Evaluation of left ventricular short- and long-axis function in severe mitral regurgitation using 2-dimensional strain echocardiography

Background: Few data exist on the changes in left ventricular (LV) short- and long-axis function and their usefulness as markers of LV contractile function in patients with chronic, severe mitral regurgitation (MR). Methods: We studied 59 patients who had severe MR with an ejection fraction ≥50% and 34 healthy controls. Speckle tracking imaging was performed to measure peak systolic radial (SR_R), circumferential (SR_C), and longitudinal strain rates (SR_L). In all patients, the peak rate of LV pressure rise (peak dP/dt) was measured using a micromanometer-tipped catheter. The patients were subdivided into patients with preserved (group 1, peak dP/dt ≥1,300 mm Hg/s [n = 30]) and depressed (group 2 [n = 29]) contractile function. Results: SR_L was significantly depressed in groups 1 and 2 when compared with the control group, but there was no difference between groups 1 and 2. In contrast, SR_R and SR_C were depressed only in group 2, whereas there were no differences between the control group and group 1. SR_R and SR_C correlated well with peak dP/dt (r = 0.71, P <.001 and r = -0.63, P <.001, respectively), whereas SR_L did not. These findings suggest that LV long-axis function becomes depressed earlier than short-axis function in the chronic remodeling process. Conclusions: Left ventricular short-axis function is a useful marker of LV contractility in patients with chronic, severe MR. Left ventricular long-axis function becomes depressed earlier in the chronic remodeling process. Therefore, evaluation of short-axis as well as long-axis function might be important for better assessment of LV contractile function in these patients.