Bioenergetic, functional and morphological consequences of postinfarct cardiac remodeling in the rat

Despite recent advances in the treatment, severe chronic heart failure (CHF ) remains a syndrome associated with high mortality. Therefore, the search for new agents to improve both patient symptoms and survival, as well as th e pursuit for detailed know ledge about pathophysiology of the failing hear t, will continue to depend on relevant animal models. Large acute myocardia l infarction (MI) initiates complex changes in the geometrical, structural, and biochemical architecture of both infarcted and non-infarcted regions o f ventricular myocardium, which can profoundly affect left ventricular func tion and prognosis. In this paper we present a new model for non-invasive c ardiac P-31 MRS in the rat. volume-selective P-31 magnetic resonance spectr oscopy and echocardiograph; were used for evaluation of myocardial energy m etabolism, cardiac morphology and function in rats 3 days and 3 weeks after induction of large MI. The phosphocreatine:adenosine triphosphate (PCr:ATP ) ratio was decreased in rats with MI comparing with controls both at 3 day s (1.6+/-0.06 vs 2.7+/-0.04; mean+/-S.E.M.; P<0.0001) and 3 weeks (1,6+/-0, 07 v 2.7+/-0,02: P<0.0001) postinfarct. The results from the study demonstr ate that postinfarct cardiac remodeling is a rapid process of changes riot only in cardiac geometry, structure and function but also in myocardial ene rgy metabolism after large transmural MI in the rat. (C) 1999 Academic Pres s.