Left Ventricular Twist and Ventricular–Arterial Coupling in Hypertensive Patients

Abstract

Background: Left ventricular (LV) twist is usually influenced by LV hypertrophy resulting from hyp erten- sion or vascular stiffness. Vascular stiffness would increase arterial elastance (Ea), whereas LV end-systolic stiffness (Ees) could be influenced by LV hyp ertrophy. Therefore, in hypertensive patients, we assessed the extent to which ventricular–arterial coupling (VAC; Ea/Ees) affects LV twist, which may be a com- pensatory mechanism for systolic dysfunction. Methods: Hypertensive patients (n = 128) and healthy controls (n = 40) underwent conven tional and speckle tracking echocardiography including LV twist. Ea and Ees were estimated noninvasiv ely by echocardiography. Patients were divided into 3 tertiles according to the twist angle. Univariate and mul tivariate regression analyses were perf ormed to test the influence of VAC on twist. Results: Patients in the lowest LV twist tertile had larger LV end-systolic vol- ume, lower ejection fraction, lesser mid-wall fractional shortening (MWFS), and higher LV mass index (LVMI), compared to those with the highest tertile. They showed the lower septal tissue Doppler veloc- ity, and global longitudinal and circumferential strain. With regard to VAC, Ea was simi lar among 3 groups, but Ees was significantly decreased in patient with lower tertile, resulting in increased VAC (1.1  0.2 vs. 0.9  0.1 vs. 0.7  0.1, P < 0.001). While LV twist showed significant correlations with Ees, MWFS, and LVMI, VAC (b = 14.92, P < 0.001) was most associated with twist in a multivariate analysis. Conclusions: LV twist was significantly associated with VAC in acco rdance with LV function; LV twist and VAC decreased progressively as LV systolic function deteriorated, while being enhanced dur- ing the well-compensated phase. (Echocardiography 2014;31:1274–1282) Key words: ventricular–arterial coupling, stiffness, elastance, echocardiography