Haemodynamic effects of nifedipine and propranolol in patients with hypertrophic obstructive cardiomyopathy.

Abstract

SUMMARY The haemodynamic effects of nifedipine, propranolol, and the combined administration of the two drugs were studied in 12 patients with hypertrophic obstructive cardiomyopathy. The combined administration of nifedipine and propranolol appeared to be superior to that of nifedipine alone. The spontaneous heart rate was reduced in most cases after nifedipine plus propranolol, and at atrial pacing the following results were obtained: left ventricular peak systolic pressure was reduced from 200+39 to 157+ 30 mmHg; a positive correlation was found between the pre-drug left ventricular end-diastolic pressure and the magnitude of reduction in left ventricular end-diastolic pressure; systolic blood pressure was reduced from 125±31 to 111±27 mmHg, and total peripheral resistance was reduced from 1403±307 to 1160±209 dyne s-1 cm-5. The combined administration reduced the resting left ventricular outflow gradient from 76± 19 to 45±26 mmHg, while cardiac index was left unchanged. The effects on mean pulmonary arteriolar resistance and mean pulmonary arteriolar and mean pulmonary capillary venous pressure were in most cases slight and insignificant. The results indicate an improved haemodynamic condition in patients with hypertrophic obstructive cardiomyopathy after the combined administration of nifedipine and propranolol: a treatment that might provide a new and useful alternative to already existing medication.Drugs depresssing myocardial contractility should diminish the degree of left ventricular outflow obstruction in patients with hypertrophic obstructive cardiomyopathy,' and medical treatment of this disorder with beta adrenergic receptor blockers has been in use for many years. While propranolol reduces left ventricular outflow (LV-Ao) gradient at rest, on exercise, and during isoprenaline infusion,2 and improves exercise performance,3 and relieves the symptoms of angina pectoris,46 the drug neither reduces the incidence of asymptomatic ventricular arrhythmias nor the risk of sudden death.9 Calcium antagonists such as verapamil and nifedipine depress contractile force by inhibiting transmembrane calcium influx during excitation. [10][11][12] Hereditary hamster cardiomyopathy is thought to be the result of a membrane disease, and abnormal calcium flux probably plays a prominent role in its pathogenesis.'3 The possible relation between this cardiomyopathy and hypertrophic obstructive cardiomyopathy has been discussed.14 It has been shown that calcium antagonistic drugs, and, to a lesser extent, beta adrenergic receptor Accepted for publication 23 February 1982 blockers are able to prevent the development of heart lesions in hamsters with hereditary cardiomyopathy.'3 Recently, it has been reported that the calcium antagonistic drug verapamil reduces the resting left ventricular outflow gradient, increases the heart rate and cardiac output, and lowers systolic blood pressure in patients with hypertrophic obstructive cardiomyopathy. 15 With long term treatment by this drug exercise tolerance increased, and heart...

Calcium channel antagonism and beta blockade in combination—A therapeutic alternative in cardiovascular disorders. A review

“…Landmark and coworkers [131] studied the hemodynamic effects of nifedipine, propranolol, and the combination in 12 patients with hypertrophic obstructive cardiomyopathy. The combination reduced the resting left ventricular outflow gradient from 76 +_ 19 mmHg to 45 + 26 mmHg, reduced left ventricular peak systolic pressure, reduced total peripheral resistance, and left cardiac index intact.…”