Coronary Artery Anomalies, Myocardial Bridging Associated with Fistula to Pulmonary Artery Trunk. Case Reports

Case Series

Austin J Clin Cardiolog. 2023; 9(1): 1105.

Coronary Artery Anomalies, Myocardial Bridging Associated with Fistula to Pulmonary Artery Trunk. Case Reports

Marian Gaspar*

Department of Cardiac Surgery, University of Medicine and Pharmacy “Victor Babes”, Timisoara, Romania

*Corresponding author: Marian Gaspar Department of Cardiac Surgery, University of Medicine and Pharmacy “Victor Babes”, Timisoara, Romania. Tel: +40-723995444. Email: mariangaspar24@yahoo.ro

Received: February 13, 2023 Accepted: March 28, 2023 Published: April 04, 2023

Abstract

Between coronary artery anomalies, myocardial bridging means an epicardial coronary artery, mostly Left Anterior Descending artery (LAD), running through intramyocardial “tunnel” (usually in the middle segment), leading during systolic contraction, flow reduction, through the vessel. When this anomaly is associated with a coronary fistula, who “steal” more from the bloodstream, the symptoms are more pronounced and the management complex, surgical in particular. Despite the presence from birth remains a symptomatic and it becomes clinically manifest later in the third to fourth decade of the life, with a diverse palette of symptoms; angina, arrhythmias, acute myocardial infarction up to sudden death. Diagnosis and particular management, medical, interventional and surgical should avoid major cardiac complications and sudden death. We present two adult patients, with coronary artery bridging, one case associated with coronary artery fistula, LAD to pulmonary artery trunk, very symptomatic with surgical management and the second only myocardial bridging controlled with medication and supervision.

Keywords: Myocardial bridging; Coronary fistula

Introduction

This congenital anomaly in which a coronary artery, usually Left Anterior Descending (LAD), it follows a deep path in the myocardium bridge, “tunnel”, was described morphological several hundred years ago (Reyman, 1737), but first angiographic documented, later by Portmann and Iwig in 1960 [1]. The prevalence of myocardial “bridge” at angiography is lower (0,5–2,5%) than at autopsy (15–85%). The coronary filling flow in the most part occurs in diastole, systolic compression of the artery should have only a little impact on total effective myocardial perfusion, but more refined studies using frame-by-frame quantitative coronarography with IVUS study, reveal that compression of the vessel extending also into diastole and as the result affect the myocardial perfusion [2]. Coronary bridge syndrome are also common in hypertrophic cardiomyopathy, with a frequency of 25-80% and in the patient with orthotropic heart transplant 33%. Due to this association, sudden death has been described in young people, athletes. An intriguing clinical situation is myocardial infarction in young persons, without atherosclerotic lesions discernible by coronary angiography. In the absence of atherosclerosis, myocardial infarction may result from several aetiologies including; vascular spasm, transient dysrhythmia, drugs abuse, hypercoagulability and coronary thrombus formation, and dissection of acquired or congenital vascular anomalies [3]. The patients are admitted with; angina, arrhythmias, even acute myocardial infarction with left ventricular dysfunction or the worse, sudden death in young, active person [4,5]. Another congenital anomaly is coronary fistula, is an anomalous communication between one or two coronary arteries and a cardiac chamber or any of the great vessels (the coronary sinus, the superior vena cava, and the pulmonary artery). Prevalence, in general population is 0.002%, within all congenital heart disease 0.08–0.4% and 0.3–0.8% of all patients who undergo selective coronary angiography [6]. The most common site of drainage is the right ventricle, followed by the right atrium and the Pulmonary Artery (PA). The blood flow from the coronary, usually LAD to PA shunt, leads to ‘coronary steal’, drawing blood away from the normal coronary tree, the results are symptoms and signs of myocardial ischaemia.

Even more, if two anomalies are associated, coronary bridging and fistula, then the symptomatology is obvious and the management much more complex, medical, interventional and surgical [7].

We do not have any specific medical therapy for coronary fistula, this should be occluded by transcatheter embolization (coils, vascular plug, covered stent) or surgical intervention (dissection and ligature of fistula on the both sides).

We present two cases; first case a LAD bridging associated with fistulae between LAD and PA trunk, very symptomatic in spite of medical treatment and the second only with LAD bridge, managed with medication and surveillance.

Case Report 1

The first patient F. C, 46 years old male, presented with typical angina by exercise and at the rest, was admitted for diagnosis and management.

ECG: Sinus rhythm, intermediate QRS axis, HR=80bpm. Eco-cardiography. LV hypertrophy, FE:55%, mild mitral regurgitation, mild tricuspid regurgitation. Normal pericardial fluid.

Chest X-ray: Heart and lungs according to age. No pulmonary condensation or fluid collections.

In spite of complex medication; Aspirin 75mg/day, selective beta-blocker (Bisoprolol 5mg/day), Candesartan cilexetil –(Atacand) 16mg/day, diuretics 50/20mg/day, ivabradine (Corlentor) 5mgx2/day, atorvastatina (Zetovar) 40/10mg/day, to control angina, blood hypertension, mixt-dyslipidemia, the patient continueto have exercise and rest angina. The patient was admitted for more investigation.

Angiocoronarography: Right radial artery approach. Coronary system with right dominance. Left main, normal. Coronary arteries show marked spasm that improves with the administration of intracoronary NTG. Upon injection into the ACD, a marked negation of T waves is observed in the lower leads on the EKS. LAD presents in the middle segment, over a length of 4cm, an accentuated muscular bridge after administration of intracoronary NTG, with 80% stenotic systolic compression. A coronary fistula emerges from the proximal ADA that drains into the pulmonary circulation. Proximal and distal LAD, circumflex artery and RCA do not present lesions visible angiographically (Figure 1). Coronary artery fistulas between the LAD and the PA are rare congenital malformations. However, concomitant significant coronary artery stenosis and fistula can cause coronary steal phenomenon and this result in severe myocardial ischemia.