Definition

A cardiac murmur is an abnormal or unusual heart sound. It’s also called abnormal heart sounds or cardiac bruit. A cardiac murmur is heard by stethoscope, along with normal heart sounds.

Causes of murmur

Cardiac murmur is produced because of a change in the pattern of blood flow. Normal blood flows in streamline through the heart and blood vessels . However , during abnormal condition like valvular diseases , the blood flow becomes turbulent . It produces the cardiac murmur

Murmur is produced by valvular disease, septal defects, and vascular defects.

Classification of Murmur

1. 1. Systolic murmur
      • The incompetence of Atrioventricular Valves

        When atrioventricular Valves became weak, these valves cannot close completely. It causes the regurgitation of blood from the ventricles to the atria during ventricular systole, producing the murmur . It is a harsh blowing sound with high frequency .

      • Stenosis of Semilunar Valves

        During stenosis of the aortic valve , the left ventricularr pressure raises up to 300 Hg during systole .

      • Murmur due to Anemia

        A systolic murmur is heard in severe anemia because of the reduced viscosity and accelerated flow of blood .

      • Septal Defect

        During interventricular septal defect , blood flows from left ventricle during systole . It produces a systolic murmur .

      • Coarctation of Aorta

        Coarctation of aorta is a congenital disorder , charcterized by the narrowing of a part of systemic aorta .

   2. Diastolic murmur
      • Stenosis of Atrioventricular Valves

        When the atriovntricular valves becomes narrow , the turbulence of blood flow occurs during diastolic. It is a weak sound with a low frequency

      • The incompetence of semilunar Valves

        Murmur is produced during the regurgitation of blood from the aorta to the ventricle, through the incompetent semilunar valve during diastole

   3. Continuous murmur
      • Patent Ductus Arteriosus

It’s a harsh blowing sound and is heard best in the pulmonary area. The murmur is heard 1 year after birth