[Verapamil, diltiazem or nifedipine in severe left ventricular functional disorder? A comparative study of the...

High doses of verapamil, diltiazem or nifedipin were administered to three groups of eight patients each, with severely abnormal left-ventricular (LV) function (mean ejection fraction 0.29). Various haemodynamic measurements were made immediately before and 30 minutes after drug administration: LV ejection fraction, ratio of peak systolic pressure to endsystolic volume index, stroke index, pulmonary capillary closing pressure, and maximal diastolic filling rate. None of these were reduced. In fact, ejection fraction rose by a mean of 0.05, stroke index by a mean of 5 ml/m2, while p.c. closing pressure and contractility did not alter significantly. Verapamil and diltiazem reduced the pressure X rate product (an important determinant of oxygen consumption); nifedipine reduced total systemic resistance. It is concluded that verapamil and diltiazem can be used with advantage in cases of unstable angina, if there are severe abnormalities of LV function; they are to be preferred to beta-blockers in this situation. Nifedipin is the calcium antagonist of choice in hypertension and abnormal LV function.