Computer visualization of left ventricular geometry during the cardiac cycle

Mathematical expressions regulating ventricular dimensions during the cardiac cycle have been defined. Classical, static images are limited in comparison with ventriculograms, are not intuitive for teaching, and do not effectively convey effects of hypertrophy or dilatation. Accordingly we developed Tachycardia, an interactive menu-driven graphics program. The program allows three-dimensional visualization of the kinetics of the thick-walled, ellipsoidal left ventricle (LV). The user may specify mass, ejection fraction, end-diastolic volume, major to minor axis ratio, and diastole to systole time ratio. Real-time animation of heart rates ranging from 50-150/min is achieved. A library contains animations representing the normal LV, including dilatation and concentric or eccentric hypertrophy. For comparison of differences in LV geometry among ventricles, multiple animations can be viewed simultaneously. We conclude that computerized animation provides an intuitive understanding of the dynamic geometry of the cardiac cycle. User definition of the visualization can provide clinical utility and teaching value.