Purkinje trigger mapping in postinfarction ventricular fibrillation storm with ventricular abnormal activities detection

Figures

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  Figure 1. 12-lead electrocardiogram during sinus rhythm showing the culprit PVC that consistently triggered VF. The PVC exhibits a complete right bundle branch block morphology and superior axis deviation (red arrows), consistent with an origin from the inferior septal left ventricular Purkinje network. After ablation, neither the PR interval nor the QRS axis changed. Calibration: 1 mV vertical and 200 ms horizontal. PVC = premature ventricular contraction.

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  Figure 2. Electroanatomic maps of the left ventricle in sinus rhythm. Left: Voltage map illustrating an extensive low-voltage scar (<0.5 mV) from the inferior wall to the apex. Right: VAAD map created with the EML algorithm at a 30% lower threshold, revealing slow conduction zones (white) within the scar. The culprit Purkinje network (white arrow) and the earliest activation site of the triggered PVC (yellow arrow) are highlighted. The color bar indicates LAT in ms. EML = early meets late; LAT = local activation time; LV = left ventricular; PVC = premature ventricular contraction; VAAD = ventricular abnormal activities detection.

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  Figure 3. Left: Activation map during the culprit PVC showing the earliest activation site (white circle) in the inferoseptal LV, colocalized with Purkinje potentials. Right: Intracardiac electrograms from this site demonstrate a short stimulus-to-QRS latency (28 ms) during pace mapping, reproducing the clinical PVC morphology, and mid-diastolic Purkinje potentials (arrows) immediately preceding VF onset. The subsequent pacing shown after VF onset represents programmed pace map pacing that continued inadvertently because VF occurred unexpectedly during the pacing protocol. These findings implicate the Purkinje network in both triggering and maintaining VF. LV = left ventricular; PVC = premature ventricular contraction; VF = ventricular fibrillation.

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  Figure 4. Intraprocedural electrogram recordings during ablation at the PVC origin. Radiofrequency delivery induced VF (red arrow), which spontaneously terminated after 7.7 seconds (green arrow) without external defibrillation. Lower left: Zoomed-in tracing shows mid-diastolic Purkinje potentials (arrows) recorded at the ablation site during VF. Lower right: Subsequent zoomed-in view demonstrates disappearance of these Purkinje potentials during ablation, coinciding with VF termination. After this, linear lesions were applied to complete Purkinje denetworking, after which VF was no longer inducible. VF = ventricular fibrillation.