Tailored cardioneuroablation for recurrent reflex syncope due to paroxysmal atrioventricular block: Utility of extracardiac vagal stimulation

Figures

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  Figure 1. Asystole recorded during a 24-hour Holter ECG. At the onset of the tracing, a 2:1 atrioventricular block is evident, followed by an episode of asystole lasting 6.2 seconds owing to the occurrence of a complete atrioventricular block. Red boxes indicate P waves. Progressive shortening of P-P CL is noted owing to a compensatory increase in sinus rate. CL = cycle length; ECG = electrocardiogram.

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  Figure 2. Electroanatomic mapping of the left atrium, right atrium, and proximal coronary sinus. Green dots indicate the course of the phrenic nerve, yellow dot indicates the location of the His potential, white dots indicate the pulmonary vein antra and the inferior vena cava, and purple dots indicate the sweet spots for the ablation of the superior (SPSGP) and inferior paraseptal ganglionated plexi (IPSGP). The expected location of GPs is marked by red arrows. The final lesion set is displayed with pink dots. Anteroposterior view (A). Posteroanterior view (B). GP = ganglionated plexus.

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  Figure 3. Catheter location for extracardiac vagal stimulation according to the ultrasound- and the fluoroscopy-guided approach. A: Fluoroscopic image showing stimulation catheters placed under the skull base near the jugular foramen, with a posteromedial bend. B: Ultrasound image showing the vagus nerve located between the common carotid artery and the internal jugular vein (yellow circle) and decapolar catheter positioned in close proximity to the nerve. C: Fluoroscopic image showing the location of the stimulation catheters with the ultrasound guidance (right jugular vein) and the fluoroscopy guidance (left jugular vein).

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  Figure 4. Vagal response after left-sided extracardiac vagal stimulation guided by fluoroscopy. Occurrence of atrioventricular block lasting 7 seconds, induced by left extracardiac vagal stimulation performed during coronary sinus pacing. The pacing stimulus, denoted by “S,” is delivered from the CS 9–10 electrode pair. Yellow boxes indicate P waves and the corresponding atrial activation pattern recorded in the CS catheter, whereas orange boxes mark the QRS complexes and the associated ventricular activation far field in the CS electrograms. Orange dashed boxes highlight the absence of ventricular activation. CS = coronary sinus.

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  Supplemental Figure 1.

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  Supplemental Figure 2.