Multiple Coronary Fistulae
A Cause of Subendocardial Ischemia
A 61-year-old woman with a 3-month history of exertional chest pain was referred for further investigation. She was a smoker with a history of hypertension and hypercholesterolemia. Sublingual nitrates exacerbated her symptoms. A resting ECG demonstrated sinus rhythm with anterolateral and inferior T-wave inversion (Figure 1A). Echocardiography demonstrated normal left ventricular (LV) function with no regional wall motion abnormalities or hypertrophy. ECG stress testing was terminated early because of chest discomfort in stage 2 of the Bruce protocol. At peak exercise, there were non-diagnostic ST changes, with pseudonormalization of the resting T-wave inversion seen both at peak exercise and in recovery (Figure 1B and 1C).
Selective coronary angiography demonstrated unobstructed tortuous coronary arteries. All 3 main coronary arteries drained into the LV via a diffuse plexus of multiple intramyocardial fistulae (Figure 2 and Movie I). Further assessment with cardiovascular magnetic resonance was performed on a 1.5-T system (Magnetom Avanto, Siemens Medical Systems). This confirmed that the patient’s LV volumes and mass were within body surface area–indexed normal values (Figure 3 and Movie II). First-pass myocardial perfusion imaging at rest and during peak dose of adenosine stress demonstrated global inducible subendocardial ischemia (Figure 4 and Movie III). There was no late gadolinium enhancement.
Multiple coronary artery fistulae arising from all 3 major coronary arteries emptying into the LV are extremely rare. There are case reports and small series that have demonstrated inducible ischemia on myocardial nuclear studies.1 There are no reports that demonstrate the subendocardial nature of inducible ischemia as observed in this case by cardiovascular magnetic resonance imaging. It is commonly believed that the perfusion defect corresponds to the region of myocardium that is bypassed by the intramyocardial fistulae. Adenosine-induced hyperemia decreases the diastolic perfusion gradient, increasing shunting by the fistulae and hence causing a coronary steal phenomenon. This steal phenomenon explains the clinical finding that sublingual nitrates exacerbate ischemic symptoms. In the present case, symptoms were abolished by β-blockade.
Dr Pennell has received research support from and served as a consultant to Siemens. The other authors report no conflicts.
The online-only Data Supplement, which contains Movies I through III, is available with this article at http://circ.ahajournals.org/cgi/ content/full/117/6/853/DC1.
Oshiro K, Shimabukuro M, Nakada Y, Chibana T, Yoshida H, Nagamine F, Sunagawa R, Gushiken M, Murakami K, Mimura G. Multiple coronary LV fistulas: demonstration of coronary steal phenomenon by stress thallium scintigraphy and exercise hemodynamics. Am Heart J. 1990; 120: 217–219.