Evaluation of left ventricular function in an experimental model of congestive heart failure due to combined pressure and volume overload.

During a 6 month observation period after operation, typical symptoms of congestive heart failure, such as cyanosis, systemic oedema, ascites and pleural effusion occur in the majority of rats which have a combined arteriovenous shunt (AV-shunt) and renal hypertension (Goldblatt II). In the present study, the left ventricle dilated to twice the size of that of age-matched Wistar controls. Developed wall stress increased significantly due to an augmented ratio of radius to wall thickness. Normalized stress-length (stress-midwall circumference) area and maximum rate of stress development (d sigma/dtmax) indicated decreased myocardial work and power capacity. Although the congestive symptoms can only partially be related to impaired cardiac function, this model may be useful for pathophysiological and pharmacological studies of chronic heart failure.