Hypertrophic obstructive cardiomyopathy with multiple coronary arteries to right ventricular microfistulas: a case report and review of the literature
© The Author(s). 2016
Received: 30 September 2016
Accepted: 25 November 2016
Published: 31 January 2017
Coronary artery microfistulas are a rare anomaly; their association with hypertrophic cardiomyopathy is even rarer and can lead to serious cardiac complications owing to coronary steal phenomena such as angina pectoris, myocardial infarction, congestive heart failure, ventricular and supraventricular arrhythmias, syncope, and sudden death.
A 32-year-old Indian woman presented to our institute with severe angina on exertion and multiple episodes of pre-syncope. Echocardiography revealed hypertrophic obstructive cardiomyopathy. Coronary angiography showed no significant atherosclerotic lesions; however, it revealed multiple microfistulas originated from all three major coronary arteries and draining into her right ventricle. This finding was confirmed by the rapid filling of the pulmonary artery after dye was injected into her left coronary artery during a cardiac catheterization study and by a significant oxygen step up of 15 % seen from her right atria to right ventricle during oximetry analysis. We treated our patient’s condition with medical therapy including metoprolol and nicorandil. She improved and angina grade had decreased from class III to class II on a follow-up visit 1 month after discharge.
In this case report and literature review, we highlight an unusual but important association that can lead to symptomatic worsening of angina in young patients with hypertrophic cardiomyopathy owing to coronary steal phenomena.
KeywordsCongenital coronary anomaly HOCM Angina in young Coronary angiography
Coronary artery fistulas (CAFs) are a rare anomaly affecting the coronary arteries, with a prevalence of 0.13–0.2 %. They can cause serious cardiac complications such as angina pectoris, myocardial infarction, congestive heart failure, ventricular and supraventricular arrhythmias, syncope, and sudden death. Coronary artery microfistulas are even more rare and usually arise from either the right or left coronary system . They most commonly present as angina on exertion but can also present with other symptoms that are similar to those of solitary CAFs. Their association with hypertrophic cardiomyopathy has been documented in eight previously published cases reporting altered symptomatology and atypical presentation.
To the best of our knowledge, this is first case report showing an association between hypertrophic obstructive cardiomyopathy (HOCM) and microfistulas arising from all three epicardial arteries in a patient presenting with angina and pre-syncope. In this case report, we aimed to document this important association that led to severe symptomatic worsening of angina on exertion owing to coronary steal phenomena.
We report the case of a 32-year-old Indian woman admitted to our institute with angina on exertion. This symptom first appeared 2 years prior to her presentation, with gradual onset and progressive worsening from class I to class III associated with multiple episodes of pre-syncope. She had no history of diabetic mellitus, arterial hypertension, palpitation, or syncope and no family history of similar complaints or sudden death. On physical examination, our patient appeared generally well. Her blood pressure and pulse rate were 128/84 mmHg and 57 beats per minute, respectively.
Additional file 1: Coronary angiogram
Additional file 2: Coronary angiogram
Additional file 3: Coronary angiogram
Outcome and follow-up
Our patient was discharged 5 days after the completion of her clinical investigation on medical therapy including metoprolol and nicorandil. At a follow-up 1 month later, her angina grade had decreased from class III to class II.
Coronary artery microfistulas are congenital coronary artery anomalies that are associated with serious cardiac complications due to coronary steal phenomena. According to a recent Dutch survey, multiple coronary artery microfistulas are found in one quarter of all coronary artery fistulas detected by angiography; only one case has been reported in the age group of 20–50 years .
Comparative evaluation of all previously published case reports
Anatomy of fistulae
Angina on exertion, pre-syncope
LCX-RV, RCA-RV, LAD-RV
Yildiz et al. 
Distal septal branch of LAD-LV
Distal RV branch of the RCA-LV
Alyan et al. 
Angina on exertion
Hong et al. 
Dyspnea, angina on exertion
Dresios et al. 
Caputo et al. 
Monmeneu et al. 
Angina on exertion
Delarche et al. 
Multiple coronary artery-LV fistulas
Kiyokawa et al. 
On angiography, CAFs are classified into two major types: solitary CAFs and coronary artery–ventricular multiple microfistulas. Solitary CAFs are defined as an abnormal connection between the coronary artery and any cardiac chamber or any part of the pulmonary or systemic circulation. They can be differentiated by identifying the origin, termination, and pathway. Coronary microfistulas are characterized as multiple fistulas of a small caliber that opacify the ventricular cavity; they are also known as generalized myocardial microfistulas.
In a Dutch registry, bilateral and multilateral fistulas were detected in 24 % and 4 % of the patients, respectively . The pathogenesis of microfistula is obscure and usually attributed to a persistence of the embryonic myocardial sinusoids that originate from endothelial protrusions into intertrabecular spaces; fetal regression of these protrusions results in the formation of the Thebesian vessels. Thus interference with the developmental of embryonic myocardial sinusoids produces multiple coronary microfistulas [4–10]. Previous case reports have shown the RCA as the most frequent site of origin , whereas more recent studies suggest that the left coronary system is the more frequent site of origin, most commonly draining to the RV  and pulmonary artery.
Patients usually have an atypical presentation that depends on many factors, such as age of patient, amount of shunting, degree of coronary steal leading to cardiac ischemia, and resistance of recipient chamber. The majority of these patients are asymptomatic; in symptomatic patients, chest pain is the most common presenting symptom. In a study by Durán et al., 57 % of 51 patients with CAFs with no underlying coronary artery disease had angina pectoris due to coronary steal . Other symptoms include rupture or thrombosis of fistula, coronary arterial aneurysm, pulmonary artery hypertension, and congestive heart failure .
Coronary angiography remains the gold standard and helps to define the artery of origin, the recipient chamber, and the site of communication. Combined two-dimensional and pulsed Doppler echocardiography is useful only in cases of solitary CAF, in which they demonstrate a dilated coronary artery and turbulent flow in the fistula, and identify the recipient chamber . Magnetic resonance imaging and multi-detector computed tomography are alternative noninvasive methods to evaluate the anatomy of both solitary macro- and microfistulas.
There are limited data available regarding the management of CAFs. Management is largely determined on the basis of the anatomical type of fistula, the amount of shunting, and any secondary complications caused by progressive enlargement of the fistula, such as bacterial endocarditis, thromboembolism, and pulmonary artery hypertension. All patients with hemodynamically significant solitary CAFs should undergo closure if they become symptomatic or develop complications. However, the amount of flow that is considered hemodynamically significant is still largely unknown, although a pulmonary to systemic flow ratio >1.5 is usually considered significant . Previously, the only form of treatment available for coronary fistula after their identification was surgical ligation. However, subsequent to the first non-operative occlusion of a large coronary artery-to-bronchial anastomosis described by Reidy et al. (using a detachable balloon), catheter-based interventional techniques have become popular . Over time, a variety of percutaneous techniques has emerged. Armsby et al. published a case series of 33 patients in whom transcatheter closure included coils in 28 patients, umbrella devices in six patients, and a Grifka vascular occlusion device in one patient; the different techniques showed similar early effectiveness, morbidity, and mortality compared to surgical ligation . Currently, many catheter-based interventional methods are used. Coils are used primarily in smaller CAFs, because they offer the advantages of smaller sheath and catheter delivery sizes as well as a lower cost; double umbrella devices are used in larger fistulae because they allow more precise positioning, especially in cases where the coronary branches are close to the occlusion site [14, 15].
There are no data available on the management of patients with HOCM with coronary microfistula owing to the rarity of this disease. Treatment of isolated HOCM with coronary microfistula is essentially by medical management. We discharged our patient on medical therapy with metoprolol and nicorandil. She showed significant symptomatic improvement and an angina grade decrease from class III to class II on a follow-up visit 1 month after discharge.
Our case contributes to the growing evidence regarding the rare association of microfistulas from multiple coronary arteries to the RV with HOCM. Understanding the pathophysiological implications of this association on clinical presentation and symptomatic progression will enhance the management of theses unusual cases.
Coronary artery fistula
Hypertrophic obstructive cardiomyopathy
Left anterior descending coronary artery
Left coronary artery
Left circumflex artery
Right coronary artery
The authors declare that they have not received any funding for processing of data or for publication of this case report.
Availability of data and material
The tools and data described in the manuscript are available for testing by reviewers.
DSM gave final approval of the submitted manuscript and takes public responsibility for its content; he contributed to the intellectual content, conception and design, acquisition of data, analysis and interpretation of data; and he participated in drafting the manuscript and critical revision of the manuscript for important intellectual content. CBM and JP both contribute in collecting ECHO & CATH data. All authors read and approved the final manuscript.
The authors declare that they have no competing interests.
Consent for publication
Written informed consent was obtained from the patient for publication of this case report and any accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal.
Ethics approval and consent to participate
The ethical committee of Swai Man Singh Medical College reviewed and approved this case report.
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- Gillebert C, Van Hoof R, Van de Werf F, Piessens J, De Geest H. Coronary artery fistulas in an adult population. Eur Heart J. 1986;7:437–43.PubMedGoogle Scholar
- Said SA, van der Werf T. Dutch survey of coronary artery fistulas in adults: congenital solitary fistulas. Int J Cardiol. 2006;106(3):323–32.View ArticlePubMedGoogle Scholar
- Yildiz BS, et al. A case of multiple coronary microfistulas to the left ventricle. J Saudi Heart Assoc. 2013;25:209–11.View ArticlePubMedPubMed CentralGoogle Scholar
- Alyan O, Ozeke O, Golbasi Z. Coronary artery-left ventricular fistulae associated with apical hypertrophic cardiomyopathy. Eur J Echocardiogr. 2006;7:326–9.View ArticlePubMedGoogle Scholar
- Hong GR, Choi SH, Kang SM, Lee MH, Rim SJ, Jang YS, et al. Multiple coronary artery-left ventricular microfistulae in a patient with apical hypertrophic cardiomyopathy: a demonstration by transthoracic color Doppler echocardiography. Yonsei Med J. 2003;44:710–4.View ArticlePubMedGoogle Scholar
- Dresios C, Apostolakis S, Tzortzis S, Lazaridis K, Gardikiotis A. Apical hypertrophic cardiomyopathy associated with multiple coronary artery–left ventricular fistulae: a report of a case and review of the literature. Eur J Echocardiogr. 2010;11(4):E9.View ArticlePubMedGoogle Scholar
- Caputo S, Capozzi G, Santoro G, Pacileo G, Bigazzi MC, Russo MG, et al. Multiple right coronary artery fistulae in a patient with diffuse hypertrophic cardiomyopathy: a case report. J Am Soc Echocardiogr. 2005;18:884.View ArticlePubMedGoogle Scholar
- Monmeneu JV, Bodi V, Sanchis J, Chorro FJ, Llopis R, Insa L, et al. Apical hypertrophic myocardiopathy and multiple fistulae between the coronary vessels and the left ventricle. Rev Esp Cardiol. 1995;48:768–70.PubMedGoogle Scholar
- Delarche N, Colle JP. Multiple left coronary-ventricular microfistula and apical hypertrophy. Arch Mal Coeur Vaiss. 1993;86:75–8.PubMedGoogle Scholar
- Kiyokawa H, Iuchi K, Ishikawa T, Kaseno K. Two cases of coronary artery-left ventricular fistula associated with left ventricular hypertrophy. Kokyu To Junkan. 1992;40:505–9.PubMedGoogle Scholar
- Durán A, Michelis V, Díaz P, et al. Evaluación de pacientes portadores de fístulas coronario-ventriculares múltiples. Rev Med Uruguay. 2003;19:237–41.Google Scholar
- Angelini P. Coronary artery anomalies-current clinical issues: definitions, classification, incidence, clinical relevance, and treatment guidelines. Tex Heart Inst J. 2002;29:271–8.PubMedPubMed CentralGoogle Scholar
- Reidy JF, Sowton E, Ross DN. Transcatheter occlusion of coronary to bronchial anastomosis by detachable balloon combined with coronary angioplasty at same procedure. Br Heart J. 1983;49(3):284–7.View ArticlePubMedPubMed CentralGoogle Scholar
- Armsby LR, Keane JF, Sherwood MC, Forbess JM, Perry SB, Lock JE. Management of coronary artery fistulae. Patient selection and results of transcatheter closure. J Am Coll Cardiol. 2002;39(6):1026–32.View ArticlePubMedGoogle Scholar
- Raju MG, et al. Coronary artery fistula: a case series with review of the literature. J Cardiol. 2009;53(3):467–72.View ArticlePubMedGoogle Scholar