Another recent evidence of the clinical utility of the high-power, short-duration radiofrequency ablation strategyKoichiro Ejima, MD, PhD,1, 2 Kyoichiro Yazaki, MD,1 Morio Shoda, MD, PhD, 1, 2Nobuhisa Hagiwara, MD, PhD 11. Department of Cardiology, Tokyo Women’s Medical University2. Clinical Research Division for Heart Rhythm Management, Department of Cardiology, Tokyo Women’s Medical UniversityDepartment of Cardiology, Tokyo Women’s Medical University, Tokyo, Japan8-1, Kawada-cho, Shinjuku-ku, Tokyo, 162-8666 JapanFunding : (None)Disclosures : (None)Corresponding author : Koichiro EjimaE-mail address : koichiro@qf6.so-net.ne.jpDepartment of Cardiology, Tokyo Women’s Medical University, Tokyo, Japan8-1, Kawada-cho, Shinjuku-ku, Tokyo, 162-8666 JapanTel : +81-3-3353-8111 FAX : +81-3-3356-0441Winkle et al. reviewed the literature of the high-power, short-duration (HPSD) radiofrequency ablation strategy.1We appreciate that they included our study that compared an HPSD ablation with a low-power, long-duration (LPLD) ablation using unipolar signal modification (USM) as a local endpoint during atrial fibrillation (AF) ablation.2 This study included 32 patients (paroxysmal 22, persistent 10) who underwent AF ablation using the HPSD strategy and 32 using the LPLD, and the median follow-up period was 10 months. After that, we reported another study that compared the HPSD ablation with the LPLD ablation using the USM as a local endpoint during AF ablation, which included only patients with paroxysmal AF.3 The number of patients included in the study was larger (HPSD 60, LPLD 60), and the follow-up duration was longer (mean follow-up period of the HPSD group, 12.5 months) than that in our former study. In this study, the freedom from recurrence after a single ablation procedure without any antiarrhythmic drugs was higher in the HPSD group than LPLD group (88.3% vs. 73.3% at 12-months after the procedure, log-rank; P=0.0423). This article was electrically published on May 15, 2020, more than 6 months before Winkle’s review article was received by the editorial office of the Journal of Cardiovascular Electrophysiology (December 4, 2020).We believe that this study is also worth being included the Winkle’s review article and might contribute to future investigators.

A 42-year-old woman with tricuspid atresia who underwent a Fontan surgery (atrio-pulmonary connection) was admitted to our hospital due to symptomatic ventricular tachycardia. A defibrillation lead was implanted in a distal site of a coronary vein since there was no usual entry to the ventricle. Ventricular pacing was impossible due to the high threshold, however, good sensing was obtained. Three years later, she felt palpitations and a subsequent shock therapy while climbing stairs. The cardioverter data showed that an appropriate cardioversion therapy successfully converted ventricular tachycardia to normal rhythm.

Introduction: Some patients with cardiac implantable electronic devices (CIEDs) require atrial fibrillation (AF) ablation, and the superior vena cava (SVC) has been identified as one of the most common non-pulmonary vein foci of AF. This study aimed to investigate the interaction between SVC isolation (SVCI) and CIED leads implanted through the SVC. Methods and Results: We studied 34 patients with CIEDs who had undergone SVCI as part of AF ablation (CIED group), involving a total of 71 CIED leads. A similar number of age-, sex-, and AF type-matched patients without CIEDs formed a control group (non-CIED group). Patients’ background and procedural characteristics were compared between the groups. In the CIED group, lead parameters before and after AF ablation were compared, and lead failure after AF ablation was also examined in detail. Procedural characteristics other than fluoroscopic time were similar in both groups. The success rate of SVCI after the final ablation procedure was 91.2% in the CIED group and 100% in the non-CIED group; however, these differences were not statistically significant. Lead parameters before and after the AF ablation did not significantly differ between the 2 groups. Lead failure was observed in 3 patients, with a sensing noise in 1 patient and an impedance increase in 2 patients after SVCI. Conclusions: SVCI was achievable without lead failure and significant change in lead parameters in most patients with CIEDs; however, the 8.8% incidence of lead failure observed after SVCI should be noted.

Introduction: Acute pulmonary vein reconnection (PVR) is associated with longer procedure time and radiofrequency time during pulmonary vein isolation (PVI). However, determinants of acute PVR after high-power, short-duration PVI (HPSD-PVI) in the guidance with unipolar signal modification (USM) remain unclear. Methods and Results: We evaluated 62 patients (age, 62±12 y; 45 men) with paroxysmal atrial fibrillation undergoing USM-guided HPSD-PVI. A 50-W radiofrequency (RF) was applied for 3–5 s after unipolar signal modification. In the segments adjacent to the esophagus (SAE), RF time was limited to 5 s. Each circle was subdivided into 12 segments. For each radiofrequency tag within the circle, possible predictors of acute PVR, including minimum contact force, minimum force-time integral, minimum ablation index (AImin), minimum impedance drop (Imp-min), and maximum inter-lesion distance (ILDmax) were assessed. Acute PVR was observed in 43 (7%) SAE and 21 (17%) other segments (p = 0.001). RF energy, RF application time and bilateral isolation time were 28±8 kJ, 10±3 min, and 27±11 min, respectively. Imp-min and ILDmax had the highest area under the curve (0.69 and 0.68) and of all indices, and were the sole independent predictors of acute PVR in segments other than the SAE and SAE, respectively, after adjusting for other cofounders (odds ratio [OR]: 0.90 [0.85–0.95], p = 0.0003; and OR: 1.39 [1.11–1.74], p=0.005). Conclusions: In HPSD-PVI, a non-negligible amount of acute PVR was still observed, which was possibly dealt with an optimal target value of impedance drop and lesion distance.

Background: Management of pacemaker (PM) infections in patients with an advanced age is one of the most sensitive issues, since they possess particular clinical challenges due to higher rates of medical comorbidities. The novel leadless pacemaker (LP) requiring no transvenous lead or device pocket, may provide new opportunities for the management of PM infections among patients with an advanced age. Methods: We reviewed 8 octogenarians (median age of 86 [minimum 82 – maximum 90], male 63%) who received an LP implantation following a transvenous lead extraction (TLE) of an infectious PM. Results: All patients had more than 2 medical comorbidities. The indications for the LP implantations were atrioventricular block in 3 patients, atrial fibrillation bradycardia in 3, and sinus node dysfunction in 2. Five patients were bridged with a temporary pacing using an active fixation lead (median interval of 14.5 days), while one patient with severe dementia underwent a concomitant LP implantation and TLE during the same procedure. Successful TLEs and LP implantations were accomplished in all patients. There were no major or minor complications including vascular access troubles. All patients were discharged 2–8 days after the implantation. All patients stayed free of infection during the follow-up period of 6 months Conclusions: LP implantations were safe and effective after infected pacemaker removals in all 8 octogenarians. The novel LP technology may offer an alternative option in considering re-implantation of a PM even among patients with an advanced age and who are PM dependent.