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Concealed Conduction and Dual Pathway Physiology of the Atrioventricular Node
Author(s) -
LIU SHAOWEN,
OLSSON S. BERTIL,
YANG YANZONG,
HERTERVIG EVA,
KONGSTAD OLE,
YUAN SHIWEN
Publication year - 2004
Publication title -
journal of cardiovascular electrophysiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.193
H-Index - 138
eISSN - 1540-8167
pISSN - 1045-3873
DOI - 10.1046/j.1540-8167.2004.03301.x
Subject(s) - reentry , nodal , medicine , refractory period , nodal signaling , tachycardia , ablation , effective refractory period , cardiology , atrioventricular node , gastrulation , biochemistry , chemistry , embryonic stem cell , gene
Introduction: Both concealed conduction and dual pathway physiology are important electrophysiologic characteristics of the AV node. The interaction of AV nodal concealment and duality, however, is not clearly understood. Methods and Results: The properties of AV conduction curves in the presence and absence of a conditioning blocked impulse were prospectively studied during premature atrial stimulation in 20 patients with AV nodal reentrant tachycardia before and after slow pathway ablation and in 14 control patients. AV nodal duality in the control conduction curve in the absence of a conditioning impulse was observed in 19 (95%) of 20 patients with AV nodal reentrant tachycardia. However, AV nodal duality in the modulated conduction curve in the presence of a blocked impulse was only identified in 2 (10%) of 20 patients (2/20 vs 19/20, P < 0.0001). The modulated curve was characterized by a significantly longer AV nodal effective and functional refractory periods compared to the control curve (P < 0.0001) in both patients with and without AV nodal reentry and in AV nodal reentry patients after successful slow pathway ablation. The maximum AH interval (AH max ) of the modulated curve was significantly shorter than the control curve in both patients with (217 ± 74 ms vs 347 ± 55 ms, P < 0.0001) and without AV nodal reentry (178 ± 50 ms vs 214 ± 54 ms, P = 0.02). AH max of the control curve was significantly longer in AV nodal reentry patients than in controls (P < 0.0001). AH max of the modulated curve, however, was not significantly different between the two groups. After slow pathway ablation, AH max of the control curve was significantly reduced (347 ± 55 ms vs 191 ± 40 ms, P < 0.0001). Significant reduction in AH max of the modulated curve was not observed. Conclusion: An interaction of AV nodal concealed conduction and dual pathway physiology was demonstrated by our data. Slow pathway conduction of the AV node was prevented by the concealed beat in both patients with and without AV nodal reentry. (J Cardiovasc Electrophysiol, Vol. 15, pp. 144‐149, February 2004)