Coronary artery anomalies (CAAs) are a relatively uncommon, diverse group of congenital disorders of coronary arterial anatomy with a wide variety of clinical presentations. Apart from about one-fifth of coronary anomalies may lead to life-threatening manifestations such as arrhythmias, syncope, sudden death or myocardial infarction, in most of the cases it is benign.

Presence of a coronary anomaly should be suspected in a young individual who experiences exertional syncope, exercise ­induced arrhythmias, myocardial infarction, or cardiac arrest.

There are widespread geographic variations in incidence and patterns of CAAs. The study was planned to estimate the incidence, patterns and atherosclerotic involvement of anomalous coronaries in patients undergoing invasive coronary angiography at our tertiary care institution.



Serial coronary angiographies performed at our institution over a period of 2.5 years (from January 2017 to June 2019) were retrospectively analysed. We identified patients with anomalous coronaries and studied their clinical characteristics and angiographic profiles.



Among 3,233 coronary angiograms analysed, CAAs were found in 99 patients with an incidence of 3.06%. Mean age of the patients was 56.2 ± 12.9 years (range: 20 - 86 years), with 74.75% being males and 25.25% females.

Split right coronary artery (RCA) was the most common coronary anomaly, being seen in 27 patients; with an angiographic incidence of 0.84%. Dual left anterior descending artery (LAD) was the second most common anomaly and was seen in 22 cases with an angiographic incidence of 0.68%. Absent left main trunk was noted in 14 patients (0.43%).

Ectopic origin of RCA from left sinus was seen in 12 patients (0.37%), while ectopic origin of RCA from ascending aorta was seen in four patients (0.12%). Ectopic origin of left circumflex artery (LCX) from right sinus or RCA was noted in 13 patients (0.40%). One patient (0.03%) had a super dominant LAD supplying the posterior descending artery (PDA). Coronary artery fistulae were seen in six patients (0.18%).

Significant coronary artery disease (CAD) was seen in 89 of 268 (33.21%) normal vessels, whereas it was seen in 56 of 114 (49.12%) of anomalous vessels. This difference was statistically significant (P = 0.003).



CAAs are a group of diverse disorders of coronary arterial anatomy which are rarely seen in general population. Study shown the anomalies of intrinsic coronary anatomy were the most common type, with split RCA being the single most common type of CAA with an incidence of 0.84% and Dual LAD was the second most common type of CAA with an incidence of 0.68%. Absent left main trunk with separate origin of LAD and LCX from left sinus was the third most common anomaly detected in the study, with an incidence of 0.43%.

Coronary artery fistulae are abnormal communications between one or more coronary arteries and the cardiac chambers or another blood vessel, such as vena cave, coronary sinus, pulmonary artery and bronchial veins. Incidence of coronary artery fistulae has been reported in several large selected series. The study had higher incidence of atherosclerotic involvement of anomalous vessels as compared to normal vessels. CAAs are more frequently involved in atherosclerosis than the normal coronaries.