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Preload dependence of new Doppler techniques limits their utility for left ventricular diastolic function assessment
Eric H Y Ie1, Wim B Vletter, Folkert J ten Cate
1Department of Medicine, Erasmus MC, Dr. Molewaterplein 40, 3015 GD Rotterdam, The Netherlands. e.ie@erasmusmc.nl
Insights
New Doppler techniques for assessing diastolic dysfunction in hemodialysis patients showed limited advantage. Timing assessments relative to hemodialysis is crucial for accurate left ventricular diastolic function evaluation.
Area of Science:
- Cardiology
- Nephrology
- Medical Imaging
Background:
- Left ventricular (LV) hypertrophy is a common complication in patients undergoing hemodialysis (HD), often leading to diastolic dysfunction.
- Standard Doppler measurements of transmitral and pulmonary vein (PV) flow are preload-dependent, complicating diastolic function assessment in HD patients with fluctuating fluid status.
Purpose of the Study:
- To evaluate the utility of novel, potentially preload-independent Doppler techniques, including mitral annulus velocity by Doppler tissue imaging (DTI) and LV inflow propagation velocity (Vp) from color M-mode, for assessing LV diastolic function in HD patients.
- To compare these newer methods with conventional Doppler parameters before and after HD with ultrafiltration.
Main Methods:
- Ten HD patients (seven with LV hypertrophy) underwent serial Doppler echocardiography 1 hour before, 1 hour after, and 1 day after HD.
- Measurements included transmitral flow velocities (E/A), PV flow velocities (s/d), DTI mitral annulus velocities (e/a), and LV inflow propagation velocity (Vp).
Main Results:
- After HD, transmitral E/A, DTI e/a, and Vp significantly decreased, while PV s/d increased, indicating changes in diastolic function parameters.
- These changes persisted 24 hours after HD, suggesting a sustained effect of fluid status alteration.
- Despite using newer techniques, pseudonormalization due to pre-HD volume overload led to an underestimation of diastolic dysfunction severity.
Conclusions:
- The advantage of advanced Doppler techniques (DTI, color M-mode Vp) over conventional methods for assessing LV diastolic function in HD patients is limited due to preload dependency and pseudonormalization.
- Accurate assessment of LV diastolic function in HD patients requires careful consideration of the timing relative to the HD procedure, avoiding measurements shortly before treatment.
Abstract:
Left ventricular (LV) hypertrophy leads to diastolic dysfunction. Standard Doppler transmitral and pulmonary vein (PV) flow velocity measurements are preload dependent. New techniques such as mitral annulus velocity by Doppler tissue imaging (DTI) and LV inflow propagation velocity measured from color M-mode have been proposed as relatively preload-independent measurements of diastolic function. These parameters were studied before and after hemodialysis (HD) with ultrafiltration to test their potential advantage for LV diastolic function assessment in HD patients. Ten patients (seven with LV hypertrophy) underwent Doppler echocardiography 1 h before, 1 h after, and 1 d after HD. Early (E) and atrial (A) peak transmitral flow velocities, peak PV systolic (s) and diastolic (d) flow velocities, peak e and a mitral annulus velocities in DTI, and early diastolic LV flow propagation velocity (V(p)) were measured. In all patients, the E/A ratio after HD (0.54; 0.37 to 1.02) was lower (P < 0.01) than before HD (0.77; 0.60 to 1.34). E decreased (P < 0.01), whereas A did not. PV s/d after HD (2.15; 1.08 to 3.90) was higher (P < 0.01) than before HD (1.80; 1.25 to 2.68). Tissue e/a after HD (0.40; 0.26 to 0.96) was lower (P < 0.01) than before HD (0.56; 0.40 to 1.05). Tissue e decreased (P < 0.02), whereas a did not. V(p) after HD (30 cm/s; 16 to 47 cm/s) was lower (P < 0.01) than before HD (45 cm/s; 32 to 60 cm/s). Twenty-four hours after the initial measurements values for E/A (0.59; 0.37 to 1.23), PV s/d (1.85; 1.07 to 3.38), e/a (0.41; 0.27 to 1.06), and V(p) (28 cm/s; 23 to 33 cm/s) were similar as those taken 1 h after HD. It is concluded that, even when using the newer Doppler techniques DTI and color M-mode, pseudonormalization, which was due to volume overload before HD, resulted in underestimation of the degree of diastolic dysfunction. Therefore, the advantage of these techniques over conventional parameters for the assessment of LV diastolic function in HD patients is limited. Assessment of LV diastolic function should not be performed shortly before HD, and its time relation to HD is essential.