The positive inotropic effect of digitalyzers is due to invitation of Na+/K+ ATPase pump in cardiac muscle cell membrane leading to
Ref-Goodman and Gillman 12/e p802,803 The positive inotropic effect of digitalis is due to inhibition of Na+/K+ ATPase pump in cardiac muscle cell membrane leading to decreased activity of Na+/Ca++ exchanger causing decrease the influx of sodium and decreased efflux of CA++ in the sarcolemma