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[Differences in loading condition and its effects for valve replacement between chronic aortic and mitral
H Maeta1, S Imawaki, Y Shiraishi
1First Department of Surgery, Kagawa Medical School.
Kyobu Geka. the Japanese Journal of Thoracic Surgery
|June 1, 1990
Summary
Chronic aortic regurgitation (AR) and mitral regurgitation (MR) show distinct left ventricular mechanics. AR patients experience higher peak systolic wall stress, which improves effectively after aortic valve replacement (AVR).
Area of Science:
- Cardiology
- Cardiovascular Physiology
- Cardiac Surgery
Background:
- Chronic aortic regurgitation (AR) and mitral regurgitation (MR) impact left ventricular (LV) mechanics differently.
- Understanding these differences is crucial for surgical intervention outcomes.
Purpose of the Study:
- To clarify the distinct left ventricular (LV) mechanics between chronic aortic regurgitation (AR) and mitral regurgitation (MR).
- To evaluate the effects of valve replacement on LV mechanics in both conditions.
Main Methods:
- Noninvasive assessment of LV mechanics in 23 AR patients and 17 MR patients.
- Comparison of parameters before and one month after valve replacement (VR).
Main Results:
- AR patients had significantly higher peak systolic wall stress (PSWS), end-systolic volume index (ESVI), and systolic blood pressure (sBP) compared to MR patients.
- After aortic valve replacement (AVR), AR patients showed significant decreases in most parameters, except increased posterior wall thickness (PWTd).
- After mitral valve replacement (MVR), MR patients had reduced LV dimensions and PSWS, but unchanged blood pressure, LV systolic size, and LV mass.
Conclusions:
- High PSWS in AR is effectively reduced post-AVR due to decreased LV volume and sBP.
- In MR, PSWS reduction post-MVR is primarily due to volume reduction, as sBP remains low.
- Systolic function post-MVR for MR with impaired myocardium may be compromised by persistent high afterload due to difficulty in volume reduction.