Heart Sounds

Question 1

What are Heart sounds

Answer 1

• S1: Closure of the mitral and tricuspid valves, marking the start of systole.
  • S2: Closure of the aortic and pulmonic valves, marking the start of diastole.
  • S3: ventricular gallop, comes after S2 - early diastole, splashing sound of blood due to turbulence - caused by rapid filling of a dilated or weak ventricle with a existing pool of blood inside it, often seen in heart failure(faulty pump)/overly compliant heart, also called as atrial gallop. It sounds like “Ken-tuck-y.” The rhythm: S1 (Ken) - S2 (tuck) - S3 (y).
  • S4: atrial gallop, also after S2, but late diastole, i.e right before systole, i.e right before S1,
  Thud sound caused when atrial contraction happens into a stiff ventricle, seen in conditions like hypertension, or aortic stenosis, LVH.
  It sounds like “Ten-nes-see.” The rhythm: S4 (Ten) - S1 (nes) - S2 (see

S3- normal in atheletes/young
S3/S4 : best heard at apex
S3/S4 both come after the S2 - but S3 is early distole, S4 is late disstole

Question 2

Constrictive pericarditis

Answer 2

S4 is more characteristic of constrictive pericarditis due to the stiff, non-compliant ventricle.

S3 might also be heard if there’s significant fluid overload and rapid filling of the ventricle, even in constrictive pericarditis.