Vasovagal syncope with isolated atrioventricular block following cardioneuroablation demonstrating distinct innervation of the sinus and atrioventricular nodes

Figures

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  Figure 1. Baseline electrocardiogram (ECG) and syncope episode. A: ECG with sinus rate 58 bpm and PR interval of 207 ms. B: Heart rate (HR) plot from implantable loop recorder during a syncopal episode. C: Implantable loop recorder ECG tracing during syncope, with sinus slowing, sinus arrest, and few nonconducted P waves (red asterisks) showing vagal effects on both the sinus and atrioventricular nodes.

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  Figure 2. Cardioneuroablation procedure. A: Biatrial map from the index cardioneuroablation showing the ablation lesion tags (red tags), fragmented atrial bipolar electrograms (EGMs) (purple tags; inset: with atrial EGM), and sites with vagal response during radiofrequency (RF) ablation (blue tags; inset: ECG of vagal episode). B: Biatrial map from the redo ablation targeting the posteromedial ganglionated plexus (PMGP) and showing the ablation lesions (red tags), fragmented atrial bipolar EGMs (purple tags), His-bundle EGM locations (yellow tags), and areas with PR prolongation or transient atrioventricular (AV) block with RF application (black tags; inset of with AV block). Ao-SVC GP = aortic–superior vena cava ganglionated plexus; CS = coronary sinus; LA = left atrium; LAO = left anterior oblique; LIGP = left inferior ganglionated plexus; LSGP = left superior ganglionated plexus; MTGP = Marshall tract ganglionated plexus; PA = posteroanterior; RA = right atrium; RAO = right anterior oblique; RIGP = right inferior ganglionated plexus; RSGP = right superior ganglionated plexus.

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  Figure 3. Implantable loop recorder episodes. A: Implantable loop recorder heart rate plot and electrocardiographic tracing showing 11 seconds of atrioventricular (AV) block. B: Postablation prodromal episode without bradycardia. C: Time plots of average heart rate, patient activity, and heart rate variability with markers showing the time of the initial cardioneuroablation (CNA), recurrent syncope with isolated AV block, and redo cardioneuroablation targeting the posteromedial ganglionated plexus. Note the sustained increase in heart rate and sustained drop in heart rate variability after the initial ablation.