Left Ventricular Diastolic Performance in Patients with Old Myocardial Infarction

Abstract

To study the left ventricular (LV) diastolic performance of patients with old myocardial infarction (MI), the atrial filling fraction (AFF) and the rapid filling fraction (RFF) were determined using the aortic root echocardiogram during isometric handgrip exercise. Patients with old MI were divided into two groups. The LV ejection fraction in group 1 (n = 22) was >40%, in group 2 (n = 29) <40%. Thirty healthy volunteers were studied as the control group. At rest, the AFF values in group 1 (42 ± 9%) and in group 2 (46 ± 10%) were significantly larger than in the controls (36 ± 7%; p < 0.05 and < 0.01). The resting RFF was 56 ± 11% in controls, 47 ± 11 in group 1, and 41 ± 14% in group 2. The value in group 2 was significantly lower than in controls (p < 0.01). During exercise, the changes in AFF were 3.5 ± 1.2, 5.6 ± 1.8, and 10.3 ± 2.0% for controls and groups 1 and 2, respectively. The changes in RFF were –5.0 ± 1.6, –5.8 ± 1.4, and –11.0 ± 2.1% in controls and group 1 and 2 patients, respectively. The changes in AFF and RFF in group 2 were more pronounced than in controls or group 1 patients. Thus, the increased afterload during isometric exercise led to an increase in AFF with a simultaneous decrease in RFF, reflecting that LV performance was restricted in old MI and that the left atrial booster pump action was mobilized especially in old MI patients with a low LV ejection fraction.