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Mathematically, three components of normal strain (εx, εy, and εz) and three components of shear strain (εxy, εxz, and εyz) are recognized. Congruently, when applied to the left ventricle , left ventricular deformation is defined by the three normal strains (longitudinal, circumferential, and radial) and three shear strains ...
Strain rate imaging during stress has been shown to give incremental value over ordinary echocardiography, both diagnostic [28] [29] and prognostic. [30] In stress echo, the increased heart rate has speckle tracking at a disadvantage, due to the limited frame rate that affects tracking at higher heart rates. [citation needed]
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 ...
The annular shape of the LV wall will change and become thicker (radial strain) with a smaller inner circle (circumferential strain). In a normal heart, the circumferential strain or positives negative as measured from end-diastole. Note that: Strain has a sign: A contraction of a muscle fiber yields a negative strain measurement along the ...
Age dependent normal values for S', e' and a'. The e'/a' ratio becomes <1 about 60 years of age, which is similar to the E/A ratio of mitral flow. Women has slightly higher S' and e' velocities than men, although the difference disappears with age.
Heart rate and rhythm - loss of a normal atrial rhythm (e.g., atrial fibrillation causes loss of the A wave). The height of the E wave becomes dependent on the length of the cardiac cycle (variable) rather than a measure of diastolic function. Similarly, pacing and tachycardia result in alterations, whereas bradycardia increases the E/A ratio.
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] On an electrocardiogram (ECG), there are multiple ways RV strain can be demonstrated. A finding of S1Q3T3 [b] is an insensitive [10] sign of right heart strain. [11]
There are many ways to calculate the valve area of aortic stenosis. The most commonly used methods involve measurements taken during echocardiography. For interpretation of these values, the area is generally divided by the body surface area, to arrive at the patient's optimal aortic valve orifice area.