Remote magnetic navigation and arrhythmia ablation.

Radiofrequency treatment is the first-choice treatment for arrhythmias, in particular complex arrhythmias and especially atrial fibrillation, due to the greater benefit/risk ratio compared with antiarrhythmic drugs. However, complex arrhythmias such as atrial fibrillation require long procedures with additional risks such as X-ray exposure or serious complications including tamponade. Given this context, robotic magnetic navigation is a technique well suited to the treatment of complex arrhythmias, on account of its efficacy and reliability, the significant reduction in X-ray exposure for both patient and operator, and the very low risk of perforation. As ongoing developments will likely improve results and procedure times, this technology will become one of the most advanced for treating arrhythmias.

A single-centre experience concerning the safety of Sprint Fidelis defibrillator lead extraction at the time of pulse generator replacement or in case of evidence of lead failure.

BACKGROUND: The reported failure rate of the Sprint Fidelis defibrillator lead (SFDL) has increased more than initially expected, with emerging evidence of accelerating fracture rates. Current consensus guidelines continue to discourage prophylactic lead extraction, citing major complication rates of 1.4-7.3%. Therefore, data relating to the risks of systematic SFDL extraction are lacking, with no methodical extraction protocol reported to date. Moreover, few statistical analyses have identified predictors of SFDL failure. OBJECTIVES: The aims of this single-centre study were: to examine the safety and feasibility of systematic SFDL extraction at the time of pulse generator replacement or in case of lead failure; and to identify predictors of SFDL failure. METHODS: Between January 2005 and October 2007, 218 consecutive patients underwent transvenous SFDL implantation in our centre. RESULTS: During a mean follow-up of 43 ± 15 months, SFDL extraction was performed in 49 patients (22.5%) for the following reasons: inappropriate shocks (n = 21; 9.6%), systematic extraction at time of pulse generator extraction (n = 23; 10.5%), high impedance (n = 3; 1.4%), high SFDL threshold (n = 1; 0.4%) and cardiac device-related infection (n = 1; 0.4%). No severe complications occurred, although two minor complications were reported (lead dislodgments). SFDL fracture was observed in 25 patients (11.5%; 3.2%/year incidence). The only predictor associated with SFDL fracture was the number of leads (P = 0.01). CONCLUSION: In our series, SFDL extraction at the time of pulse generator extraction or in case of evidence of lead failure was feasible and safe. Number of leads was identified as a new predictive factor for SFDL fracture.

Single-centre experience with an 8-mm tip catheter for radiofrequency catheter ablation of outflow tract ventricular ectopic beats.

BACKGROUND: Radiofrequency ablation (RFA) of outflow tract ventricular ectopic beats (OTVEBs) can be performed using a 4-mm or externally-cooled tip RFA catheter, but no data are available concerning the safety and efficacy of a large-tip (8-mm) catheter. AIMS: To evaluate the feasibility of using an 8-mm tip catheter in patients with OTVEBs. METHODS: In this prospective cohort study, the 8-mm tip catheter was tested in patients who were referred to our centre for RFA of symptomatic OTVEBs. RESULTS: The mean age of the 16 patients recruited between September 2008 and March 2010 was 53±18 years and 56.3% were male. Mean left ventricular ejection fraction was 62±9%, mean ventricular ectopic beat width was 144±21 ms, and all patients had left bundle branch block. Fourteen patients had inferior axis QRS morphology and two had superior. The main symptoms were palpitations and pre-syncope. RFA parameters were: procedure time 94±35 min; duration of application 11±10 min; impedance 81±12 Ω; temperature 50±5 °C; and power 46±17 W. RFA succeeded in 15 over 16 patients (93.8%); and recurrence was seen in one patient after a mean follow-up time of 11±6 months. No complications were noted. CONCLUSIONS: This preliminary study suggests that an 8-mm tip catheter may represent an alternative for RFA in patients with OTVEBs in whom a 4-mm tip was not successful. Larger randomized studies are therefore warranted.

Anatomical factors involved in difficult cardiac resynchronization therapy procedure: a non-invasive study using dual-source 64-multi-slice computed tomography.

AIMS: In cardiac resynchronization therapy (CRT) procedure, left ventricular (LV) lead implantation is time consuming. In this clinical setting, no study has investigated the impact of right atrium anatomical parameters on both CRT implantation procedure duration and X-ray exposure. Additionally, only few studies have examined the coronary sinus (CS) using dual-source 64-multi-slice computed tomography (DS 64-MSCT), and its impact on CRT procedure parameters has not yet been investigated. The aim of this prospective study was to identify local anatomical predictive factors of difficult CRT implantation procedure using DS 64-MSCT. METHODS AND RESULTS: Between January and July 2010, 50 consecutive patients underwent primo CRT implantation. The patient population had a mean age of 70 ± 10 years, and was 34% female, with New York Heart Association Class 3.2 ± 0.3 heart failure, left ventricle ejection fraction 30 ± 4%, and QRS width 157 ± 30 ms. Cardiac resynchronization therapy implantation was attempted in 50 patients, and first LV lead implantation was obtained in 49 of 50 patients (98% primary success). One implantation failed (2%) due to unsuccessful LV lead implant. Procedure parameters were as follows: LV threshold, 1.4 ± 0.8 V; LV wave amplitude, 17 ± 8 mV; LV impedance, 830 ± 240 Ω; median procedure time (skin to skin), 51 min (38 min); median fluoroscopy procedure time, 11.9 min (22 min); and median LV fluoroscopic time, 10.3 min (22 min). In 10 patients (20%), procedures were difficult requiring an implantation lasting ≥ 85 min. The only predictive factor for difficult CRT implantation was the insertion level of the CS ostium (CSO), evaluated by the distance between the CSO and the bottom floor of the right atrium (14.8 ± 4 vs. 9.5 ± 4; P= 0.01). Neither the right atrium dilation nor right ventricular dysfunction was associated with difficult CRT implantation procedures. CONCLUSIONS: Today, despite improvements in the materials used, problems still remain in the CRT procedure. In this clinical setting, the only predictive factor for very long CRT procedures is the CSO-level insertion (located high). This anatomical anomaly identified by DS 64-MSCT prior to surgery is responsible for 20% of difficult CRT device implantation procedures.