Histological findings in sinus rhythm and atrial fibrillation
In order to further evaluate the impact of atrial fibrillation or tachycardia itself on endomyocardial biopsy findings, we compared patients in atrial fibrillation (n = 112) on admission and those in sinus rhythm (n = 553), irrespective of their admission heart rate. In this comparison, we were not able to demonstrate any significant difference between patients in sinus rhythm and those in atrial fibrillation with respect to CD 3 positive cells (0.84 ± 0.86 versus 0.82 ± 0.76 cells in HPF; p = 0.88), CD 68 positive cells (0.93 ± 0.72 versus 0.97 ± 0.75 cells in HPF; p = 0.58), MHC II (55.7 % versus 60.4 % positive biopsies; p = 0.75), fibrosis score (2.0 ± 1.2 versus 2.2 ± 1.2; p = 0.14), and cleaved caspase 3 (46 ± 16 % versus 45 ± 16 %; p = 0.46) – Figure 4.
Figure 4:Immunohistochemical findings in patients with sinus rhythm versus atrial fibrillation
(A) CD3+ T cells and CD68+macrophages, (B) immunohistological score of myocardial fibrosis (trichrome staining), (C) MHC-II (anti–major histocompatibility complex class II) expression, and (D) anti–cleaved caspase 3 are compared in myocardial biopsy samples from patients with tachycardia-induced cardiomyopathy (TCM), inflammatory cardiomyopathy (ICM), and dilated cardiomyopathy (DCM).
ns: not significant compared to TCM