EFFECT OF ISRADIPINE AND NIFEDIPINE ON DIASTOLIC FUNCTION IN PATIENTSWITH LEFT-VENTRICULAR DYSFUNCTION DUE TO CORONARY-ARTERY DISEASE - A RANDOMIZED, DOUBLE-BLIND, NUCLEAR, STETHOSCOPE STUDY

To elucidate the effect of isradipine and nifedipine on left ventricul ar (LV) systolic and diastolic function, each drug was given intraveno usly (i.v.) in equihypotensive doses to 10 patients accepted for coron ary arteriography for stable angina pectoris. All 20 patients had LV e jection fraction (LVEF) of <40% owing to previous myocardial infarctio n (MI). Systolic and diastolic function was assessed by standard hemod ynamic parameters and pressure-volume relations measured by nuclear st ethoscope. All measurements were taken at rest and during ischemia cau sed by right atrial pacing. Both systolic and diastolic parameters imp roved equally with isradipine and nifedipine. LVEF and cardiac output (CO) increased owing to peripheral vasodilatation. A decrease in P/V-m ax, indicating a negative inotropic effect, was noted in patients at r est with both medications, but not during pacing-induced ischemia. Wit h either medication, the time constant of relaxation and the end-diast olic elasticity constant decreased during pacing, indicating improveme nt in diastolic function, probably owing to relief of myocardial ische mia.