Transthoracic echocardiography in rats Evalution of commonly used indices of left ventricular dimensions, contractile performance, and hypertrophy in a genetic model of hypertrophic heart failure (SHHF-Mcc-fa^cp-Rats) in comparison with Wistar rats during aging

Abstract.

Two-weekly echocardiographic examinations were conducted in nine SHHF-Mc-fa^cp rats in comparison with eight age-matched Wistar rats. In the SHHF-rats, characterized by progressive LV-dilation and decreasing contractile function between 77–87 weeks of age, left ventricular (LV) hypertrophy was most sensitively demonstrated by increased LV-mass-index (p < 0.001). LV-areas and area-ejection fraction (EF) (2D-images) discriminated more sensitively in the early stages than M-mode-derived diameters and fractional shortening (FS); midwall shortening was the most sensitive parameter of reduced systolic function. Post-mortem measurements showed an excellent correlation with calculated LV-mass (r = 0.91). Post-mortem LV-volumes correlated significantly with diastolic LV-diameters, LV-areas, and calculated LV-volumes (r = 0.56–0.59). Mean within-subject standard deviations in controls were 0.5–0.6 mm (LV-diameters), 3.1–4.6 mm² (LV-areas), ~10% of the mean for FS, area-EF and midwall shortening, and ~20% for wall thickness and LV-mass. The data might be used to choose the most sensitive parameters, and to estimate sample size for echocardiographic investigations in rats.