Background: The aims of this study were to assess the sequential changes of left ventricular(LV) systolic and diastolic synchrony in patients with acute myocardial infarction(AMI) and to assess their relation with LV recovery and remodeling.
Methods: Forty-patients with acute ST-elevation MI were examined within 2days, 6weeks and 6months after primary coronary intervention. Fifteen-age matched subjects were enrolled as control. The time from the onset of QRS complex to peak systolic velocity(Ts) and to peak early diastolic velocity(Te) were measured on color-coded tissue Doppler imaging. To assess LV synchrony, SDs of Ts(Ts-SD) and Te(Te-SD) of all 12 segments were calculated(within 2days, at 6weeks and 6months; SD1, SD2 and SD3, respectively). LV recovery was defined as the improvement of wall motion at least more than two segments at 6 weeks.
Results: In all AMI patients, the wall motion score index was 1.72±0.27 and LV ejection fraction was 45.9±9.9%. The Ts-SD1 was higher in AMI patients than in controls(45.4±13.5 vs 29.4±13.3ms,p<0.05), but Te-SD1 was not different (18.7±6.9 vs 16.2±10.0). Twenty-two patients(group1) showed a recovery and 18 patients(group2) showed no recovery. The Ts-SD1 was smaller in group1 than in group2 (43.4±12.6 vs 47.9±11.7 ms,p<0.05). In group1, Ts-SD were much decreased as follow up(Ts-SD2, 3; 36.6±14.0 and 31.1±9.5, respectively,p<0.05). In contrast, in group2, Ts-SD was not significantly changed(Ts-SD2,3; 46.7±13.2 and 43.7±8.8, respectively) but Te-SD was increased as follow up(Te-SD1,2,3; 17.8±5.5, 20.4±4.3 and 25.0±3.8, respectively,p<0.05). The LV end-diastolic and systolic volume were increased and the deceleration time of early diastolic mitral inflow velocity was shortened in group2(p<0.05).
Conclusions: This study shows: 1)in acute phase, the regional wall motion abnormalities of AMI had an impact on LV systolic synchrony; 2)the AMI patients with recovery showed better LV systolic synchrony; 3)the LV systolic synchrony became better as regional wall motion was improved; and 4)in chronic phase, the LV diastolic synchrony became worse in AMI patients with no recovery, which might be related to LV remodeling and worsening of LV diastolic function.
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