Dual LAD is an interesting coronary artery anomaly proposed originaly by Spindola in 1983 .He classified it into 4 types. In recent years the dual LAD has increased from 4 to 6 types.
The essential criteria to diagnose could be summarised.
- Two LADs should be identified.
- One would be large and another small
- Both should give a diagonal branch .
* Ramus is virtually unknown if there is dual LAD .
The origin of second LAD can be from
- Direct from Right coronary sinus
- Can be epicardial
- Intra -myocardial
- Or both
- or Both
- Highly variable
Implication for intervention
- Apart from the surprise element , the second LAD has little impact on the interventional protocol.
- However , it may confer a ischemic protection as the critical anterior wall has a twin blood supply.
- Whether they are protected from primary VT or VF is to be studied because of better electrical stability
- Second LAD may act as an additional collateral channel.
Spindola’s classification of Dual LAD (Types 1 to 4 was called sometimes A,B,C,D )
Surgical issues ( This is excellent data from India . I convey my greetings to one the authors Dr D.B Baruah, my friend from CMC Vellore !)