Analysis of Ventricular Dimension in the Unanesthetized Dog.

• In the analysis of left ventricular dynamics, geometric measurements provide one important index of cardiac performance. Although previous studies ' suggest that the major change during the ejection phase of systole is a decrease of transverse dimension, the details of this change at rest and during exercise remain to be established. Moreover, these dimensional changes, coincident with the decrease of chamber volume, and those occurring during the isovolumetric phases of the cardiac cycle, have not been adequately studied and analyzed by appropriate statistical sampling methods. The present study was undertaken to supply such information.