Prolongation of Atrial Effective Refractory Period with Biatrial Nonexcitatory Stimulation

2005 ◽  
Vol 16 (8) ◽  
pp. 853-857 ◽  
Author(s):  
JOSEPH Y.S. CHAN ◽  
JEFFERY W.H. FUNG ◽  
HAMISH C.K. CHAN ◽  
WINNIE W.L. CHAN ◽  
CHEUK MAN YU ◽  
...  
2017 ◽  
Vol 18 (3) ◽  
pp. 147032031772928 ◽  
Author(s):  
Wenfeng Shangguan ◽  
Wen Shi ◽  
Guangping Li ◽  
Yuanyuan Wang ◽  
Jian Li ◽  
...  

Introduction: The effect of Angiotensin-(1–7) (Ang-(1–7)) on atrial autonomic remodeling is still unknown. We hypothesized that Ang-(1–7) could inhibit sympathetic nerve remodeling in a canine model of chronic atrial tachycardia. Materials and methods: Eighteen dogs were randomly assigned to sham group, pacing group and Ang-(1–7) group. Rapid atrial pacing was maintained for 14 days in the pacing and Ang-(1–7) groups. Ang-(1–7) was administered intravenously in the Ang-(1–7) group. The atrial effective refractory period and atrial fibrillation inducibility level were measured at baseline and under sympathetic nerve stimulation after 14 days of measurement. The atrial sympathetic nerves labeled with tyrosine hydroxylase were detected using immunohistochemistry and Western blotting, and tyrosine hydroxylase and nerve growth factor mRNA levels were measured by reverse transcription polymerase chain reaction. Results: Pacing shortened the atrial effective refractory period and increased the atrial fibrillation inducibility level at baseline and under sympathetic nerve stimulation. Ang-(1–7) treatment attenuated the shortening of the atrial effective refractory period and the increase in the atrial fibrillation inducibility level. Immunohistochemistry and Western blotting showed sympathetic nerve hyperinnervation in the pacing group, while Ang-(1–7) attenuated sympathetic nerve proliferation. Ang-(1–7) alleviated the pacing-induced increases in tyrosine hydroxylase and nerve growth factor mRNA expression levels. Conclusion: Ang-(1–7) can attenuate pacing-induced atrial sympathetic hyperinnervation.


2001 ◽  
Vol 12 (1) ◽  
pp. 85-92 ◽  
Author(s):  
MARKUS ZARSE ◽  
CHRISTOPH STELLBRINK ◽  
EVANGELIA ATHANATOU ◽  
JENS ROBERT ◽  
ULRICH SCHOTTEN ◽  
...  

Author(s):  
Ryo Nishinarita ◽  
Shinichi Niwano ◽  
Hiroe Niwano ◽  
Hironori Nakamura ◽  
Daiki Saito ◽  
...  

Background Recent clinical trials have demonstrated the possible pleiotropic effects of SGLT2 (sodium–glucose cotransporter 2) inhibitors in clinical cardiovascular diseases. Atrial electrical and structural remodeling is important as an atrial fibrillation (AF) substrate. Methods and Results The present study assessed the effect of canagliflozin (CAN), an SGLT2 inhibitor, on atrial remodeling in a canine AF model. The study included 12 beagle dogs, with 10 receiving continuous rapid atrial pacing and 2 acting as the nonpacing group. The 10 dogs that received continuous rapid atrial pacing for 3 weeks were subdivided as follows: pacing control group (n=5) and pacing+CAN (3 mg/kg per day) group (n=5). The atrial effective refractory period, conduction velocity, and AF inducibility were evaluated weekly through atrial epicardial wires. After the protocol, atrial tissues were sampled for histological examination. The degree of reactive oxygen species expression was evaluated by dihydroethidium staining. The atrial effective refractory period reduction was smaller ( P =0.06) and the degree of conduction velocity decrease was smaller in the pacing+CAN group compared with the pacing control group ( P =0.009). The AF inducibility gradually increased in the pacing control group, but such an increase was suppressed in the pacing+CAN group ( P =0.011). The pacing control group exhibited interstitial fibrosis and enhanced oxidative stress, which were suppressed in the pacing+CAN group. Conclusions CAN and possibly other SGLT2 inhibitors might be useful for preventing AF and suppressing the promotion of atrial remodeling as an AF substrate.


1999 ◽  
Vol 84 (10) ◽  
pp. 1261-1264 ◽  
Author(s):  
Yasutaka Tanabe ◽  
Masaomi Chinushi ◽  
Kohji Taneda ◽  
Satoshi Fujita ◽  
Hidehiro Kasai ◽  
...  

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