Pulsus alternans with alternation of mitral flow and motion patterns

A 41-year-old man with dilated cardiomyopathy had persistent pulsus alternans on physical examination and on cardiac catheterization. On M-mode echocardiography patterns of mitral valve diastolic motion showed alternation such that the E phase was longer and the A phase shorter after stronger ventricular contractions. At faster rates the A peak was apparently absent in alternate diastoles. Doppler recordings of mitral flow exhibited alternation such that the peak velocity and duration of early diastolic flow were larger after stronger ventricular contractions; diastolic mitral regurgitation was noted only in such (alternate) diastoles.