Aorto - Left atrial fistula after mitral valve replacement.

Acquired aorto-left atrial fistula is uncommon. A rare case of aorto-left atrial fistula following mitral valve replacement is reported with echocardiographic, computed tomograpic and angiographic images.

A 48 years old male was admitted with progressive dyspnea and chest pain for the last three years. There was history of mitral valve replacement (MVR) 4 years ago using 23 mm St. Jude metallic bi-leaflet prosthesis. Clinical examination revealed atrial fibrillation (AF), a well functioning mitral prosthesis and findings of severe aortic stenosis. There was no clinical or laboratory evidence of infective endocarditis. ECG revealed AF, ventricular rate of 70 min−1 and left ventricular (LV) hypertrophy. Transthoracic echocardiography revealed normally functioning mitral bi-leaflet prosthesis. Aortic stenosis was severe with valve area of 0.75 cm2, peak and mean gradients of 73 and 45 mmHg and LV ejection fraction of 55%. Color Doppler in parasternal long axis view revealed an unusual continuous flow from aorta, above the left coronary cusp toward the left atrium (LA) (Fig. 1, panel A and video 1). Computed tomographic aortography failed to demonstrate any fistula (Fig. 2, panel A) as the peripheral vein contrast reached LA before aorta. The pressure gradient between high pressure aorta and low pressure LA did not permit visualization of small fistula. Aortography demonstrated passage of contrast from left coronary cusp in to LA (Fig. 2, panel B and video 2). Angiography after selective cannulation (Fig. 3, panel A, B and video 3) confirmed communication from aorta to LA. At surgery a small fistula from the left coronary cusp to the left atrium was visualized without any evidence of active or healed endocarditis. Closure of fistula using 5-0 prolene and AVR using 19 mm St. Jude metallic prosthesis was uneventful. Post-operative Doppler confirmed absence of flow from aorta to LA (Fig. 1, panel B) and normal functioning of both prosthesis.

Fig. 1

Transthoracic echocardiography with Doppler in parasternal long axis view demonstrating continuous flow from aorta above the left aortic cusp toward the LA (white arrow) (panel A). Panel B showing absence of flow from aorta to LA after surgery. Abbreviations: AO – aorta; LA – left atrium; LV – left ventricle.

Fig. 2

Panel A: Computed tomographic aortography failed to demonstrate the fistula. Panel B: Aortography demonstrated passage of contrast from left coronary cusp in to LA (white arrow). Abbreviations: AO – aorta; LA – left atrium.

Fig. 3

Panel A: Crossing of fistula with wire. Panel B: Selective angiography confirmed communication from aorta to LA (white arrow). Abbreviations: AO – aorta; LA – left atrium.

Supplementary video related to this article can be found, in the online version, at doi:10.1016/j.ihj.2016.07.008.

Acquired aorto-LA fistula following MVR is extremely rare and seems related to damage of the coronary cusp during prior surgery. Clinical presentation includes accidental detection, pulmonary edema or chronic heart failure. Such fistulas have been reported after infective endocarditis, aortic dissection or AVR.

Conflicts of interest

The authors have none to declare.