Physical Finding |
Associated cardiac condition(s) |
First heart sound (S1) |
|
Loud S1 |
Mitral stenosis, tricuspid stenosis, Lown-Ganong-Levine syndrome, tachycardia |
Soft S1 |
Mitral regurgitation, severe congestive heart failure, calcified mitral valve, left bundle branch block, long PR interval (1st degree atrioventricular block) |
Widely split S1 |
Right bundle branch block, Ebstein's anomaly, right atrial myxoma |
Reversed splitting of S1 |
Severe mitral stenosis, left atrial myxoma, left bundle branch block |
Variable intensity S1 |
Atrial fibrillation |
Second heart sound (S2) |
Aortic valve closure (A2) and Pulmonary closure (P2) |
Soft / absent A2 |
Severe aortic stenosis |
Loud S2 - Loud A2 |
Systemic hypertension |
Loud S2 - Loud P2 |
Pulmonary hypertension |
Reduced splitting of S2 |
Pulmonary hypertension |
Increased splitting of S2 - early A2 |
Mitral regurgitation |
Increased splitting of - late P2: - electrical delay of P2 |
Right bundle branch block
|
Increased splitting of - late P2: - mechanical delay of P2 |
Pulmonary stenosis, ventricular septal defect, obstruction right ventricle, right ventricular failure, mitral regurgitation (with pulmonary hypertension) |
Fixed splitting of S2 |
Atrial septal defect |
Paradoxically split S2
- electrical delay of A2
|
left bundle branch block, right ventricular pacing, right ventricular ectopic beat (delayed excitation of left ventricular systole) |
Paradoxically split S2
- mechanical delay of A2
|
Severe aortic outflow obstruction (aortic stenosis), systolic hypertension, large aorta-to-pulmonary artery shunt, ischemic heart disease, cardiomyopathy, aortic coarctation, patent ductusarteriosus |
Single S2 (absence of physiologic splitting) |
Tetralogy, truncusarteriosus, tricuspid atresia |
Muffled heart sounds |
Pericardial effusion |
Third heart sound (S3) |
|
S3 present, 0.14–0.16 seconds after S2 |
Ventricular septal defect, atrial septal defect, aortic regurgitation, mitral regurgitation, tricuspid regurgitation, patent ductusarteriosus, pregnancy, congestive heart failure, hyperdynamic circulation (fever, anemia, atrioventricular fistula, thiamine deficiency, hyperthyroidism, infection, Paget’s disease, pregnancy), physiological < 40 years old |
Fourth heart sound (S4) |
|
S4 present, 0.08-0.12 seconds before S1 |
Hypertension (systemic or pulmonary), hypertrophic cardiomyopathy, acute myocardial infarction, coronary artery disease, congestive heart failure, aortic stenosis, pulmonary stenosis |