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Valverde de la Virgen, Spain

Dagres N.,National and Kapodistrian University of Athens | Cantu F.,Electrophysiology | Geelen P.,Arrhythmia Unit | Lewalter T.,Isar Heart Center Munich | And 2 more authors.
Europace | Year: 2012

We performed a survey on current practice of ventricular tachycardia (VT) ablation in patients with implantable cardioverter-defibrillators among the European Heart Rhythm Association Research Network. The main indication for the procedure is the occurrence of multiple shocks or electrical storm, while prophylactic ablation is only rarely performed. The epicardial approach is seldom used and mostly only after failure of endocardial ablation. The main ablation strategy is targeting the clinical VT only by substrate mapping and ablation, and by targeting fractionated potentials with utilization of modern electroanatomical mapping systems. Still, a considerable number of centres frequently perform the procedure using conventional mapping catheters only. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2011. For permissions please.

Defaye P.,University Hospital | De La Cruz I.,University of Seville | Marti-Almor J.,Arrhythmia Unit | Villuendas R.,Electrophysiology and Arrhythmia Unit | And 6 more authors.
Heart Rhythm | Year: 2014

Background Sleep apnea (SA) is associated with cardiovascular diseases and is highly prevalent in patients with pacemakers (PMs). Objective To validate a transthoracic impedance sensor with an advanced algorithm (sleep apnea monitoring) for identifying severe SA. Methods Patients with indications for PM (VVI/DDD) were enrolled regardless of symptoms suggesting SA. Severe SA diagnosis was acknowledged when the full polysomnography gave an apnea-hypopnea index (PSG-AHI) of >30 events/h. The PSG-AHI was compared with the respiratory disturbance index evaluated by the SAM algorithm (SAM-RDI) compiled from the device during the same diagnosis night, and the performance of the device and the SAM algorithm was calculated to identify patients with severe SA. The agreement between methods was assessed by using Bland and Altman statistics. Results Forty patients (mean age 73.8 ± 19.1 years; 67.5% men; body mass index 27.7 ± 4.4 kg/m2) were included. Severe SA was diagnosed by PSG in 56% of the patients. We did not retrieve SAM-RDI data in 14% of the patients. An optimal cutoff value for the SAM-RDI at 20 events/h was obtained by a receiver operator characteristic curve analysis, which yielded a sensitivity of 88.9% (95% confidence interval [CI] 65.3%-98.6%), a positive predictive value of 88.9% (95% CI 65.3%-98.6%), and a specificity of 84.6% (95% CI 54.6%-98.1%) (n = 31). The Bland-Altman limits of agreement for PSG-AHI (in events per hour) were [-14.1 to 32.4]. Conclusion The results suggest that an advanced algorithm using PM transthoracic impedance could be used to identify SA in patients with PMs outside the clinic or at home. © 2014 Heart Rhythm Society.

Brugada J.,University of Barcelona | Blom N.,Leiden University | Sarquella-Brugada G.,University of Barcelona | Blomstrom-Lundqvist C.,Uppsala University | And 14 more authors.
Europace | Year: 2013

In children with structurally normal hearts, the mechanisms of arrhythmias are usually the same as in the adult patient. Some arrhythmias are particularly associated with young age and very rarely seen in adult patients. Arrhythmias in structural heart disease may be associated either with the underlying abnormality or result from surgical intervention. Chronic haemodynamic stress of congenital heart disease (CHD) might create an electrophysiological and anatomic substrate highly favourable for re-entrant arrhythmias.As a general rule, prescription of antiarrhythmic drugs requires a clear diagnosis with electrocardiographic documentation of a given arrhythmia. Risk-benefit analysis of drug therapy should be considered when facing an arrhythmia in a child. Prophylactic antiarrhythmic drug therapy is given only to protect the child from recurrent supraventricular tachycardia during this time span until the disease will eventually cease spontaneously. In the last decades, radiofrequency catheter ablation is progressively used as curative therapy for tachyarrhythmias in children and patients with or without CHD. Even in young children, procedures can be performed with high success rates and low complication rates as shown by several retrospective and prospective paediatric multi-centre studies. Three-dimensional mapping and non-fluoroscopic navigation techniques and enhanced catheter technology have further improved safety and efficacy even in CHD patients with complex arrhythmias.During last decades, cardiac devices (pacemakers and implantable cardiac defibrillator) have developed rapidly. The pacing generator size has diminished and the pacing leads have become progressively thinner. These developments have made application of cardiac pacing in children easier although no dedicated paediatric pacing systems exist. © 2013 The Author.

Aramendi E.,University of the Basque Country | Irusta U.,University of the Basque Country | Pastor E.,Arrhythmia Unit | Bodegas A.,Arrhythmia Unit | Benito F.,Hospital Infantil de la Paz
Physiological Measurement | Year: 2010

Since the International Liaison Committee on Resuscitation approved the use of automated external defibrillators (AEDs) in children, efforts have been made to adapt AED algorithms designed for adult patients to detect paediatric ventricular arrhythmias accurately. In this study, we assess the performance of two spectral (A2 and VFleak) and two morphological parameters (TCI and CM) for the detection of lethal ventricular arrhythmias using an American Heart Association (AHA) compliant database that includes adult and paediatric arrhythmias. Our objective was to evaluate how those parameters can be optimally adjusted to discriminate shockable from nonshockable rhythms in adult and paediatric patients. A total of 1473 records were analysed: 751 from 387 paediatric patients (≤16 years of age) and 722 records from 381 adult patients. The spectral parameters showed no significant differences (p > 0.01) between the adult and paediatric patients for the shockable records; the differences for nonshockable records however were significant. Still, these parameters maintained the discrimination power when paediatric rhythms were included. A single threshold could be adjusted to obtain sensitivities and specificities above the AHA goals for the complete database. The sensitivities for ventricular fibrillation (VF) and ventricular tachycardia (VT) were 91.1% and 96.6% for VFleak, and 90.3% and 99.3% for A2. The specificities for normal sinus rhythm (NSR) and other nonshockable rhythms were 99.5% and 96.3% for VFleak, and 99.0% and 97.7% for A2. On the other hand, the morphological parameters showed significant differences between the adult and paediatric patients, particularly for the nonshockable records, because of the faster heart rates of the paediatric rhythms. Their performance clearly degraded with paediatric rhythms. Using a single threshold, the sensitivities and specificities were below the AHA goals, particularly VT sensitivity (60.4% for TCI and 65.8% for CM) and the specificity for other nonshockable rhythms (51.7% for TCI and 34.5% for CM). The specificities, particularly for the adult case, improve when the thresholds are independently adjusted for each adult and paediatric database. © 2010 Institute of Physics and Engineering in Medicine.

Kumar S.,Arrhythmia Unit | Barbhaiya C.R.,Arrhythmia Unit | Sobieszczyk P.,Interventional Cardiology and Vascular Medicine | Eisenhauer A.C.,Interventional Cardiology and Vascular Medicine | And 11 more authors.
Circulation: Arrhythmia and Electrophysiology | Year: 2015

Background - Ventricular tachycardia (VT) refractory to antiarrhythmic drugs and standard percutaneous catheter ablation techniques portends a poor prognosis. We characterized the reasons for ablation failure and describe alternative interventional procedures in this high-risk group. Methods and Results - Sixty-seven patients with VT refractory to 4±2 antiarrhythmic drugs and 2±1 previous endocardial/epicardial catheter ablation attempts underwent transcoronary ethanol ablation, surgical epicardial window (Epi-window), or surgical cryoablation (OR-Cryo; age, 62±11 years; VT storm in 52%). Failure of endo/epicardial ablation attempts was because of VT of intramural origin (35 patients), nonendocardial origin with prohibitive epicardial access because of pericardial adhesions (16), and anatomic barriers to ablation (8). In 8 patients, VT was of nonendocardial origin with a coexisting condition also requiring cardiac surgery. Transcoronary ethanol ablation alone was attempted in 37 patients, OR-Cryo alone in 21 patients, and a combination of transcoronary ethanol ablation and OR-Cryo (5 patients), or transcoronary ethanol ablation and Epi-window (4 patients), in the remainder. Overall, alternative interventional procedures abolished ≥1 inducible VT and terminated storm in 69% and 74% of patients, respectively, although 25% of patients had at least 1 complication. By 6 months post procedures, there was a significant reduction in defibrillator shocks (from a median of 8 per month to 1; P<0.001) and antiarrhythmic drug requirement although 55% of patients had at least 1 VT recurrence, and mortality was 17%. Conclusions - A collaborative strategy of alternative interventional procedures offers the possibility of achieving arrhythmia control in high-risk patients with VT that is otherwise uncontrollable with antiarrhythmic drugs and standard percutaneous catheter ablation techniques. © 2015 American Heart Association, Inc.

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