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Pericardial friction murmur
Last reviewed: 07.06.2024
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In some pathologic conditions, a pericardial friction murmur may occur. It is important to be able to recognize it, as it can have an important diagnostic value. Most often in the literature, you can find a description of this noise as a certain crunch, creaking, scratching. To some, these sounds remind one of the squeak of boots on snow on a frosty evening. In any case, the noise occurs when the two walls of the pericardium rub against each other. Experienced doctors know and recognize this sound without difficulty. Nowadays, you can find quite a few audio recordings of pericardial friction noises on the Internet. In some cases, these sounds do not differ from normal mixed noises, but this is extremely rare. The sounds can be superficial, and can be easily heard even without special equipment or a stethoscope.
When analyzing this noise, it is worth noting that the noise is represented by three components. The first of them is heard during systole, the second occurs at the beginning of diastole, the third is heard closer to the end of diastole. That is, instead of the appearance of the third heart tone, there is a pericardial friction noise. There are cases when three murmurs are heard at once during one systolic interval. The most frequently observed clinical cases are those in which one most significant component of the friction murmur completely replaces the first heart tone. The other two components are heard in diastole. In fact, the murmur can replace any heart tone.
It is also noteworthy that pericardial friction murmurs are often amplified on inhalation. This clinical picture is observed in about 2/3 of cases.
There may be several reasons for this. First, there is a contraction of the diaphragm, and consequently its downward displacement. This contributes to the pericardium also moving downwards. There is tension on the heart, which explains the occurrence of the murmur. Secondly, there may not be enough fluid in the pericardial cavity, causing the sheets to rub against each other. When you breathe in, the sheets are stretched more, which explains the increase in the murmur.
The pericardial friction sound is often confused with the pericardial sound. It is particularly common if there is an effusion in the pericardial cavity.
It should also be taken into account that there are certain conditions in which a false noise resembling pericardial friction occurs. This condition is most often observed in pneumothorax. A small pneumothorax, localized in the region of the apex of the lung, can lead to the development of noises resembling pericardial friction. Often such a condition is diagnosed during fluorography and chest X-ray. Such a noise can occur with the appearance of air pockets in the area of the lung. Air bubbles in this case act as a source of noise.