Intramyocardial radiofrequency ablation of ventricular arrhythmias using intracoronary wire mapping and a coronary reentry system: Description of a novel technique

Figures

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  Figure 1. A: Standard 12-lead electrocardiogram (ECG) (paper speed 25 mm/s) showing premature ventricular contraction (PVC) with left bundle branch block morphology and inferior axis with early transition in precordial leads (ie, lead V2). Notice the very positive deflection in inferior leads and the QS complexes in leads aVR and aVL. All these finding suggest a left ventricular outflow tract (LVOT) origin. B: A 12-lead ECG (paper speed 100 mm/s) demonstrating similar PVC morphology except for an earlier transition in precordial leads owing to slightly different lead placement during ablation procedure. Maximum deflection index (0.57), pseudodelta wave 63 ms, and intrinsicoid deflection time of 97 ms are all suggestive of an LVOT epicardial origin (LV summit). However, an aVL/aVR Q ratio < 1.6 (patients’ aVL/aVR Q ratio was 1.2) and an R-wave ratio III/II < 1.4 (patients’ R-wave ratio III/II was 1.1) are predictive of an origin in the inaccessible area of the LV summit.

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  Figure 2. A: Electroanatomic mapping showing earliest site of activation at the great cardiac vein/anterior interventricular vein junction. B, C: Angiographic images in (B) left anterior oblique and (C) right anterior oblique projections depicting the relation between the ablation catheter tip and the proximal left anterior descending artery (LAD). Noticeably, the earliest activation found within the anterior interventricular vein (marked by the tip of the ablation catheter) is clearly in close proximity with the first septal perforator branch (*). D: A perfect pace map (12/12 leads) was achieved in this site. E: Activation mapping of the clinical premature ventricular contraction in the CS showing earliest site of activation (red) at the anterior interventricular vein (−24 ms pre-QRS). ABL = ablation catheter; CS = coronary sinus; His = His bundle; RV = right ventricle.

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  Figure 3. A: A 0.014-inch Vision guidewire (Biotronik SE&CO KG, Berlin, Germany) was advanced into the first septal perforator, over which the Stingray LP system balloon (Boston Scientific, Marlborough, MA) was advanced. B: Radiopaque marks (seen near the tip of the ablation catheter) are used to guide balloon placement. C: Once the Stingray balloon was in place, the Vision guidewire was removed, and the Stingray guidewire was advanced into the myocardium. D: Earliest activation in this initial intramyocardial location was −28 ms.

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  Figure 4. Illustration depicting ablation technique using the Stingray CTO system. A Stingray balloon was advanced into the first septal perforator, and a hydrophilic Stingray guidewire was used to perforate the arterial wall and advanced into the interventricular myocardium. The proximal end of the wire was then introduced into a saline bath along with the ablation catheter, and radiofrequency was delivered in this way, achieving successful premature ventricular contraction ablation. LAD = left anterior descending artery; LCC = left coronary cusp; LCx = left circumflex artery; LV = left ventricle; RCA = right coronary artery; RCC = right coronary cusp.

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  Figure 5. Final position of the Stingray system. A, B: The balloon is positioned deep into the first septal perforator (A), and the Stingray wire has been advanced deeper into the myocardium (B). C: An early activation site (−59 ms) was found, and ablation using a nonirrigated 8-mm catheter dipped in a saline bath alongside the guidewire was undertaken. D: After ablation, repeat coronary angiogram shows patency of the first septal perforator, limiting the amount of myocardium suffering damage to the target area.

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  Figure 6. Cardiac magnetic resonance imaging performed before the ablation (A–C) and the following day after ablation (D–F). No scar can be seen at baseline, and after ablation delayed enhancement (representing myocardial lesion formation; red arrows, panels D–F) can be observed in the anterior basal septum and left ventricular summit.