In what condition does aortic ejection click vary with respiration?
Aortic ejection click in Tetralogy of Fallot has a phasic nature with expiratory augmentation similar to that of the phasic ejection click in valvar pulmonary stenosis.
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 venous pressure, which in turn causes further elevation of pulmonary artery pressure leading to enhanced compression of the vertical vein. A vicious cycle of increasing pulmonary venous and arterial pressures is setup.
What is the classical chest x-ray finding in TAPVC?
The classical chest x-ray finding in total anomalous pulmonary venous connection (TAPVC) is “snow man in snow storm appearance”. It is also called “figure of eight appearance” and “cottage loaf appearance”. The lower part of the figure of eight is the heart and the upper part is contributed by the vertical vein on the left and dilated superior vena cava on the right side. The dilated left brachiocephalic vein forms the superior link. The snow man in snow storm description is because the lung fields are congested, mimicking snow storm.
Differential pulmonary blood flow in TGA
The orientation of right ventricular outflow is towards the right pulmonary artery in transposition of great arteries (TGA) and causes increased blood flow in the right lung.
Dilated pulmonary arteries in TOF with absent pulmonary valve
In Tetralogy with absent pulmonary valve, the main pulmonary artery and intramediastinal portion of right and left pulmonary arteries are dilated. Hence the dilatation of right and left pulmonary arteries may not be evident on chest x-ray and visualised only on pulmonary angiogram. The reason for dilatation of the intramediastinal portion alone is thought to be because this region is not surrounded by lungs.
What is the feature of ductal (PDA) calcification of x-ray chest?
Calicified patent ductus arteriosus produces an inverted Y shaped pattern of calcification on x-ray chest PA view.