Frederic Sacher

University of Bordeaux, Burdeos, Aquitaine, France

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Publications (279)1347.13 Total impact

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    ABSTRACT: A 77-year-old male presented for ablation of recurrent VT (CL ∼416ms) in the setting of dilated cardiomyopathy (ejection fraction 45%) secondary to prior myocarditis. Pre-procedural contrast-enhanced CT was used to segment anatomy and map ventricular wall thickness, localizing scar to the basal posterolateral wall (Figure part A, upper panel). Given the myocarditis history, and VT 12-lead ECG showing slurred QRS onset in precordial leads (Figure part B), an epicardial origin was suspected, and a percutaneous epicardial approach selected. Epicardial substrate was continuously mapped (31783 points) during 30 minutes of right ventricular pacing, using the Orion(TM) catheter (Boston Scientific) in a collapsed state (see Figure Legend for beat-acquisition criteria). This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
    Journal of Cardiovascular Electrophysiology 04/2015; DOI:10.1111/jce.12685 · 2.88 Impact Factor
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    ABSTRACT: -Left ventricular assist devices (LVADs) are increasingly used as a bridge to cardiac transplantation or as destination therapy. Patients with LVADs are at high risk for ventricular arrhythmias (VA). This study describes VA characteristics and ablation in patients implanted with a Heart Mate 2 (HM2) device. -All patients with a HM2 device who underwent VA catheter ablation at 9 tertiary centers were included. Thirty-four patients (30 male, age 58 ± 10 years) underwent 39 ablation procedures. The underlying cardiomyopathy etiology was ischemic in 21 and non-ischemic in 13 patients with a mean left ventricular ejection fraction of 17±5% before LVAD implantation. One hundred and ten ventricular tachycardias (VTs) (cycle lengths: 230-740ms, arrhythmic storm n=28) and 2 ventricular fibrillation triggers were targeted (25 transseptal, 14 retrograde aortic approaches). Nine patients required VT ablation <1 month after LVAD implantation due to intractable VT. Only 10/110 (9%) of the targeted VTs were related to the HM2 cannula. During follow-up, 7 patients were transplanted and 10 died. Of the remaining 17 patients, 13 were arrhythmia-free at 25 ± 15 months. In 1 patient with VT recurrence, change of turbine speed from 9400 to 9000 rpm extinguished VT. -Catheter ablation of VT among LVAD recipients is feasible and reasonably safe even soon after LVAD implantation. Intrinsic myocardial scar, rather than the apical cannula, appears to be the dominant substrate.
    Circulation Arrhythmia and Electrophysiology 04/2015; DOI:10.1161/CIRCEP.114.002394 · 5.42 Impact Factor
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    ABSTRACT: Ventricular tachycardia (VT) ablation for ventricular arrhythmias is a validated approach, typically performed endocardially, or combined with an epicardial approach if endocardial ablation failed or in case of non-ischaemic cardiomyopathy. We report our experience with epicardial only procedure in a subset of patients with incessant VT or VT storm. This was a single centre retrospective study. Between 2011 and 2014, all patients referred for VT ablation were reviewed at CHU Bordeaux. All patients with an epicardial only (anterior percutaneous approach) mapping and ablation procedure were included. In total, 296 patients underwent a VT ablation and 4 (all male, 70 ± 7 years, 27 ± 11% left ventricular ejection fraction) of them underwent an epicardial only procedure: two ischaemic patients had an endocardial left ventricular thrombus and incessant VT. One patient post-myocarditis had a failed a previous endocardial procedure without local abnormal ventricular activity (LAVA). The fourth patient had a dilated cardiomyopathy and a complicated epicardial puncture followed by mild continuous bleeding (200 mL) precluding anticoagulation associated with left ventricular endocardial access. Local abnormal ventricular activity elimination was verified only epicardially in all and obtained in two patients and non-inducibility was tested and achieved in the two patients without thrombus. No further complications occurred. After a mean follow-up of 21 ± 12 months, one patient (25%) had recurrence of VT and no patient death was observed. Epicardial only ablation seems feasible and effective and useful in a limited subset of patients with incessant VT. However, endpoints are more difficult to evaluate and long-term follow-up is needed. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.
    Europace 04/2015; DOI:10.1093/europace/euv072 · 3.05 Impact Factor
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    ABSTRACT: -Brugada syndrome (BrS) is a highly arrhythmogenic cardiac disorder, associated with an increased incidence of sudden death. Its arrhythmogenic substrate in the intact human heart remains ill-defined. -Using noninvasive ECG imaging (ECGI), we studied 25 BrS patients to characterize the electrophysiologic substrate, and 6 patients with right bundle branch block (RBBB) for comparison. Seven normal subjects provided control data. Abnormal substrate was observed exclusively in the right ventricular outflow tract (RVOT) with the following properties (compared to normal controls; p<0.005): (1)ST-segment elevation (STE) and inverted T-wave of unipolar electrograms (EGMs) (2.21±0.67 vs. 0 mV); (2)delayed RVOT activation (82±18 vs. 37±11 ms); (3)low amplitude (0.47±0.16 vs. 3.74±1.60 mV) and fractionated EGMs, suggesting slow discontinuous conduction; (4)prolonged recovery time (RT; 381±30 vs. 311±34 ms) and activation-recovery intervals (ARIs; 318±32 vs. 241±27 ms), indicating delayed repolarization; (5)steep repolarization gradients (ΔRT/Δx= 96±28 vs. 7±6 ms/cm, ΔARI/Δx= 105±24 vs. 7±5 ms/cm) at RVOT borders. With increased heart rate in 6 BrS patients, reduced STE and increased fractionation were observed. Unlike BrS, RBBB had delayed activation in the entire RV, without STE, fractionation, or repolarization abnormalities on EGMs. -The results indicate that both, slow discontinuous conduction and steep dispersion of repolarization are present in the RVOT of BrS patients. ECGI could differentiate between BrS and RBBB.
    Circulation 03/2015; DOI:10.1161/CIRCULATIONAHA.114.013698 · 14.95 Impact Factor
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    ABSTRACT: Mitral isthmus (MI) ablation is an effective option in patients undergoing ablation for persistent atrial fibrillation (AF). Achieving bidirectional conduction block across the MI is challenging, and predictors of MI ablation success remain incompletely understood. We sought to determine the impact of anatomical location of the ablation line on the efficacy of MI ablation. A total of 40 consecutive patients (87% Male; 54 ± 10 years) undergoing stepwise AF ablation were included. MI ablation was performed in sinus rhythm. MI ablation was performed from the left inferior PV to either the posterior (Group 1) or the anterolateral (Group 2) mitral annulus depending on randomization. The length of the MI line (measured with the 3D mapping system) and the amplitude of the EGMs at 3 positions on the MI were measured in each patient. MI block was achieved in 14/19 (74%) patients in group 1 and 15/21 (71%) patients in group 2 (p = NS). Total MI radiofrequency time (18 ± 7 min vs. 17 ± 8 min; p = NS) was similar between groups. Patients with incomplete MI block had a longer MI length (34 ± 6 mm vs. 24 ± 5 mm; p < 0.001), a higher bipolar voltage along the MI (1.75 ± 0.74 mV vs. 1.05 ± 0.69mV; p < 0.01), and a longer history of continuous AF (19 ± 17 months vs. 10 ± 10 months; p < 0.05). In multivariate analysis, decreased length of the MI was an independent predictor of successful MI block (OR 1.5; 95% CI 1.1-2.1; p < 0.05). Increased length but not anatomical location of the MI predicts failure to achieve bidirectional MI block during ablation of persistent AF. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
    Journal of Cardiovascular Electrophysiology 03/2015; DOI:10.1111/jce.12667 · 2.88 Impact Factor
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    ABSTRACT: We studied the extent and distribution of left atrial (LA) fibrosis on delayed-enhanced (DE) MRI in a general cardiology population. 190 consecutive patients referred for cardiac MRI underwent DE imaging using a free breathing method. The population comprised 60 AF patients and 130 patients without AF, including 75 with structural heart disease (SHD). DE was quantified using histogram thresholding, expressed in% of the wall. Regression analysis was performed to identify predictors of DE. Additionally, DE was registered on a template to study its distribution in subpopulations. In the total population, age, AF and SHD were independently associated with DE. DE was increasingly observed from 11.1 ± 4.7% in patients with no SHD nor AF, 18.8 ± 7.8% in SHD and no AF history, 22.9 ± 7.8% in paroxysmal AF, to 27.8 ± 7.7% in persistent AF. Among non-AF patients, age and SHD were independently associated with DE. Among AF patients, female gender and AF persistence were independently associated with DE. DE was variably distributed but more frequently detected in the posterior wall. Age, history of AF and SHD are the most powerful predictors of atrial fibrosis, as detected by MRI, in a general cardiology population. Atrial fibrosis predominates in the posterior LA wall. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
    Journal of Cardiovascular Electrophysiology 02/2015; DOI:10.1111/jce.12651 · 2.88 Impact Factor
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    ABSTRACT: -Epicardial ventricular tachycardia (VT) ablation is associated with risks of coronary artery (CA) and phrenic nerve (PN) injury. We investigated the role of multidetector CT (MDCT) in visualizing CA and PN during VT ablation. -Ninety-five consecutive patients (86 males, age 57±15) with VT underwent cardiac MDCT. The PN detection rate and anatomical variability were analyzed. In 49 patients undergoing epicardial mapping, real-time MDCT integration was used to display CAs/PN locations in 3D mapping systems. Elimination of local abnormal ventricular activities (LAVA) was used as ablation endpoint. The distribution of CAs/PN with respect to LAVA was analyzed and compared between VT etiologies. MDCT detected PN in 81 patients (85%). Epicardial LAVAs were observed in 44/49 patients (15 ICM, 15 NICM, 14 ARVC) with a mean of 35±37 LAVA points/patient. LAVAs were located within 1cm from CAs and PN in 35(80%) and 18(37%) patients, respectively. The prevalence of LAVA adjacent to CAs was higher in NICM and ARVC than in ICM (100% vs. 86% vs. 53%, P<0.01). The prevalence of LAVAs adjacent to PN was higher in NICM than in ICM (93% vs. 27%, P<0.001). Epicardial ablation was performed in 37 patients (76%). Epicardial LAVAs could not be eliminated due to the proximity to CAs or PN in 8 patients (18%). -The epicardial electrophysiological VT substrate is often close to CAs and PN in patients with NICM. High-resolution image integration is potentially useful to minimize risks of PN and CA injury during epicardial VT ablation.
    Circulation Arrhythmia and Electrophysiology 02/2015; DOI:10.1161/CIRCEP.114.002420 · 5.42 Impact Factor
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    ABSTRACT: Patients with ventricular tachycardia (VT) and ventricular fibrillation (VF) and no reversible cause are difficult to treat. While implantable defibrillators prolong survival, many patients remain symptomatic due to device shocks and syncope. To address this, there have been recent advances in the catheter ablation of VT and VF. For example, non-invasive imaging has improved arrhythmia substrate characterisation, 3D catheter navigation tools have facilitated mapping of arrhythmia and substrate and ablation catheters have advanced in their ability to deliver effective lesions. However, the long-term success rates of ablation for VT and VF remain modest, with nearly half of treated patients developing recurrence within 2-3 years, and this drives the ongoing innovation in the field. This review focuses on the challenges particular to ablation of life-threatening ventricular arrhythmia, and the strategies that have been recently developed to improve procedural efficacy. Patient sub-groups that illustrate the use of new strategies are described.
    Expert Review of Cardiovascular Therapy 02/2015; 13(3):1-14. DOI:10.1586/14779072.2015.1009039
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    ABSTRACT: The Brugada syndrome (BrS) is a rare heritable cardiac arrhythmia disorder associated with ventricular fibrillation and sudden cardiac death. Mutations in the SCN5A gene have been causally related to BrS in 20-30% of cases. Twenty other genes have been described as involved in BrS, but their overall contribution to disease prevalence is still unclear. This study aims to estimate the burden of rare coding variation in arrhythmia-susceptibility genes among a large group of patients with BrS. We have developed a custom kit to capture and sequence the coding regions of 45 previously reported arrhythmia-susceptibility genes and applied this kit to 167 index cases presenting with a Brugada pattern on the electrocardiogram as well as 167 individuals aged over 65 year-old and showing no history of cardiac arrhythmia. By applying burden tests, a significant enrichment in rare coding variation (with a minor allele frequency below 0.1%) was observed only for SCN5A, with rare coding variants carried by 20.4% of cases with BrS versus 2.4% of control individuals (p=1.4 x 10(-7)). No significant enrichment was observed for any other arrhythmia-susceptibility gene, including SCN10A and CACNA1C. These results indicate that, except for SCN5A, rare coding variation in previously reported arrhythmia-susceptibility genes do not contribute significantly to the occurrence of BrS in a population with European ancestry. Extreme caution should thus be taken when interpreting genetic variation in molecular diagnostic setting, since rare coding variants were observed in a similar extent among cases versus controls, for most previously reported BrS-susceptibility genes. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
    Human Molecular Genetics 02/2015; DOI:10.1093/hmg/ddv036 · 6.68 Impact Factor
  • Archives of Cardiovascular Diseases Supplements 01/2015; 7(1):66. DOI:10.1016/S1878-6480(15)71677-0
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    ABSTRACT: The early repolarization (ER) pattern is associated with an increased risk of arrhythmogenic sudden death. However, strategies for risk stratification of patients with the ER pattern are not fully defined. This study sought to determine the role of electrophysiology studies (EPS) in risk stratification of patients with ER syndrome. In a multicenter study, 81 patients with ER syndrome (age 36 ± 13 years, 60 males) and aborted sudden death due to ventricular fibrillation (VF) were included. EPS were performed following the index VF episode using a standard protocol. Inducibility was defined by the provocation of sustained VF. Patients were followed up by serial implantable cardioverter-defibrillator interrogations. Despite a recent history of aborted sudden death, VF was inducible in only 18 of 81 (22%) patients. During follow-up of 7.0 ± 4.9 years, 6 of 18 (33%) patients with inducible VF during EPS experienced VF recurrences, whereas 21 of 63 (33%) patients who were noninducible experienced recurrent VF (p = 0.93). VF storm occurred in 3 patients from the inducible VF group and in 4 patients in the noninducible group. VF inducibility was not associated with maximum J-wave amplitude (VF inducible vs. VF noninducible; 0.23 ± 0.11 mV vs. 0.21 ± 0.11 mV; p = 0.42) or J-wave distribution (inferior, odds ratio [OR]: 0.96 [95% confidence interval (CI): 0.33 to 2.81]; p = 0.95; lateral, OR: 1.57 [95% CI: 0.35 to 7.04]; p = 0.56; inferior and lateral, OR: 0.83 [95% CI: 0.27 to 2.55]; p = 0.74), which have previously been demonstrated to predict outcome in patients with an ER pattern. Our findings indicate that current programmed stimulation protocols do not enhance risk stratification in ER syndrome. Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.
    Journal of the American College of Cardiology 01/2015; 65(2):151-9. DOI:10.1016/j.jacc.2014.10.043 · 15.34 Impact Factor
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    ABSTRACT: Purpose To evaluate an automated method for the quantification of fat in the right ventricular (RV) free wall on multidetector computed tomography (CT) images and assess its diagnostic value in arrhythmogenic RV cardiomyopathy (ARVC). Materials and Methods This study was approved by the institutional review board, and all patients gave informed consent. Thirty-six patients with ARVC (mean age ± standard deviation, 46 years ± 15; seven women) were compared with 36 age- and sex-matched subjects with no structural heart disease (control group), as well as 36 patients with ischemic cardiomyopathy (ischemic group). Patients underwent contrast material-enhanced electrocardiography-gated cardiac multidetector CT. A 2-mm-thick RV free wall layer was automatically segmented and myocardial fat, expressed as percentage of RV free wall, was quantified as pixels with attenuation less than -10 HU. Patient-specific segmentations were registered to a template to study fat distribution. Receiver operating characteristic (ROC) analysis was performed to assess the diagnostic value of fat quantification by using task force criteria as a reference. Results Fat extent was 16.5% ± 6.1 in ARVC and 4.6% ± 2.7 in non-ARVC (P < .0001). No significant difference was observed between control and ischemic groups (P = .23). A fat extent threshold of 8.5% of RV free wall was used to diagnose ARVC with 94% sensitivity (95% confidence interval [CI]: 82%, 98%) and 92% specificity (95% CI: 83%, 96%). This diagnostic performance was higher than the one for RV volume (mean area under the ROC curve, 0.96 ± 0.02 vs 0.88 ± 0.04; P = .009). In patients with ARVC, fat correlated to RV volume (R = 0.63, P < .0001), RV function (R = -0.67, P = .001), epsilon waves (R = 0.39, P = .02), inverted T waves in V1-V3 (R = 0.38, P = .02), and presence of PKP2 mutations (R = 0.59, P = .02). Fat distribution differed between patients with ARVC and those without, with posterolateral RV wall being the most ARVC-specific area. Conclusion Automated quantification of RV myocardial fat on multidetector CT images is feasible and performs better than RV volume in the diagnosis of ARVC. © RSNA, 2015 Online supplemental material is available for this article.
    Radiology 01/2015; DOI:10.1148/radiol.14141140 · 6.21 Impact Factor
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    ABSTRACT: Biventricular pacing (BVP) may not achieve complete electrical resynchronization. To assess whether the resynchronizing effect of BVP varies among patients depending on the underlying electrical substrate. High resolution electrocardiographic mapping with invasive measurement of Left Ventricular (LV) dP/dtmax were performed during baseline activation and during BVP in 61 heart failure patients with various conduction delays: 13 narrow QRS (<120ms), 22 nonspecific intraventricular conduction disturbance and 26 left bundle branch block. Electrical dyssynchrony, both during baseline and BVP, was quantified by total and LV activation times (TAT and LVTAT) and by ventricular electrical uncoupling (VEU = mean LV - mean RV activation time). Response to BVP was defined as a ≥10% LVdP/dtmax increase. The electrical activation pattern during BVP was similar for all patient groups and, hence, not dependent on the baseline conduction disturbance. During BVP, TAT, LVTAT and VEU were similar for all groups and correlated not/weakly with the change in LVdP/dtmax. In contrast, the changes in electrical dyssynchrony correlated significantly with the change in LVdP/dtmax: r=0.71, 0.69, and 0.69 for ∆TAT, ∆LVTAT and ∆VEU, respectively (all p<0.001). Responders showed higher baseline dyssynchrony levels and BVP-induced dyssynchrony reduction than nonresponders (all p<0.001); in nonresponders BVP worsened activation times compared to baseline. BVP does not eliminate electrical dyssynchrony but rather brings it to a common level independent of the patient's underlying electrical substrate. Therefore, BVP is of benefit to dyssynchronous patients but not to patients with insufficient electrical dyssynchrony in whom it induces an iatrogenic electropathy. Copyright © 2014. Published by Elsevier Inc.
    Heart rhythm: the official journal of the Heart Rhythm Society 12/2014; DOI:10.1016/j.hrthm.2014.12.031 · 4.92 Impact Factor
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    ABSTRACT: Several decades of research has led to the development of a 252-lead electrocardiogram-based three-dimensional imaging modality to refine noninvasive diagnosis and improve the management of heart rhythm disorders. This article reviews the clinical potential of this noninvasive mapping technique in identifying the sources of electrical disorders and guiding the catheter ablation of ventricular arrhythmias (premature ventricular beats and ventricular tachycardia). The article also briefly refers to the noninvasive electrical imaging of the arrhythmogenic ventricular substrate based on the electrophysiologic characteristics of postinfarction ventricular myocardium. Copyright © 2015 Elsevier Inc. All rights reserved.
    Cardiac electrophysiology clinics 12/2014; 7(1). DOI:10.1016/j.ccep.2014.11.014
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    ABSTRACT: -This study aimed to determine five-year efficacy of catheter ablation for persistent atrial fibrillation (PsAF) using AF termination as a procedural endpoint. -150 patients (57±10 years) underwent PsAF ablation using a stepwise ablation approach (pulmonary vein isolation, electrogram-guided and linear ablation) with the desired procedural endpoint being AF termination. Repeat ablation was performed for recurrent AF or atrial tachycardia (AT). AF was terminated by ablation in 120 patients (80%). Arrhythmia-free survival rates after a single procedure were 35.3±3.9%, 28.0±3.7%, and 16.8±3.2% at 1, 2, and 5 years, respectively. Arrhythmia-free survival rates after the last procedure (mean 2.1±1.0 procedures) were 89.7±2.5%, 79.8±3.4%, and 62.9±4.5%, at 1, 2, and 5 years, respectively. During a median follow-up of 58 (IQR 43-73) months following the last ablation procedure, 97 of 150 (64.7%) patients remained in sinus rhythm without antiarrhythmic drugs (AADs). Another 14 (9.3%) patients maintained sinus rhythm after re-initiation of AADs, and an additional 15 (10.0%) patients regressed to paroxysmal recurrences only. Failure to terminate AF during the index procedure (HR 3.831; 95%CI: 2.070-7.143; p<0.001), left atrial diameter ≥50mm (HR 2.083; 95%CI: 1.078-4.016; p=0.03), continuous AF duration ≥18 months (HR 1.984; 95%CI: 1.024-3.846; p<0.04) and structural heart disease (HR 1.874; 95% CI: 1.037-3.388; p=0.04) predicted arrhythmia recurrence. -In patients with PsAF, an ablation strategy aiming at AF termination is associated with freedom from arrhythmia recurrence in the majority of patients over a 5-year follow up period.Procedural AF non-termination and specific baseline factors predict long-term outcome after ablation.
    Circulation Arrhythmia and Electrophysiology 12/2014; 8(1). DOI:10.1161/CIRCEP.114.001943 · 5.42 Impact Factor
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    ABSTRACT: Little is presently known about the outcome of atrial lesions performed with high-intensity focused ultrasound (HIFU) for atrial fibrillation ablation. We aimed to assess endocardial atrial lesions 6 months after epicardial HIFU ablation (Epicor(™)) and to evaluate the benefit of a combined ablation approach.
    Journal of Interventional Cardiac Electrophysiology 11/2014; DOI:10.1007/s10840-014-9949-0 · 1.55 Impact Factor
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    ABSTRACT: Purpose: Radio frequency catheter ablation (RFCA) is a well-established clinical procedure for the treatment of atrial fibrillation (AF) but suffers from a low single-procedure success rate. Recurrence of AF is most likely attributable to discontinuous or nontransmural ablation lesions. Yet, despite this urgent clinical need, there is no clinically available imaging modality that can reliably map the lesion transmural extent in real time. In this study, the authors demonstrated the feasibility of shear-wave elastography (SWE) to map quantitatively the stiffness of RFCA-induced thermal lesions in cardiac tissues in vitro and in vivo using an intracardiac transducer array. Methods: SWE was first validated in ex vivo porcine ventricular samples (N = 5). Both B-mode imaging and SWE were performed on normal cardiac tissue before and after RFCA. Areas of the lesions were determined by tissue color change with gross pathology and compared against the SWE stiffness maps. SWE was then performed in vivo in three sheep (N = 3). First, the stiffness of normal atrial tissues was assessed quantitatively as well as its variation during the cardiac cycle. SWE was then performed in atrial tissue after RFCA. Results: A large increase in stiffness was observed in ablated ex vivo regions (average shear modulus across samples in normal tissue: 22 ± 5 kPa, average shear-wave speed (ct ): 4.5 ± 0.4 m s−1 and in determined ablated zones: 99 ± 17 kPa, average ct : 9.0 ± 0.5 m s−1 for a mean shear modulus increase ratio of 4.5 ± 0.9). In vivo, a threefold increase of the shear modulus was measured in the ablated regions, and the lesion extension was clearly visible on the stiffness maps. Conclusions: By its quantitative and real-time capabilities, Intracardiac SWE is a promising intraoperative imaging technique for the evaluation of thermal ablation during RFCA.
    Medical Physics 10/2014; 41(11):2901. DOI:10.1118/1.4896820 · 3.01 Impact Factor
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    ABSTRACT: -Congenital Long QT syndrome (LQTS) is an arrhythmogenic disorder that causes syncope and sudden death. While its genetic basis has become well-understood, the mechanisms whereby mutations translate to arrhythmia susceptibility in the in situ human heart have not been fully defined. We used noninvasive ECG imaging (ECGI) to map the cardiac electrophysiologic substrate and examine whether LQTS patients display regional heterogeneities in repolarization, a substrate which promotes arrhythmogenesis.
    Circulation 10/2014; DOI:10.1161/CIRCULATIONAHA.114.011359 · 14.95 Impact Factor
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    ABSTRACT: Catheter ablation of ventricular tachycardia (VT) is proven effective therapy particularly in patients with frequent defibrillator shocks. However, the optimal endpoint for VT ablation has been debated and additional endpoints have been proposed. At the same time, ablation strategies aiming at homogenizing the substrate of scar related VT have been reported.Our method to homogenize the substrate consists of local abnormal ventricular activity (LAVA) elimination. LAVA are high frequency sharp signals that represent near-field signals of slowly conducting tissue and hence potential VT isthmuses. Pacing maneuvers are sometimes required to differentiate them from far-field signals. Delayed enhancement on cardiac MRI and/or wall thinning on Multi-Detector Computed Tomography are also extremely helpful to identify the areas of interest during ablationA strategy aiming at careful LAVA mapping, ablation and elimination is feasible and can be achieved in about 70% of patients with scar related VT. Complete LAVA elimination is associated with a better outcome when compared to LAVA persistence even when VT is rendered non-inducible.This is a simple approach, with a clear endpoint and the ability to ablate in sinus rhythm. This strategy significantly benefits from high definition imaging, mapping, and epicardial access.This article is protected by copyright. All rights reserved.
    Journal of Cardiovascular Electrophysiology 10/2014; DOI:10.1111/jce.12565 · 2.88 Impact Factor
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    ABSTRACT: Background-The optimal contact force (CF) for ventricular mapping and ablation remains unvalidated. We assessed CF in different endocardial and epicardial regions during ventricular tachycardia substrate mapping using a CF-sensing catheter (Smartouch; Biosense-Webster) and compared the transseptal versus retroaortic approach. Methods and Results-In total, 8979 mapping points with CF, and force vector orientation (VO) were recorded in 21 patients, comprising 13 epicardial, 12 left ventricular (6 transseptal and 6 retroaortic approach), and 12 right ventricular endocardial maps. VO was defined as adequate when the vector was directed toward the myocardium. During epicardial mapping, 46% of the points showed an adequate VO and a median CF of 8 (4-13) g, however, with significant differences among the 8 regions. When VO was inadequate, median CF was higher at 16 (10-24) g (P<0.0001). During left ventricular and right ventricular endocardial mapping, 94% of VO were adequate. Median CF of adequate VO was higher in the left ventricular and right ventricular endocardium than in the epicardium (15 [8-25] and 13 [7-22] g versus 8 [4-13] g, respectively; both P<0.001). Global median left ventricular CF with transseptal approach was not statistically different from retroaortic approach, but CF in the apicoinferior and apicoseptal regions was higher with transseptal approach (P< 0.001). Conclusions-Ventricular mapping demonstrates important regional variations in CF, but in general, CF is higher endocardially than epicardially where poor catheter orientation is associated with higher CF. A transseptal approach may lead to improved contact particularly in the apicoseptal and inferior regions.
    Circulation Arrhythmia and Electrophysiology 09/2014; 7(6). DOI:10.1161/CIRCEP.113.001219 · 5.42 Impact Factor

Publication Stats

7k Citations
1,347.13 Total Impact Points

Institutions

  • 2006–2015
    • University of Bordeaux
      Burdeos, Aquitaine, France
    • Yokohama Rosai Hospital
      Yokohama, Kanagawa, Japan
  • 2004–2015
    • Université Victor Segalen Bordeaux 2
      Burdeos, Aquitaine, France
  • 2013
    • French National Centre for Scientific Research
      Lutetia Parisorum, Île-de-France, France
  • 2010
    • University-Hospital Brugmann UVC
      Bruxelles, Brussels Capital Region, Belgium
    • Brigham and Women's Hospital
      Boston, Massachusetts, United States
  • 2008–2010
    • Harvard University
      Cambridge, Massachusetts, United States
    • Isala Klinieken
      • Department of Cardiology
      Zwolle, Overijssel, Netherlands
  • 2009
    • University of Amsterdam
      • Faculty of Medicine AMC
      Amsterdamo, North Holland, Netherlands
  • 2004–2009
    • Centre Hospitalier Universitaire de Bordeaux
      Burdeos, Aquitaine, France
  • 2007–2008
    • Harvard Medical School
      • Department of Medicine
      Boston, Massachusetts, United States
    • Universität Heidelberg
      Heidelburg, Baden-Württemberg, Germany