Cardiac murmurs are abnormal heart sounds caused by turbulent blood flow through heart valves or openings. There are two types: functional murmurs caused by conditions like anemia without structural valve changes, and organic murmurs caused by structural valve abnormalities. Murmurs can be systolic (early, mid, or late), diastolic (early, mid, or late), or continuous. They are classified based on when they occur in relation to the heart sounds.
3. Cardiac murmur
Murmur are abnormal heart sound produced by
circulatory sequence through the valve or through the
abnormal openings.
When the normal luminal blood flow is converted into
turbulent stream, there will be production of
additional sounds which are audible as murmur.
4. Etiology
Constriction in front of blood stream.
Regurgitation of the blood stream.
Increased viscosity of the blood flow.
Roughening of the walls of the vessels.
Falling of blood into a dilated chamber.
5. Types of murmurThere are two types of cardiac murmur.
(1) Functional murmur.
(2) Organic murmur.
6. Functional murmur.
Murmur produced within the heart without any
structural alternations of the valves
e.g. Severe enaemia.
Organic murmur
Murmur produced by structural alteration of the
valve
7. Timing of murmur
Systolic murmur
(a) Early systolic murmur:
Observed along the 1st heart sound as found in mitral
incompetence and tricuspid incompetence.
8. (b) Mid systolic murmur
It is found in aortic stenosis and pulmonary stenosis.
Audible after 1st heart sound and before 2nd heart
sound.
There is gap between 1st and 2nd murmur.
9. (c) Late systolic murmur
Observed just before 2nd heart sound.
Seen in myocardial infarction.
10. Diastolic murmur
(a) Early diastolic murmur.
It begins with 2nd heart sound or
immediately after 2nd heart sound.
11. (b) Mid diastolic murmur
Murmur begins slightly after 2nd murmur.
There is gap between 2nd heart sound and murmur.
12. (c) Late diastolic murmur
It occurs just before the 1st heart sound as in mitral
stenosis.
