Isolated myocyte contractile function is normal in postinfarct remodeled rat heart with systolic dysfunction

Postinfarction ventricular remodeling is associated with lengthening and contractile dysfunction of the remote noninfarcted myocardium. Mechanisms underlying this phenomenon remain unclear. We studied serial changes in global left ventricular (LV) structure and function in infarcted (1, 2, 4, and 6 weeks after myocardial infarction) and sham-operated rat hearts and correlated them with structural and functional changes in myocytes isolated from the remote LV myocardium in the same hearts. Rats with myocardial infarction developed significant remodeling. The heart weight-to-body weight ratios were increased. LV volumes at filling pressure of 10 mm Hg were higher (305+/-28 versus 215+/-12 microL, P