Reduced left ventricular relaxation velocity after acute myocardial infarction

Diastolic left ventricular function is usually described using Doppler recording of the early to atrial (E/A) ratio. However, because of pseudonormalization in patients with moderately impaired diastolic function, the E/A ratio does not allow a meaningful comparison between a group of patients with varying degrees of dysfunction, e.g. after acute myocardial infarction (AMI), and a group of healthy control subjects. In this study, diastolic function was assessed using the E/A ratio, deceleration time of early mitral inflow and maximal longitudinal relaxation velocity. The relaxation velocity was measured using echocardiographic M-mode recording of mitral annulus motion. Mitral annulus motion was recorded in four- and two-chamber views. Relaxation velocities were measured in the septal, lateral, anterior and posterior parts of the mitral annulus and the mean value (RVm) was calculated. Twenty-two consecutive patients were investigated 3-21 days after first transmural AMI. Twenty-two healthy subjects of similar age served as a control group. The group of patients with AMI had an RVm of 40.9 +/- 15.4 mm s-1 compared with 68.5 +/- 12.4 mm s-1 in the control group (P < 0.0001). In contrast, the E/A ratio, deceleration time and heart rate did not differ significantly between the two groups. The results suggest that maximal longitudinal relaxation velocity is a simple and appropriate measure of diastolic function in patients with transmural AMI.