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A Reappraisal of Atrioventricular Nodal Excitability During Functional 2:1 Block: What Should be the Gauge? *
Author(s) -
YOUNG MINGLON
Publication year - 1990
Publication title -
pacing and clinical electrophysiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.686
H-Index - 101
eISSN - 1540-8159
pISSN - 0147-8389
DOI - 10.1111/j.1540-8159.1990.tb06869.x
Subject(s) - nodal , medicine , refractory period , prolongation , impulse (physics) , atrioventricular node , cardiology , interval (graph theory) , effective refractory period , basal (medicine) , node (physics) , combinatorics , tachycardia , mathematics , physics , quantum mechanics , insulin
YOUNG, M.‐L.: A Reappraisal of Atrioventricular Nodal Excitability During Functional 2:1 Block: What Should be the Gauge? By using extrastimulation technique the effective refractory period (ERP) of the atrioventricular (AV) node is conventionally defined as the longest A 1 A 2 interval at which conduction of A 2 is blocked within the node. With the prolongation of the AV nodal transit time that is associated with this technique, the delayed AV nodal arrival of the A 1 impulse will cause an overestimation of the true interval if the A 1 A 2 interval is used as the gauge. Under this condition, the conventional approach will not accurately delineate the ERP of the AV node. However, this prolongation of the nodal transit time can be calculated by subtracting the basal conduction time from the conducted A‐H interval. By subtracting out the prolongation from the longest A 1 A 2 at which A 2 impulse is blocked, not only an interval more indicative of the true AV nodal ERP can be obtained, but also the apparent discrepancies between the in vitro and human AV nodal recovery curves disappear.