Geographic variations in the incidence of different congenital coronary ano
malies are well known, but infrequently studied in the Indian population. A
mong 4100 adult patients who underwent diagnostic coronary arteriography, 3
9 (0.95%) patients (34 males, 5 females) had one or more anomalous coronary
arteries. Their mean age was 46.4+/-8.2 years (range, 26-68 years). Thirty
-five (89.74%) had anomalies of origin and distribution, while the remainin
g four (10.25%) had coronary artery fistulae. Right coronary artery was the
commonest anomalous vessel, involved in 19 (48.74%) patients. It was origi
nating from the left sinus of Valsalva in 15 and from the non-facing aortic
sinus in four patients. Anomalous left circumflex artery was the second co
mmonest anomaly, seen in 14 (35.89%) patients. Anomalous left anterior desc
ending artery and anomalous left coronary artery from pulmonary artery were
: seen in one patient each. Among patients with coronary fistulae, two had
fistulae between the left anterior descending artery and the main pulmonary
artery, one between the conal artery and the right atrium, while the fourt
h patient had fistulae from the right coronary as well as from the left ant
erior descending artery to the left atrium. Atherosclerotic plaques in the
anomalous arteries were seen in only 13 (33.33%) patients, much less than t
he overall incidence of coronary artery disease in patients with congenital
coronary anomalies in this series (66.66%). In four (10.25%) patients, onl
y the anomalous vessels were involved in coronary artery disease. Thus, in
a small subgroup there does not appear to be an increased risk for developm
ent of atherosclerotic coronary artery disease in anomalous coronary arteri
es. Recognition of coronary anomalies is important in patients undergoing c
oronary arteriography, coronary interventions and cardiac surgery. Variatio
ns in the frequency of primary congenital coronary anomalies may possibly h
ave a genetic background. (C) 2000 Elsevier Science Ireland Ltd. All rights
reserved.