A SIMPLE, AUTOMATIC METHOD FOR MORPHOMETRIC ANALYSIS OF THE LEFT-VENTRICLE IN RATS WITH MYOCARDIAL-INFARCTION

Induction of acute myocardial infarction in the rat is an established model for studying effects of therapeutic interventions. Images of sec tions of the rat left ventricle, stained with nitroblue tetrazolium, w ere digitized and several parameters estimated by dedicated software o n an image analyzer (IBAS 2.0). The method was tested on 7 rats with 4 8-hr-old myocardial infarction and 4 sham-operated controls. Infarct s ize can be evaluated by two largely used methods, based on area or on angular extension of the lesion. Results of the two methods are linear ly correlated, but area calculations give values half of those obtaine d from angular extension. Five minutes were needed for a complete eval uation of a section of the left ventricle. Estimates of the parameters showed a relatively low between- and within-operator variability and a good correlation with a classic, but time-consuming, planimetric met hod. The method simultaneously measures infarct size and left ventricu lar geometry in the rat. The advantages over previous nonautomatic met hods are simplicity, good reproducibility, and speed of execution, whi ch make it particularly useful in the evaluation of drug effects.