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Visualizes heart in real time with ultrasound; Doppler recordings noninvasively assess hemodynamics and abnormal flow patterns. Imaging may be compromised in pts with chronic obstructive lung disease, thick chest wall, or narrow intercostal spaces.
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Chamber Size and Ventricular Performance
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Assessment of atrial and ventricular dimensions, global and regional systolic wall motion abnormalities, ventricular hypertrophy/infiltration, evaluation for pulmonary hypertension: RV systolic pressure (RVSP) is calculated from maximum velocity of tricuspid regurgitation (TR):
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RVSP = 4 × (TR velocity)2 + RA pressure
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(RA pressure is same as JVP estimated by physical exam.) In absence of RV outflow obstruction, RVSP = pulmonary artery systolic pressure.
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LV diastolic function is assessed by transmitral Doppler (see Fig. 229-9, p. 1844, in HPIM-18) and Doppler tissue imaging, which measures velocity of myocardial relaxation.
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Valvular Abnormalities
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Thickness, mobility, calcification, and regurgitation of each cardiac valve can be assessed. Severity of valvular stenosis is calculated by Doppler [peak gradient = 4 × (peak velocity)2]. Structural lesions (e.g., flail leaflet, vegetation) resulting in regurgitation may be identified, and Doppler (Fig. 121-2) estimates severity of regurgitation.
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