Demonstration of Dual A-V Nodal Pathways in Patients with Paroxysmal Supraventricular Tachycardia

Abstract

SUMMARYElectrophysiological evidence suggestive of dual atrioventricular (A-V) nodal pathways is presented in two patients with normal P-R interval and reentrant paroxysmal supraventricular tachycardia (PSVT). His bundle recordings and atrial stimulation were used to obtain this electrophysiological evidence. Recently reported studies in man suggest that A-V nodal reentrance is a common mechanism of paroxysmal supraventricular tachycardia (PSVT) .6-8 A-V nodal reentrance implies either the presence of dual A-V nodal pathways or reentry by "reflection" in an area of depressed conduction.9' 10 The purpose of this report is to describe two patients with history of PSVT and normal P-R 549 by guest on May 7, 2018 http://circ.ahajournals.org/ Downloaded from

Electrophysiologic and pharmacologic characteristics of automatic ectopic atrial tachycardia.

“…These fibers were under abnormal conditions of external potassium and catecholamine stimulation and the situation may not be clinically applicable in the absence of myocardial infarction. In any event, the clinical electrophysiologic division into ectopic versus re-entry mechanisms is useful in that it F[CURLE 6. Graph of the response of a re-entry supraventricular tachYcardia to progressively more premature stimuli.…”

Cooling dynamics: a new predictor of long-term efficacy of atrioventricular nodal reentrant tachycardia cryoablation

“…The underlying electrophysiological mechanism is the presence of a dual atrioventricular (AV) node physiology, including a fast and a slow pathway [1], characterized by different refractory periods. Dual AV node physiology is a frequent finding, being described in up to 90% of patients in a small case sample of heavily sedated patients undergoing electrophysiological study (EPS) [2], but does not always imply an AVNRT.…”

Electrophysiologic mechanisms for modification and abolition of atrioventricular junctional tachycardia with simultaneous and sequential atrial and ventricular pacing.

“…The coupling intervals (A1A2 or V1V2) were progressively shortened until refractoriness of the atrium or ventricle occurred. The functional properties of the AV conduction system and initiation of PSVT were studied in all patients using different protocols of cardiac stimulation, which we numerically designated as methods [1][2][3][4][5][6] as follows: 1) Premature stimulation from atrium (A2) with the basic cycle length (BCL) consisting of atrial pacing alone.…”

“…The ability to induce PSVT in patients [4][5][6] with both methods 1 and 2 when comparable ant SH delays were achieved indicates that effect of method 2 on ret AV nodal pathways was not sufficient to prevent PSVT. Also, direct comparison of ret AV nodal conduction times (H2-A2 intervals) with methods 5 and 6 showed that simultaneous AV stimulation did not significantly affect the H,A2 intervals except in patient 1.…”

“…The ant and ret conduction characteristics during PSVT in these *I1 patient 7 the PSVT was inducible with incremental atrial pacing. 1444 CIRCULATION 4 After control studies with the conventional technique of atrial premature stimulation (i.e., method 1), the initiation of PSVT was attempted with method 2 and the entire cycle length was scanned with progressively shorter A1A2 intervals. In patients 1 and 2 (table 1), the PSVT zone was completely abolished with method 2 (fig.…”