heart and blood vessel disorders
Angina
Unusual causes of angina
Microvascular angina (previously called syndrome X) is a form of angina caused neither by spasm nor by any apparent blockage in the large coronary arteries. Temporary narrowing of much smaller coronary arteries may be responsible, at least in some people. The reasons for the temporary narrowing are unknown but may involve a chemical imbalance in the heart or abnormalities in the functioning of small arteries (arterioles). Other unusual causes of angina include the following: Severe High Blood Pressure None Narrowing of the aortic valve ( Aortic Stenosis ) Leakage of the aortic valve ( Aortic Regurgitation ) Thickening of the walls of the ventricles ( Hypertrophic Cardiomyopathy ), especially thickening of the wall separating the ventricles (hypertrophic obstructive cardiomyopathy) These conditions increase the heart’s workload and thus the amount of oxygen needed by the heart muscle. When the need for oxygen exceeds the supply, angina results. Abnormalities of the aortic valve may reduce blood flow through the coronary arteries, because the openings of the coronary arteries are located just beyond this valve. 