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The Shunt equation (also known as the Berggren equation) quantifies the extent to which venous blood bypasses oxygenation in the capillaries of the lung.. “Shunt” and “dead space“ are terms used to describe conditions where either blood flow or ventilation do not interact with each other in the lung, as they should for efficient gas exchange to take place.
where is the pulmonary vein, is the pulmonary artery, is the systemic arterial, and is the mixed-venous The Qp:Qs ratio is based upon the Fick principle and it is reduced to the above equation and eliminates the need to know cardiac output and hemoglobin concentration.
Overriding aorta (aortic valve is enlarged and appears to arise from both the left and right ventricles instead of the left ventricle, as occurs in normal hearts) Right ventricular hypertrophy (thickening of the muscular walls of the right ventricle, this is a result of the increased amount of work the heart has to do)
The test score is the time taken on the test, in minutes. This can also be converted to an estimated maximal oxygen uptake score using the calculator below and the following formulas, where the value "T" is the total time completed (expressed in minutes and fractions of a minute e.g. 9 minutes 15 seconds = 9.25 minutes). As with many exercise ...
It is normal to have a narrow QS and rSr' patterns in V 1, and this is also the case for qRs and R patterns in V 5 and V 6. The transition zone is where the QRS complex changes from predominantly negative to predominantly positive (R/S ratio becoming >1), and this usually occurs at V 3 or V 4 .
Tissue Doppler echocardiography (TDE) is a medical ultrasound technology, specifically a form of echocardiography that measures the velocity of the heart muscle through the phases of one or more heartbeats by the Doppler effect (frequency shift) of the reflected ultrasound.
Modalities applied to measurement of ejection fraction is an emerging field of medical mathematics and subsequent computational applications. The first common measurement method is echocardiography, [7] [8] although cardiac magnetic resonance imaging (MRI), [8] [9] cardiac computed tomography, [8] [9] ventriculography and nuclear medicine (gated SPECT and radionuclide angiography) [8] [10 ...
When normal, the RV is about half the size of the left ventricle (LV). When strained, it can be as large as or larger than the LV. [5] An important potential finding with echo is McConnell's sign, where only the RV apex wall contracts; [7] it is specific for right heart strain and typically indicates a large PE. [8]