Temporal evolution of left ventricular dyssynchrony after myocardial infarction: relation with changes in left ventricular systolic function.

AIMS The relationship between temporal changes in left ventricular (LV) dyssynchrony and LV functional recovery after acute myocardial infarction (MI) remains unclear. Accordingly, the aim of the present study was to evaluate the temporal evolution of LV synchronicity after acute MI, and to explore the relationship between changes in LV systolic function and LV synchronicity. METHODS AND RESULTS In 193 patients with a first acute MI, LV dyssynchrony (SDI) and global systolic function were evaluated with real-time three-dimensional echocardiography 48 h after percutaneous coronary intervention and at 6 months follow-up. Changes in LV systolic function and synchronicity were evaluated at the follow-up and the relationship between these changes was explored. A total of 59 (40%) patients had an anterior acute MI. Median peak value of troponin T was 2.97 µg/L (1.41-6.06 µg/L). Mean LVEF was 47 ± 8% and mean SDI was 5.01 ± 2.10%, respectively. At 6 months follow-up, a significant improvement in LVEF (50 ± 9 vs. 47 ± 8%; P < 0.001) and SDI (4.52 ± 1.97 vs. 5.01 ± 2.10%; P = 0.003) was noted. A strong correlation was found between LVEF change and SDI change (β = -0.63; P < 0.001). At multivariate analysis, SDI change was an independent factor associated with changes in LVEF. Importantly, an addition of SDI change to the multivariate model significantly increased the R(2) from 0.41 to 0.57 (F change 49.0, P < 0.001). CONCLUSION A temporal evolution of LV synchronicity was observed after a first, mechanically reperfused, acute MI. The reduction in LV dyssynchrony independently influenced LV functional recovery in these patients.