Left atrial volume and its changes in heart disease

Left atrial volume and volume change during the heart cycle were determined and compared with left ventricular stroke volume and forward, or effective, stroke volume in 57 patients who were grouped as follows: normal, primary cardiomyopathy, aortic valve disease, predominant mitral insufficiency, predominant mitral stenosis, and combined aortic and mitral valve disease. In this study left atrial cyclic volume change averaged 41% of the left ventricular stroke volume and was in no case more than 72% of the left ventricular stroke volume, regardless of the type of heart disease. Some patients with aortic valve disease or primary cardiomyopathy have left atrial maximum volumes as large as those seen in many patients with mitral stenosis. Three features of left atrial volume and volume change per heart beat were observed in patients with mitral insufficiency: (1) a large left atrial volume (all patients with a left atrial volume greater than 365 ml had mitral insufficiency), (2) a large left atrial cyclic volume change, and (3) a left atrial volume change per beat equal to or greater than the forward, or effective, left ventricular stroke volume. It was also demonstrated that the left atrial cyclic volume change in patients with atrial fibrillation may be large and in this study showed no significant difference from values observed in patients with normal rhythm.