Chest pain secondary to membranous subaortic stenosis in a young woman.

Left ventricular outflow obstruction can be divided into three distinct categories: valvular aortic stenosis, the most common form; supravalvular aortic stenosis, which is often seen in early childhood; and subvalvular stenosis, which can be further subdivided into muscular, tunnel, and fibromembranous subtypes. All may be found in a patient seen with symptoms of angina, syncope, or heart failure as a precursor to sudden death. Prompt clinical recognition is essential as is a high degree of suspicion when these signs are associated with a systolic ejection murmur on clinical examination. Echocardiography and a meticulous Doppler examination are very useful in the diagnosis of these disorders as well as in further distinguishing among the different subtypes. The authors describe the case of a 40-year-old woman with chest pain refractory to medical therapy and a long systolic ejection murmur.