Septal Perforating Arteries of the LAD

arteriae perforantes septales (LAD)

The septal perforating arteries (septal branches) arise perpendicularly from the LAD and penetrate the interventricular septum to supply the anterior two-thirds of the ventricular septum and the bundle branches of the His-Purkinje system. The first septal perforator is the largest and most constant, supplying the AV node in right-dominant systems and providing the critical blood supply to the His bundle.

Region: Chest

Clinical Relevance

Clinical Notes

The first septal perforator is the target vessel in alcohol septal ablation for hypertrophic obstructive cardiomyopathy (HOCM). Injection of ethanol through a balloon catheter into the first septal perforator creates a controlled septal infarction that reduces the subaortic gradient. The procedure risks complete heart block from His bundle infarction, requiring temporary and sometimes permanent pacemaker implantation. In LAD stenting, care must be taken to identify septal perforators to avoid side-branch occlusion causing septal infarction and conduction disturbance.

Pathology

Common Injuries & Conditions

First Septal Perforator Ablation in HOCM

Selective alcohol injection into the first septal perforating artery creates a controlled septal infarction reducing the subaortic obstruction in hypertrophic obstructive cardiomyopathy; complete heart block from His bundle involvement occurs in 20-30% of cases requiring permanent pacemaker, and the procedure is performed under echocardiographic guidance to confirm the target territory.