Diastolic dysfunction echocardiography
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Diastolic dysfunction Microchapters |
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Diastolic dysfunction echocardiography On the Web |
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American Roentgen Ray Society Images of Diastolic dysfunction echocardiography |
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Risk calculators and risk factors for Diastolic dysfunction echocardiography |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Overview
Echocardiography
Correlates of Left ventricle diastolic dysfunction
- Left ventricular mass and/or thickness- The left ventricular mass is difficult to measure with 3-dimensional echocardiography . 2-dimensional echocardiography can also be used to assess the wall thickness (wall thickness is increased in both hypertrophy and remodelling).
- Left atrial volume- Highly reliable and best measured using 4-chamber and 2-chamber views. It is clinically relevant as this is a reflection of the extent of left ventricular remodelling over time. An index of 34 ml/m2 is considered as an independent predictor of death, heart failure, atrial fibrillation, and ischemic stroke. Dilated left atrial volume is however not specific to diastolic dysfunction. Other conditions like high output states, bradycardia and 4-chamber enlargement, atrial flutter or atrial fibrillation, mitral valve disease and few cases of athletes also have dilated atria. It is vital therefore to differentiate on clinical basis, other echo volumes etc.
- Left atrial function- The reservoir, conduit, and stroke volumes of the left atrium can be computed and expressed as percentages of LA stroke volume. The systolic function of left atrium (which contributes to filling in late diastole) is assessed using a combination of 2D and Doppler. It can be measured as follows-
- LA ejection force (0.5 X 1.06 X Mitral annular area X [Peak A velocity]2]) and,
- Kinetic energy (0.5 X 1.06 X LA stroke volume X [A velocity]2)
- Patients with diastolic dysfunction have increased pulmonary artery pressures. Derivation of the PA systolic pressure is made using peak velocity of the tricuspid regurgitation (TR) jet and systolic right atrial pressure by continuous wave (CW) Doppler. The end-diastolic velocity of pulmonary regurgitation (PR) jet can be applied to derive PA diastolic pressure. PA diastolic pressure by Doppler echocardiography correlates well with mean pulmonary wedge pressure and may be used as its surrogate but the assumption is not true in every case.
Mitral inflow
- Pulsed wave Doppler is performed in the apical 4-chamber view to obtain mitral inflow velocities to assess LV filling.
- A 1-mm to 3-mm sample volume is then placed between the mitral leaflet tips during diastole to record a crisp velocity profile.
- Primary measurements include peak E (early diastolic) and A (late diastolic) velocities, E/A ratio, deceleration time (DT), and isovolumic relaxation time (IVRT).
- Mitral inflow patterns could include normal, impaired LV relaxation, pseudonormal left ventricle filling (PNF), and restrictive LV filling.
- In patients with dilated cardiomyopathies, filling patterns correlate better with filling pressures, functional class, and prognosis than LV ejection fraction (EF).
- In patients with coronary artery disease and those with hypertrophic cardiomyopathy in whom the LV EFs are >50%, mitral velocities correlate poorly with hemodynamics.