A-dip of the aortic valve by M-mode echocardiography.

We present a case with the previously unreported finding of an a-dip in the M-mode tracing of the aortic valve. An a-dip is commonly seen in the M-mode tracing of the pulmonic valve motion, and represents near equalization of pulmonary artery and right ventricular end- -diastolic pressures during atrial contraction. M-mode echocardiography has become an ancillary study to the basic two-dimensional examination, but can often convey important features of cardiac hemodynamics quite elegantly, as the present case demonstrates.