V.M. Kovalenko, E.G. Nesukay, O.O. Danylenko.Assessment of the intraventricular dyssynchrony in patients after Q-wave myocardial infarction.

The aim of the study was to assess intraventricular mechanical dyssynchroniy in patients with different localizations of acute Q-wave myocardial infarction (Q-MI) and to establish the relationship between left ventricular (LV) remodeling, mitral valve geometry, mechanical intraventricular dyssynchrony and mitral regurgitation (MR). Sixty patients with Q-MI were divided into groups 1a – 32 patients with posterior localization, and 1b – 28 patients with anterior localization of Q-MI. Indicators of longitudinal LV intraventricular dyssynchrony were considered postsystolic shortening index (PSSІ), strain delay index (SDI) and standard deviation (SD) of time to peak longitudinal strain in 12 basal and mid segments of LV – SD12(LS). To evaluate circumferential and radial dyssynchrony we determined SD time of 6 LV segments to circumferential peak strain – SD6(CC) and peak radial strain – SD6(RS) as well as difference of time to peak circumferential and radial strain in two segments of LV opposite wall. We measured systolic tenting area (TA) and coaptation distance (CD) to assess mitral valve geometry. Values of PSSІ and SD12(LS) were significantly lower in 1b group compared to 1a group. We observed a significant longitudinal dyssynchrony in 38.2 % of patients, radial – in 14.3 % and circumferential – in 7.8 % of patients. LV ejection fraction (LVEF) correlated inversely with PSSI (r=–0.48, Р<0.001), SDI (r=–0.39, Р=0.002), SD12(LS) (r=–0.35, Р=0.005) and SD6(CC) (r=–0.28, Р=0.042). Wall motion score index (WMSI) was significantly correlated with PSSІ, SDI, SD12(LS), SD6(CC) and SD6(RS). The LV end-diastolic volume index (EDVI) correlated with PSSI, SDI and SD6(CC). The odds ratio to have mild MR was more along with increasing EDVI and WMSI, reducing LVEF and global longitudinal systolic strain, increasing longitudinal and circumferential dyssynchrony, as well as with increasing TA and CD. In conclusion, longitudinal dyssynchrony was more common (38.3 %) compared with circumferential (7.8 %) and radial (14.3 %) dyssynchrony in patients with Q-MI and preserved LVEF. Global longitudinal systolic dyssynchrony (SD12(LS)) was greater by in average 20.7 % in anterior localization versus posterior localization of Q-MI.

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