To study vascular tone in medicine, professionals in this field use a special technique called PVR tests. In the course of the PVR test, fluctuations in the volume of the human body and an individual organ or part are recorded due to their filling with blood. In contemporary medical practice, there are several types of plethysmography, each of which can be performed using certain equipment – plethysmographs. Any plethysmograph includes a receiving and transmitting part, a tape drive mechanism, and a recorder.
What is a PVR test itself?
This procedure is a method of recording changes in the volume of the body or part of it associated with blood circulation dynamics. General plethysmography or body plethysmography is used to study the functions of external respiration and cardiac output. With the help of making a PVR test for legs, it’s possible to assess vascular tone and, using various tests, form an idea of vascular changes’ organic or functional nature.
Registration of the results is performed with special devices, plethysmographs, and various designs (water, electro-, photoplethysmography). With this test’s help, the doctor can diagnose complex forms of disturbance of regional blood flow, cerebral blood flow, organic stenosis of the internal carotid artery, etc.
The equipment for plethysmography can be mechanical and electrical. A mechanical plethysmograph, either indirectly or directly, registers the arising fluctuations in the volumes of the objects under study. Electric testing helps assess vascular filling over a large study area. Professional clinics also use photoelectric techniques designed for studies on planes, for example, on the patient’s skin and mechanoelectrical devices.
Indications for PVR testing
Pvr tests should be performed in cases where there are the following medical indications:
- various vascular diseases;
- numerous circulatory disorders;
- cardiac pathologies;
- diagnosing Raynaud’s syndrome;
- varicose veins;
- violations of the blood supply to the brain.
Diagnostics allows the doctor to determine the tone of veins, arteries and monitor the therapy’s effectiveness. Plethysmography also makes it possible to investigate conditioned vascular reflex states. Moreover, this type of examination is usually prescribed by neuropathologists, therapists, vascular surgeons, phlebologists. The procedure is carried out in many hospitals and clinics, where they have special equipment and a qualified specialist.
What is a PVR test process?
The method of carrying out a general PVR test, contraindications to it, and the essence of the procedure’s preparation process directly depend on which part of the body needs to be diagnosed and what apparatus it will be performed with. A good result is given by studies carried out in parallel on the affected and healthy vessels and multiple plethysmography.
To improve diagnostics’ accuracy in the process of PVR test for legs, the doctor may carry out thermal and pharmacological tests or samples that are removed during periods of physical activity. In this case, blood circulation indicators before and after manipulations with the examined organ should be recorded. Such tests help assess the extent and speed of restoration of normal blood flow in the affected area.
Moreover, PVR tests make it possible to optimally select the necessary medications that effectively eliminate the pathology diagnosed during the study. When evaluating the results of plethysmography, it’s important to have fast fluctuations, provided by the heart and the respiratory system’s work, and slow, formed in the process of filling the vascular system with blood. In case of having problems with your cardiovascular system, do a PVR test to prevent future repercussions.
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