[Effect of sulmazol on left ventricular function in congestive cardiomyopathy]

In 11 patients with congestive cardiomyopathy (NYHA class III and IV, mean cardiothoracic ratio 0.59) the effect of a new positive inotropic agent, 2[(2-methoxy-4-methylsulfinyl)phenyl ))-1H-imidazo[4,5-b]pyridine (AR-L 115 BS, sulmazol, Vardax), on haemodynamics was studied. Simultaneously plasma levels of the drug were measured. All patients were pretreated with digitalis and diuretics. The following results were obtained: Heart rate increased only slightly, by 8% (n.s.), maximal left ventricular pressure rise by 37% (p less than 0.01), left ventricular enddiastolic pressure decreased by 42% (p less than 0.01), mean pulmonary artery pressure by 23% (p less than 0.01) and pulmonary vascular resistance by 22% (p less than 0.05). Left ventricular enddiastolic volume was reduced by 20% and left ventricular systolic volume by 31% (p less than 0.01). Ejection fraction increased by 36% (p less than 0.05), cardiac index, stroke index, stroke work index and systolic aortic pressure as well as systemic vascular resistance remained unchanged. In conclusion, sulmazol is an effective inotropic agent with vasodilating properties (especially on the venous capacity system). The lacking increase of cardiac output despite the augmentation of ejection fraction must be due to the prominent reduction of preload, decrease of left ventricular volume and heart size. Sulmazol therefore should not increase oxygen consumption of the heart and should be especially advantageous in patients with predominant backward failure.