Interval training program improves cardiac function and physical performance in heart failure mice

Abstract

This study was designed to verify the effect of an eight week interval training program (IT) in systolic and diastolic functions and physical performance in heart failure mice (C57B16, n=24). The animals were divided in three groups: 1) Intact sedentary (C), 2) infarcted sedentary (MI-s); and 3) infarcted trained (MI-i). At the begining (M1) and at the end of IT (M2), time of maximal running performance (Tvmáx) was quantified. The ejection fraction (EF), shortening fraction (SF) and isovolumetric relaxation time (IVRT) were accessed by echocardiography in M2. At 60 days after coronary artery occlusion the IT was started (4min at 80% Vmáx x 4min at 40% Vmáx during 60min). The results are presented in mean and SEM. Myocardial infarction area was not different between groups in both evaluation time (M1vsM2). The EF and SF in MI-s were lower than C (44±3.7vs58±3.0% and 22±2vs31±2%, respectively; p≤0.05) but similar between MI-i and C (56±5vs58±3% and 25±3vs31±2%, respectively). The IVRT was higher (p≤0.05) in MI-s (25.6±4ms) than C (13±1ms) while similar in MI-i (15±0.8ms) and C. At the M1 both MI-s and MI-i Tvmáx decreased in comparison with C (620±16 and 644±28vs840±17s, respectively). At the M2, Tvmáx delta percent was higher in MI-i than MI-s (64±8vs15±6%, respectively; p≤0.05) and C (0.53±3%). The results suggest that IT improves cardiac function and physical performance in heart failure mice.