Noise Changeable Seitz

Seitz's variable murmur (SN) is a physical symptom described by Czech surgeon Alfred Seitz in 1918, which consists of an intermittent noise that you hear when you try to feel the pulsation of the carotid artery in the neck. But what causes this noise and why is it named so?

As mentioned earlier, variable noise (VN). This means that the amplitude of a sound can vary in both time and volume. This sound occurred when the surgeon pressed on the respiratory artery to check its pulsation. One theory to explain the origin of the Seitz variability murmur is that when pressure is applied to the arterial wall, air moving through the vessel creates a small noise that changes over time.

One of the reasons for changes in pressure may be dilation of a blood vessel during arrhythmia or brain stroke. This causes the artery to pulsate at the same rate as the heart rate, creating a variable noise. In addition, the alternating vibrations of air and tissue in the tissues create music and create mechanical noise consisting of different frequencies.

Another theory explains the Seits variability noise as a constant flow of blood through the gaps between the arteries and the outflow tubules in the area of ​​pulsation of the artery. Constant flows of pumped blood affect the amplification of sound. Rounding of arteries and adjacent tissues, contraction of airway muscles, and narrowing of vascular orifices may also contribute to the murmur of variability.

Another theory is that the noise occurs due to resonance under the influence of processes in the cardiovascular system.

This sound is considered useful in determining the heart rate in cases where the patient is lying on his back and cannot follow his pulse.