convert to sinus rhythm, six of whom were -ather unstable clinically (four postoperative from cardiac or lung surgery, and two with acute myocardial infarction). Two died within 48 hours. One failure, in a patient with an atrial infarction, was treated with intravenous potassium chloride and spontaneously converted the next day. This suggests that patients in unstable situations who develop arrhythmias may best be cardioverted when better stability has been obtained if they can be carried

28 2 2 2 4 68

over the acute episode safely. However, when the arrhythmia is of immediate danger to the patient, attempted cardioversion is certainly indicated. Failure to convert long-standing arrhythmias is probably associated with the underlying heart disease. When possible, digitalis is now withdrawn several days prior to cardioversion of atrial fibrillation because many of the postconversion arrhythmias appear to be .. •••• Igt toxicity. • .I'f d ue to dizitalis Long-term success of conversion is not good. Only 47 per cent of our patients have maintained a normal sinus rhythm longer than three months. Those with rheumatic and hypertensive heart disease have a higher incidence of long-term failure than those with coronary artery disease. The patients who are able to maintain sinus rhythm are benefited by the increased cardiac output and reduction in occurrence of embolic phenomena. There appears to be minimal danger associated with the procedure and the positive results outweigh the number of

TABLE 4--ETIOLOGY OF HEART DISEASE AND LoNG TERM FOLLOW-UP AFTER ONE OR MORE CARDIOVEJlSION ATTEMPTS·

Type of Heart Diseue Coronary artery disease Coronary artery disease with acute myocardial infarction Hypertensive cardiovascular disease Rheumatic heart disease Myocardopathy No known heart disease Heart disease of unknown etiology Miscellaneous

Number of Patients

Failures··

Died in NSR

NSR

17 4 9 25 2 2 2 5 66

6 2 5 16 0 0 1 2 32

2 0 1 2 0 0 0 2 .,

9 2 3 5 1 2 1 1 24

·Three patients lost to follow-up. . ··Failure to convert and reversion to the arrhythmia in less than six hours are grouped together.

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DIRECT CURRENT COUNTERSHOCK

failures. Patients who remain in nonnal sinus rhythm for at least three months before recurrence of the arrhythmia are benefited by repeated countershock therapy. SUMMARY

Sixty-six patients were cardioverted 82 times for various arrhythmias. Eigthy-three per cent were successfully converted to normal sinus rhythm. Those with acute arrhythmias who were in unstable situations (postoperative and acute myocardial infarctions), and those with long-standing arrhythmias associated with severe heart disease were less likely to be converted. Complications of the procedure were minimal except for two cerebral emboli which left no significant impairment. Forty-seven per cent of patients were able to maintain a sinus mechanism during the period of follow-up (3 to 26 months). With two exceptions, those who reverted to the previous arrhythmia did so within three months. Rheumatic heart disease (64 per cent) and hypertensive cardiovascular disease (56 per cent) were less likely to maintain a normal mechanism than those with coronary artery disease (38 per cent). RESUMEN

Sesenta y seis pacientes fueron cardiovertidos 82 veces por diversas arritmias. De estos, 83% fueron efectivamente convertidos al ritrno sinosal. Aquellos con arritmias agudas debidas a situaciones inestables (casas postoperatorios 0 de inIarto reciente del miocardio) y los que presentaban arritmias de larga duraci6n y cardiopatias graves resultaron mas diflciles de convertir. Las complicaciones de este rnetodo fueron mlnimas, exceptuando dos embolias cerebrales sin efectos permanentes. Un 45% de los pacientes mantuvieron un regimen sinusa I durante todo el periodo de observaci6n (3 a 26 meses). Con dos excepeiones, los 'que revertieron al ritmo anterior 10 hicieron dentro de un termino de tres rneses, Los sujetos con cardiopadas reumaticas 0 hipertensivas (56%) se mostraron menos propensos a mantener el ritmo normal que aquellos con afecciones coronarias (38%).

en mauvais equilibre circulatoire (cas post-operatoires et infarctus myocardiques aigus) , et ceux qui avaient des arythmies anciennes associeees a des cardiopathies sev~res, soot candidau pour la regularisation. Les complications de ces techniques son minimes, mises a part deux embolies cerebrales qui n'ont pas lawe de sequelle significative. Quarante-sept pour cent des malades ont pu maintenir un rythme sinusal pendant la periode de survellaince (3 a 26 mois). A deux exceptions pres ceux qui sont revenus it leur arythmie ancienne I'ont fait dans Ie trois mois. Les cas de cardiopathies rhumatismale (64%) et hypertensives (56%) ont moins de chances de maintenir un rythme regulier que ceux avant une maladie coronarienne (38%). ZUSAMMENFASSUNG

66 Patienten wurden kardiovertiert wegen verschiedener Arrhythmiefonnen und zwar 82 mal. 83% kehrten mit Erfolg zu einem norrnalen Sinusrhythrnus zuriick. Solche mit akuten Rhythmusstorungen, die sich in Situationen besonderer Belastung befanden (sei es nach einer Operation oder sei es auch nach einem akuten Herzinfarkt ) und solche mit schon lange vorliegenden Arrhythmien in Verbindung mit schweren Herzleiden. hatten eine geringere WahrSl.:heinlichkeit zu normalen Rhythmus werten konvertiert zu werden. Die Komplikationen des Verfahrens waren gering, abgesehen von zwei cerebralen Embolien. die keine signifikante Schadigung zuriicklie~n.· 47% der Patienten vermochten einen normalen Sinusrhythmus aufrechtzuerhalten, wahrend der ganzen Zeit der Nachfiinorge (3-26 Monate). Mit 2 Ausnahmen kam es zu einem Wiederauftreten der vorher bestandenen Arrhythmie und zwar innerhalb von 3 Monaten. Bei rheumatischen Herzerkrankungen (64%) und mit Hypertonie einhergehenden Herzkreislauf-Erkrankungen (56%) war es weniger wahrscheinlich, daP ein normaler Mechanismus bestand als bei solchen mit Coronararterien-Erkrankungen (38%).

2 3

4

REsuMt

Soixante-six malades ont subi un choc electrique 82 fois pour des arythmie diverses. Quatrevingt-trois Pour cent ont ete ramenes en rythme sinusal. Ceux qui avaient des arythmies aigues et

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REFER.ENCES ALEXANDER., S., KLEIOER., R. AND LoWN, B.: "Use of External Countenhock in the Treatment of Ventricular Tachycardia," lAMA, 177 :916, 1961. HURST, J. W., PAULK, E. A., PROCTOR, H. AND SCHLANT, R.: "Management of Patients with Atrial Fibrillation," Am. t. M.d., 37: 728,1964. Kn.L1P, T.: "Synchronized DC Precordial Shock for Arrhythmias. Safe New Technique to Establish Normal Rhythm May Be Utilized on an Elective Basis," ]AMA, 186: 1, 1963. Lows, B., PEJlLROTH, M. G., KAmBERG, S., ABE, T. AND HAR.KEN, D. E.: "Cardioversion of Atrial Fibrillation. A Report on the Treatment of 65 Episodes in 50 Patients," New Engl. t. 269:325, 1963. Lows, B., BEY, S. K. AND PER.LROTH, M. G.: "Cardioversion of Ectopic Tachycardias," Ame,. t. M.d. Sei., 246:257, 1963.

u-«,

CHARMS, 6 LoWN, B., AIIAIlASINGILUI, R. AND NEWMAN. J.: "New Method of Terminating Cardiac Arrhythmias," lAMA, 182:548, 1962. 7 MELTZER, L. E., AYTAN, H., YUII, D., URAL, M., PALIION, F. AND KITCHELL, J.: "Atrial Fibrillation Treated with Direct Current Countershock," Arch. Int. M6d., 115:537, 1965. 8 MoRlUs, j., KONG, Y., NORTH, W. AND McINTOSH, H.: "Experience with Cardiovenion of Atrial Fibrillation and Flutter," Am. I. Car-

diol., 14:94, 1964. 9 OaAM, S., DAVIES, j. P., WEINBREN, I., TAGGART, P. AND KITCHEN, L. D.: "Conversion of Atrial Fibrillation to Sinus Rhythm by Direct Current Shock," Lancet, 2: 159, 1963. 10 ZoLL, P. M. AND UNENTHAL, A.: "Termination of Refractory Tachycardia by External Countershock," Circ.dation, 25: 596, 1962. 11 CASTELLANOS, A., LEIIBERG, L., GoSSELIN, A. AND FONSECA, E.: "Evaluation of Countershock Treatment of Atrial Flutter," Arch. Int. M6d., 115:426, 1965.

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12 MoRlUs, J. j. JR., ENTMAN, M. L., THOMPSON, H. K., NORTH, W. C. AND MciNTOSH, H. D.: "Cardiac Output in Atrial Fibrillation and Sinus Rhythm," Circulation, 28: 772, 1963. 13 STOCK, R. J.: "Cardiovenion Without Anesthesia," New Engl. J. Med., 269:534, 1963. 14 LoWN, B., KLEIGER, R. AND WOLFF, G.: "The Technique of Cardiovenion," Amer. Heart I., 67:282, 1964. 15 CASTELLANOS, A., GILMORE, III, H., LEMBERG, L. AND JOHNSON, D.: Countushod Expos6d Quinidine Syncope. Paper presented at the American College of Cardiology Meeting, February 18-21, 1965. Boston, Massachusetts. 16 LEMBERG, L., CASTELLANOS, A., SWENSON, J. AND GoSSELIN, A.: "Arrhythmias Related to Cardioversion,' Circulation, 30: 163, 1964. 17 GILBEJlT, R. AND CUDDY, R. P.: Digitalis Intoxication Following Convenion to Sinus Rhythm," Circulation, 32: 58, 1965. For reprints, please write Dr. Charms, Mt. Sinai Hospital, Cleveland.

VENTILATION AND BLOOD CHEMISTRY IN HEART DISEASE Slmuhbneous stu4Jes of the effects of exercise on the hemedynamles, ventilation and arterial and venous blood chemistry have been carried out In normal subjects and In patients with heart disease. Changes In arterial blood gases and pH were usually those found as a result of hyperventilation. No evidence has been obtaIned to suggest that the venous chemistry was responsible for excessive ventilatory response. The ftndlngs In patients with pulmonary venous hypertension support the previously-

expressed view that this proVides a dominant stimulus to the ventilation. Hyperventilation In patients with .pulmonary stenosis has been conftrmed, and does not seem to be due to changes In arterial and venous blood gases. The lactate production Is greater than In normal subjects at the same exerdSE loads. N., DAVIES. H. AND o.UCHAa, D.: '"Ventilation in Relation to Arterial and Venous Blood Chemis· try in Heart Disease,'" B,i,. H,.rr l.. 28:16, 1966.

GAZE TOPOU LOS.

PULMONARY EMBOLECTOMY IN MASSIVE PULMONARY EMBOLISM Experience gained In the management of 13 patients with massive puImOD8I')' embolism InvolvLng an entire lung Indicates that hypotension may be the most Important indication for emergency embolectomy, since all eight patients with hypotension died. P u 1m 0 n a r y scanning and arteriography are both Indicated preoperatively If the patient's condition permits. Spontaneous return of pulmonary blood flow has been documented by means of serial scan-

nlng In several patients with this degree of massive embolism. This Indicates that extreme caution IE necessary In making a decision to perform an embolectomy. Vena caval plication or llgatlon may be the preferred procedure In many Instances. R. R. AND WAGNEa. H. N.: '"Pulmonary Embolectomy in the Treatment of Massive Pulmonary Embolism.'" S.r,. G""c. ••• 122:nJ. 1966.

BAKU.

O"s",.,