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Nodal recovery, dual pathway physiology, and concealed conduction determine complex AV dynamics in human atrial tachyarrhythmias.
Am J Physiol Heart Circ Physiol 2012; 303(10):H1219-28AJ

Abstract

The genesis of complex ventricular rhythms during atrial tachyarrhythmias in humans is not fully understood. To clarify the dynamics of atrioventricular (AV) conduction in response to a regular high-rate atrial activation, 29 episodes of spontaneous or pacing-induced atrial flutter (AFL), covering a wide range of atrial rates (cycle lengths from 145 to 270 ms), were analyzed in 10 patients. AV patterns were identified by applying firing sequence and surrogate data analysis to atrial and ventricular activation series, whereas modular simulation with a difference-equation AV node model was used to correlate the patterns with specific nodal properties. AV node response at high atrial rate was characterized by 1) AV patterns of decreasing conduction ratios at the shortening of atrial cycle length (from 236.3 ± 32.4 to 172.6 ± 17.8 ms) according to a Farey sequence ordering (conduction ratio from 0.34 ± 0.12 to 0.23 ± 0.06; P < 0.01); 2) the appearance of high-order alternating Wenckebach rhythms, such as 6:2, 10:2, and 12:2, associated with ventricular interval oscillations of large amplitude (407.7 ± 150.4 ms); and 3) the deterioration of pattern stability at advanced levels of block, with the percentage of stable patterns decreasing from 64.3 ± 35.2% to 28.3 ± 34.5% (P < 0.01). Simulations suggested these patterns to originate from the combined effect of nodal recovery, dual pathway physiology, and concealed conduction. These results indicate that intrinsic nodal properties may account for the wide spectrum of AV block patterns occurring during regular atrial tachyarrhythmias. The characterization of AV nodal function during different AFL forms constitutes an intermediate step toward the understanding of complex ventricular rhythms during atrial fibrillation.

Authors+Show Affiliations

Department of Physics and BioTech, University of Trento, Povo-Trento, Italy. mase@science.unitn.itNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

23001833

Citation

Masè, Michela, et al. "Nodal Recovery, Dual Pathway Physiology, and Concealed Conduction Determine Complex AV Dynamics in Human Atrial Tachyarrhythmias." American Journal of Physiology. Heart and Circulatory Physiology, vol. 303, no. 10, 2012, pp. H1219-28.
Masè M, Glass L, Disertori M, et al. Nodal recovery, dual pathway physiology, and concealed conduction determine complex AV dynamics in human atrial tachyarrhythmias. Am J Physiol Heart Circ Physiol. 2012;303(10):H1219-28.
Masè, M., Glass, L., Disertori, M., & Ravelli, F. (2012). Nodal recovery, dual pathway physiology, and concealed conduction determine complex AV dynamics in human atrial tachyarrhythmias. American Journal of Physiology. Heart and Circulatory Physiology, 303(10), pp. H1219-28. doi:10.1152/ajpheart.00228.2012.
Masè M, et al. Nodal Recovery, Dual Pathway Physiology, and Concealed Conduction Determine Complex AV Dynamics in Human Atrial Tachyarrhythmias. Am J Physiol Heart Circ Physiol. 2012 Nov 15;303(10):H1219-28. PubMed PMID: 23001833.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Nodal recovery, dual pathway physiology, and concealed conduction determine complex AV dynamics in human atrial tachyarrhythmias. AU - Masè,Michela, AU - Glass,Leon, AU - Disertori,Marcello, AU - Ravelli,Flavia, Y1 - 2012/09/21/ PY - 2012/9/25/entrez PY - 2012/9/25/pubmed PY - 2013/1/18/medline SP - H1219 EP - 28 JF - American journal of physiology. Heart and circulatory physiology JO - Am. J. Physiol. Heart Circ. Physiol. VL - 303 IS - 10 N2 - The genesis of complex ventricular rhythms during atrial tachyarrhythmias in humans is not fully understood. To clarify the dynamics of atrioventricular (AV) conduction in response to a regular high-rate atrial activation, 29 episodes of spontaneous or pacing-induced atrial flutter (AFL), covering a wide range of atrial rates (cycle lengths from 145 to 270 ms), were analyzed in 10 patients. AV patterns were identified by applying firing sequence and surrogate data analysis to atrial and ventricular activation series, whereas modular simulation with a difference-equation AV node model was used to correlate the patterns with specific nodal properties. AV node response at high atrial rate was characterized by 1) AV patterns of decreasing conduction ratios at the shortening of atrial cycle length (from 236.3 ± 32.4 to 172.6 ± 17.8 ms) according to a Farey sequence ordering (conduction ratio from 0.34 ± 0.12 to 0.23 ± 0.06; P < 0.01); 2) the appearance of high-order alternating Wenckebach rhythms, such as 6:2, 10:2, and 12:2, associated with ventricular interval oscillations of large amplitude (407.7 ± 150.4 ms); and 3) the deterioration of pattern stability at advanced levels of block, with the percentage of stable patterns decreasing from 64.3 ± 35.2% to 28.3 ± 34.5% (P < 0.01). Simulations suggested these patterns to originate from the combined effect of nodal recovery, dual pathway physiology, and concealed conduction. These results indicate that intrinsic nodal properties may account for the wide spectrum of AV block patterns occurring during regular atrial tachyarrhythmias. The characterization of AV nodal function during different AFL forms constitutes an intermediate step toward the understanding of complex ventricular rhythms during atrial fibrillation. SN - 1522-1539 UR - https://www.unboundmedicine.com/medline/citation/23001833/Nodal_recovery_dual_pathway_physiology_and_concealed_conduction_determine_complex_AV_dynamics_in_human_atrial_tachyarrhythmias_ L2 - http://www.physiology.org/doi/full/10.1152/ajpheart.00228.2012?url_ver=Z39.88-2003&amp;rfr_id=ori:rid:crossref.org&amp;rfr_dat=cr_pub=pubmed DB - PRIME DP - Unbound Medicine ER -