2019 HRS/EHRA/APHRS/LAHRS expert consensus statement on catheter ablation of ventricular arrhythmias.

Ventricular arrhythmias are an important cause of morbidity and mortality and come in a variety of forms, from single premature ventricular complexes to sustained ventricular tachycardia and fibrillation. Rapid developments have taken place over the past decade in our understanding of these arrhythmias and in our ability to diagnose and treat them. The field of catheter ablation has progressed with the development of new methods and tools, and with the publication of large clinical trials. Therefore, global cardiac electrophysiology professional societies undertook to outline recommendations and best practices for these procedures in a document that will update and replace the 2009 EHRA/HRS Expert Consensus on Catheter Ablation of Ventricular Arrhythmias. An expert writing group, after reviewing and discussing the literature, including a systematic review and meta-analysis published in conjunction with this document, and drawing on their own experience, drafted and voted on recommendations and summarized current knowledge and practice in the field. Each recommendation is presented in knowledge byte format and is accompanied by supportive text and references. Further sections provide a practical synopsis of the various techniques and of the specific ventricular arrhythmia sites and substrates encountered in the electrophysiology lab. The purpose of this document is to help electrophysiologists around the world to appropriately select patients for catheter ablation, to perform procedures in a safe and efficacious manner, and to provide follow-up and adjunctive care in order to obtain the best possible outcomes for patients with ventricular arrhythmias.

Total laser cycles-a measure of transvenous lead extraction difficulty.

BACKGROUND: Several variables have been identified as predictors for difficult or complicated transvenous lead extraction (TLE), including age and number of implanted leads, as well as patient's age; however, a standard measure of TLE difficulty has not been described. OBJECTIVE: Total laser cycles (TLCs) delivered during laser-assisted TLE is an objective variable that could reflect the difficulty of TLE. This study investigated whether TLC is correlated with known predictors of difficult TLE. METHODS: In a retrospective study of TLE procedures using the laser sheath, we analyzed TLC delivered and compared it to established predictors of procedural failure and complications. RESULTS: Of 166 patients undergoing TLE, the laser sheath (SLS II or Glidelight, Spectranetics Inc.,) was used as the primary extraction sheath in 130 patients, and 100 patients had complete TLC data available. The mean age of the oldest lead (AOL) was 7.1 ± 3.2 years with a median of 6.91 (interquartile range [IQR] 0.48-16.69) years, and 1.6 ± 0.7 leads (range, 1-4) were extracted per procedure. Two thirds of procedures involved ICD leads. Clinical success was 99%, with one patient (1%) experiencing a major complication. Median TLC delivered was 1165 (IQR, 567-2062; range, 49-9522). TLC was positively correlated with AOL (r = 0.227, p = 0.023), and the combined age of leads was extracted (r = 0.307, p = 0.002). TLC was also positively correlated with number of leads extracted per procedure (ρ = 0.227, p = 0.024). There was a non-significant negative trend towards correlation between TLC and patient's age (r = -0.112, p = 0.268). CONCLUSION: TLC showed significant correlation with known predictors of difficulty during TLE using the laser sheath. TLC is an objective method to report the difficulty of TLE and could usefully be reported in future series of laser lead extractions.

Right Ventricular Pacing Increases Risk of Appropriate Implantable Cardioverter-Defibrillator Shocks Asymmetrically: An Analysis of the ALTITUDE Database.

BACKGROUND: Right ventricular pacing (RVP) increases risk of atrial fibrillation in patients with implantable cardioverter-defibrillators (ICDs), but ventricular proarrhythmia is less clear. We analyzed a large remote monitoring database to assess this question. METHODS AND RESULTS: Patients with single- or dual-chamber ICDs, engaged in remote monitoring for at least 6 months and with unchanged tachycardia programming, were included. %RVP was derived for each weekly transmission. ICD electrograms preceding the first shock were adjudicated. Among 425 625 transmissions received from 8435 patients, 389 appropriate shocks occurred over a mean follow-up of 15.0±8.8 months. In a time-dependent Cox proportional hazards model, transmissions with 80% to 98% RVP were associated with a hazard ratio of 1.56 for an appropriate shock in the subsequent week compared with <1% RVP (95% CI, 1.01-2.41; P=0.04). By contrast, ≥98% RVP trended toward a lower risk of an appropriate shock (hazard ratio, 0.61; 95% CI, 0.33-1.12; P=0.108). Lifetime cumulative %RVP was closely correlated with weekly %RVP (R2=0.907) and was similarly associated with increased risk of appropriate shocks at 80% to 98% RVP (hazard ratio, 1.57; 95% CI, 1.01-2.44; P=0.046) but not at ≥98% RVP (hazard ratio, 0.49; 95% CI, 0.24-1.01; P=0.052). These results were driven by dual-chamber devices, but unaffected by PVC counts or programming. Male sex and age were also associated with appropriate ICD shocks. CONCLUSIONS: Increasing frequency of RVP is associated with a progressively increased risk of appropriate ICD shocks until ≥98% RVP. RVP may have ventricular proarrhythmia because of competition of paced and intrinsic rhythm in ICD patients.

Real-time guidewire localization using impedance-based electroanatomic mapping: experimental results and clinical validation during cryoballoon ablation of atrial fibrillation.

AIMS: Cryoballoon ablation is an emerging therapy for atrial fibrillation (AF). However, the Arctic Front cryoballoon (Medtronic) cannot be localized on current electroanatomic mapping (EAM) systems. We describe a technique to visualize guidewires in an impedance-based EAM system. METHODS AND RESULTS: A novel technique for real-time guidewire localization in an EAM (Ensite Velocity, St Jude Medical) was prospectively evaluated among patients referred for cryoballoon AF ablation. The guidewire was visualized as an 'orb' on the EAM and localization in each of the pulmonary veins (PVs) compared with orthogonal fluoroscopy, contrast venography, and intra-cardiac echocardiography. Application of the technique in 21 consecutive patients [median age 58 (interquartile range 21); 71.4% male; 85.7% paroxysmal AF] demonstrated agreement with respect to guidewire localization in 82 of 82 (100%) PVs. Discrimination of guidewire position in the left atrial appendage from the left PVs was also demonstrated. When compared with 21 consecutive cryoballoon procedures over the same time period in which the technique was not used, fluoroscopy time was reduced [median 53.2 (25.9) vs. 72.3 (47.6) min, P = 0.008], and a trend towards reduced radiation exposure [median 372 (656.0) vs. 581 (849.9) mGy, P = 0.08] was noted, without effect on acute procedural or mid-term endpoints. Ex vivo assessment of the technique in a saline bath left atrial model demonstrated that the 'orb' localizes to the centroid of the exposed portion of the guidewire. CONCLUSION: This simple, novel technique provides real-time, accurate guidewire localization to enable guidewire and catheter navigation during cryoballoon AF ablation.