[Show abstract][Hide abstract] ABSTRACT: Background:
Isolated cases of monomorphic ventricular tachycardia (MVT) in patients with Brugada syndrome (BrS) have been reported.
We aimed to describe the incidence and characteristics of MVT in a cohort of BrS patients who had received an implantable cardioverter defibrillator (ICD).
Data from 834 BrS patients with an ICD in 15 tertiary hospitals between 1993 and 2014 were included.
Mean age was 45.3 ± 13.9; 200 patients (24%) were women. During a mean follow-up of 69.4 ± 54.3 months, 114 patients (13.7%) experienced at least one appropriate ICD intervention, with MVT recorded in 35 patients (4.2%) (sensitive to antitachycardia pacing in 15 (42,8%)). Only QRS width was an independent predictor of MVT in the overall population. Specifically, 6 patients presented with right ventricular outflow tract tachycardia (RVOT) (successfully ablated from the endocardium in 4 and epi + endocardial ablation in one), two patients with MVT arising from the left ventricle (LV) (one successfully ablated in the supra lateral mitral annulus) and two patients with bundle branch reentry VT (BBRVT). Significant structural heart disease was ruled out by echocardiography and/or CMR.
In this retrospective study, 4.2% of the patients with BrS implanted with an ICD presented with MVT confirmed as arising from the RVOT in 6, the LV in 2 and BBRVT in 2. Endocardial +/- epicardial ablation was successful in 80% of these cases. These data imply that the occurrence of MVT should not rule out the possibility of BrS. This finding may also be relevant for ICD model selection and programming.
Heart rhythm: the official journal of the Heart Rhythm Society 11/2015; DOI:10.1016/j.hrthm.2015.10.038 · 5.08 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Pacemaker mediated tachycardia (PMT) is the term used to describe a repetitive sequence of sensed retrograde P waves followed by ventricular pacing at or below the maximum tracking rate. The following events can promote AV dissociation, retrograde conduction and the onset of PMT: ventricular or atrial extrasystole, an excessively long programmed AV delay, external interference or myopotentials sensed by the atrial channel, atrial sensing or pacing failure, the absence of post ventricular atrial refractory period extension after removal of a magnet, VDD pacing at a higher rate than sinus rate. In contemporary devices, each manufacturer has a proprietary algorithm to detect and terminate PMT. Because of the increase in the number and complexity of the pacing algorithms and because of manufacturer-driven differences, a basic understanding of these new algorithms is important for patient care. We review here the main elements of the physiopathology of this type of tachycardia, describe the specific characteristics of the different manufacturers and present representative clinical cases. This article is protected by copyright. All rights reserved.
Pacing and Clinical Electrophysiology 09/2015; DOI:10.1111/pace.12750 · 1.13 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Ten years ago, electrocardiographic imaging (ECGI) started to demonstrate its efficiency in clinical settings. The initial application to localize focal ventricular arrhythmias such as ventricular premature beats was probably the easiest to challenge and validates the concept. Our clinical experience in using this non-invasive mapping technique to identify the sources of electrical disorders and guide catheter ablation of atrial arrhythmias (premature atrial beat, atrial tachycardia, atrial fibrillation), ventricular arrhythmias (premature ventricular beats) and ventricular pre-excitation (Wolff-Parkinson-White syndrome) is described here.
Journal of electrocardiology 09/2015; DOI:10.1016/j.jelectrocard.2015.08.028 · 1.36 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: A 60-year-old woman presented for radiofrequency ablation of persistent atrial tachycardia (AT) one year after pulmonary vein isolation and mitral isthmus linear ablation for atrial fibrillation. The AT (CL 288ms) was mapped using the Orion(TM) multipolar basket catheter and Rhythmia(TM) mapping system (Boston Scientific, MA, USA). Mapping points (n = 12,385) were obtained from the basket catheter (64 electrodes of 0.4mm(2) area; 2.5mm spacing) using continuous (automated) acquisition over 16 minutes, with standard beat acceptance criteria: (i) variation of CL < 13 ms, (ii) variation of activation time difference between coronary sinus (CS) electrograms < 5ms, (iii) respiration phase gated to within 13.6 μV, (iv) catheter motion < 1.7 mm per beat, and (v) catheter tracking uncertainty < 3 mm. The activation map (figure panel A) revealed localized counter-clockwise reentry within the previous mitral isthmus ablation line, appreciated in more detail in the accompanying cine frames (panel A) and Online Movie. This article is protected by copyright. All rights reserved.
Journal of Cardiovascular Electrophysiology 09/2015; DOI:10.1111/jce.12841 · 2.96 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Background:
-VT recurrence can occur after VT ablation due to incomplete and/or non-transmural ventricular lesion formation. We sought to compare the lesions made by a novel irrigated needle catheter to conventional radiofrequency (RF) lesions.
Methods and results:
-Thirteen female sheep (4.6±0.7yrs, 54±8kg) were studied. In 7 sheep, 60s RF applications were performed using an irrigated needle catheter. In 6 sheep, conventional lesions were made using a 4mm-irrigated catheter. 1.5 T in vivo and high-density MRI (9.4Tesla) were performed on explanted hearts from animals receiving needle RF. Conventional lesion volume was calculated as (1/6)∗π∗(A∗B(2)+C∗D(2)/2). Needle lesion volume was measured as Σ(π∗r(2))/2 with a slice thickness of 1mm. The dimensions of all lesions were also measured on gross pathology. Additional histological analysis of the needle lesions was performed. 120 endocardial left ventricular ablation lesions (conventional, n=60; needle, n=60) were created. At necropsy, more lesions were found using needle vs. conventional RF (90% vs. 75%, p<0.05). Comparing needle vs. conventional RF: Lesion volume was larger (1030±362mm3 vs. 488±384mm3, p<0.001), lesion depth was increased (9.9±2.7mm vs. 5±2.4mm, p<0.001) and more transmural lesions were created (62.5% vs. 17%, p<0.01). Pericardial contrast injection was observed in 4 apical attempts using needle RF, however with no adverse effects. Steam pops occurred in 3 attempts using conventional RF.
-Irrigated needle ablation is associated with more frequent, larger, deeper, and more often transmural lesions compared to conventional irrigated ablation. This technology might be of value to treat intramural or epicardial VT substrates resistant to conventional ablation.
Circulation Arrhythmia and Electrophysiology 09/2015; DOI:10.1161/CIRCEP.115.002963 · 4.51 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: This study sought to determine if the acute procedural outcome of ventricular tachycardia (VT) substrate ablation is associated with a mortality benefit in patients with implantable cardioverter-defibrillators (ICD).
A total of 195 ICD recipients (65±11years) with ischemic or non-ischemic dilated cardiomyopathy underwent substrate-based ablation targeting elimination of local abnormal ventricular activities (LAVA). Acute procedural success, which was defined as elimination of all identified LAVA in addition to the lack of VT inducibility, was achieved in 95 (49%) patients. During a median follow-up of 23 months, patients with acute procedure success had a significantly lower incidence of ICD shocks compared to those with ablation failure (8% vs. 30%, p<0.001). In multivariate analysis, acute procedural success was associated with a lower risk of VT recurrence (hazard ratio [HR] 0.30, 95% confidence interval [CI] 0.18-0.49, P<0.001) and all-cause mortality (HR 0.32, 95%CI 0.17-0.60, P<0.001). While the impact of ablation success on mortality was not statistically significant in patients with LVEF>35% (HR 0.45, 95%CI 0.15-1.34, P = 0.15) and those with NYHA class I/II (HR 0.63, 95%CI 0.29-1.40, P = 0.26), it was marked in patients with LVEF≤35% (HR 0.30, 95%CI 0.14-0.62, P = 0.001) and NYHA class III/IV (HR 0.17, 95%CI 0.05-0.57, P = 0.004).
LAVA elimination in addition to VT non-inducibility as a procedural outcome for substrate-based ablation is associated with reduced mortality and better VT-free survival during follow-up. This prognostic benefit may be most pronounced in patients with severe heart failure as indicated by severely depressed LV function and NYHA class III/IV symptoms. This article is protected by copyright. All rights reserved.
This article is protected by copyright. All rights reserved.
Journal of Cardiovascular Electrophysiology 09/2015; DOI:10.1111/jce.12825 · 2.96 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The demonstration of severe complications in patients implanted with a transvenous implantable cardioverter defibrillator (ICD) has led to the development of devices equipped with a subcutaneous lead. This new technique offers numerous advantages but also certain disadvantages. Various studies or anecdotal clinical cases have specifically been conducted with this subcutaneous defibrillation system in children and/or patients with congenital heart disease. Results of these studies suggest: 1) a high feasibility despite being limited by a selection process that excludes patients requiring permanent pacing and patients declared ineligible during pre-screening; 2) good efficacy of electrical shocks in reducing induced or spontaneous ventricular arrhythmias; 3) in this specific subset of patients, 2 types of complications have been particularly described: a risk of device exteriorization and infection, and a large number of inappropriate therapies primarily related to T-wave oversensing. The subcutaneous ICD could therefore constitute the gold standard for patients with complex congenital heart disease with no venous access to the heart or with a persistent shunt increasing the risk of systemic emboli as well as in young patients with channelopathy or hypertrophic cardiomyopathy not requiring long-term pacing. Technological change (reduction in device size, better differentiation between R- and T-waves, possibility of pacing if device coupled with a leadless pacemaker) could reduce the limitations and complications and thereby increase the indications in this sub-group of patients.
International journal of cardiology 09/2015; 203. DOI:10.1016/j.ijcard.2015.09.083 · 4.04 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Remote monitoring of cardiac implantable devices is rapidly becoming the standard of care for implantable cardiac device follow-up. Large randomized trials demonstrate early detection of technical and clinical problems, but this depends on device-based diagnosis. Transmission of random EGM (rEGM) is a new feature of recent devices which allows for human assessment of the device function. Random EGMs consist in a 7 to 30 second sequence of endocavitary signals (1 to 4 channels), acquired randomly. The objectives of this review are to 1/explain the rEGM specificities according to devices type and manufacturer; 2/ highlight the value of rEGM for device and patient management. Representative examples of rEGM mediated diagnosis of device malfunctions/arrhythmias are presented. The series includes rEGM with apparent: 1) P wave, R wave and noise ventricular oversensing, 2) P wave and R wave undersensing, 3) loss of right ventricular and left ventricular capture, 4) non detected atrial fibrillation and ventricular tachycardia. None triggered conventional alert notifications. Methods to improve rEGM efficiency are also proposed. Detailed analysis of each rEGM must be included in a complete cardiac device remote monitoring evaluation. rEGMs may contain information potentially critical to patients' outcomes.
Heart rhythm: the official journal of the Heart Rhythm Society 09/2015; DOI:10.1016/j.hrthm.2015.09.031 · 5.08 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: -The correlates of left ventricular (LV) substrate in arrhythmogenic right ventricular cardiomyopathy (ARVC) are largely unknown.
-Thirty-two ARVC patients (47±14years, 6 women) were included. RV and LV dysplasia were defined from MDCT and CMR imaging. Arrhythmias were characterized as right-sided or left-sided on 12-lead ECG recordings at baseline and during isoproterenol testing. In 14 patients, the imaging substrate was compared to voltage mapping and local abnormal ventricular activity (LAVA). Imaging abnormalities were found in 32(100%) and 21(66%) patients on the RV and LV, respectively, intra-myocardial fat on MDCT being the most sensitive feature. LV involvement related to none of the Task Force criteria. Right-sided arrhythmias were more frequent than left-sided arrhythmias (P=0.003), although the latter were more frequent in case of LV involvement (P=0.02). The agreement between low voltage and fat on MDCT was high on the RV when using either endocardial unipolar or epicardial bipolar data (k=0.82 and k=0.78, respectively), but lower on the LV (k=0.54 for epicardial bipolar). LV LAVA was found in all patients with LV involvement, and none of the others. The density of LAVA within fat areas was similar between the RV and LV (P=0.57).
-LV substrate is frequent in ARVC, but poorly identified by current diagnostic strategies. Left-sided arrhythmias are more frequent in case of LV involvement. LV fat hosts the same density of LAVA as RV fat, but is less efficiently detected by voltage mapping. These results support the need for alternative diagnostic strategies to identify LV dysplasia.
Circulation Arrhythmia and Electrophysiology 08/2015; DOI:10.1161/CIRCEP.115.003213 · 4.51 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Surgical repair of Tetralogy of Fallot (TOF) is highly successful but may be complicated in adulthood by arrhythmias, sudden death, and right ventricular or biventricular dysfunction. To better understand the molecular and cellular mechanisms of these delayed cardiac events, a chronic animal model of postoperative TOF was studied using microarrays to perform cardiac transcriptomic studies. The experimental study included 12 piglets (7 rTOF and 5 controls) that underwent surgery at age 2 months and were further studied after 23 (+/- 1) weeks of postoperative recovery. Two distinct regions (endocardium and epicardium) from both ventricles were analyzed. Expression levels from each localization were compared in order to decipher mechanisms and signaling pathways leading to ventricular dysfunction and arrhythmias in surgically repaired TOF. Several genes were confirmed to participate in ventricular remodeling and cardiac failure and some new candidate genes were described. In particular, these data pointed out FRZB as a heart failure marker. Moreover, calcium handling and contractile function genes (SLN, ACTC1, PLCD4, PLCZ), potential arrhythmia-related genes (MYO5B, KCNA5), and cytoskeleton and cellular organization-related genes (XIRP2, COL8A1, KCNA6) were among the most deregulated genes in rTOF ventricles. To our knowledge, this is the first comprehensive report on global gene expression profiling in the heart of a long-term swine model of repaired TOF.
PLoS ONE 08/2015; 10(8):e0134146. DOI:10.1371/journal.pone.0134146 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Since more than 100 years, 12-lead electrocardiography (ECG) is the standard-of-care tool, which involves measuring electrical potentials from limited sites on the body surface to diagnose cardiac disorder, its possible mechanism, and the likely site of origin. Several decades of research has led to the development of a 252-lead ECG and computed tomography (CT) scan-based three-dimensional electro-imaging modality to non-invasively map abnormal cardiac rhythms including fibrillation. These maps provide guidance towards ablative therapy and thereby help advance the management of complex heart rhythm disorders. Here, we describe the clinical experience obtained using non-invasive technique in mapping the electrical disorder and guide the catheter ablation of atrial arrhythmias (premature atrial beat, atrial tachycardia, atrial fibrillation), ventricular arrhythmias (premature ventricular beats), and ventricular pre-excitation (Wolff-Parkinson-White syndrome).
Current Cardiology Reports 08/2015; 17(8):616. DOI:10.1007/s11886-015-0616-6 · 1.93 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Substrate-based VT ablation is mostly based on maps acquired with ablation catheters. We hypothesized that multipolar mapping catheters are more effective for identification of scar and local abnormal ventricular activity (LAVA).
Phase1: In a sheep infarction model (2 months post-infarction), substrate mapping and LAVA tagging (CARTO(®) 3) was performed, using a Navistar (NAV) vs. a PentaRay (PR) catheter (Biosense Webster). Phase2: Consecutive VT ablation patients from a single center underwent NAV vs. PR mapping. Point pairs were defined as a PR and a NAV point located within a 3D-distance of ≤3mm. Agreement was defined as both points in a pair being manually tagged as normal or LAVA. Four sheep (4 years, 50±4.8kg) and 9 patients were included (53±14 years, 8 male, 6 ischaemic cardiomyopathy). Mapping density was higher within the scar with PR vs. NAV (3.2 vs. 0.7points/cm(2) , p = 0.001) with larger bipolar scar area (68±55cm(2) vs. 58±48cm(2) , p = 0.001). In total, 818 point pairs were analyzed. Using PR, far-field voltages were smaller (PR vs. NAV; bipolar: 1.43±1.84mV vs. 1.64±2.04mV, p = 0.001; unipolar; 4.28±3.02mV vs. 4.59±3.67mV, p<0.001). More LAVA were also detected with PR (PR vs. NAV; 126±113 vs. 36±29, p = 0.001). When agreement on LAVA was reached (overall: 72%; both LAVA, 40%; both normal, 82%) higher LAVA voltages were recorded on PR (0.48±0.33mV vs. 0.31±0.21mV, p = 0.0001).
Multipolar mapping catheters with small electrodes provide more accurate and higher density maps, with a higher sensitivity to near field signals. Agreement between PR and NAV is low. This article is protected by copyright. All rights reserved.
This article is protected by copyright. All rights reserved.