Ventricular Structure and Function in Aged Dogs With Renal Hypertension

Background— Heart failure (HF) with normal ejection fraction (diastolic HF [DHF]) usually occurs in elderly patients with hypertension. The presence and significance of altered systolic and diastolic ventricular function in DHF is increasingly controversial. Our objective was to develop a clinically relevant large-animal model to better understand the pathophysiology of DHF. Methods and Results— Ventricular structure and function were characterized in young control (YC group; n=6), old control (OC group; n=7), and old dogs made hypertensive by renal wrapping (experimental DHF [ExDHF] group; n=8). The ExDHF group was associated with normal left ventricular (LV) volume, increased LV mass, and myocardial fibrosis. LV relaxation was impaired in ExDHF (τ=53±6 ms) compared with OC (τ=35±3 ms; P<0.05) and YC (τ=33±6 ms; P<0.05) dogs. The percent diastole at which relaxation is complete was increased in ExDHF (116±30%) compared with OC (69±8%; P<0.05) and YC (35±5%; P<0.05) dogs. The coefficient of LV diastolic s...