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What are Arrhythmogenic Substrates in Diabetic Rat Atria?
Author(s) -
KATO TAKESHI,
YAMASHITA TAKESHI,
SEKIGUCHI AKIKO,
SAGARA KOUICHI,
TAKAMURA MASAYUKI,
TAKATA SHIGEO,
KANEKO SHUICHI,
AIZAWA TADANORI,
FU LONGTAI
Publication year - 2006
Publication title -
journal of cardiovascular electrophysiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.193
H-Index - 138
eISSN - 1540-8167
pISSN - 1045-3873
DOI - 10.1111/j.1540-8167.2006.00528.x
Subject(s) - medicine , atrial fibrillation , diabetes mellitus , endocrinology , fibrosis , atrium (architecture) , cardiology , refractory period , electrophysiology , pathophysiology , nerve conduction velocity
Diabetes mellitus is one of the significant independent risk factors for the development of atrial fibrillation (AF). However, the pathophysiological mechanisms of the relationship have not been fully elucidated. Methods and Results: The genetic type II diabetes (GK) rats and their original (Wistar) ones were subjected to electrophysiological (n = 8 per group) and histological ( n = 7 per group) studies. At 40 weeks old, when GK rats had significantly (P < 0.01) more increased plasma glucose and HbA 1c values than Wistar rats, atrial electrical stimuli in the isolated‐perfused hearts induced significantly greater number of repetitive atrial responses in GK rats than in Wistar rats (47.9 ± 17.5 vs 3.1 ± 1.3 beats, respectively, P < 0.01) . GK rats showed significantly longer intra‐atrial activation time than Wistar rats (18.3 ± 0.4 ms vs 15.9 ± 0.5 ms, P < 0.01) without any significant difference in the atrial refractoriness. The histological examination revealed significantly increased diffuse fibrotic deposition in GK rats atria compared with Wistar ones (P < 0.01). Conclusion: The present diabetic GK rat showed increased atrial arrhythmogenicity with intra‐atrial conduction disturbance, and thus indicated that the structural remodeling of atrium characterized by diffuse interstitial fibrosis would be a major substrate for diabetes‐related AF.