Differentiation of Atrioventricular Nodal Reentrant Tachycardia from Orthodromic Reciprocating Tachycardia by the Resetting Response to Ventricular Extrastimuli: Comparison to Response to Continuous Ventricular Pacing

Back to Basics: The Value of Simple Diagnostic Maneuvers in Diagnosing Supraventricular Tachycardias

“…The results of the paper by Garcia‐Fernández et al . in this issue of the Journal suggest that yes, another diagnostic test is useful.…”

Unexpectedly short postpacing interval in a left free wall accessory pathway mediated tachycardia: A pitfall of the corrected postpacing interval algorithm?

“…The basis of the analysis is the subtraction of the tachycardia cycle length (TCL) from the postpacing interval (PPI) measured at the pacing site, so called “PPI-TCL”, as first described for the differential diagnosis between AV nodal reentrant tachycardias (AVNRT) and tachycardias using a septal accessory pathways (AP) [1] . Further refinements of the maneuver included a correction for the rate-related increase in AV node delay (subtraction of the AH interval during tachycardia from the AH interval resulting from the last paced beat, the “corrected PPI-TCL”) [2] , the use of single premature extrastimuli resulting in resetting [3] or a simplification of the maneuver by just subtracting the ventriculoatrial interval during tachycardia (VA interval) from stimulus to atrial interval during entrainment (SA interval), leading to the “SA-VA” value [1] , [4] . Shorter intervals of all these measurements are found in tachycardias mediated by AP as compared to AVNRT because the ventricles are part of the circuit in the former [1] , [2] , [3] , [4] .…”

“…Further refinements of the maneuver included a correction for the rate-related increase in AV node delay (subtraction of the AH interval during tachycardia from the AH interval resulting from the last paced beat, the “corrected PPI-TCL”) [2] , the use of single premature extrastimuli resulting in resetting [3] or a simplification of the maneuver by just subtracting the ventriculoatrial interval during tachycardia (VA interval) from stimulus to atrial interval during entrainment (SA interval), leading to the “SA-VA” value [1] , [4] . Shorter intervals of all these measurements are found in tachycardias mediated by AP as compared to AVNRT because the ventricles are part of the circuit in the former [1] , [2] , [3] , [4] . However, within AP mediated tachycardias, those using septal pathways have shorter intervals as compared to tachycardias mediated by left free-wall AP [2] , [3] , [4] .…”

Differential Responses of the Septal Ventricle and the Atrial Signals During Ongoing Entrainment

“…If there was some irregularity in the tachycardia cycle length (here defined as beat-to-beat variability exceeding 15 ms), any advancement of the atrial or the ventricular signals was measured considering the shortest tachycardia cycle length as a reference. 5 For appropriate timing at the bipolar records, we consistently selected for measurement the point at which the largest rapid deflection crosses the baseline or the peak of the largest deflection because they more or less correspond with the maximum dV/ dt (intrisicoid deflection) of the unipolar records. 10 If the signal was fragmented (multicomponent electrogram), and no clear deflection behaved as the largest, we selected the peak of the first positive deflection of the electrogram for timing.…”

“…5 In these instances, the utility of RVA pacing during tachycardia at the beginning of the entrainment attempt has received less attention as a diagnostic technique. Recently, AlMahameed et al elegantly © 2015 American Heart Association, Inc. ).…”