What causes a heart murmur?

In life, if you feel discomfort in the heart area, such as palpitations, chest tightness, etc., many people will choose to go to the hospital for examination. As a result, they will find heart murmurs. Many people will panic about such examination results, not knowing what is happening to their heart. Heart murmurs refer to sounds that are different from the normal heart sounds. Heart murmurs can help doctors diagnose the disease.

Heart murmurs may be caused by:

1. Blood Viscosity

Hematocrit Generally speaking, hematocrit is the most important factor determining blood viscosity. The larger the hematocrit, the higher the blood viscosity. Temperature The viscosity of blood increases as the temperature decreases. The surface temperature of the human body is lower than the deep temperature, so the viscosity of blood increases when it flows through the surface of the body. For example, in anemia, due to the decrease in red blood cells, blood viscosity decreases, and vortices occur when blood flows, which may produce noise.

2. Blood flow acceleration

For some reason, the faster the blood flows, the easier it is to produce vortices and the louder the noise. Some people cannot hear any murmurs when they are quiet, but can hear obvious murmurs after exercise; some people produce murmurs when they have a fever due to increased myocardial contractility and accelerated blood flow. Even in the absence of valvular disease or stenosis, murmurs may occur or existing murmurs may be intensified when blood flow accelerates, such as in normal people after strenuous exercise, fever, severe anemia, or hyperthyroidism.

3. Heart valve stenosis or valvular insufficiency

The opening of the valve or the large blood vessels are narrow, the valve orifice is narrow (such as mitral stenosis) or the large blood vessels are narrow (such as congenital aortic coarctation, etc.), or the valve orifice is relatively narrow due to heart enlargement or expansion of large blood vessels (pulmonary artery or aorta), which may produce vortices and cause murmurs when blood flows through. This is one of the reasons for the noise.

4. Heart Murmurs Caused by Physical Exercise

If a person who exercises has a heart murmur, it may be that the heart was diseased before the exercise, or it may be a normal physiological phenomenon. However, no matter which situation it is, you should not have any concerns in your mind. At the same time, a detailed examination should be done immediately. When it is confirmed to be a pathological murmur, you can no longer participate in strenuous physical exercise, but should engage in medical sports activities under the guidance of a doctor. If pathological murmurs are ruled out, then they are physiological murmurs. This type of murmur often appears when the person is quiet, disappears after activity, and the sound is relatively localized and does not transmit to other areas. This murmur does not prevent a person from participating in any sport.

5. Abnormal blood flow channels

There are abnormal pathways within the heart or between large blood vessels, such as ventricular septal defect, patent ductus arteriosus, arteriovenous fistula, etc. Blood flow can be diverted through abnormal channels, forming vortices and producing noise.

6. Foreign bodies or abnormal structures in the heart

In the human body, the false chordae tendineae or the ruptured stumps of the chordae tendineae and papillary muscles in the ventricles swing and float in the heart cavity, disturbing the blood and generating vortices, resulting in noise.

7. Large blood vessel aneurysmal dilatation

Large vessel aneurysm is a localized dilation of the arterial wall due to disease or trauma. When blood flows from the normal arterial lumen through the dilated area, it can produce vortices and cause noise.