Cardiac function, fiber shortening, and dynamic geometry.

Many models for the study of the pump function of the heart emphasize the importance of cardiac geometry and detailed dimensional data. Because of the lack of accurate measuring techniques, approximate geometries such as shells of revolution have been applied. In this study, methods are presented that measure the dynamic geometry of the working, isolated canine heart by means of ultrasound-velocity tomography techniques.

Method for measuring cardiac dimensions and intramural deformations.

Information about the geometry and intramural deformations of the left ventricle of the heart throughout the cardiac cycle is necessary for the analysis of contractile function of the intact heart. In this study a method is developed to measure dimensions and intramural deformations of the left ventricle of a dog heart during the cardiac cycle. Radiopaque markers (platinum spheres of 1mm diameter) were implanted in the wall of the left ventricle.