Etiology of Murmurs by Timing

Mid systolic (ejection)

Outflow obstruction (aortic sclerosis, aortic stenosis, coarctation of the aorta, hypertrophic cardiomyopathy, subvalvular stenosis, supravalvular stenosis)

Dilation of ascending aorta (aneurysm of aorta, aortitis, atheroma )

Dilation of pulmonary artery

Increased blood flow across the aortic valve (aortic regurgitation, hyperkinetic states)

Increased blood flow across the pulmonic valve (hyperkinetic states, left-to-right shunt due to atrial septal defect, ventricular septal defect)

Pulmonic obstruction (infundibular stenosis, pulmonic stenosis, supravalvular pulmonary artery stenosis, branch pulmonary artery stenosis)

Mid-late systolic

Mitral valve prolapse

Papillary muscle dysfunction

Holosystolic

Mitral regurgitation

Tricuspid regurgitation

Ventricular septal defect

Early diastolic (regurgitant)

Aortic regurgitation:

• Acquired or congenital valve abnormality (eg, endocarditis, myxomatous or calcific degeneration, rheumatic fever), dilation of valve ring (eg, annuloaortic ectasia, aortic dissection, cystic medial necrosis, hypertension), widening of commissures (eg, syphilis)

• Congenital bicuspid aortic valve with or without ventricular septal defect

Pulmonic regurgitation:

• Acquired or congenital valve abnormality

• Dilation of valve ring (eg, pulmonary hypertension, Marfan syndrome)

• Tetralogy of Fallot

• Ventricular septal defect

Mid diastolic

Atrial ball-valve thrombi

Increased blood flow across nonstenotic mitral valve (eg, mitral regurgitation, ventricular septal defect, patent ductus arteriosus, high-output states, complete heart block)

Increased blood flow across nonstenotic tricuspid valve (eg, tricuspid regurgitation, atrial septal defect, anomalous pulmonary venous return)

Left or right atrial tumors

Mitral stenosis (eg, due to rheumatic fever, congenital stenosis, cor triatriatum)

Tricuspid stenosis

Continuous

Patent ductus arteriosus

Venous hum

Coronary-cameral fistula

Coarctation of the aorta or pulmonary artery

Severe pulmonary artery branch stenosis

Anomalous left coronary artery

Aortic–right ventricular or atrial fistula

Bronchial collateral circulation

Coronary or intercostal arteriovenous fistula

Mammary souffle (venous hum from engorged breast vessels during pregnancy)

Proximal coronary artery stenosis

Ruptured aneurysm of sinus of Valsalva

Small (restrictive) atrial septal defect with mitral stenosis