Varying ejection fractions of both ventricles in paradoxical pulses: demonstration by radionuclide study.

A noninvasive radionuclide study of the paradoxical pulse in pericardial effusion is described. The study shows complementary changes of the right and left ventricular ejection fractions in a patient with paradoxical pulse, supporting the theory that the inspiratory reduction of the left ventricular stroke volume is an immediate and direct result of the inspiratory increase of the right ventricular filling. The technique may be sensitive to detect early paradoxical pulse and cardiac tamponade.