Coronary constriction impairs cardiac function and induces myocardial damage and ventricular remodeling in mice

Abstract

To establish whether coronary artery narrowing (CAN) in mice was accompanied by depressed ventricular function, tissue injury, and modifications in cardiac anatomy, the left coronary artery was constricted in FVB/N mice and the animals were killed 7 days later. CAN consisted of a 53% reduction in luminal diameter, which resulted in a twofold increase in left ventricular end-diastolic pressure. Left ventricular systolic pressure and left ventricular + and -dP/dt decreased 15, 21, and 11%, respectively. Left ventricular weight-to-body weight ratio increased 33%. This hypertrophic adaptation was characterized by a 9 and 20% increase in the longitudinal and transverse cavitary diameters, which provoked a 1.5-fold expansion in chamber volume. In contrast, wall thickness decreased 15%. These anatomic and functional changes induced a threefold elevation in diastolic stress. Foci of reparative fibrosis were found in the endomyocardium and epimyocardium, involving 2-3% of the tissue. Finally, myocyte loss in the ventricle was 15%, and myocyte hypertrophy was 38%. Impaired ventricular function, diastolic Laplace overloading, myocyte loss, and decompensated eccentric hypertrophy in mice after CAN mimic the ischemic cardiomyopathic heart in humans.