Significance of papillary muscle function of the mitral valve and adjacent left ventricular segments in the progression of ischemic mitral regurgitation in patients with coronary heart disease after surgical treatment

Aim. To determine the significance of papillary muscle (PM) dysfunction of the mitral valve (MV) and adjacent left ventricular (LV) segments in the genesis of ischemic mitral regurgitation (MR) by myocardial tissue Doppler (MTD) in patients with coronary heart disease (CHD) after surgical treatment. Subjects and methods. One hundred and one CHD patients with moderate (grade I—II) MR were examined before surgical treatment. For analysis, the patients were divided into 4 groups: 1A) 40 patients without progressive, none or moderate MR after isolated aortocoronary bypass surgery (ACBS); 1B) 17 patients with progressive MR to its clinically relevant degree after isolated ACBS; 2A) 30 patients without progressive, none, or moderate MR after ACBS and surgical repair of postinfarction LV aneurysm; 2B) 14 patents with progressive MR to its clinically relevant degree after ACBS and surgical LV repair. The mean follow-up after surgery was 5.35±0.58 years. Results. MTD analysis of the PM function of the MV and adjacent LV segments in the patients with CHD after surgical treatment indicated that those with progressive MR had 1) a decrease in the contractility of both PMs and adjacent LV segments; 2) a restrictive pattern of segmental diastolic dysfunction caused by the high myocardial rigidity of both PMs and adjacent LV segments; 3) an inverse correlation of the posterior PM systolic velocity S with the severity of MR, which is suggestive of the clinically important contribution of posterior PM contractility to the development of MR. There were correlations indicating that the high LV and PM rigidities leading to the restrictive pattern of myocardial diastolic impairments are involved in the development of MR in the patients with CHD. Conclusion. The results confirm that PM and adjacent LV segment dysfunctions are of significance in the mechanisms of progressive ischemic MR in the patients with CHD after surgical treatment.

ischemic mitral regurgitation, progressive mitral regurgitation, aortocoronary bypass surgery, surgical left ventricular repair, mitral valve papillary muscle function, myocardial tissue Doppler