Abstract
BackgroundTachycardiomyopathy or tachycardia-induced cardiomyopathy (TCM) has been known for decades as a reversible form of nonischemic cardiomyopathy. However, its mechanism and properties remain poorly understood. ObjectivesThe current study investigated endomyocardial biopsy samples from patients with TCM and compared them with samples from patients with dilated cardiomyopathy (DCM) and inflammatory cardiomyopathy (ICM). MethodsThe study included 189 patients with new-onset heart failure and severely reduced ejection fraction not caused by valvular or ischemic heart disease. Nineteen patients retrospectively fulfilled common criteria of TCM, 79 patients had a diagnosis of DCM, and 91 had a diagnosis of ICM. ResultsPatients with TCM, on the basis of clinical criteria, had stronger myocardial expression of major histocompatibility complex class II molecule and enhanced infiltration of CD68+ macrophages compared with patients with DCM. Furthermore, when compared with patients with ICM, the presence of T cells and macrophages was significantly reduced in TCM. Myocardial fibrosis was detected to a significantly lower degree in patients with TCM compared with patients with DCM and ICM. Electron microscopic examination revealed severe structural changes in patients with TCM. A disturbed distribution pattern of mitochondria was predominantly present in TCM. Quantitative assessment of myocyte morphology revealed significantly enhanced myocyte size compared with patients with ICM. Ribonucleic acid expression analysis identified changes in metabolic pathways among the patient groups. ConclusionsTCM is characterized by changes in cardiomyocyte and mitochondrial morphology accompanied by a macrophage-dominated cardiac inflammation. Thus, further prospective studies are warranted to characterize patients with TCM by endomyocardial biopsy more clearly.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
