Pulmonary artery dilatation – Cardiology MCQ

In valvar pulmonary stenosis:
a) Main pulmonary artery alone is dilated
b) Main pulmonary artery and left pulmonary artery are dilated
c) Main pulmonary artery and right pulmonary artery are dilated
d) Main pulmonary artery, right pulmonary artery and left pulmonary artery are dilated
Correct answer: b) Main pulmonary artery and left pulmonary artery are dilated
In valvar pulmonary stenosis, the main pulmonary artery is dilated due to the eddy currents produced by the high velocity jet of pulmonary stenosis. As the left pulmonary artery is in the same direction as the jet, it is also dilated. The right pulmonary artery is not dilated as the direction of the artery is almost perpendicular to that of the high velocity jet.
Main pulmonary artery and both branch pulmonary arteries are dilated in pulmonary hypertension.