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One parameter to quantify this difference is the pulsatility index (PI), which is equal to the difference between the peak systolic velocity and the minimum diastolic velocity divided by the mean velocity during the cardiac cycle. This value decreases with distance from the heart.
This occurs in the setting of valvular disease i.e. pulmonary valve, and in the setting of respiratory disease whereby the pressure in the pulmonary artery becomes elevated (e.g., left heart failure and fluid congestion to the right heart, chronic obstructive pulmonary disease, pulmonary hypertension).
The pulmonary artery pressure (PA pressure) is a measure of the blood pressure found in the main pulmonary artery. This is measured by inserting a catheter into the main pulmonary artery. [ 13 ] : 190–191 The mean pressure is typically 9–18 mmHg, [ 14 ] and the wedge pressure measured in the left atrium may be 6–12 mmHg.
Pulmonary interstitial pressure (Pi) rises as lung volume decreases due to reduced radial tethering of the lung parenchyma. Pi is highest at the base of the lung due to the weight of the above lung tissue. Pi can also rise due to an increased volume of 'leaked' fluid from the pulmonary vasculature (pulmonary edema). An increase in Pi causes ...
In fluid dynamics, a flow with periodic variations is known as pulsatile flow, or as Womersley flow.The flow profiles was first derived by John R. Womersley (1907–1958) in his work with blood flow in arteries. [1]
Selective pulmonary angiogram revealing significant thrombus (labelled A) causing a central obstruction in the left main pulmonary artery. Pulmonary angiography (or pulmonary arteriography,conventional pulmonary angiography, selective pulmonary angiography) is a medical fluoroscopic procedure used to visualize the pulmonary arteries and much less frequently, the pulmonary veins.
The theory of the velocity of the transmission of the pulse through the circulation dates back to 1808 with the work of Thomas Young. [9] The relationship between pulse wave velocity (PWV) and arterial wall stiffness can be derived from Newton's second law of motion (=) applied to a small fluid element, where the force on the element equals the product of density (the mass per unit volume ...
It is regarded as a highly sensitive and specific test for pulmonary embolism. [1] CTPA is typically only requested if pulmonary embolism is suspected clinically. If the probability of PE is considered low, a blood test called D-dimer may be requested. If this is negative and risk of a PE is considered negligible, then CTPA or other scans are ...