Long-term canine model for echocardiography

A reliable long-term canine model for the echocardiographic evaluation of myocardial dimensions has not been previously described. Because of the configuration of the dog's chest wall, surface echocardiography is difficult to perform. Therefore, a small ultrasound transducer was designed for both short- and long-term experimental studies. In six dogs, a 1.7 by 0.5 cm, 2.25 megahertz lead titanate-zirconate echo transducer was sutured to the anterior epicardial surface of the right ventricle. The transducer was positioned to measure septal thickness, left ventricular posterior wall thickness and left ventricular transverse diameter in a manner similar to that used in clinical echocardiography. The animals were studied 2 weeks to 3 months postoperatively in the closed chest unanesthetized state. Echocardiographic determinations of septal and left ventricular wall thickness were in close agreement with results obtained at necropsy.