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