Aggravation of symptoms of angina in a patient when given nitrates is seen in :

Ans. is 'd' i.e Idiopathic Hypertrophic Sub Aortic Stenosis As already explained in Nov. 2000, idiopathic hypertrophic subaortic stenosis (or HOCM) is a dynamic outflow obstruction which is increased by any mechanism decreasing the preload (Nitrates decrease the preload significantly)Nitrates decrease the obstruction in AR & MRIn single left coronary artery stenosis, nitrates are helpful. By decreasing the preload decrease the cardiac work done (and hence decreased 02 requirement). A decrease in preload also improves the subendocardial perfusion (because of decrease in end-diastolic pressure, the sub-endocardial crunch is abolished).