Which papillary muscle most commonly rupture following an MI?

• [A] Anterior
• [B] Septal
• [C] Anterolateral
• [D] Posteromedial

Posteromedial papillary muscle most commonly rupture following an MI.

Why Posteromedial papillary muscle mst commonly rupture following an MI?

ANSWER

The anterolateral papillary muscle has a dual blood supply, whereas the posteromedial papillary muscle has blood supply only from the posterior descending coronary; thus in most patients, it is the posteromedial papillary muscle that will rupture following an MI.

• Antero-lateral papillary muscle blood supply is from the left anterior descending and the diagonal or a marginal branch of the circumflex artery.
• The left circumflex or right coronary artery (depending on dominance) provides the blood supply to the postero-medial papillary muscle