Hypertrophic obstructive cardiomyopathy with multiple coronary arteries to right ventricular microfistulas: a case report and review of the literature.

Background: Coronary artery microfistulas are a rare anomaly; their association with hypertrophic cardiomyopathy is even rarer and can lead to serious cardiac complications owing to coronary steal phenomena such as angina pectoris, myocardial infarction, congestive heart failure, ventricular and supraventricular arrhythmias, syncope, and sudden death.

Case Presentation: A 32-year-old Indian woman presented to our institute with severe angina on exertion and multiple episodes of pre-syncope. Echocardiography revealed hypertrophic obstructive cardiomyopathy. Coronary angiography showed no significant atherosclerotic lesions; however, it revealed multiple microfistulas originated from all three major coronary arteries and draining into her right ventricle. This finding was confirmed by the rapid filling of the pulmonary artery after dye was injected into her left coronary artery during a cardiac catheterization study and by a significant oxygen step up of 15 % seen from her right atria to right ventricle during oximetry analysis. We treated our patient's condition with medical therapy including metoprolol and nicorandil. She improved and angina grade had decreased from class III to class II on a follow-up visit 1 month after discharge.

Conclusions: In this case report and literature review, we highlight an unusual but important association that can lead to symptomatic worsening of angina in young patients with hypertrophic cardiomyopathy owing to coronary steal phenomena.