This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Boineau, J. P. Articles by Brockus, C. W. Search for Related Content PubMed PubMed Citation Articles by Boineau, J. P. Articles by Brockus, C. W.

Circulation, Vol 58, 1036-1048, Copyright © 1978 by American Heart Association

ARTICLES

Multicentric origin of the atrial depolarization wave: the pacemaker complex. Relation to dynamics of atrial conduction, P-wave changes and heart rate control

JP Boineau, RB Schuessler, CR Mooney, AC Wylds, CB Miller, RD Hudson, JM Borremans and CW Brockus

In studies to ascertain the basis of dynamic changes in the P wave, bipolar epicardial potentials were recorded from multiple atrial electrodes in dogs. One hundred to 120 activation times were displayed by a digital computer and used to construct atrial isotemporal activation sequence maps. Changes in heart rate or beat-to-beat cycle length were induced by vagal stimulation or infusion of autonomic mediating drugs. Changes in cycle length were associated with dynamic changes in the atrial activation sequence and surface P-wave. A conspicuous finding was that epicardial atrial depolarization began at three widely separated locations. These three points were consistently present in all animals and were generally located at the 12, 3, and 6 o'clock positions of the superior vena cava-right atrial junction. The dynamic changes in P waves and atrial activation sequence which accompanied the changes in cycle length were due to sudden shifts in the point of earliest activity between the three early sites. Asymmetric atrial depolarization with more rapid conduction along the crista terminalis, superior interatrial band, and pectinate muscles was present in all dogs. Although the anisotropic atrial geometry played an important role in the asymmetric conduction, the widely distributed onset of activity contributed significantly to the uneven spread. The multiple points of origin of the atrial wavefront might be explained by either a trifocal, distributed pacemaker or the epicardial exits of three specialized pathways conducting an impulse emanating from a single focus. These data explain the dynamic variation in P-wave morphology in normal hearts and also imply a relationship between the altered origin of atrial depolarization, atypical P waves, brady- or tachyarrhythmias, and heart rate control.

This article has been cited by other articles:

				V. V. Fedorov, R. B. Schuessler, M. Hemphill, C. M. Ambrosi, R. Chang, A. S. Voloshina, K. Brown, W. J. Hucker, and I. R. Efimov Structural and Functional Evidence for Discrete Exit Pathways That Connect the Canine Sinoatrial Node and Atria Circ. Res., April 10, 2009; 104(7): 915 - 923. [Abstract] [Full Text] [PDF]

				D Sanchez-Quintana, J A Cabrera, J Farre, V Climent, R H Anderson, and S Y Ho Sinus node revisited in the era of electroanatomical mapping and catheter ablation Heart, February 1, 2005; 91(2): 189 - 194. [Abstract] [Full Text] [PDF]

				W. Singer, W.-K. Shen, T. L. Opfer-Gehrking, B. R. McPhee, M. J. Hilz, and P. A. Low Evidence of an Intrinsic Sinus Node Abnormality in Patients With Postural Tachycardia Syndrome Mayo Clin. Proc., March 1, 2002; 77(3): 246 - 252. [Abstract] [PDF]

				M.R. Boyett, H. Honjo, and I. Kodama The sinoatrial node, a heterogeneous pacemaker structure Cardiovasc Res, September 1, 2000; 47(4): 658 - 687. [Abstract] [Full Text] [PDF]

				Y. Furukawa, Y. Miyashita, K. Nakajima, M. Hirose, F. Kurogouchi, and S. Chiba Effects of Verapamil, Zatebradine, and E-4031 on the Pacemaker Location and Rate in Response to Sympathetic Stimulation in Dog Hearts J. Pharmacol. Exp. Ther., June 1, 1999; 289(3): 1334 - 1342. [Abstract] [Full Text]

				J. M. Kalman, R. J. Lee, W. G. Fisher, M. C. Chin, P. Ursell, C. A. Stillson, M. D. Lesh, and M. M. Scheinman Radiofrequency Catheter Modification of Sinus Pacemaker Function Guided by Intracardiac Echocardiography Circulation, November 15, 1995; 92(10): 3070 - 3081. [Abstract] [Full Text]

				S. L. Beau, D. E. Hand, R. B. Schuessler, B. I. Bromberg, B. Kwon, J. P. Boineau, and J. E. Saffitz Relative Densities of Muscarinic Cholinergic and ß-Adrenergic Receptors in the Canine Sinoatrial Node and Their Relation to Sites of Pacemaker Activity Circ. Res., November 1, 1995; 77(5): 957 - 963. [Abstract] [Full Text]