An androgenic steroid decreases left ventricular compliance and thus performance in rats

The effect of chronic administration of a high dose of an androgenic steroid on left ventricular (LV) compliance and contractility was studied in rats. Rats received a biweekly intramuscular injection of 5 mg/kg (Steroid) or the vehicle (Control) of nandrolone decanoate. Cardiac performance was measured in anaesthetized, open chest, ventilated rats. LV compliance was assessed from the LV end-diastolic pressure (LVEDP) versus LV end-diastolic strain (LVED STRAIN) relation, where LVED STRAIN was calculated from LV antero-lateral wall segmental length measurements. Cardiac contractility was determined from the LV end-systolic pressure versus LV end-systolic strain relation. Systolic performance was also assessed from the pressure-length area (P-L AREA) or stroke work versus LVED STRAIN relation. Nandrolone decanoate decreased body weight and heart weight but increased the heart weight to body weight ratio. Nandrolone decanoate also reduced LV compliance in steroid group (LVEDP versus LVED STRAIN, slope of Steroid versus Control, p<0.01). Slopes (m) and intercepts Co) of the iinearized relations: log LVEDP=Iog b-m (LVED STRAIN)