loud second (2nd) heart sound

Last reviewed 01/2018

Loud second heart sounds can be loud A2 or a loud P2.

  • loud A2 occurs in systemic hypertension where there is a dilated proximal aorta

  • a loud P2 is heard in pulmonary hypertension

  • a loud P2 occurs in an atrial septal defect without pulmonary hypertension. This is caused by a sharp rise and fall of pulmonary arterial pressure

  • in thin-chested people with a forward projecting aorta


  • Kirby B (1993).Clinical examination of the heart. Medicine International, 21(8), 294-99.