Area of the pressure-strain loop during ejection as non-invasive index of left ventricular performance: a population study

摘要

Previous studies highlighted the usefulness of integrating left ventricular (LV) deformation (strain) and hemodynamic parameters to quantify LV performance. In a population sample, we investigated the anthropometric and clinical determinants of a novel non-invasive index of LV systolic performance derived from simultaneous registration of LV strain and brachial pressure waveforms. Three hundred fifty-six randomly recruited subjects (44.7% women; mean age, 53.9?years; 47.5% hypertensive) underwent echocardiographic and arterial data acquisition. We constructed pressure-strain loops from simultaneously recorded two-dimensional LV strain curves and brachial pressure waveforms obtained by finger applanation tonometry. We defined the area of this pressure-strain loop during ejection as LV ejection work density (EWD). We reported effect sizes as EWD changes associated with a 1-SD increase in covariables. In multivariable-adjusted analyses, higher EWD was associated with age, female sex and presence of hypertension (P?≤?0.0084). In both men and women, EWD increased independently with augmentation pressure (effect size: +?59.1?Pa), central pulse pressure (+?65.7?Pa) and pulse wave velocity (+?44.8?Pa; P?≤?0.0006). In men, EWD decreased with relative wall thickness (??29.9?Pa) and increased with LV ejection fraction (+?23.9?Pa; P?≤?0.040). In women, EWD increased with left atrial (+?76.2?Pa) and LV end-diastolic (+?43.8?Pa) volume indexes and with E/e’ ratio (+?51.1?Pa; P?≤?0.026). Older age, female sex and hypertension were associated with higher EWD. Integration of the LV pressure-strain loop during ejection might be a useful tool to non-invasively evaluate sex-specific and interdependent effects of preload and afterload on LV myocardial performance.