Anterior interventricular branch of left coronary artery

Where does the anterior interventricular artery run?

It follows the anterior interventricular sulcus around the pulmonary trunk. It runs in front of the interventricular septum, from the base of the heart to the apex. (OpenStax A&P 2e, 19.1; StatPearls, Heart Left Anterior Descending Artery)

It runs on the outer surface of the heart, the epicardium, which limits how much the contracting muscle squeezes it. (StatPearls, Heart Left Anterior Descending Artery)

What are the branches of the anterior interventricular artery?

Septal branches dive into the interventricular septum and supply its front two thirds. They are numbered S1, S2 and onward from the base toward the apex. (StatPearls, Heart Left Anterior Descending Artery)

Diagonal branches cross the front of the left ventricle. They are numbered D1, D2 and onward from the start of the artery to its end. (StatPearls, Heart Left Anterior Descending Artery)

A small left conus branch and small right ventricular branches can also arise from it. (StatPearls, Heart Left Anterior Descending Artery)

What does the anterior interventricular artery supply?

It is the main supply to the front wall of the left ventricle and to most of the interventricular septum, about 50% to 60% of the left ventricle. It carries about half of all coronary blood flow. (StatPearls, Heart Left Anterior Descending Artery)

Blocking it often causes a large myocardial infarction, and clinicians call it the widow-maker for that reason. (StatPearls, Heart Left Anterior Descending Artery)

Where does the anterior interventricular artery meet other vessels?

Its end joins the end branches of the posterior interventricular artery in the posterior interventricular groove in about 90% of hearts. In the other 10% the two do not join. (StatPearls, Heart Left Anterior Descending Artery)

Inside the septum its septal branches connect with those of the posterior descending artery. These links carry too little blood to make up for a sudden blockage. (StatPearls, Heart Left Anterior Descending Artery)

The great cardiac vein climbs the same sulcus beside it and drains the area it supplies. (OpenStax A&P 2e, 19.1; StatPearls, Heart Veins)

Does the anterior interventricular artery vary?

By length it falls into four types. Type 1 does not reach the apex, type 2 supplies part of it, type 3 supplies all of it, and type 4, the wrap-around LAD, supplies the apex and more than 25% of the inferior wall. (StatPearls, Heart Left Anterior Descending Artery)

Of all the coronary arteries, the LAD most often has a segment that runs under a band of heart muscle, a myocardial bridge. (StatPearls, Heart Left Anterior Descending Artery)

In a rare variant, two separate LADs share its territory, a short one and a long one. (StatPearls, Heart Left Anterior Descending Artery)