Potential Linkage between High Normalized Electromechanical Activation Time (EMAT), an Early Systolic Time Interval Abnormality with Metabolic Syndrome.

Abstract

High electromechanical activation time (EMAT) is associated with paroxysmal atrial fibrillation and heart failure. Little is known about the association between EMAT and metabolic syndrome (MetS), a precursor of cardiovascular disease. To explore the association between EMAT and MetS. A total of 429 male volunteers were divided into MetS (n = 135, age 60.3 ± 3.7 years) and non-MetS (n = 294, age 58.1 ± 26.6 years) groups in this cross-sectional study. A complete medical history, fasting blood analysis and phonoelectrocardiographic parameters were recorded. EMAT was defined as the time from the onset of Q- wave to the peak first heart sound (Q-S1 interval), and this interval divided by the R-R interval for heart rate correction was calculated as normalized EMAT (nEMAT). The subjects with MetS had a significantly higher rate of positive nEMAT (nEMAT ≥ 15%: 6.7% vs. 2%, p = 0.015), higher heart rate (HR, 71.9 ± 12.0 vs. 69.2 ± 11.1 bpm, p = 0.022) but shorter left ventricular ejection time (LVST = 312.4 ± 33.5 vs. 319.8 ± 31.8 msec, p = 0.029). However, the normalized LVST (nLVST) was not significantly different after adjusting for HR. In multivariate analysis, nEMAT was significantly associated with MetS (odds ratio = 3.43, 95% confidence interval = 1.195-9.837, p = 0.022). Positive nEMAT, a prolonged early phase of contraction, was significantly associated with MetS in males. High nEMAT may be an earlier sign of cardiac function abnormality in MetS.