Exercise and Ventricular Remodeling Post-Acute Myocardial Infarction in the Rabbit

pp 536-539

Abstract

The effect of exercise on ventricular remodeling after myocardial infarction (MI) is under discussion. The aim of our study was to evaluate whether moderate exercise initiated at early stages of MI modifies the degree of ventricular dilation. New Zealand rabbits were used, divided in three groups. Group 1, "sham infarcted group" (G1, n= 7); Group2 (G2, n = 4),rabbits submitted to ligation of a prominent branch of the left coronary artery, and Group3 (G3, n =6), animals with MI and submit-ted to moderate exercise on motor-driven treadmill, after 18 days of evolution. Rabbits were sacrificed at day 56 post-surgery, and hearts were perfused using Langendorff technique. Left ventricular end diastolic pressure (LVEDP)-volume curves were drawn. The size of MI was determined by morphometric analysis. MI size was (X±SEM) G1:0.0 ±0.0; G2: 20.55 ± 0.94, and G3:19.15 ± 1.47. The LVEDP-volumen relationship in the group with MI shifted to the right and in G3these change was increased (p< 0.05versus GI and G2). We can conclude that moderate exercise initiated at early stages of MI evolution has an unfavourable effect on ventricular remodeling