Utility of a guiding catheter for conduction system pacing: An early multicenter experience.

Background: Conduction system pacing (CSP), either as His bundle pacing (HBP) or as left bundle branch area pacing (LBBAP), may be superior to right ventricular apical or septal pacing. Objective: The study sought to present acute results for a new guiding catheter (Biotronik Selectra 3D) designed for CSP implantations of a retractable screw-in lead (Biotronik Solia S). Methods: The primary endpoint of the prospective, international nonrandomized BIO|MASTER.Selectra 3D study was freedom from catheter-related serious adverse device effects (SADEs) within 1 week of lead implantation. Results: Of 157 enrolled patients, CSP was achieved in 147 (93.6%) patients. No SADEs occurred within 7 days. LBBAP was achieved in 82 patients (45 as crossover from an HBP attempt) and HBP in 65 (44.2%) patients. In centers considering both HBP and LBBAP, the CSP implantation success approached 99%. Successful CSP implantations lasted on average ∼50 minutes (fluoroscopy ∼6 minutes). Most procedures (87.9%) needed only 1 catheter, even after switch from HBP to LBBAP. The catheter's handling was rated largely positive. In patients without bundle branch block, mean QRS duration increased from 106 ms (intrinsic) to 122 ms (CSP) (P = .001). In patients with bundle branch block, mean QRS duration decreased from 151 ms (intrinsic) to 137 ms (CSP) (P = .004). Conclusion: The Selectra 3D catheter is a valuable tool for HBP and LBBAP implantations of the stylet-supported pacemaker leads. When implanters considered both HBP and LBBAP, the success rate was ∼99%. Flexibility to change between different approaches may be advisable in heterogeneous and challenging areas, such as CSP implantations.

Hybrid Totally Thoracoscopic Maze and Catheter Ablation for Persistent Atrial Fibrillation: Initial Experience.

Atrial fibrillation is now a pandemic in our ageing community. Although James L. Cox devised a surgical procedure with near-universal curative success in 1987, catheter-based interventions have flourished. For persistent atrial fibrillation (AF), however, an isolated endocardial approach has limitations: procedural times are long, carry risk, and the outcomes are not durable. By combining left atrial endocardial and epicardial interventions with staged mapping, we optimise the benefits of both approaches. Our initial series of hybrid ablation for persistent atrial fibrillation reports excellent early outcomes, freedom from complications and excellent success at follow-up.

Safety and effectiveness of the first contact force ablation catheter with a flexible tip.

Background: Catheter ablation is an established therapy for paroxysmal atrial fibrillation (PAF). The TactiFlex Ablation Catheter, Sensor Enabled (TactiFlex SE) is a next-generation radiofrequency ablation catheter incorporating fiber optics-based contact force-sensing technology with a flexible, laser-cut tip. Objective: The study sought to evaluate the safety and effectiveness of the TactiFlex SE ablation catheter for treatment of drug-refractory PAF. Methods: The TactiFlex AF investigational device exemption was a prospective, nonrandomized, multicenter clinical study. Enrollment began on June 26, 2020 and completed June 18, 2021. Subjects with PAF underwent de novo pulmonary vein isolation and, if indicated, ablation for typical atrial flutter. Subjects were followed for 12 months. Results: Of the 355 subjects enrolled at 37 sites worldwide, 334 underwent ablation with the TactiFlex SE catheter. The Kaplan-Meier estimate of 12-month freedom from AF/atrial flutter (AFL)/atrial tachycardia recurrence was 72.9% (95% confidence interval [CI] 95% CI 67.2%-77.8%) and clinical success was 83.6% (95% CI 95% CI 78.1%-87.2%). As-treated analyses compared subjects treated at high power (left atrium time-averaged power setting 40-50 W; n = 222) vs low power (<40 W; n = 97). The Kaplan-Meier estimate of 12-month freedom from AF/AFL/atrial tachycardia recurrence was 76.4% (95% CI 69.3%-82.0%) and clinical success was 83.9% (95% CI 77.5%-88.6%) in the high-power group compared with 66.8% (95% CI 56.1%-75.5%) and 80.7% (95% CI 70.8%- 87.5%), respectively, in the low-power group. The primary safety event rate in all treated subjects was 4.3%; 4.1% in the HP group and 5.2% in the LP group (P = .7671). Conclusion: TactiFlex SE is safe and effective for treatment of drug-refractory PAF and concomitant AFL and enables more efficient procedures than previous generation catheters.

Long-term longevity and clinical outcomes of Linox S/SD implantable cardioverter-defibrillator leads: a single-center experience.

PURPOSE: Since the introduction of the Biotronik Linox S/SD leads in 2006, there have been multiple reports of premature lead failure. The purpose of this study was to investigate the longevity of the Linox S/SD leads and to identify the possible predictors of lead failure in a single tertiary implant center. METHODS: We retrospectively reviewed patients who underwent implantation of Linox S/SD leads or Sorin Vigila 1CR/2CR leads (the same Linox S/SD leads marketed by Sorin) at our center. The cumulative lead survival was estimated using the Kaplan-Meier curve, and variables associated with lead failure were assessed by Cox proportional hazard model. RESULTS: A total of 187 patients (154 (82%) male) underwent Linox S/SD or Vigila 1CR/2CR implantation between 2007 and 2013. During follow-up with a median time of 75 months, nine lead failures were identified (4.8%). The mean and median times from lead implantation to lead failure were 70.7 ± 21 months and 64 (45-111) months, respectively. The cumulative survival probability for the Linox S/SD at 5 years was 97.1% and at 12 years was 90.3%. Non-physiological high-rate sensing was the most common type of lead failure in patients. In two-thirds of these patients, this led to inappropriate shock. We did not find any significant relationships between patients' clinical and procedural characteristics and lead failure. CONCLUSIONS: At our center, the 5-year lead survival of the Linox S/SD has been better than reports from other centers. The majority of lead failures presented as non-physiological high-rate sensing with subsequent inappropriate therapy.

Junctional ectopic tachycardia (JET).

Junctional ectopic tachycardia (JET) is a tachyarrhythmia arising from the atrioventricular node and His bundle area. Enhanced normal automaticity has been postulated as the mechanism of JET in the majority of patients. It is more common in children and can be seen as congenital or in postoperative settings. It is often a narrow complex tachycardia but can present as a wide complex tachycardia as a result of aberrant conduction. Its differentiation from other arrhythmias especially atrioventricular nodal reentrant tachycardia (AVNRT) can be challenging. Medical treatment of JET is difficult, and catheter ablation remains the mainstay of treatment in refractory cases with a high risk of atrioventricular block and recurrence.

Pacemaker-mediated arrhythmias.

Pacemakers can be directly involved in initiating or sustaining different forms of arrhythmia. These can cause symptoms such as dyspnea, palpitations, and decompensated heart failure. Early detection of these arrhythmias and optimal pacemaker programming is pivotal. The aim of this review article is to summarize the different types of pacemaker-mediated arrhythmias, their predisposing factors, and mechanisms of prevention or termination.

Loss of cardiac resynchronization therapy in a patient with a biventricular implantable cardioverter-defibrillator.

Here, we discuss the case of a man with a history of ischemic cardiomyopathy and cardiac resynchronization therapy defibrillator implantation, who presented to emergency department with decompensated heart failure due to the loss of resynchronization therapy. The reason for the malfunction was left ventricle upper rate interval lock-in due to inappropriate programming of the device.

Aborted sudden cardiac death in a patient with implantable loop recorder.

We discuss a 46-year-old man with history of hypertension and inferior wall myocardial infarction and mild left ventricular dysfunction who presented with aborted sudden cardiac death due to episodes of ventricular tachyarrhythmia detected by a Reveal-LINQ which had been implanted one year prior to presentation.