Posterior descending artery

Artery supplying the inferior wall of the heart

The posterior descending artery (PDA), also known as the inferior interventricular artery, is a vital blood vessel that supplies the inferior wall of the heart. It is a branch of the coronary arteries, which are responsible for delivering oxygenated blood to the heart muscle itself.

Diagram of the heart showing the coronary arteries, including the posterior descending artery.

Anatomy

The PDA typically arises from the right coronary artery (RCA) in about 70% of the population, a configuration known as "right dominance." In approximately 10% of individuals, the PDA originates from the left circumflex artery, a condition referred to as "left dominance." In the remaining 20% of the population, the PDA receives contributions from both the RCA and the left circumflex artery, a situation termed "co-dominance."

The PDA travels along the inferior interventricular sulcus, a groove on the heart's surface that separates the left and right ventricles. It supplies blood to the inferior portion of the heart, including the inferior wall of the left ventricle and, in some cases, the inferior portion of the right ventricle.

Illustration of the heart's blood vessels, highlighting the posterior descending artery.

Function

The primary function of the PDA is to supply oxygen-rich blood to the myocardium of the heart's inferior wall. This is crucial for maintaining the heart's pumping efficiency, particularly during physical exertion when the heart's demand for oxygen increases.

Clinical Significance

Blockage or narrowing of the PDA can lead to myocardial infarction, commonly known as a heart attack, particularly affecting the inferior wall of the heart. This condition is often diagnosed using coronary angiography, a procedure that visualizes the coronary arteries.

In cases of significant blockage, medical interventions such as angioplasty or coronary artery bypass grafting (CABG) may be necessary to restore adequate blood flow.

Diagram showing the coronary arteries, including the posterior descending artery.

Variations

The origin and course of the PDA can vary significantly among individuals. Understanding these variations is important for cardiologists and surgeons when planning interventions or surgeries involving the coronary arteries.

Surgical Considerations

During coronary artery bypass surgery, the PDA may be bypassed using a graft from another blood vessel, such as the saphenous vein or the internal thoracic artery. The choice of graft and surgical technique depends on the patient's specific anatomy and the extent of coronary artery disease.

Detailed view of the inferior interventricular artery, also known as the posterior descending artery.

Related Pages

• Coronary artery disease
• Myocardial infarction
• Coronary angiography
• Coronary artery bypass surgery

Human heart with coronary arteries, including the posterior descending artery.