Dr.S.Venkatesan MD

LAD is  graded into three types according to

Type 1  :  Falls short  of Apex

Type 2 :   Reach up to the LV apex

Type 3 : Wraps around LV apex and travels some distance in the posterior Inter-ventricular groove.

Clinical  Importance of Wrap around LAD

As the name implies , LAD   should descend only in anterior aspect  in about 15 %  population it can take a posterior descending course as well .

When LAD  wants to conquer more areas of heart is it a clinical advantage  ?

When LAD wraps around the LV apex,  anterior MI due to LAD occlusions can show changes in inferior leads. (Antero Inferior MI )

In ideal anatomic /Physiologic conditions  LAD  should nearly  meet the  PDA   to prevent any water shed  area.

There is usually a trade off between the  terminal LAD and  length of PDA ( whether it arises from LCX or RCA.)

There is some evidence to  suggest the site of ventricular rupture in anterior MI is related to the gap  in the LAD/PDA drainage zones.

Patients with Type  1 LAD  are at risk of   LV apical  ischemia if the  dominant LCX /RCA is  not supportive .

Final message

A long LAD is definitely a  hemo-dynamic  advantage   in physiology ,   Of course  it goes  without saying    . . .   when  it’s   likely  to get  obstructed it is always better to have a Type 1 !