The acute effects on left ventricular function of nisoldipine were studied in six patients 56 _+ 12 hours (range 44 to 72 hours) after the onset of uncomplicated acute myocardial infarction. Nisoldipine was administered as a 4.5 pg/kg intravenous bolus over 3 minutes followed by an infusion of 0.2 pg/kg during 60 minutes. Radionuclide angiography and two-dimensional echocardiography were performed before and during infusion with nisoldipine. The left ventricular ejection fraction increased significantly from 38% _+ 10% to 49% _+ 10% (P = 0.028) during nisoldipine infusion. Regional wall motion index was determined both by radionuclide and by two-dimensional echocardiography and showed a significant change during nisoldipine infusion from 1.9 ± 0.3 to !.5 + 0.3 (p = 0.028, radionuclide angiography) and from 0.7 _+ 0.2 to 0.3 _+ 0.2 {p = 0.043, two dimensional cchocardiography). Heart rate increased significantly from 78 _+ 12 rain -l to 92 ± 13 min -1 (p = 0.028), but mean double product did not change significantly during nisoldipine infusion. It is concluded that nisoldipine significantly improves global and regional left vcntricular function in patients shortly after acute myocardial infarction. This beneficial effect may, however, be partially offset by an increase in heart rate. Since mean double product did not change, it is suggested that nisoldipinc may improve coronary blood flow in patients with acute myocardial infarction.
KEY WORDS. nisoldipine, acute myocardial infarction, left ventricular function, radionuclide angiography, echocardiography
N isoldipine is a dihydropyridine derivate and is four to ten times more potent in the inhibition of vascular smooth muscle contraction than nifedipine and less potent in the inhibition of contraction of isolated heart muscle . In animal studies nisoldipine has been shown to be a stronger coronary vasodilator than nffedipine . At concentrations producing vascular changes the electrophysiologic effects are minimal . Preliminary studies in humans have shown that nisoldipine is effective in reducing peripheral and coronary vascular resistance, leading to an increase of coronary blood flow, cardiac output, and stroke volume