Echocardiographic patterns of pulmonary valve motion in valvular pulmonary stenosis

Echocardiographic tracings of the pulmonary valve were examined in 14 patients with isolated pulmonary stenosis, 20 normal subjects, 26 patients with pulmonary hypertension, 10 patients with a left to right shunt and 28 patients with various forms of heart disease other than pulmonary stenosis. Because of the plane of pulmonary valve motion and the angle of the ultrasonic beam, usually the echoes from only one posterior pulmonary leaflet were recorded. In normal patients atrial systole caused slight posterior motion of the pulmonary valve leaflet in late diastole (average 3, range 0 to 7 mm). The degree of valvular motion after atrial systole (the a wave) increased with inspiration. The position of the leaflet at the onset of ventricular systole varied with the depth of the a wave and the length of the P-R interval, but in the normal subjects the leaflet always returned to a base line or closed position at some time during the respiratory cycle. In 10 patients with moderate or severe pulmonary stenosis (gradient 50 to 142 mm Hg) the depth of the a wave increased markedly (average 10, range 8 to 13 mm). In patients with a gradient of more than 65 mm Hg (8 of 10) the leaflet never returned to a base line or closed position before ventricular systole. In three of four patients with mild pulmonary stenosis (gradient less than 50 mm Hg) and all patients with a left to right shunt or heart disease without pulmonary involvement the a wave was within the normal range. In 25 of 26 patients with pulmonary hypertension no a wave was present. In moderate to severe pulmonary stenosis, the exaggerated leaflet motion after atrial systole probably reflects increased right ventricular end-diastolic pressure and force of atrial contraction which, in the face of a normal or reduced pulmonary arterial pressure, produces a positive gradient across the valve in end-diastole.