Potent vasodilatory with minor cardiodepressant actions ofmibefradil in human cardiac tissue

摘要

The present study compared the cardiovascular effects of mibefradil(MIB), a novel Ca~2+ -channelantagonist with high selectivity for T-type Ca~2+ -channels to the effect of the L-type Ca~2+ -channel-antagonists nifedipine (NIF) and diltiazem(DIL) in l eft ventricular myocardium and coronary arteries ofhearts obtained from patients suffering from dilated cardiomyopathy (NYHA IV). Right atrialmyocardium from patents undergoing aortocoronary bypass surgery without signs of cardiac failure wasstudied as w ell.NIF and DIL (100 μmol 1~-1) completely depressed force of contraction(FOC) in electrically driven Left ventricular myocardium (NIF 6.5±1.4/100 and DIL 7.1±1.2/100 of control), whereas a similar Concentration of MIB only reduced force of contraction to 55.1±4.0/100 of the basal FOC.