By Haley Masterson
All Physicians Take Money
(Aortic, Pulmonic, Tricuspid, Mitral)
From left to right across your chest: A is the right upper sternal border (the second right interspace), P is the left upper sternal border (the second left interspace), T is the left lower sternal border, and M is the apex.
Please note that these are guidelines to aid you in diagnosis on test questions; they are not necessarily going to be physiologically true in all cases.
Mitral murmurs can be heard best at the mitral auscultation position (the apex) while tricuspid murmurs are best heard at the tricuspid position. Further diagnostic information can be obtained by listening to the sound of S2 over the aortic and pulmonic areas.
Increased Aortic S2 Intensity: Systemic hypertension or aortic root dilation.
If the aorta is dilated or under high pressure, it will be closer to the chest wall and you will hear S2 louder than usual at this position (right upper sternal border).
Decreased Aortic S2 Intensity: Aortic stenosis
The valve has difficulty opening due to calcification, and S2 will sound much softer at the aortic valve auscultation position (right upper sternal border).
Increased Pulmonic S2 Intensity: Pulmonary hypertension, dilated pulmonary artery, atrial septal defect.
Normally, A2 will be louder than P2. If P2 is louder, it raises the question of pulmonary hypertension or a dilated pulmonary artery –a gain, because the pulmonary artery becomes much closer to the chest wall. Atrial septal defect is also a possible diagnosis as it creates a left to right shunt when blood is able to follow the path of least pressure (the right atrium is under less pressure than the left).
Decreased Pulmonic S2 Intensity: Pulmonic stenosis or normal aging.
The valve has difficulty opening in pulmonic stenosis, though normal aging is a more common cause of a decreased S2 at the pulmonic valve aucultation position (left upper sternal border).
Note that aortic regurgitation is actually best heard at the lower left sternal border, even though the aortic auscultation position is the upper right sternal border. Although this is an exception to the rule, this example still makes sense because the blood rushes back toward the left ventricle as it regurgitates.