in depolarized myocardium ( rabbit sa- and av-node , guinea-pig papillary muscle depolarized by ( k+ ) 0 = 27 mmol/l ) diltiazem greater than or equal to 0.3 mumol/l reduces amplitude and maximum upstroke velocity of the calcium-dependent action potentials .
C0027061
myocardium
C0030352
papillary muscle