Abstract 15018: Idiopathic, Isolated, Fibrotic Atrial Cardiomyopathy: An Overlooked Type of Cardiomyopathy
Introduction Myocardium fibrosis is a hallmark of cardiomyopathy and a proposed substrate for cardiac arrhythmias. Nevertheless, fibrosis of atrial myocardium and fibrotic atrial cardiomyopathy has not been systemically addressed.
Hypothesis We hypothesized that idiopathic, isolated, fibrotic atrial cardiomyopathy (IIF-ACM) is a specific cardiomyopathy, which is characterized by atrial fibrosis and related arrhythmias.
Methods In the past 8 years, 34 patients (male 13, mean age 46.5±13.3 yrs) were diagnosed with IIF-ACM based on: 1) clinical evaluation; 2) cardiac image examination; and 3) electro-anatomic mapping detected atrial scarring. Serum biomarkers of collagen metabolism and cardiomyopathy-related genetic screening were performed. Tissue pathology and virus detections were done for two patients.
Results During clinical evaluation, electric silent areas were detected in all patients by intra-cardiac electro-anatomical mapping. Among 34 patients, 26 presented with atrial tachycardia (AT), 5 with sick sinus syndrome (SSS) and 3 with atrial standstill. 5 AT patients further developed SSS during the correction of AT by radiofrequency ablation. Late gadolinium-enhancement cardiovascular magnet resonance showed mild to severely dilated atria, without bilateral ventricular scarring or functional impairment. Serum biomarkers of collagen screening demonstrated significant increased collagen synthesis than collagen degradation in IIF-ACM patients. Cardiomyopathy-related genetic screening depicted no clinically relevant mutation. Histological studies showed global fibrosis of atria (Fig. 1).
Conclusions We systemically reported 34 patients with IIF-ACM, which is characterized by atrial scarring and relevant arrhythmias. Ventricular functions of note were preserved in all patients. However, the underlying etiology of IIF-ACM remains to be investigated.
Author Disclosures: M. Chen: None. W. Ju: None. D. Wang: None. M. Li: None. R. Qi: None. L. Tang: None. B. Yang: None. H. Chen: None. F. Zhang: None. J. Wang: None. H. Liu: None. C. Cui: None.
- © 2015 by American Heart Association, Inc.