SYSTEMIC AND REGIONAL HEMODYNAMICS IN CONSCIOUS BIO T0-2 CARDIOMYOPATHIC HAMSTERS

Objective: The recently developed BIO T0-2 strain of cardiomyopathic hamster shows a uniform pathogenesis of dilated cardiomyopathy and represents a useful model of congestive heart failure. Although used in biochemical studies, BIO T0-2 animals have not been characterised by haemodynamic measurements. The aim was to compare the systemic and the regional haemodynamic variables in conscious BIO T0-2 animals at a stage of compensated heart failure with those of age matched normal hamsters of BIO F1B designation. Methods: Hamsters were studied at 8-10 months of age, a stage at which the BIO T0-2 animals have been found to have non-oedematous heart failure. Catheters were implanted in normal and cardiomyopathic hamsters. Following a 3 h recovery, systemic and regional haemodynamic variables were measured with pressure transducers and radioactive microspheres. Results: BIO T0-2 hamsters had lower (p<0.05) mean arterial pressure [83(SEM 3) v 126(2) mm Hg] and cardiac index [205(19) v 338(25) ml.min(-1).kg(-1)], and higher (p<0.05) left ventricular end diastolic pressure [21(1) v 4(1) mm Hg] and total peripheral resistance index [30(4) v 15(2) mm Hg.min.ml(-1).kg(-1)] than BIO F1B animals. Blood flows to the heart and kidneys were less (p<0.05) in BIO T0-2 than in BIO F1B animals. Conclusions: The haemodynamic profile in the BIO T0-2 strain of cardiomyopathic hamsters is characterised by low cardiac output, increased preload, and reduced renal blood flow, and resembles that in many patients with congestive heart failure.