Mechanisms of sinoatrial node dysfunction in a canine model of pacing-induced atrial fibrillation.

Heart Rhythm : the Official Journal of the Heart Rhythm Society
Boyoung JoungMithilesh Kumar Das

Abstract

The mechanism of sinoatrial node (SAN) dysfunction in atrial fibrillation (AF) is unclear. The purpose of this study was to test the hypothesis that defective spontaneous sarcoplasmic reticulum (SR) Ca(2+) release (Ca(2+) clock) is in part responsible for SAN dysfunction in AF. Arrhythmic events and SAN function were evaluated in pacing-induced AF dogs (n = 7) and in normal dogs (n = 19) with simultaneous intracellular calcium (Ca(i)) and membrane potential recording. AF dogs had frequent sinus pauses during Holter monitoring. Isolated right atrium (RA) from AF dogs showed slower heart rate (P = .001), longer SAN recovery time (P = .001), and longer sinoatrial conduction time (P = .003) than normal. In normal RAs, isoproterenol 0.3 and 1 mumol/L increased heart rate by 96% and 105%, respectively. In contrast, in RAs from AF dogs, isoproterenol increased heart rate by only 60% and 72%, respectively. Isoproterenol induced late diastolic Ca(i) elevation (LDCAE) at superior SAN in all 19 normal RAs but in only 3 of 7 AF RAs (P = .002). In AF RAs without LDCAE (n = 4), heart rate increased by the acceleration of ectopic foci. Caffeine (20 mmol/L) injection increased heart rate with LDCAE in all 6 normal RAs but did not result in LDC...Continue Reading

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Citations

Dec 19, 2009·Circulation Journal : Official Journal of the Japanese Circulation Society·Peng-Sheng ChenShien-Fong Lin
May 16, 2014·Archives of Medical Research·Jun ZhaoGuangping Li
Aug 21, 2015·Circulation Journal : Official Journal of the Japanese Circulation Society·Jin-Kyu ParkBoyoung Joung
Feb 11, 2015·Journal of Molecular and Cellular Cardiology·O Monfredi, M R Boyett
Sep 8, 2011·Journal of Cardiovascular Electrophysiology·Siva K MulpuruSanjiv M Narayan
May 20, 2014·Circulation Journal : Official Journal of the Japanese Circulation Society·Gwilym M Morris, Jonathan M Kalman
May 30, 2015·Korean Circulation Journal·Boyoung Joung, Peng-Sheng Chen
Feb 15, 2011·Yonsei Medical Journal·Boyoung JoungShien-Fong Lin
Jun 9, 2017·The Korean Journal of Thoracic and Cardiovascular Surgery·Chang-Seok JeonPyo Won Park
Apr 26, 2018·European Journal of Preventive Cardiology·Edoardo CasigliaPaolo Palatini
May 12, 2016·Circulation·Roy M John, Saurabh Kumar
Nov 26, 2010·Current Opinion in Cardiology·Dennis H LauPrashanthan Sanders
Jul 24, 2021·Progress in Biophysics and Molecular Biology·Delphine Mika, Rodolphe Fischmeister
Aug 12, 2021·Journal of Cardiovascular Electrophysiology·Pil-Sung YangBoyoung Joung
Feb 5, 2010·Heart Rhythm : the Official Journal of the Heart Rhythm Society·Victor A Maltsev, Edward G Lakatta
Jan 1, 2011·Current Opinion in Cardiology

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