Blood Supply to the Ventricular Septum

Introduction to Septal Blood Supply

• The ventricular septum receives dual blood supply: the anterior two-thirds is supplied by septal perforator branches from the left anterior descending (LAD) coronary artery, while the posterior one-third is supplied by the posterior descending artery (PDA), which typically arises from the right coronary artery in right-dominant circulation (90% of individuals) 1

Posterior Septal Blood Supply

• The posterior one-third of the septum receives blood from the posterior descending artery (PDA), which runs in the posterior interventricular groove and gives off septal perforator branches 1
• In right-dominant circulation (approximately 90% of people), the PDA arises from the RCA 1

Clinical Implications

• VSR occurs in 1-2% of all myocardial infarctions 2, 3
• Without surgery, VSR mortality is 54% within the first week and 92% within the first year 2, 3

Anatomical Considerations

• The crista supraventricularis shares muscle fibers with the interventricular septum and serves important contractile functions during systole 4, 5

Surgical Considerations

• Septal perforator arteries are the target vessels during alcohol septal ablation for hypertrophic cardiomyopathy, where 1-3 cc of ethanol is injected to create a controlled septal infarction 6