European Journal of Cardiovascular Medicine

Coronary artery anomalies are rare congenital variations in coronary artery origin and course, often detected incidentally during coronary angiography or advanced imaging. One such anomaly involves the left circumflex artery (LCX) originating and right coronary artery (RCA) arising from right coronary sinus through a common channel and absent left main coronary artery (LMCA) .

Congenital common origin of the LCX artery and RCA from right coronary sinus with absent left main coronary artery (LMCA) is a extremely rare congenital anomaly of the cardiovascular system with incidence of 0.37% [1] It is considered as a benign anomaly, however, in certain cases, these patients may develop life-threatening clinical complications that include acute myocardial infarction, arrhythmia, stroke, or sudden cardiac death. [2 – 4]

Here, we present a clinical case of a patient found to have anomalous and common origin of left circumflex artery (LCX) and right coronary artery (RCA) from right coronary sinus and absent left main coronary artery with left anterior descending artery arising directly from left coronary sinus in a 44-year-old male presenting with chest pain and breathlessness along with a comprehensive radiological description.

This case highlights the importance of recognizing and understanding such rare anatomical variations to guide appropriate clinical management.

Congenital coronary artery anomalies, including single common origin of LCX and RCA and absent LMCA, are thought to arise from disturbances during embryogenesis. While the exact etiology remains unknown, proposed theories include agenesis or failure of normal separation of the coronary arteries.

The anomalous artery may arise as a proximal branch of the RCA, from the same ostium of the RCA, or from a separate orifice in the right aortic sinus. The anomalous vessel shows a retroaortic course between the aorta and the atrial wall, merging in the atrioventricular sulcus to pursue its usual final distribution.[5]

Clinical presentation varies widely, ranging from asymptomatic individuals to those with ischemic symptoms related to concurrent coronary atherosclerosis or inter-arterial course. [6]

Diagnostic modalities such as invasive coronary angiography, CT coronary angiography, cardiac CT or cardiac MRI play crucial roles in confirming the diagnosis and delineating associated abnormalities. The main diagnostic tool for the determination of coronary vessel anomalies has been selective coronary angiography. Although coronary angiography is an effective and important diagnostic method, it has some disadvantages owing to its invasive nature. Due to developments in technology, new non-invasive methods such as coronary computed tomography angiography (CTA) play an important clinical role in determining coronary anomalies.[7]

A 44-year-old man presented to the cardiology department with complaints of shortness of breath. The symptoms had been occurring intermittently over the past few weeks, with an increase in frequency and severity over the past few days.  There was no history of similar episodes in the past. The patient's vital signs were as follows: blood pressure 130/70 mmHg, heart rate 84 bpm, respiratory rate 16 breaths per minute, temperature 98.6°F (37°C), and oxygen saturation 98% on room air. Physical examination revealed a well-appearing middle-aged man in no acute distress, with normal cardiovascular and respiratory findings, no abdominal tenderness, and no peripheral edema. Laboratory work-up was unremarkable, including a normal troponin I level, a complete blood count, and a basic metabolic panel within normal limits, with a negative D-dimer.

A resting electrocardiogram showed normal sinus rhythm without ST-T changes, and a chest X-ray revealed no acute cardiopulmonary findings. The exercise stress test was positive for myocardial ischemia, with the patient developing chest pain and ST segment abnormalities during the test. A coronary computed tomography angiogram (CTA) revealed a common origin of left circumflex artery and right coronary artery from the right coronary sinus and absent left main coronary artery with origin of left descending artery directly from left coronary sinus. [Figure I]

CASE IMAGES

The absence of the left main coronary artery and common origin of right coronary artery and left circumflex artery from right coronary sinus is a rare congenital coronary anomaly. It may be asymptomatic but can present with symptoms of myocardial ischemia if the increased demand during exercise cannot be met. The management of this condition depends on the severity of symptoms and associated ischemia. Options may include medical management with anti-anginal medications, lifestyle modifications, and possibly interventional procedures or surgery if indicated by further assessment of myocardial perfusion and risk stratification.

This case highlights the importance of considering congenital coronary anomalies in young patients presenting with unexplained chest pain and shortness of breath. Advanced imaging techniques like coronary CTA play a crucial role in identifying these anomalies, guiding appropriate management, and improving patient outcomes.

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