Correspondence Address: Rahul Shewale 1511, Doctor Quarters, MRC Building, Bombay Hospital, Marine Lines, Mumbai - 400 020, Maharashtra India
Source of Support: None, Conflict of Interest: None
We report a case of coronary cameral fistula arising from the left circumflex artery (LCX) draining into the coronary sinus. This 55-year-old male, with no prior symptoms or risk factors, presented with sudden-onset palpitations and sweating. Contrast enhanced computed tomography coronary angiogram as well as conventional coronary angiography revealed a hugely dilated extremely tortuous fistula from the LCX draining into the coronary sinus. This case is unique because of such a giant fistula remained totally asymptomatic till the sixth decade of life and with no perfusion defect on myocardial perfusion imaging.
Keywords: Coronary cameral fistula, coronary sinus, left circumflex artery, tortuous
How to cite this article: Shewale R, Munot N, Yadav H, Pagad S. A humungous coronary cameral fistula, silent till sixth decade of life!. Heart India 2018;6:33-5
Coronary arteriovenous (AV) fistulae are rare and usually asymptomatic. “Coronary steal phenomenon” is the usual pathophysiological mechanism leading to symptoms. Complications include aneurysmal dilatation, intimal ulceration, rupture, thrombosis, and may lead to congestive heart failure or sudden cardiac death.
A 55-year-old male, with no significant past medical history, presented with sudden-onset palpitations, chest pain, and sweating in office. On physical examination, he was noted to have a 2/6 continuous heart murmur. There was no history of presyncope or syncope. There was no family history of cardiovascular disease. He again had a similar episode of palpitations and profuse sweating on the 2nd day of hospitalization. ECG showed normal sinus rhythm. Transthoracic echocardiography showed that the left and right ventricular function were normal, with no other abnormality. 24-h Holter monitoring was done which did not reveal any significant arrhythmia.
We performed coronary angiography, which showed that the LAD and RCA arteries were normal in course and caliber. The left circumflex artery (LCX) vessel was grossly dilated from its origin and a coronary cameral fistula arising out of LCX had a very tortuous course ultimately draining into the coronary sinus [Figure 1]. The obtuse marginal branches were normal sized and seen to be originating from the dilated LCX vessel. There was no significant narrowing noted in the coronaries [Video 1] and [Video 2].
Figure 1: Coronary angiogram in right anterior oblique caudal view – large, serpiginous left circumflex artery fistula
Multislice contrast-enhanced computed tomography (CT) coronary angiogram was done to further evaluate the course of fistula; it revealed that the left circumflex was significantly dilated from its proximal segment following an extremely tortuous course draining into the coronary sinus. The distal communicating part of the fistula was 1.4 cm in diameter which was very large [Figure 2] and [Figure 3]. Three-dimensional volume-rendered images accurately depict the course of the fistula and its relation to the right heart [Figure 2], [Figure 3], [Figure 4], [Figure 5] Myocardial perfusion imaging was performed and did not show any significant perfusion defect.
Figure 2: Computed tomography coronary angiogram showing the course of the fistula and relation to other coronary vessels
In view of no evidence of perfusion defect or heart failure, the patient was advised for regular follow-up and was discharged. On his last visit, he is stable and symptom-free.
Coronary AV fistulae are usually asymptomatic and an incidental finding. They are defined as an abnormal communication between coronary artery and a cardiac chamber (cameral) or to any part of pulmonary or systemic circulation (AV). Majority of the fistulas are congenital  and occur due to the persistence of abnormal sinusoidal connections to cardiac structures. Acquired causes of coronary AV fistula include traumatic injury, cardiac surgery, pacemaker implantation, or angioplasty. Large fistulas are rare. The main pathophysiologic mechanism for symptoms is due to coronary steal phenomenon. There is a runoff of blood supply from high-pressure zone to a low-pressure zone (right heart structures). This may cause myocardial ischemia.
They may be an isolated finding or found to be associated with other congenital anomalies. RCA is the most common site of origin followed by the LAD and rarely LCX artery. They usually drain into the right heart (right atrium, coronary sinus, and right ventricle) or rarely into the left ventricle. Sakakibara classified them into two types according to their origin. Type A fistulae originate from the proximal third of the native coronary. These are typically large complex coronary AV fistulae. Type B fistulae arise beyond the proximal third or represent terminal connections of the native coronary artery. These are typically small coronary cameral fistulae. Our patient had Type A variant due to its large size and tortuosity. These factors play an important role in deciding the plan of management.
Symptoms usually depend on the anatomy and hemodynamic parameters of fistula. Dyspnea, angina, syncope, and palpitation are the usual symptoms. Congestive heart failure can occur in large fistulas. A peculiar physical finding is the continuous murmur which may be heard on the chest wall depending on the location of the fistula. Apart from heart failure, several other complications such as aneurysm formation, intimal ulceration, rupture, thrombosis, and side branch obstruction can occur in due course of time with large fistulas. Spontaneous rupture of the fistula can cause hemopericardium along with tamponade or a sudden cardiac death.
Diagnostic approach involves identification and delineation of the exact anatomy including size, origin, course, and the drainage. Conventional coronary angiography remains the cornerstone of the diagnosis and assessment of a fistula defining the pattern of flow. Cardiac catheterization can provide invaluable information about the shunt fraction.
Due to superior image quality, CT has caused a paradigm shift in the way we evaluate such fistulas. It has led to further improvement in delineating the exact location, its association with other cardiac structures, course, and drainage of the fistula.
The management depends on the presence of symptoms, anatomy of the fistula, and the presence of myocardial ischemia or ventricular dysfunction. Treatment is by either surgical closure or transcatheter closure (coil/device).
Surgical closure is superior in cases with difficult anatomy or extremely tortuous course or having multiple channels. Surgical techniques include distal ligation alone, proximal and distal ligations, or internal closure of the fistula from within a cardiac chamber. Furthermore, if the coronary circulation has been compromised, a bypass graft may be placed simultaneously.
The anatomy of the fistula has to be favorable for this treatment (e.g., nontortuous vessel, the fistula should be unique with distal narrowing to avoid embolism to the drainage site, and there should be no concomitant cardiac disorders requiring additional surgical intervention). In recent times, the number of transcatheter closure procedures has increased with good success rate.
Coronary cameral fistulas are rare. Large fistulas may present with dyspnea, angina, or palpitations.
Anatomy and hemodynamics define the suitable type of closure. Our case is especially peculiar because it is rare to have such a huge Type A fistula arising from LCX artery draining into coronary sinus which was asymptomatic till the sixth decade of life. The extreme tortuosity encountered along its course and the dilated distal end makes it a challenging case.
The authors would like to thank Padmavibhushan Dr. BK Goyal for his guidance and support.