Role of left atrial booster pump function in a worsening course of congestive heart failure

We evaluated changes in left ventricular (LV) preload and the Doppler-derived transmitral late to early diastolic peak velocity ratio (A/E ratio) during the exercise in 27 patients with ischemic heart disease. After the exercise, A/E ratio decreased in 16 patients with a remarkable elevation in LV preload, and increased in 11 with a mild elevation. Further, Doppler transmitral flow in conjunction with pulmonary venous flow and hemodynamic parameters were analyzed in 11 dogs during a worsening course of heart failure induced by dextran infusion. The relationship of A/E ratio to LV end-diastolic pressure showed a quadratic curve concave to the pressure axis. A/E ratio, an index expressing left atrial (LA) contribution to LV filling, returned to that seen before volume loading under the condition of cardiac dysfunction. Pulmonary venous reflux fraction determined as the ratio of peak velocity of pulmonary venous reflux during LA systole to the sum of systolic and diastolic peak velocities of pulmonary venous antegrade flow, did not increase here. In this situation, blood could not be ejected from the left atrium into the left ventricle and even into the pulmonary veins during LA contraction. Finally, LV filling was not compensated by the left atrium, and LA booster pump function itself was deteriorated.