Interplay of cardiac remodelling and myocardial stiffness in hypertensive heart disease: a shear wave imaging study using high-frame rate echocardiography

Aims To determine myocardial stiffness by means of measuring the velocity of naturally occurring myocardial shear waves (SWs) at mitral valve closure (MVC) and investigate their changes with myocardial remodelling in patients with hypertensive heart disease. Methods and results Thirty-three treated arterial hypertension (HT) patients with hypertrophic left ventricular (LV) remodelling and results (59 +/- 14years, 55% male) and 26 aged matched healthy controls (55 +/- 15 years, 77% male) were included. HT patients were further divided into a concentric remodelling (HT1) group (13 patients) and a concentric hypertrophy (HT2) group (20 patients). LV parasternal long-axis views were acquired with an experimental ultrasound scanner at 1266 +/- 317 frames per seconds. The SW velocity induced by MVC was measured from myocardial acceleration maps. SW velocities differed significantly between HT patients and controls (5.83 +/- 1.20 m/s vs. 4.04 +/- 0.96 m/s; P<0.001). In addition, the HT2 group had the highest SW velocities (P < 0.001), whereas values between controls and the HT1 group were comparable (P=0.075). Significant positive correlations were found between SW velocity and LV remodelling (interventricular septum thickness: r= 0.786, P < 0.001; LV mass index: r= 0.761, P<0.001). SW velocity normalized for wall stress indicated that myocardial stiffness in the HT2 group was twice as high as in controls (P < 0.001), whereas values of the HT1 group overlapped with the controls (P= 1.00). Conclusions SW velocity as measure of myocardial stiffness is higher in HT patients compared with healthy controls, particularly in advanced hypertensive heart disease. Patients with concentric remodelling have still normal myocardial properties whereas patients with concentric hypertrophy show significant stiffening.