The 4 heart sounds and 4 components are commonly abbreviated in discussions of cardiac auscultatory findings; numerical subscripts are used.
S1 first heart sound
M1 mitral valve component
T1 tricuspid valve component
S2 second heart sound
A2 aortic valve component
P2 pulmonic valve component
S3 third heart sound
S4 fourth heart sound
The presence of an audible S3was consistent with the patient’s ventricular aneurysm.
An audible S4 may be due to a variety of cardiac and systemic conditions.
Sound names may be written out in full when discussed generically.
The S3 is suggestive of congestive heart failure, but an S3 gallop may be a normal finding in children and young adults.
For plurals, follow the term with “sounds” or another noun.
S3 sounds [not S3s] may be normal or pathologic.
S3 gallops may be a normal finding in children and young adults.