Published online before print October 16, 2003, doi: 10.1161/01.RES.0000101913.95604.B9
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Submitted on August 5, 2003
Revised on September 30, 2003
Accepted on October 7, 2003
Site of Origin and Molecular Substrate of Atrioventricular Junctional Rhythm in the Rabbit Heart
Halina Dobrzynski ;
From the Department of Biomedical Engineering (H.D., V.P.N., A.T.S., I.R.E.), Case Western Reserve University, Cleveland, Ohio; School of Biomedical Sciences (H.D., I.D.G., M.Y., M.R.B.), University of Leeds, Leeds, UK.
* To whom correspondence should be addressed. E-mail: ire{at}case.edu.
During failure of the sinoatrial node, the heart can be driven by an atrioventricular (AV) junctional pacemaker. The position of the leading pacemaker site during AV junctional rhythm is debated. In this study, we present evidence from high-resolution fluorescent imaging of electrical activity in rabbit isolated atrioventricular node (AVN) preparations that, in the majority of cases (11 out of 14), the AV junctional rhythm originates in the region extending from the AVN toward the coronary sinus along the tricuspid valve (posterior nodal extension, PNE). Histological and immunohistochemical investigation showed that the PNE has the same morphology and unique pattern of expression of neurofilament160 (NF160) and connexins (Cx40, Cx43, and Cx45) as the AVN itself. Block of the pacemaker current, If, by 2 mmol/L Cs+ increased the AV junctional rhythm cycle length from 611±84 to 949±120 ms (mean±SD, n=6, P<0.001). Immunohistochemical investigation showed that the principal If channel protein, HCN4, is abundant in the PNE. As well as the AV junctional rhythm, the PNE described in this study may also be involved in the slow pathway of conduction into the AVN as well as AVN reentry, and the predominant lack of expression of Cx43 as well as the presence of Cx45 in the PNE shown could help explain its slow conduction.
Key words: ablation • electrophysiology • surgery • arrhythmia • imaging
This article has been cited by other articles:
 |
|
 |
|
  M. E. Mangoni and J. Nargeot Genesis and Regulation of the Heart Automaticity Physiol Rev, July 1, 2008; 88(3): 919 - 982. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. Li, I. D. Greener, S. Inada, V. P. Nikolski, M. Yamamoto, J. C. Hancox, H. Zhang, R. Billeter, I. R. Efimov, H. Dobrzynski, et al. Computer Three-Dimensional Reconstruction of the Atrioventricular Node Circ. Res., April 25, 2008; 102(8): 975 - 985. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Q. Zhang, V. Timofeyev, L. Lu, N. Li, A. Singapuri, M. K. Long, C. T. Bond, J. P. Adelman, and N. Chiamvimonvat Functional Roles of a Ca2+-Activated K+ Channel in Atrioventricular Nodes Circ. Res., February 29, 2008; 102(4): 465 - 471. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 W. J. Hucker, V. Sharma, V. P. Nikolski, and I. R. Efimov Atrioventricular conduction with and without AV nodal delay: two pathways to the bundle of His in the rabbit heart Am J Physiol Heart Circ Physiol, August 1, 2007; 293(2): H1122 - H1130. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. Gill, J. Veinot, M. Kavanagh, and O. Pulido Human Heart Glutamate Receptors--Implications for Toxicology, Food Safety, and Drug Discovery Toxicol Pathol, April 1, 2007; 35(3): 411 - 417. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. Liu, H. Dobrzynski, J. Yanni, M. R. Boyett, and M. Lei Organisation of the mouse sinoatrial node: structure and expression of HCN channels Cardiovasc Res, March 1, 2007; 73(4): 729 - 738. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Yamamoto, H. Dobrzynski, J. Tellez, R. Niwa, R. Billeter, H. Honjo, I. Kodama, and M. R. Boyett Extended atrial conduction system characterised by the expression of the HCN4 channel and connexin45 Cardiovasc Res, November 1, 2006; 72(2): 271 - 281. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. Yoo, H. Dobrzynski, V. V. Fedorov, S.-Z. Xu, T. T. Yamanushi, S. A. Jones, M. Yamamoto, V. P. Nikolski, I. R. Efimov, and M. R. Boyett Localization of Na+ Channel Isoforms at the Atrioventricular Junction and Atrioventricular Node in the Rat Circulation, September 26, 2006; 114(13): 1360 - 1371. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. M. Kreuzberg, J. W. Schrickel, A. Ghanem, J.-S. Kim, J. Degen, U. Janssen-Bienhold, T. Lewalter, K. Tiemann, and K. Willecke Connexin30.2 containing gap junction channels decelerate impulse propagation through the atrioventricular node PNAS, April 11, 2006; 103(15): 5959 - 5964. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. Dobrzynski, J. Li, J. Tellez, I.D. Greener, V.P. Nikolski, S.E. Wright, S.H. Parson, S.A. Jones, M.K. Lancaster, M. Yamamoto, et al. Computer Three-Dimensional Reconstruction of the Sinoatrial Node Circulation, February 22, 2005; 111(7): 846 - 854. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
F. Rothenberg, V. P. Nikolski, M. Watanabe, and I. R. Efimov Electrophysiology and anatomy of embryonic rabbit hearts before and after septation Am J Physiol Heart Circ Physiol, January 1, 2005; 288(1): H344 - H351. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
I. R. Efimov, V. P. Nikolski, and G. Salama Optical Imaging of the Heart Circ. Res., July 9, 2004; 95(1): 21 - 33. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. L. Wit Atrioventricular Nodal Electrophysiology: Still Exciting After All These Years Circ. Res., November 28, 2003; 93(11): 1018 - 1019. [Full Text] [PDF]
|
|