Wednesday, May 24, 2017

Aneurysmal left main coronary fistula to RA in asymptomatic Patient with normal Left Ventricular function ( Answer to the weekly case challenges ) .

Q: An asymptomatic 32 year old woman with a murmur. What is it?

A: Aneurysmal left main coronary fistula to RA in asymptomatic pt, normal LV function.

•Learning Tips:
•Coronary artery fistulae (CAF) are rare cardiac malformations. Their prevalence has been reported at 0.1% to 0.2% of patients who undergo coronary angiography.
•Coronary artery fistulae are either congenital or acquired coronary artery abnormalities, that have different anatomical appearance; with varying degree of shunting (Qp/ Qs); and associated cardiac anomalies .
•Etiologies include high cardiac output state and congestive heart failure with shunting of blood into a cardiac chamber, great vessel, or other structures, bypassing the myocardial capillary network .
•If the fistula is large, the intracoronary diastolic perfusion pressure diminishes progressively .
•The coronary vessel usually attempts to compensate by progressive enlargement of the ostia and feeding artery.
•Nevertheless, myocardium beyond the site of the fistula’s origin is at risk for ischemia, most frequently evident in association with increased myocardial oxygen demand during exercise or activity .
•Although aneurysm formation is common in patients with coronary artery fistulae, giant aneurysms have rarely been reported.
•They are often asymptomatic and small, however, but rupture of an aneurysmal fistula can be fatal.
•Moreover, a coronary steal phenomenon can occur owing to blood shunting and perfusion away from the myocardium. This phenomenon can be manifested in the patient as angina pectoris.
•With time, the coronary artery leading to the fistulous tract dilates progressively, that in turn, may progress to frank aneurysm formation, intimal ulceration, medial degeneration, intimal rupture, atherosclerotic deposition, calcification, side- branch obstruction, mural thrombosis, and, rarely, rupture.
•Treatment is recommended in the presence of symptoms, a giant aneurysm, or progressive enlargement of fistulae.
•In cases of small and easily accessible fistulae, transcatheter closure could be considered.

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