Intentional pneumothorax avoids collateral damage: Dynamic phrenic nerve mobilization through intrathoracic insufflation of carbon dioxide

Figures

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  Figure 1. A: Ventricular-overdrive pacing during clinical tachycardia with (1) V-A-A-V response and (2) distinct atrial activation sequences and P-wave morphologies between clinical tachycardia and pacing. B: Activation mapping during clinical tachycardia with (1) white outline denoting earliest activation, (2) purple tags denoting locations of phrenic nerve capture, and (3) light green tags denoting ineffective cryoablation lesions and dark green tag denoting cryoablation lesion that resulted in temporary dampening of diaphragmatic excursion. C: Attempted phrenic nerve displacement through percutaneous subxyphoid pericardial instrumentation with (1) an 8.5 French steerable sheath and a steerable catheter, (2) placeholder J wire for a second pericardial access, and (3) endovascular 4 mm mapping/ablation catheter, duodecapolar catheter (DD) for phrenic nerve pacing, and decapolar coronary sinus catheter (CS). d = distal; HIS = His bundle catheter; m = mid; p = proximal; RVA = right ventricular apex catheter.

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  Figure 2. Thoracoscopic image of heart (H), lung (L), diaphragm (D), and posteriorly displaced phrenic nerve (PN) after intentional pneumothorax with carbon dioxide insufflation.

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  Figure 3. A: Earliest activation during clinical tachycardia (white tag) and phrenic nerve capture locations with right lung collapsed (black tags) after carbon dioxide insufflation. B: Ablation lesions with termination of tachycardia (red tags). Black tags and orange tags denote phrenic nerve capture locations with and without collapsed lung, respectively.