Interatrial conduction block–related atrioventricular dyssynchrony treated with dual-site atrial pacing

Figures

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  Figure 1. Electroanatomic map (left panel) and intracardiac electrograms (right panel) demonstrating 2 different atrial flutters: (1) flutter involving lateral right atrium (blue dashed box) with tachycardia cycle length of 330 ms (blue box; could not be mapped owing to termination/lack of reinduction); (2) flutter involving right atrial septum and left atrium (red dashed box) with tachycardia cycle length of 275 ms (red box).

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  Figure 2. Representative schematic (left panel) and intracardiac electrograms (right panel) illustrating electrical perturbations owing to interatrial conduction block, with hemodynamic consequences: (1) Atrial pacing leading to local capture but with no conduction to septum and AV nodal area; (2) Ventricular pacing resulting in ventricular capture and leading to retrograde conduction that activates the right atrial septum and left atrium (3). RA = right atrium.

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  Figure 3. A: Representative schematic (left) with intracardiac electrocardiograms (right) after dual-site atrial pacing: (1) dual-site pacing; (2) atrial resynchronization with synchronous right and left atrial activation and left atrial capture documented in coronary sinus (CS) / left atrium (LA) electrograms; (3) intact native ventricular conduction without ventricular pacing. B,C: Right anterior oblique and left anterior oblique fluoroscopic view (right) demonstrating high right atrial (red arrow) and low atrial septal (yellow arrow) pacemaker leads.

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  Supplemental Figure S1. Coronary sinus pacing (yellow stars) results in conduction to the ventricle (red boxes) but no conduction into the dissociated aspect of the right atrium where isolated potentials (blue boxes) are seen confirming ‘entrance block’.

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  Supplemental Figure S2. A- High right atrial pacing showing local atrial capture (blue box) followed by ventricular pacing and retrograde additional p-waves within T-waves (white box); B-Atrial septal pacing showing atrial capture (yellow box) followed by conducted QRS complexes (red arrows) with T-wave memory; C- Dual site atrial pacing showing subtle fusion between high right atrial and atrial septal pacing (red box) followed by conducted QRS complexes.

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  Supplemental Figure S3. A- Transesophageal echocardiography (left) demonstrating dual-site atrial pacemaker with high right atrial (red arrow) and low atrial septal (yellow arrow) leads; B- Picture of Y-connector connecting bi-atrial pacemaker leads.