Human coronary artery branching pattern is unique in every individual . Left circumflex shows many variations.
The important ones are a separate origin , variation in the angle of bifurcation, the number of OMs .Further, the length of mainstem LCX and its course in the AV groove are quiet unpredictable.The diameter of LCX vs are generally equal (or LAD >LCX).
The division of left main is such that circumflex generally gets a lesser share of blood flow . If LCX is dominant this ratio may be little balanced. But if the LCX is huge LAD definitely suffers !
When left circumflex equals the size of left main the pattern is distinctly unusual.
This patient we encountered recently had 4mm sized LCX and presented with a tight LAD lesion .
This man's LCX probably will never sufffer from atherosclerosis !
Other observations about large bored LCX
- Narrow ostiums are prone for atherosclerosis .A large mouthed LCX rarely involves in left main bifurcation lesions.
- Disproportionate size of LCX when compared to LAD can have hemodynamic implication of provoking LAD disease .
The implication of differential sharing of left main blood flow is not fully understood .It needs further insights.
Dr.S.Venkatesan MD 