Outcomes in patients with dual antegrade conduction in the atrioventricular node: insights from a multicentre observational study

Figures

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  Fig. 1. Schematic and anatomical depiction of a dual antegrade conduction in the AV node. a The schematic drawing of the conduction system (yellow) of the heart depicts the dual AV nodal physiology, which is a prerequisite for dual antegrade conduction in the AV node. The green marker highlights conduction via the fast pathway, the red marker illustrates conduction via the slow pathway. b A 12-lead electrocardiogram of a dual AV nodal non-re-entrant tachycardia (DAVNNT) is presented. Note the single P wave followed by two QRS complexes. c An exemplary tracing of intracardiac electrograms during an electrophysiological study of a patient with DAVNNT is depicted. Catheters have been placed at the high right atrium (HRA), the His bundle (HIS) and the right ventricular apex (RVA). One atrial signal is followed by two ventricular responses as seen in the HRA, HIS and RVA catheters

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  Fig. 2. Induction of double ventricular response and AVNRT in the same patient. Intracardiac electrograms with catheters placed at the His bundle (HIS), the coronary sinus (CS) and the right ventricular apex (RVA) are presented. The green marker highlights conduction via the fast pathway, the red marker illustrates conduction via the slow pathway. Under baseline conditions, VA-dissociation, a functional dissociation of conduction within the AV node and spontaneous dual antegrade conduction in the AV node could be demonstrated. After administration of orciprenaline VA-conduction was present with a retrograde Wenckebach cycle length of 320 ms. Subsequently, double ventricular response and a typical AVNRT were inducible by programmed atrial stimulation. Diagnosis of typical AVNRT was confirmed by ventricular overdrive pacing with an AH response, short septal VA interval and negative preceding manoeuvre. a At baseline conditions programmed atrial stimulation via a proximal CS electrode (S1: 550 ms, S2: 450 ms) results in a double ventricular response with an A1H1V1H2V2 sequence. b After administration of orciprenaline programmed atrial stimulation (S1: 510 ms, S2: 440 ms) induces an AVNRT…

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  Fig. 3. Modulation of the autonomic nervous system induces intermittent conduction via either the slow or the fast pathway or dual antegrade conduction. The red arrows indicate the slow pathway conduction. The green arrows indicate the fast pathway conduction. a, c A 12-lead ECG and b, d the corresponding intracardiac electrograms—from three bipolar catheters placed in the high right atrium (HRA), the right ventricular apex (RVA) and the His-bundle (HIS). a/b In a patient with DAVNNT and tachycardia-induced cardiomyopathy a period of sole antegrade conduction via the slow pathway is presented. c/d After intravenous administration of orciprenaline, sole fast-pathway conduction occurred. The latter was not induced by administration of atropine. Shortly afterwards a continuous change of dual antegrade conduction, sole slow-pathway and sole fast pathway conduction was observed. Note the great difference of the conduction times of the slow and fast pathway, which is thought to be a prerequisite in patients with dual antegrade conduction