Long-term medical management of hypertrophic obstructive cardiomyopathy

Twenty-two patients, aged 15 to 61 years, with hypertrophic obstructive cardiomyopathy documented at catheterization were followed up prospectively for 2 to 8 years (mean 5) while receiving “complete” beta receptor blocking doses of propranolol (average dose 462 mg/day). Hypertension, fluid retention, pulmonary disease and arrhythmias were treated as required. Dyspnea, angina, syncope, presyncope and palpitations were graded from 0 to 3 based on severity, and the scores were added to obtain a total score. This group was compared with 14 nonrandomized control patients, aged 17 to 78 years, who were not receiving propranolol and were evaluated retrospectively for a mean follow-up period of 5 years (range 2 to 13). The average total score for the protocol group was initially 7.9 and is now 1.9. No patient died; the condition of all patients is improved, with an average improvement in dyspnea of 58 percent. Eighteen patients are currently asymptomatic during usual daily activities. In contrast, symptoms increased in severity in 13 of the 14 control patients. Their mean score increased from 2.9 to 5.4, and dyspnea increased by 133 percent. Of the 10 control patients treated only medically, 4 died suddenly.

Improvement in protocol patients was independent of the severity of subvalve obstruction. Potentially life-threatening arrhythmias were found in 11 of the 22 protocol patients, including the 3 patients without obstruction at rest. Rhythm disturbance responded to propranolol alone in four patients, but antiarrhythmic drugs or pacemaker insertion, or both, was required in the remaining seven patients. Thus, “complete” beta blockade supplemented by control of arrhythmia is optimal management for hypertrophic obstructive cardiomyopathy. Most patients do not require surgery.