Echocardiographic criteria for detection of postinfarction congestive heart failure in rats

We evaluated postinfarction myocardial function in rats and determined echo cardiographic criteria for congestive heart failure (CHF) using high perfor mance echocardiography. Extensive myocardial infarction (MI) was induced in rats by left coronary occlusion. Sham-operated animals served as controls. Five weeks later, high-frame rate (similar to 200 Hz), fully digitized, sh allow-focus (10-25 mm), two-dimensional, M-mode and Doppler echocardiograph y was performed. A J-tree cluster analysis was performed using parameters i ndicative of CHF. Reproducibility was examined. The cluster analysis joined the animals into one Sham and two MI clusters. One of the MI clusters had clinical characteristics of CHF and elevated left ventricular end diastolic pressure. Among the echocardiographic variables, only posterior wall short ening velocity separated the failing and nonfailing MI clusters. We conclud e that, by high frame rate echocardiography, it is possible to obtain high- quality recordings in rats. It is feasible to distinguish MI rats with CHF due to myocardial dysfunction from those without failure and to perform lon gitudinal studies on myocardial function.