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Surgery versus medical therapy in hypertrophic obstructive cardiomyopathy—II
LETTERS TO THE EDITOR
SURGERY HYPERTROPHIC
VERSUS
MEDICAL
OBSTRUCTIVE
THERAPY
obstructive and nonobstructive hypertrophlc cardiomyopathy Circulation 1979:59’ 866-75 McKenna WJ, Chetty S, Oakley CM, Goodwin JF. Arrhythmia in hypertrophic cardlomyopathy: exercise and 48-bow ambulatory electrocardlographlc assessment with and without beta adrenergic blockrng therapy. Am J Cardiol 1980;45.1-5 Canedo Ml, Frank MJ. Abdulla AM. Rhythm disturbances III hypertrophic cardiomyopathy: prevalence, relation to symptoms. and management Am d Cardiol 1980;45: 848-55
IN
CARDlOMYOPATHY-I
Morrow et a1.l have suggested the use of left ventricular myotomy and myectomy in patients with obstructive hypertrophic cardiomyopathy who survive cardiac arrest. Unfortunately, their data do not support this conclusion. It is well documented by the authors and others that sudden death in hypertrophic obstructive cardiomyopathy appears to be more common in patients who manifest complex ventricular ectopic activity, especially unsustained ventricular tachycardia, on 24 hour ambulatory monitoring.2p4 Morrow et al., in fact, recorded such complex arrhythmia in their two patients who underwent ambulatory recording prior to their cardiac arrest. However, these studies also indicate that the propensity for sudden death and the presence of these arrhythmias do not relate to the severity of outflow obstruction, severity of symptoms or hemodynamic findings in the persons studied either after or before cardiac arrest. The authors noted that failure of propranolol to suppress complex ectopic ventricular rhythm constituted failure of antiarrhythmic therapy. In several studie@ beta adrenergic blocking agents have been proved ineffective in suppressing such arrhythmia. No patient was given a trial of standard antiarrhythmic agents before surgery. A recent study4 supports the efficacy of these agents in suppressing complex ectopic rhythm and in alleviating syncopal and presyncopal episodes. No patient being treated with antiarrhythmic agents died suddenly over short term follow-up. In addition $0 surgery, all patients in the study of Morrow et al. were placed on effective regimens of antiarrhythmic agents. Interestingly, the death of one patient 9 months after surgery was explained by incomplete relief of obstruction. But that same patient had nondetectable blood levels of quinidine with which he had been treated postoperatively. Furthermore, postoperative ambulatory monitoring was not assessed in any of the patients to establish whether surgery and antiarrhythmic therapy in combination altered the frequency of ectopic rhythm. Although most deaths in this disorder appear to be due to ventricular fibrillation, complete heart block and sinus arrest as well as supraventricular tachyarrhythmias have been well described as a cause of sudden death. Certainly myectomy and myotomy wouId not be effective in such patients. Before such surgery is recommended, perhaps a trial of antiarrhythmic therapy should be offered, Perhaps this empiric approach might be supplemented by evaluation in the clinical electrophysiology laboratory to assess antiarrhythmic efficacy.
REPLY
Let’s agree on a couple of points right at the beginning: All patienta with obstructive cardiomyopathy who survive cardiac arrest must be treated indefinitely with an antiarrhythmic drug or drugs. And some may benefit from implanted pacemakers, with or without the creation of atrioventricular block. Surely, everybody in the world will agree. Now, about the possible benefit provided by operation in such patients. Let’s read the second sentence of Herling’s letter one more time: “Unfortunately, their data do not support this conclusion.” To what conclusion does Herling refer? I surely didn’t write one, at least I didn’t mean to write one, I did write: “It is impossible to determine with certainty whether or not operation will prolong the lives of these patients who survived cardiac arrest.” I also wrote: “Only continued follow-up of these and other such patients may ultimately permit a definitive conclusion as to the role of operation in the management of this unusual subgroup of patients with obstructive hypertrophic cardiomyopathy.” Herling states: “Although most deaths in this disorder appear to be due to ventricular fibrillation, complete heart block and sinus arrest as well as supraventricular tachyarrhythmias have been well described as a cause of sudden death. Certairzly [italics mine] myectomy and myotomy would not be effective in such patients.” How can he be certain? From what experience with survivors of cardiac arrest does he speak? Is it inconceivable to him that relief of obstruction and lowering of left ventricular systolic pressure to normal might provide protection against arrhythmia? Conversely, can he suggest a mechanism by which relief of obstruction might make a patient more likely to have a fatal arrhythmia? Finally, Herling advises that: “Before such surgery is recommended, perhaps a tria1 of antiarrhythmic therapy should be offered.” What Herling is recommending is that we should treat the survivor of cardiac arrest with the best drug regimen that we can devise; then, if he dies and is resuscitated a second time, operation might be considered. Trial indeed! Andrew G. Morrow,
MD, FACC
Clinic of Surgery National Heart, Lung, and Blood Institute Bethesda,
Maryland
Irving M. Herling, MD, FACC Critical Care Medicine Likoff Cardiovascular Hahnqrnann Philadelphia,
Medical
Institute College
SURGERY and Hospital
Pennsylvania
References 1 2
Morrow AG, Koch JP, Maron SJ, Kent KM, Epstein SE. Left ventncular rnyotomy and myectomy In patients with obstructive hyperfrophlc Cardiomyopathy and previous cardiac arrest Am J Cardlol 1980,46 313-6. Savage DO, Seides SF, Maron SJ, Myers DJ, Epstein SE. Prevalence of arrhythmras dunng 24-hour electrocardlographlc monitonng and exercise testtng in pabents with
HYPERTROPHIC
VERSUS
MEDICAL
OBSTRUCTIVE
THERAPY
IN
CARDIOMYOPATHY-II
In reference to the article by Morrow et al.1 regarding myotomy and myectomy in patients with hypertrophic cardiomyopathy and previous cardiac arrest, we point out the following: 1. Despite a statement to the contrary, we2p3recently reported on the prevention of sudden death in patients with
December 1981
The American Journal of CARDIOLOGY
Volume 48
1169
LETTERS
TO
THE
EDITOR
hypertrophic obstructive cardiomyopathy with medical treatment, based on beta blocking doses of propranolol and aggressive antiarrhythmic therapy with drugs and pacemakers. 2. It is more likely that sudden death in their surgically treated patients may have been prevented by the antiar rhythmic therapy utilized routinely postoperatively in all of their patients rather than the myotomy-myectomy itself. This view seems to be supported by the fact that previous reports by the same authors4 revealed that surgery without antiarrhythmic therapy did not prevent sudden death, despite reduction or abolition of left ventricular outflow tract gradient, and (we quote) “No significant difference was evident between the 96 survivors and the 11 patients who died late (6 suddenly) with regard to the magnitude of the preoperative left ven tricular outflow gradient under basal conditions . . . , the change between the preoperative gradients 150 mm Hg . . . , or the maximal post-operative gradient under basal conditions or with provocation.” Swan and co-workers5 also failed to find correlation between the severity outflow tract gradients and sudden death. Morrow and associates seem to acknowledge the protective effect of antiarrhythmic drugs when they emphasize that the only patient who died suddenly in the late postoperative period was noncompliant: “although antiarrhythmic therapy with quinidine had been recommended, blood analysis at necropsy showed no detectable quinidine, indicating that the patient had not taken the drug for at least eight hours before death.” 3. Malignant arrhythmias6 and sudden death7 also occur frequently in patients with hypertrophic nonobstructioe cardiomyopathy, suggesting that obstruction does not play an important role in the production of either. The authors do not offer any explanation for this fact. We believe that arrhythmias are secondary to the conduction system abnormalities described by James et al.,s including fibrosis of the sinus node, fragmentation of the body of the atrioventricular node and His bundle, and deep clefts in the muscle of the septum, independent of the severity of obstruction. In some patients, the presence of Wolff-Parkinson-white or other types of preexcitation no doubt contributes to arrhythmias and sudden death as reported by Goodwin et al.9 Therefore, to prevent sudden death, we now recommend large doses of propranolol and aggressive search and therapy of rhythm disturbances with proper documentation of its efficacy by repeated Holter monitoring.” This approach appears to provide adequate protection from sudden death, avoiding
1170
December
1981
The American
Journal
of CARDIOLOGY
the operative mortality which remains high (11 percent in Morrow’s report). Finally, myotomy-myectomy may in fact predispose to sudden death related to conduction disturbances which are a common postoperative complication3 (96 versus 27 percent preoperatively), including complete atrioventricular block in 4 percent and complete left bundle branch block in 45 percent. These conduction abnormalities have been shown to correlate with a large incidence of ventricular arrhythmias and sudden death, in patients with coronary artery disease.lO Mario I. Canedo, MD, FACC Martin J. Frank, MD, FACC Abdulla M. Abdulla, MD, FACC Hemodynamic Laboratories Department of Medicine Medical College of Georgia Augusta, Georgia References 1
2
Morrow AG, Koch JP, Maron BJ, Kent KM, Epstein SE. Left ventricular myotomy and myectomy in pabents wth obstructwe hypertrophlc cardiomyopathy and prewus cardiac arrest Am J Cardml 1980,46.313-6 Frank MJ, Abdulla AM, Canedo MI, Saylors RE. Long-term medical rrwnagement of hvoertroohz obstructive cardvxnvooathv. Am J Card0l 1978.42 993- 1001 CanedoMI,~Frank MJ, Abdulla AM: Rhythm disturbances I” hypertrophnc cardlomyopathy prevalence. relation to symptoms and management Am J Cardlol 1980,45 848-55 Maron BJ, Merrill WH, Freier PA, Kent KM, Epstein SE, Morrow AG. Long-term clinical course and symptomatic status of pabents after opsratlon for hypertrophlc subaortlc stenosis Cnxlation 1978;57 1205-13. Swan DA, Bell 8, Oakley CM, Goodwin J. Analysts of symptomatic course and prognoses and treatment of hypertrophlc obstructwe cardiomyopathy Br Heart J 1971, 33.671-85 Savage DD, Seldes SF, Maron BJ, Myers KJ, Epstein SE. Prevalence of arrhythmias during 24-hour electrocardiographic mondornng and exercise testing I” pattents wth obstructive and non-obstructwe hypertrophlc cardiomyopathy Clrculatlon 1979.59: 866-75 Frank S. Braunwald E. ldiopathlc hypertrophlc subaortlc steno% Cl~mcal analysis of 126 patuents wth emphasis on the natural hlstory Cwculatlon 1966.37 759-66. James TN, Marshall TK. De subltarws mortibus XII AsymmetrIc hypertrophy Of the heart. Cwculatlon 1975;51:1149-66 Rowland E, Davies MJ, Krlkler DM, Goodwin JF. Hypertrophtc cardiomyopathy and ventricular pre-excltatlon (abstr) Am J Cardiol 1980;45.491 Deoes P, Dhingra RC, Wu D, Wyndham CR, Amat-y-Leon F, Rosen KM. Sudden death I” pabents wth chronic blfascwlar block Arch Intern Med 1977,137 1005-10 Ark
3
4
5
6
REPLY appears to me that my letter to Dr. Herling covers most of the points raised by Drs. Canedo, Frank and Abdulla. I think nothing more need be said. Andrew G. Morrow, MD, FACC
Volume
48
SURGERY HYPERTROPHIC
VERSUS
MEDICAL
OBSTRUCTIVE
THERAPY
obstructive and nonobstructive hypertrophlc cardiomyopathy Circulation 1979:59’ 866-75 McKenna WJ, Chetty S, Oakley CM, Goodwin JF. Arrhythmia in hypertrophic cardlomyopathy: exercise and 48-bow ambulatory electrocardlographlc assessment with and without beta adrenergic blockrng therapy. Am J Cardiol 1980;45.1-5 Canedo Ml, Frank MJ. Abdulla AM. Rhythm disturbances III hypertrophic cardiomyopathy: prevalence, relation to symptoms. and management Am d Cardiol 1980;45: 848-55
IN
CARDlOMYOPATHY-I
Morrow et a1.l have suggested the use of left ventricular myotomy and myectomy in patients with obstructive hypertrophic cardiomyopathy who survive cardiac arrest. Unfortunately, their data do not support this conclusion. It is well documented by the authors and others that sudden death in hypertrophic obstructive cardiomyopathy appears to be more common in patients who manifest complex ventricular ectopic activity, especially unsustained ventricular tachycardia, on 24 hour ambulatory monitoring.2p4 Morrow et al., in fact, recorded such complex arrhythmia in their two patients who underwent ambulatory recording prior to their cardiac arrest. However, these studies also indicate that the propensity for sudden death and the presence of these arrhythmias do not relate to the severity of outflow obstruction, severity of symptoms or hemodynamic findings in the persons studied either after or before cardiac arrest. The authors noted that failure of propranolol to suppress complex ectopic ventricular rhythm constituted failure of antiarrhythmic therapy. In several studie@ beta adrenergic blocking agents have been proved ineffective in suppressing such arrhythmia. No patient was given a trial of standard antiarrhythmic agents before surgery. A recent study4 supports the efficacy of these agents in suppressing complex ectopic rhythm and in alleviating syncopal and presyncopal episodes. No patient being treated with antiarrhythmic agents died suddenly over short term follow-up. In addition $0 surgery, all patients in the study of Morrow et al. were placed on effective regimens of antiarrhythmic agents. Interestingly, the death of one patient 9 months after surgery was explained by incomplete relief of obstruction. But that same patient had nondetectable blood levels of quinidine with which he had been treated postoperatively. Furthermore, postoperative ambulatory monitoring was not assessed in any of the patients to establish whether surgery and antiarrhythmic therapy in combination altered the frequency of ectopic rhythm. Although most deaths in this disorder appear to be due to ventricular fibrillation, complete heart block and sinus arrest as well as supraventricular tachyarrhythmias have been well described as a cause of sudden death. Certainly myectomy and myotomy wouId not be effective in such patients. Before such surgery is recommended, perhaps a trial of antiarrhythmic therapy should be offered, Perhaps this empiric approach might be supplemented by evaluation in the clinical electrophysiology laboratory to assess antiarrhythmic efficacy.
REPLY
Let’s agree on a couple of points right at the beginning: All patienta with obstructive cardiomyopathy who survive cardiac arrest must be treated indefinitely with an antiarrhythmic drug or drugs. And some may benefit from implanted pacemakers, with or without the creation of atrioventricular block. Surely, everybody in the world will agree. Now, about the possible benefit provided by operation in such patients. Let’s read the second sentence of Herling’s letter one more time: “Unfortunately, their data do not support this conclusion.” To what conclusion does Herling refer? I surely didn’t write one, at least I didn’t mean to write one, I did write: “It is impossible to determine with certainty whether or not operation will prolong the lives of these patients who survived cardiac arrest.” I also wrote: “Only continued follow-up of these and other such patients may ultimately permit a definitive conclusion as to the role of operation in the management of this unusual subgroup of patients with obstructive hypertrophic cardiomyopathy.” Herling states: “Although most deaths in this disorder appear to be due to ventricular fibrillation, complete heart block and sinus arrest as well as supraventricular tachyarrhythmias have been well described as a cause of sudden death. Certairzly [italics mine] myectomy and myotomy would not be effective in such patients.” How can he be certain? From what experience with survivors of cardiac arrest does he speak? Is it inconceivable to him that relief of obstruction and lowering of left ventricular systolic pressure to normal might provide protection against arrhythmia? Conversely, can he suggest a mechanism by which relief of obstruction might make a patient more likely to have a fatal arrhythmia? Finally, Herling advises that: “Before such surgery is recommended, perhaps a tria1 of antiarrhythmic therapy should be offered.” What Herling is recommending is that we should treat the survivor of cardiac arrest with the best drug regimen that we can devise; then, if he dies and is resuscitated a second time, operation might be considered. Trial indeed! Andrew G. Morrow,
MD, FACC
Clinic of Surgery National Heart, Lung, and Blood Institute Bethesda,
Maryland
Irving M. Herling, MD, FACC Critical Care Medicine Likoff Cardiovascular Hahnqrnann Philadelphia,
Medical
Institute College
SURGERY and Hospital
Pennsylvania
References 1 2
Morrow AG, Koch JP, Maron SJ, Kent KM, Epstein SE. Left ventncular rnyotomy and myectomy In patients with obstructive hyperfrophlc Cardiomyopathy and previous cardiac arrest Am J Cardlol 1980,46 313-6. Savage DO, Seides SF, Maron SJ, Myers DJ, Epstein SE. Prevalence of arrhythmras dunng 24-hour electrocardlographlc monitonng and exercise testtng in pabents with
HYPERTROPHIC
VERSUS
MEDICAL
OBSTRUCTIVE
THERAPY
IN
CARDIOMYOPATHY-II
In reference to the article by Morrow et al.1 regarding myotomy and myectomy in patients with hypertrophic cardiomyopathy and previous cardiac arrest, we point out the following: 1. Despite a statement to the contrary, we2p3recently reported on the prevention of sudden death in patients with
December 1981
The American Journal of CARDIOLOGY
Volume 48
1169
LETTERS
TO
THE
EDITOR
hypertrophic obstructive cardiomyopathy with medical treatment, based on beta blocking doses of propranolol and aggressive antiarrhythmic therapy with drugs and pacemakers. 2. It is more likely that sudden death in their surgically treated patients may have been prevented by the antiar rhythmic therapy utilized routinely postoperatively in all of their patients rather than the myotomy-myectomy itself. This view seems to be supported by the fact that previous reports by the same authors4 revealed that surgery without antiarrhythmic therapy did not prevent sudden death, despite reduction or abolition of left ventricular outflow tract gradient, and (we quote) “No significant difference was evident between the 96 survivors and the 11 patients who died late (6 suddenly) with regard to the magnitude of the preoperative left ven tricular outflow gradient under basal conditions . . . , the change between the preoperative gradients 150 mm Hg . . . , or the maximal post-operative gradient under basal conditions or with provocation.” Swan and co-workers5 also failed to find correlation between the severity outflow tract gradients and sudden death. Morrow and associates seem to acknowledge the protective effect of antiarrhythmic drugs when they emphasize that the only patient who died suddenly in the late postoperative period was noncompliant: “although antiarrhythmic therapy with quinidine had been recommended, blood analysis at necropsy showed no detectable quinidine, indicating that the patient had not taken the drug for at least eight hours before death.” 3. Malignant arrhythmias6 and sudden death7 also occur frequently in patients with hypertrophic nonobstructioe cardiomyopathy, suggesting that obstruction does not play an important role in the production of either. The authors do not offer any explanation for this fact. We believe that arrhythmias are secondary to the conduction system abnormalities described by James et al.,s including fibrosis of the sinus node, fragmentation of the body of the atrioventricular node and His bundle, and deep clefts in the muscle of the septum, independent of the severity of obstruction. In some patients, the presence of Wolff-Parkinson-white or other types of preexcitation no doubt contributes to arrhythmias and sudden death as reported by Goodwin et al.9 Therefore, to prevent sudden death, we now recommend large doses of propranolol and aggressive search and therapy of rhythm disturbances with proper documentation of its efficacy by repeated Holter monitoring.” This approach appears to provide adequate protection from sudden death, avoiding
1170
December
1981
The American
Journal
of CARDIOLOGY
the operative mortality which remains high (11 percent in Morrow’s report). Finally, myotomy-myectomy may in fact predispose to sudden death related to conduction disturbances which are a common postoperative complication3 (96 versus 27 percent preoperatively), including complete atrioventricular block in 4 percent and complete left bundle branch block in 45 percent. These conduction abnormalities have been shown to correlate with a large incidence of ventricular arrhythmias and sudden death, in patients with coronary artery disease.lO Mario I. Canedo, MD, FACC Martin J. Frank, MD, FACC Abdulla M. Abdulla, MD, FACC Hemodynamic Laboratories Department of Medicine Medical College of Georgia Augusta, Georgia References 1
2
Morrow AG, Koch JP, Maron BJ, Kent KM, Epstein SE. Left ventricular myotomy and myectomy in pabents wth obstructwe hypertrophlc cardiomyopathy and prewus cardiac arrest Am J Cardml 1980,46.313-6 Frank MJ, Abdulla AM, Canedo MI, Saylors RE. Long-term medical rrwnagement of hvoertroohz obstructive cardvxnvooathv. Am J Card0l 1978.42 993- 1001 CanedoMI,~Frank MJ, Abdulla AM: Rhythm disturbances I” hypertrophnc cardlomyopathy prevalence. relation to symptoms and management Am J Cardlol 1980,45 848-55 Maron BJ, Merrill WH, Freier PA, Kent KM, Epstein SE, Morrow AG. Long-term clinical course and symptomatic status of pabents after opsratlon for hypertrophlc subaortlc stenosis Cnxlation 1978;57 1205-13. Swan DA, Bell 8, Oakley CM, Goodwin J. Analysts of symptomatic course and prognoses and treatment of hypertrophlc obstructwe cardiomyopathy Br Heart J 1971, 33.671-85 Savage DD, Seldes SF, Maron BJ, Myers KJ, Epstein SE. Prevalence of arrhythmias during 24-hour electrocardiographic mondornng and exercise testing I” pattents wth obstructive and non-obstructwe hypertrophlc cardiomyopathy Clrculatlon 1979.59: 866-75 Frank S. Braunwald E. ldiopathlc hypertrophlc subaortlc steno% Cl~mcal analysis of 126 patuents wth emphasis on the natural hlstory Cwculatlon 1966.37 759-66. James TN, Marshall TK. De subltarws mortibus XII AsymmetrIc hypertrophy Of the heart. Cwculatlon 1975;51:1149-66 Rowland E, Davies MJ, Krlkler DM, Goodwin JF. Hypertrophtc cardiomyopathy and ventricular pre-excltatlon (abstr) Am J Cardiol 1980;45.491 Deoes P, Dhingra RC, Wu D, Wyndham CR, Amat-y-Leon F, Rosen KM. Sudden death I” pabents wth chronic blfascwlar block Arch Intern Med 1977,137 1005-10 Ark
3
4
5
6
REPLY appears to me that my letter to Dr. Herling covers most of the points raised by Drs. Canedo, Frank and Abdulla. I think nothing more need be said. Andrew G. Morrow, MD, FACC
Volume
48