Table 1.

Lipton’s classification of single coronary artery

Originating from right cusp	Description	Originating from left cusp
RI	Solitary vessel arising from either the left or right coronary cusp, following the course of either a normal right or left coronary artery	LI
RIIA	Divided into 3 types depending on the relationship of the aberrant vessel to the great vessels. Type A courses anterior to the pulmonary trunk. Type B travels between the aorta and pulmonary trunk. Type P travels posterior to the aorta	LIIA
RIIIB		LIIB
RIIP		LIIP
RIII	Absent left coronary artery with the left anterior descending and circumflex arteries arising from the common trunk originating from right coronary cusp