Effect of Age on Left Ventricular Global Dyssynchrony in Asymptomatic Individuals: A Population Study

Left ventricular (LV) segmental dyssynchrony is common in patients with heart failure or myocardial activation abnormalities and is associated with increased cardiovascular risk. Total isovolumic time (t-IVT) and Tei index are sensitive indexes of global ventricular dyssynchrony. The aim of this study was to investigate the effect of age on t-IVT and Tei index.

We evaluated 410 individuals with no evidence for coronary heart disease or activation abnormalities. T-IVT was calculated as 60 - (total ejection time + total filling time) and Tei index as t-IVT/total ejection time. The relationship between age, LV systolic and diastolic function parameters as well as t-IVT and Tei index was studied.

Ejection fraction and stroke volume did not change with age, whereas early diastolic filling velocity fell and atrial systolic velocity increased, reducing the E/A ratio. Isovolumic contraction time (IVCT) and isovolumic relaxation time (IVRT) lengthened. With every 10 years of age, total LV ejection time shortened by 1.5 sec/min and total filling time by 2.1 sec/min. T-IVT and Tei index increased with age and strongly correlated with IVCT and E/A, but not with ejection fraction or QRS duration.

Normal aging is associated with worsening of LV global dyssynchrony shown by prolongation of isovolumic times resulting in shortening of filling and ejection times. Age also affects diastolic function as shown by E/A but not systolic function parameters, ejection fraction or stroke volume. Worsening of global dyssynchrony correlates with that of diastolic function but not with QRS duration.