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Updated: Aug 14, 2026
Blood Flow Imaging with Ultrafast Doppler
Published on: October 14, 2020
Doppler tissue imaging and color M-mode flow propagation velocity: are they really preload independent?
Shih-Hung Hsiao1, Wei-Chen Huang, Cheng-Len Sy
1Division of Cardiology, Internal Medicine Department, Center of Cardiovascular Disease, Kaohsiung Veterans General Hospital, Kaoh-siung, Taiwan.
Insights
Hemodialysis (H/D) fluid removal affects diastolic function in uremia patients. Diastolic mitral annulus Doppler tissue velocities (Ea and Aa) are preload independent below 2 kg fluid removal but not above, while flow propagation velocity (FPV) is always preload dependent.
Area of Science:
- Cardiology
- Nephrology
- Medical Imaging
Background:
- Uremia patients undergoing regular hemodialysis (H/D) often exhibit altered cardiac function.
- Assessing diastolic function is crucial for managing these patients.
- Newer echocardiographic indexes may offer better insights into cardiac changes during H/D.
Purpose of the Study:
- To investigate the changes in novel diastolic indexes in patients with uremia undergoing regular hemodialysis.
- To evaluate the preload dependency of these indexes based on the amount of fluid removed during H/D.
Main Methods:
- Eighty-one uremic patients on regular H/D with normal left ventricular systolic function were studied.
- Transthoracic echocardiography was used to measure flow propagation velocity (FPV) and mitral annulus Doppler tissue velocities (Sa, Ea, Aa).
- Measurements were taken immediately before and after H/D, with patients grouped by fluid removal: <2 kg, 2-3 kg, and >3 kg.
Main Results:
- Flow propagation velocity (FPV) showed significant changes post-H/D across all fluid removal groups.
- Diastolic mitral annulus Doppler tissue velocities (Ea, Aa) were preload independent when <2 kg fluid was removed.
- Ea and Aa became significantly altered when fluid removal exceeded 2 kg, indicating not total preload independence.
Conclusions:
- Flow propagation velocity (FPV) is preload dependent in patients with normal systolic function undergoing H/D.
- Diastolic mitral annulus Doppler tissue velocities (Ea, Aa) exhibit preload dependency that varies with the volume of fluid removed during H/D.
- Systolic mitral annulus Doppler tissue velocity (Sa) appears to be preload independent.
Objective:
This study investigated the change in new diastolic indexes in patients with uremia who undergo regular hemodialysis (H/D).
Methods:
We studied 81 patients with uremia (41 men and 40 women) receiving regular H/D. All patients were in sinus rhythm before H/D. They had normal left ventricular systolic performance without regional wall-motion abnormality. Three patients were excluded because of atrial fibrillation after H/D. Patients were separated by the amount of body fluid removed during H/D procedure: 30 patients with H/D amount less than 2 kg (group 1), 33 patients with H/D amount between 2 and 3 kg (group 2), and 18 patients with H/D amount larger than 3 kg (group 3). They received complete transthoracic echocardiographic examinations. Flow propagation velocity (FPV) was measured by color M-mode echocardiography in apical 4-chamber view. Mitral annulus Doppler tissue velocities (peak systolic [Sa], early diastolic [Ea], and late diastolic [Aa]) were measured from septal, lateral, inferior, and posterior walls. All these parameters were obtained immediately before and after H/D. Paired data were compared.
Results:
In patients with removed fluid amount less than 2 kg (group 1), the change of all diastolic parameters showed insignificant change except FPV (peak mitral E, P = .14; peak mitral A, P = .916; FPV, P = .009; septal Sa, P = .173; septal Ea, P = .295; septal Aa, P = .649). In patients with H/D amount between 2 and 3 kg, the change of all diastolic parameters showed statistically significant difference except Sa (peak mitral E, P = .001; peak mitral A, P = .001; FPV, P = .001; Sa, P = .589; Ea, P = .001; Aa, P = .015). In patients with H/D amount larger than 3 kg, Sa still showed insignificant change. Ea, Aa, and FPV showed significant difference after H/D (peak mitral E, P = .001; peak mitral A, P = .035; FPV, P = .008; septal Sa, P = .777; septal Ea, P = .014; septal Aa, P = .048).
Conclusion:
In patients with normal left ventricular systolic function, FPV was preload dependent. Diastolic phase mitral annulus Doppler tissue velocities (Ea and Aa) behaved differently according to the amount removed during H/D. They were preload independent when the amount removed during H/D was less than 2 kg. When the amount removed during H/D was larger than 2 kg, diastolic phase mitral annulus Doppler tissue velocities changed significantly. That is to say, diastolic phase mitral annulus Doppler tissue velocities were not totally preload independent. For systolic phase mitral annulus Doppler tissue velocity index (Sa), it was preload independent.
