Catheter Ablation of Atrial Fibrillation in Patients with Previous Lobectomy or Partial Lung Resection: Long-Term Results of an International Multicenter Study.

INTRODUCTION: Data regarding the efficacy of catheter ablation in patients with atrial fibrillation (AF) and patients' previous history of pulmonary lobectomy/pneumonectomy are scanty. We sought to evaluate the efficacy and long-term follow-up of catheter ablation in this highly selected group of patients. MATERIAL AND METHODS: Twenty consecutive patients (8 females, 40%; median age 65.2 years old) with a history of pneumonectomy/lobectomy and paroxysmal or persistent AF, treated by means of pulmonary vein isolation (PVI) at ten participating centers were included. Procedural success, intra-procedural complications, and AF recurrences were considered. RESULTS: Fifteen patients had a previous lobectomy and five patients had a complete pneumonectomy. A large proportion (65%) of PV stumps were electrically active and represented a source of firing in 20% of cases. PVI was performed by radiofrequency ablation in 13 patients (65%) and by cryoablation in the remaining 7 cases. Over a median follow up of 29.7 months, a total of 7 (33%) AF recurrences were recorded with neither a difference between patients treated with cryoablation or radiofrequency ablation or between the two genders. CONCLUSIONS: Catheter ablation by radiofrequency ablation or cryoablation in patients with pulmonary stumps is feasible and safe. Long-term outcomes are favorable, and a similar efficacy of catheter ablation has been noticed in both males and females.

Early and late ventricular arrhythmias complicating ST-segment elevation myocardial infarction.

BACKGROUND: Ventricular arrhythmias can be life-threatening complications of ST-segment elevation myocardial infarction (STEMI). AIMS: To describe the incidence, predictors and in-hospital impact of early ventricular arrhythmia (EVA, occurring

Electrophysiological Study-Guided Permanent Pacemaker Implantation in Patients With Conduction Disturbances Following Transcatheter Aortic Valve Implantation.

Conduction disturbances remain common following transcatheter aortic valve implantation (TAVI). Aside from high-degree atrioventricular block (HAVB), their optimal management remains elusive. Invasive electrophysiological studies (EPS) may help stratify patients at low or high risk of HAVB allowing for an early discharge or permanent pacemaker (PPM) implantation among patients with conduction disturbances. We evaluated the safety and diagnostic performances of an EPS-guided PPM implantation strategy among TAVI recipients with conduction disturbances not representing absolute indications for PPM. All patients who underwent TAVI at a single expert center from June 2017 to July 2020 who underwent an EPS during the index hospitalization were included in the present study. False negative outcomes were defined as patients discharged without PPM implantation who required PPM for HAVB within 6 months of the initial EPS. False positive outcomes were defined as patients discharged with a PPM with a ventricular pacing percentage <1% at follow-up. A total of 78 patients were included (median age 83.5, 39% female), among whom 35 patients (45%) received a PPM following EPS. The sensitivity, specificity, positive and negative predictive values of the EPS-guided PPM implantation strategy were 100%, 89.6%, 81.5%, and 100%, respectively. Six patients suffered a mechanical HAVB during EPS and received a PPM. These 6 patients showed PPM dependency at follow-up. In conclusion, an EPS-guided PPM implantation strategy for managing post-TAVI conduction disturbances appears effective to identify patients who can be safely discharged without PPM implantation.

Implantable cardiac defibrillator leads dysfunction after LVAD implantation.

BACKGROUND: Implantable cardioverter-defibrillator (ICD) lead dysfunction has been reported after left ventricular assist device (LVAD) implantation in limited single-center studies. We aimed at describing and characterizing the incidence of ICD lead parameters dysfunction after LVAD implantation. METHODS: Among the 652 patients enrolled in the ASSIST-ICD study, only patients with an ICD prior to LVAD were included (n = 401). ICD lead parameters dysfunction following LVAD implantation is defined as follows: (a) >50% decrease in sensing threshold, (b) pacing lead impedance increase/decrease by >100Ω, and (c) >50% increase in pacing threshold. RESULTS: One hundred twenty-two patients with an ICD prior to LVAD had available ICD interrogation reports prior and after LVAD. A total of 67 (55%) patients exhibited at least one significant lead dysfunction: 17 (15%) exhibited >50% decrease in right ventricular (RV) sensing, 51 (42%) had >100 Ω increase/decrease in RV pacing impedance, and 24 (20%) experienced >50% increase in RV pacing threshold. A total of 52 patients experienced ventricular arrhythmia during follow-up and all were successfully detected and treated by the device. All lead dysfunction could be managed conservatively. CONCLUSION: More than 50% of LVAD-recipients may experience >1 significant change in lead parameters but none had severe clinical consequences.

Wireless Pacing Using an Asynchronous Three-Tiered Inductive Power Transfer System.

Despite numerous advancements in pacemaker technology for the treatment of cardiac arrhythmias and conduction disorders, lead-related complications associated with these devices continue to compromise patient safety and survival. In this work, we present a system architecture that has the capacity to deliver power to a wireless, batteryless intravascular pacer. This was made possible through a three-tiered, dual-sub-system, four-coil design, which operates on two different frequencies through intermittent remote-controlled inductive power transfer. System efficiency was enhanced using coil design optimization, and validated using numerical simulations and experimental analysis. Our pacemaker design was concepted to achieve inductive power transfer over a 55 mm range to a microscale pacer with a 3 mm diameter. Thus, the proposed system design enabled long-range wireless power transfer to a small implanted pacer with the capacity for intravascular deployment to the anterior cardiac vein. This proposed stent-like fixation mechanism can bypass the multitude of complications associated with pacemaker wires while wireless power can eliminate the need for repeated procedures for battery replacement.

Incidence, predictors, and clinical impact of electrical storm in patients with left ventricular assist devices: New insights from the ASSIST-ICD study.

BACKGROUND: Ventricular arrhythmias (VAs) can occur after continuous flow left ventricular assist device (LVAD) implantation as a single arrhythmic event or as electrical storm (ES) with multiple repetitive VA episodes. OBJECTIVE: We aimed at analyzing the incidence, predictors, and clinical impact of ES in LVAD recipients. METHODS: Patients analyzed were those included in the multicenter ASSIST-ICD observational study. ES was consensually defined as occurrence of ≥3 separate episodes of sustained VAs within a 24-hour interval. RESULTS: Of 652 patients with an LVAD, 61 (9%) presented ES during a median follow-up period of 9.1 (interquartile range [IQR] 2.5-22.1) months. The first ES occurred after 17 (IQR 4.0-56.2) days post LVAD implantation, most of them during the first month after the device implantation (63%). The incidence then tended to decrease during the initial years of follow-up and increased again after the third year post LVAD implantation. History of VAs before LVAD implantation and heart failure duration > 84 months were independent predictors of ES. The occurrence of ES was associated with an increased early mortality since 20 patients (33%) died within the first 2 weeks of ES. Twenty-two patients (36.1%) presented at least 1 recurrence of ES, occurring 43.0 (IQR 8.0-69.0) days after the initial ES. Patients experiencing ES had a significantly lower 1-year survival rate than did those free from ES (log-rank, P = .039). CONCLUSION: There is a significant incidence of ES in patients with an LVAD. The short-term mortality after ES is high, and one-third of patients will die within 15 days. Whether radiofrequency ablation of arrhythmias improves outcomes would require further studies.