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Aims: Changes in the anatomical relationship between left phrenic nerve and coronary veins may occur due to the reverse remodelling observed in super-responders to cardiac resynchronization therapy (CRT) and might be the underlying mechanism in patients developing late-onset phrenic nerve stimulation (PNS) without evidence of lead dislodgement (LD). In this study, we sought to evaluate the role of super-response (SR) to CRT as a potential predictor of late-onset PNS.Methods and results: Consecutive patients implanted with a left ventricular (LV) lead in a single centre were retrospectively analysed. Phrenic nerve stimulation was classified as 'early' when it occurred within 3 months of implantation and 'late' for occurrences thereafter. 'Late' PNS was considered related to LD (LD-PNS) when LV threshold differed by > 1 V or impedance >250 Ω from baseline values or in case of radiological displacement. Cases not meeting the former criteria were classified as 'non-LD-PNS'. Super-response was defined as a decrease ≥30% of the left ventricluar end-systolic volume at 1-year echocardiography. At 32 ± 7 months follow-up, PNS occurred in 20 of 139 patients. Late non-LD-PNS incidence was significantly higher in the SR group (8/61; 13.1%) when compared with the non-SR (1/78; 1.3%) (P = 0.010). Super-response remained the only predictor of non-LD-PNS at multivariate analysis (odds ratio: 11.62, 95% confidence interval 1.41-95.68, P = 0.023).Conclusion: Incidence of late non-LD-PNS is higher among SR to CRT, suggesting a potential role of the changes in the anatomical relationship between left phrenic nerve and coronary veins. [ABSTRACT FROM AUTHOR]

Aims: Phrenic paralysis is a known complication of central venous catheterization, but it is not listed as a complication related to cardiac implantable electronic device (CIED) implants. The aim of this study is to describe the incidence, causes, clinical picture, and management of phrenic paralysis occurring in this scenario.Methods and Results: We retrospectively analysed data from our CIED implantation database and identified those patients who suffered phrenic paralysis during the implantation procedure. Four of 891 patients (subclavian puncture in 626) developed phrenic paralysis during pacemaker or defibrillator implant procedures. Severe respiratory failure needing ventilatory support occurred in two, being the phrenic paralysis transient in all of the cases.Conclusions: Transient phrenic paralysis may occur during CIED implantation probably related to the infiltration of local anaesthesia in the subclavian area. Mechanism, prevention, and management are discussed. [ABSTRACT FROM AUTHOR]

Aims A new remote catheter system (AMIGO™ Remote Catheter System) compatible with conventional ablation catheters is now commercially available but no data about its performance in clinical use during ablation have been reported. This study evaluates the feasibility, efficacy, and safety of cavo-tricuspid isthmus (CTI) ablation with this system in patients with typical atrial flutter (AFl). Methods and results Sixty patients with typical AFl underwent CTI ablation using the new remote catheter navigation system with 8 mm tip or irrigated catheters in three centres following each centre's routine practice. The endpoint was stable bidirectional CTI block. CTI ablation was successful in 98% of patients. Ablation was completed manually in one patient. The overall procedure, fluoroscopy, and radiofrequency times (median ± standard deviation, range) were 123 ± 42 (50–250), 24 ± 13 (3–82), and 10 ± 8 (1.17–43.3) min, respectively. Three patients had vascular complications not requiring surgical intervention. There were no complications related to the remote catheter manipulation system. Conclusion Cavo-tricuspid isthmus ablation for typical AFl can be safely and effectively performed with the AMIGO™. The learning curve seems to be short even for physicians with limited ablation experience. [ABSTRACT FROM PUBLISHER]