Heart sounds Flashcards
What produces the first heart sound (S1)?
Closing of the mitral (M1) and tricuspid (T1) valves. M1 is louder than T1, making M1 the dominant component.
What causes a split S1 sound?
when the mitral valve closes slightly before the tricuspid valve,
common during inspiration and can be accentuated by right bundle branch block (RBBB).
In which condition is the S1 sound accentuated?
a short PR interval, such as tachycardia or high flow states like anemia and sepsis.
What causes a split S2 sound?
A split S2 occurs when A2 (aortic valve closure) occurs before P2 (pulmonic valve closure), and is normally accentuated by inspiration.
The split disappears in expiration.
What is a paradoxical split S2?
when the split is heard during expiration and disappears during inspiration, often due to
severe aortic stenosis, hypertrophic obstructive cardiomyopathy, or LBBB.
What is the cause of a fixed split S2?
atrial septal defect (ASD), where the delay in closure of the pulmonic valve persists regardless of respiration.
What does a third heart sound (S3) indicate?
a compliant left ventricle and is often seen in systolic heart failure.
It is a low-pitched sound best heard at the apex in the left lateral decubitus position.
In which conditions is the fourth heart sound (S4) typically heard?
An S4 is heard in diastolic heart failure, left ventricular hypertrophy (LVH), or during active ischemia. It is a low-pitched sound best heard at the apex in the left lateral decubitus position.
What does a systolic ejection click suggest?
Bicuspid aortic valve, where the aortic valve leaflets dome before opening.
What is a mitral valve prolapse (MVP) click?
mid-systolic click, usually followed by a high-pitched murmur due to mitral regurgitation.
When is an opening snap heard, and what condition does it suggest?
mitral stenosis (MS) when the mitral valve leaflets tense and dome during early diastole.
What is a pericardial knock, and when is it heard?
Constrictive pericarditis, occurring earlier than an S3 due to restricted LV filling.
What is a tumor plop?
An early diastolic low-pitched sound associated with a tumor obstructing mitral valve inflow.
