Heart murmurs

Heart murmurs

1. Causes

   • This are caused by audible vibrations that are due to increased turbulence from accelerated blood flow through normal or abnormal orifices, flow through a narrowed or irregular orifice into dilated vessel or chamber, or backward flow through an incompetent valve, ventricular septal defect or patent ductus arteriosus

2. Systolic murmurs

   • Early systolic murmurs
     • Begin with S1 and extend for a variable period ending well before S2. Are usually decrescendo; best heard at or medial to the apical impulse
       • Causes:
         • Acute mitral regurgitation, ventricular septal defect, tricuspil regurgitation
   • Midsystolic murmurs
     • Begin at a short interval after S1 and end before S2. Are usually crescendo-decrescendo
       • Causes:
         • Aortic or pulmonary obstruction
   • Late systolic murmurs
     • They are often introduced by one or more non-ejection clicks, a late systolic murmur is usually due to Mitral Valve Prolapse and is best heard at the left ventricular apex.
       • Causes:
         • Acute myocardial ischemia
   • Holosystolic murmurs
     • Begin with S 1 and continue through systole to S 2. Indicative of chronic mitral or tricuspid valve regurgitation or a VSD
       • Causes:
         • Endocarditis, rheumatic disease, carcinoid, Ebstein's anomaly

3. Diastolic murmurs

   • Early diastolic murmurs
     • Chronic aortic regurgitation results in a high-pitched, blowing, decrescendo, early to mid-diastolic murmur that begins after the aortic component of S 2 and is best heard at the second right interspace.
       • Pulmonic regurgitation results in a decrescendo, early to mid-diastolic murmur that begins after the pulmonic component of S 2
   • Mid-diastolic murmurs
     • Result from obstruction and/or augmented flow at the level of the mitral or tricuspid valve. Rheumatic fever is the most common cause of mitral stenosis. The murmur of MS is low-pitched and this is best heard with the bell of the stethoscope.

4. Continuous murmurs

   • Begin in systole, near to the second heart sound, and continue into the diastole. The murmur is louder in systole.
   • These murmurs are associated with a patent ductus arteriosus, a ruptured sinus of Valsalva aneurysm, coronary arteriovenous fistula, and more heart diseases.
   • Not all continuous murmurs are pathologic, you can hear in healthy children and young adults, especially during pregnancy.

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