1) Cardiovascular physiology 
Lusitropy is myocardial relaxation. The increase in cytosolic calcium of cardiomyocytes via increased uptake leads to increased myocardial contractility (positive inotropic effect), but the myocardial relaxation, or lusitropy, decreases. This should not be confused, however, with catecholamine-induced calcium uptake into the sarcoplasmic reticulum...
Type: Term Pronunciation: lūs-it′rō-pē Definitions: 1. Relaxation functions of cardiac muscle and chambers.