What is the mechanism of phasic ejection click in valvar pulmonary stenosis?
During inspiration the systemic venous return increases and enhances the right ventricular filling. This elevates the right ventricular end diastolic pressure causing a cephalad excursion of the pulmonary valve at the end of diastole. Hence the opening movement during systole is less as the valve is already partially domed at the end of diastole. In expiration the right ventricular end diastolic pressures are lower and presystolic doming of pulmonary valve does not occur. Hence the systolic excursion of pulmonary valve is more in systole and produces a prominent click. The click is nearer to first heart sound in inspiration, apparently fusing with it and moves away from the first heart sound in expiration. What is hemodynamic vise? The vertical vein in total anomalous pulmonary venous connection passes between the pulmonary artery and the left bronchus and gets compressed when the pulmonary artery pressure goes up. This produces pulmonary venous obstruction and increased pulmonary veno
