Co-Author(s):
Saligrama Ramegowda Kalpana, MD
Deepak Padmanabhan, MD, DM
Manish K Rai, MD, DM
Ankit Singh, MD, DM
Bharatraj Banavalikar, MD, DM
Darshan Krishnappa, MD, DM
SRI JAYADEVA INSTITUTE OF CARDIOVASCULAR SCIENCES & RESEARCH
SRI JAYADEVA INSTTUTE OF CARDIOVASCULAR SCIENCES & RESEARCH
BANNERGHATTA MAIN ROAD, PHASE 3 9TH BLOCK, JAYANAGAR, BENGALURU- 560069
Introduction | Objectives: Atrial fibrillation and left atrial thrombus are less common in
isolated mitral regurgitation than mitral stenosis or mixed mitral valve
disease of rheumatic etiology. The histopathologic changes in patients
with and without atrial fibrillation in patients with isolated rheumatic
mitral regurgitation are unknown. We aimed to discern the differences in
histological findings in patients with severe rheumatic mitral
regurgitation with and without atrial fibrillation.
Methods: Patients with severe isolated rheumatic mitral regurgitation undergoing
valve replacement surgery underwent endocardial biopsy from right atrial
appendage (RAA), left atrial appendage (LAA), right atrial free wall
(RAFW), left atrial free wall (LAFW), left posterior wall (LPW) and
mitral valve. Group I consisted of patients in sinus rhythm and Group II
included patients with atrial fibrillation. We analyzed and compared
these samples between the two groups for myocyte hypertrophy,
interstitial and endocardial fibrosis, inflammatory cells, Aschoff
bodies, interstial adipose tissue, cellular vacuolation, and
iron/amyloid deposition.
Results: Of the 25 patients , 12 were in Group I and 13 in group II. Myocyte
hypertrophy was the most common histological finding and was more
prevalent in Group I (100% vs 92.3%, p=0.33). More severe myocyte
hypertrophy was seen in Group I (60% vs 18% showing severe
hypertrophy, p=0.04) and in right atrium (22.7% vs 11.4%, p=0.059).
Interstitial fibrosis was another common finding with near even
distribution at all sites and without significant difference between the
two groups. Prevalence and severity of vacuolar degeneration was higher
in Group II (91% vs 60% showing severe changes, p=0.09). Interstitial
adipose tissue deposition was more common in Group I (30% vs 25%,
p=0.06).
Conclusions: Patients with severe rheumatic mitral regurgitation and atrial
fibrillation have more vacuolar degeneration whereas myocyte hypertrophy
and interstitial adipose tissue deposition are more common in sinus
rhythm.