Stroke volume and mitral annular velocities: insights from uremic patients with significant valvular regurgitation
Shih-Hung Hsiao1, Wei-Chen Huang, Tao Yu Lee
1Division of Cardiology, Internal Medicine Department, Center of Cardiovascular Disease, Kaohsiung Veterans General Hospital. Taiwan, ROC.
Insights
Hemodialysis significantly alters diastolic indices in uremic patients without aortic or mitral regurgitation. However, in patients with significant regurgitation, these diastolic indices remain stable, suggesting preload independence.
Area of Science:
- Cardiology
- Nephrology
- Echocardiography
Background:
- Uremic patients undergoing regular hemodialysis (H/D) often exhibit cardiovascular changes.
- Assessing diastolic function is crucial for managing these patients.
- New diastolic indices require evaluation in the context of H/D.
Purpose of the Study:
- To investigate the impact of H/D on novel diastolic indices in uremic patients.
- To compare changes in these indices between patients with and without significant aortic or mitral regurgitation (AR or MR).
Main Methods:
- Transthoracic echocardiography was performed on uremic patients before and after H/D.
- Patients were categorized into groups based on the presence of significant AR or MR.
- Key parameters measured included stroke volume (SV), flow propagation velocity (FPV), and mitral annular velocities.
Main Results:
- Hemodialysis significantly reduced stroke volume in patients without AR/MR, but not in those with significant AR/MR.
- Patients without AR/MR showed significant changes in mitral inflow velocities and mitral annular velocities post-H/D.
- In contrast, patients with significant AR/MR exhibited no statistical difference in new diastolic indices before and after H/D.
Conclusions:
- New echocardiographic diastolic indices appear relatively preload-independent in uremic patients with significant AR or MR.
- This stability is likely due to the insignificant changes in stroke volume observed in this patient group after H/D.
Objective:
This study investigates the change in new diastolic indices in uremic patients who undergo regular hemodialysis (H/D).
Materials And Methods:
We studied uremic patients receiving regular H/D. All patients were sinus rhythm before H/D. They had normal left ventricular systolic performance without regional wall motion abnormality. Patients were separated into two groups according to whether they had significant aortic or mitral regurgitation (AR or MR) or not. They received complete transthoracic echocardiographic examinations. Stroke volume (SV) was calculated as the product of the time-velocity integral (TVI) and cross-sectional area of aortic annulus. Flow propagation velocity (FPV) was measured by color M-mode echocardiography in apical four-chamber view. Mitral annulus tissue Doppler velocities--peak systolic (Sa), early diastolic, and late diastolic--were measured from septal and lateral wall. All these parameters were obtained immediately before and after H/D. Paired data were compared.
Result:
H/D amount was strongly correlated with the change of SV. After H/D, the reduction of SV in patients without AR or MR (control group) was obvious but it was not significant in patients with significant AR or MR (study group). There were significant differences in mitral inflow velocities, FPV, and mitral annular velocities (except septal Sa) in the control group. In the study group, predialytic and postdialytic parameters of new diastolic indexes had no statistical difference.
Conclusion:
New echocardiographic indexes of uremic patients with significant AR or MR were relatively preload-independent. The phenomenon was possibly related to insignificant change of SV after H/D.
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