Lutembacher's syndrome: Is the mitral pathology always rheumatic?

Abstract

The mitral valve disease (MVD) in Lutembacher's syndrome has been infrequently analyzed from a pathological standpoint. In this study, we have attempted to elucidate the pathology of MVD in this interesting syndrome in 44 autopsied cases of combined non-primum atrial septal defect (ASD) and MVD collected over 16 years. The patients were divided into 3 groups: Group 1: non-primum ASD with clinically diagnosed mitral stenosis (MS)±regurgitation, Group 2: non-primum ASD with clinically diagnosed mitral regurgitation (MR) and, Group 3: non-primum ASD with no clinically evident MVD, but with mitral valve pathology diagnosed at autopsy. All 44 patients were symptomatic. There were 26 males (59%). The ages ranged from 13 to 73 years. A history of rheumatic fever was available in 2 patients while 16 patients had undergone surgery or intervention for the disease. Of the 18 patients in Group 1, six patients did not show histological features of rheumatic heart disease, although they shared similar gross morphological features. Furthermore, the mitral regurgitation in 12 of 19 patients in Group 2 was non-rheumatic. Also, only one patient had histological evidence of rheumatic activity among seven cases in Group 3. In spite of a high rheumatic load at our center, more than half (54.5%) of patients had "non-rheumatic" mitral valve pathology. Thus, the mitral valvular lesions commonly labeled 'rheumatic' in Lutembacher's syndrome are not always so. The distinction into rheumatic and non-rheumatic MVD in non-primum ASD has to be made on the basis of microscopic criteria.

Keywords: Atrial septal defect; Lutembacher's syndrome; Mitral valve pathology; Rheumatic heart disease.

Fig. 1

(A) Opened out left ventricular inflow tract showing a patch P covering a large secundum atrial septal defect. There was rheumatic mitral stenosis with characteristic leaflet thickening, commissural fusion and accompanying sub-valvular chordal pathology and (B) a large secundum atrial septal defect with a non-rheumatic mitral valvular affliction. Note plastering (arrow) of the posterior leaflet PML to the underlying left ventricular LV endocardium. Both images show predominant involvement of valvular components at its postero-medial region (ALC, antero-lateral commissure; AML, anterior mitral leaflet; LA, left atrium; PMC, postero-medial commissure).