Multiple left anterior descending coronary artery to left ventricular fistula – A case series and literature review

Abstract

Coronary artery fistulas (CAFs) are found in 0.3–0.8% of patients who undergo coronary angiography. CAFs are defined as single or multiple, small or large direct communications that arise from one or more coronary arteries and enter into one of the four cardiac chambers or major vessels. We present two cases of multiple coronary artery fistulas arising from diagonal and left anterior descending (LAD) branches of left coronary artery draining into the left ventricle. In both the cases, No intervention was performed. Of the congenital fistulas, two major groups are identified: solitary CAFs or coronary artery-left ventricular multiple micro-fistulas (CALVMMFs). Noninvasive techniques such as transthoracic echocardiography, transesophageal echocardiography and magnetic resonance imaging are becoming increasingly popular for diagnosis and follow-up of CAFs. Despite the advent of these newer non-invasive modalities, coronary angiography remains the gold standard for diagnosis. Treatment of CAFs is indicated when the patients are symptomatic with left ventricular volume overload, myocardial ischemia, left ventricular dysfunction or in the presence of a large or increasing left-to-right shunt. If the fistula is small and hemodynamically insignificant, it can be managed with conservative management. Multiple left anterior descending to left ventricle (LV) fistulas are extremely rare and, as per our literature review, we noted only a few case reports of coronary artery fistulas between branches of LAD and left ventricle.

Multiple Coronary Fistulas as a Rare Cause of Stable Angina Pectoris

“…Angina in the absence of CAD is thought to be a consequence of the "steal" phenomenon, which induces ischemia by diverting blood from the high-resistance myocardial capillary bed into the low-resistance fistula [10]. Patients with multiple fistulas in the left ventricle usually present with typical or atypical anginal symptoms [5]. The hemodynamic consequences of CAF vary depending on shunt size, shunt site, and other underlying cardiac diseases.…”

“…CAFs have two distinctive angiographic appearances, which could be solitary or multiple and drain into different vascular bed/cardiac chambers [4]. Most CAFs are small, and the patient is usually asymptomatic, but when symptoms and complications occur, they include angina, myocardial infarction, heart failure, arrhythmias, and endocarditis [5]. The management of CAFs is controversial, and recommendations are based on cases or small retrospective series [2].…”

Coronary artery–left ventricular multiple microfistulas, a rare disease that is easily missed: case report and literature review

“…2,5,13 The shunt flow through the fistula mainly depends on the size of the fistula and the pressure gradient between the coronary artery and the drainage site. 14 Because of the small fistula diameter and pressure gradient of CALVMMFs, the resultant hemodynamic changes are generally of little clinical significance. In addition, our patients' coronary angiography results suggest that during systole, the microvascular fistulas close under pressure and the abnormal blood flow stops, which also reduces the degree of "coronary steal" to some extent.…”

“…In addition, our patients' coronary angiography results suggest that during systole, the microvascular fistulas close under pressure and the abnormal blood flow stops, which also reduces the degree of "coronary steal" to some extent. This special hemodynamic change means that the degree of myocardial ischemia and cardiac load increase in most patients with CALVMMFs may not be obvious, 11,14 and these patients may therefore have no obvious clinical symptoms or will require a long time to develop obvious symptoms. In our case series, the cardiac function of all except one patient with left ventricular diastolic dysfunction was not markedly decreased, indicating that these patients may have a good prognosis.…”

Three vessel coronary artery-left ventricular multiple micro-fistulas: a rare angiographic finding

“…Coronary artery fistulas (CAFs) are found in 0.3–0.8% of patients undergoing coronary angiography [ 1 ], and MMFs draining blood from all three major coronary arteries to the LV is an exceptionally rare entity with a reported incidence of 0.001% [ 2 ]. The congenital abnormality is a result of the failure of obliteration of large intra-trabecular embryonic sinusoids.…”