Related Experiment Videos
Evaluation of transient mitral regurgitation in coronary artery disease
G Fehrenbacher1, D H Schmidt, W J Bommer
1Department of Medicine, University of Wisconsin Medical School, Milwaukee.
Insights
Transient mitral regurgitation (MR) during stress is linked to severe ventricular dyskinesia and specific coronary stenoses. This study clarifies factors contributing to stress-induced MR in coronary artery disease patients.
Area of Science:
- Cardiology
- Cardiac Imaging
- Pathophysiology
Background:
- Transient mitral regurgitation (MR) induced by myocardial ischemic stress is not well understood.
- Factors contributing to stress-induced MR and its associated clinical characteristics require investigation.
Purpose of the Study:
- To investigate changes in valvular and ventricular parameters during transient, stress-induced MR.
- To identify clinical characteristics of patients experiencing stress-induced MR.
Main Methods:
- Color flow Doppler echocardiography was used to assess MR in 42 patients.
- Measurements included MR color area, mitral leaflet coaptation, mitral valve anulus diameter, and left ventricular function.
- Echocardiography was performed before and after exercise or during percutaneous transluminal coronary angioplasty (PTCA).
Main Results:
- New transient MR developed in 4/27 patients post-exercise and 7/15 patients during PTCA.
- New MR was associated with more severe stress-induced ventricular dyskinesia (p<0.05) and specific coronary stenoses.
- Stress-induced MR was linked to apical displacement of mitral leaflets (p<0.05) but not to changes in blood pressure, anulus diameter, or mitral valve prolapse.
Conclusions:
- Stress-induced MR is primarily associated with significant ventricular dyskinesia and specific coronary artery stenoses.
- Apical displacement of mitral leaflets is a key factor in stress-induced MR.
- New stress-induced MR has smaller flow areas compared to chronic MR.
Abstract:
The pathoanatomy and factors associated with transient mitral regurgitation (MR) induced by myocardial ischemic stress are unknown. Changes in valvular and ventricular parameters during transient, stress-induced MR in patients with coronary artery disease were investigated, and the clinical characteristics of these patients were identified. Color flow Doppler echocardiography was used to quantify the MR color area, the coaptation point of the mitral leaflets, the mitral valve anulus diameter, and left ventricular volumes and wall motion in 42 patients before and immediately after exercise echocardiography (group 1, n = 27), or before and during percutaneous transluminal coronary angioplasty (PTCA) (group 2, n = 15). Of the 27 patients with exercise echocardiography, 4 developed new, transient MR (group 1B) and 9 had MR both at rest and during exercise (group 1C). Of the 15 patients with PTCA, 7 developed new MR (group 2B). New MR (groups 1B and 2B) was associated with more severe stress-induced ventricular dyskinesia (p less than 0.05) than was seen in patients with chronic MR (group 1C) or in patients without MR, and occurred predominantly in patients with left anterior descending or right coronary artery stenoses. Stress-induced MR was not associated with changes in blood pressure or in mitral valve anulus diameter, nor with the development of mitral valve prolapse. It was associated with apical displacement of the mitral leaflets in patients in group 1B and C (p less than 0.05). New MR flow areas were significantly smaller than those in patients with chronic MR (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)