Auscultation of the Heart
- The first heart sound S1 is produced by the mitral and tricuspid valve closure.
- The second heart sound S2 is produced by the closure of the aortic and pulmonary valves.
- A2 or aortic closure sound comes earlier than P2 or pulmonary closure sound.
- During inspiration the split between A2 and P2 is increased and during expiration the split between A2 and P2 is decreased.
- An ejection sound may be heard after S1, in cases of pulmonary hypertension, systemic hypertension, dilatation of Pulmonary artery or aorta.
- A pericardial knock may be heard after S2 in cases of pericardial disease.
Causes of loud first sound
- Hyperdynamic circulation – fever, thyrotoxicosis, exercise, AR, PDA
- Short PR interval
Causes of loud second sound (S2,)
- Loud A2 – is found in systemic hypertension, dilatation of the ascending aorta as in rheumatic fever and syphilis.
- Loud P2 – is found in pulmonary hypertension, corpulmonale, ASD, VSD, PDA.
Causes when split between A2 and P2 is increased —
- Pulmonary stenosis
- Pulmonary hypertension
- Idiopathic dilatation of pulmonary artery WPW syndrome
- LV ectopics
- RV failure
Causes of single second heart sound (S2)
- Tetralogy of Fallot
- Severe PS
- Truncus arteriosus Tricuspid atresia
Causes of reversed (paradoxical) splitting of the second heart sound (S2)
- WPW syndrome
Causes of S3 or ventricular or diastolic gallop
- LVF and LV dysfunction
Causes of S4 or atrial gallop
Causes of pericardial knock
- Constrictive pericarditis
- Pericardial effusion
Systolic murmurs at the apex may be due to :
- · Mitral regurgitation
- · Papillary muscle dysfunction
- · Cardiomyopathy
- · Aortic stenosis ejection systolic murmur
Diastolic murmurs at the apex may be due to:
- · Mitral stenosis (diastolic thrill is usually present)
- · Mitral flow murmur in MR
- · Austin Flint murmur in AR
- · Carey Coombs murmur in rheumatic carditis
Systolic murmurs in parasternal area may be due to-:–
- · Aortic stenosis – ejection systolic murmur, increasing on expiration, radiating to carotids
- · Tricuspid regurgitation (increasing in inspiration and best heard at the lower e ge of sternumf
- · Pulmonary hypertension – ejection systolic murmur
- · Ventricular septal defect (VSD) – Pansystolic murmur
- · Pulmonary stenosis (left second intercostal space) – ejection systolic murmur
Diastolic murmurs in parasternal area may be due to: –
- Aortic regurgitation
- Tricuspid stenosis
- Graham Steell murmur of pulmonary regurgitation
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