<prompt> The positive inotropic effect of digitalyzers is due to invitation of NaK ATPase pump in cardiac muscle cell membrane leading toDecrease the activity of NaCa exchanger causing decrease the influx of sodium and decreased efflux of Ca in the sarcolemmaDecreased efflux of Na leading to less negative resting membrane potential and opening of voltage gated Ca channels on the T tubulesIncreased intracellular Na causing increased efflux of any place and increase the influx of Ca through Na Ca exchanges in sarcolemmaIncreased intracellular Na decreasing the activity of Ca pump in the sarcoplasmic reticulum  <response>: Ref-Goodman and Gillman 12e p802,803 The positive inotropic effect of digitalis is due to inhibition of NaK ATPase pump in cardiac muscle cell membrane leading to decreased activity of NaCa exchanger causing decrease the influx of sodium and decreased efflux of CA in the sarcolemma 