Felipe Atienza

Hospital General Universitario Gregorio Marañón, Madrid, Madrid, Spain

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Publications (86)425.03 Total impact

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    ABSTRACT: Current indications for implantable cardioverter defibrillators (ICDs) in patients with channelopathies and cardiomyopathies of non-ischemic origin are mainly based on non-randomized evidence. In patients with nonischemic dilated cardiomyopathy (NIDCM) there is a tendency towards a beneficial effect on total mortality of ICD therapy in patients with significant left ventricular (LV) dysfunction. Although an important reduction in sudden cardiac death (SCD) seems to be clearly demonstrated in these patients, a net beneficial effect on total mortality is unclear mostly in cases with good functional status. Risk stratification has been changing over the last two decades in patients with hypertrophic cardiomyopathy (HCM). Its risk profile has been delineated in parallel with the beneficial effect of ICD in high risk patients. Observational results based on "appropriate" ICD interventions does support its usefulness both in primary and secondary SCD prevention in these patients. Novel risk models quantify the rate of sudden cardiac death in these patients on individual basis. Less clear risk stratification is available for cases of arrhythmogenic right ventricular cardiomyopathy (ARVC) and in other uncommon familiar cardiomyopathies. Main features of risk stratification vary among the different channelopathies (long QT syndrome -LQTS-, Brugada syndrome, etc) with great debate on the management of asymptomatic patients. For most familiar cardiomyopathies ICD therapy is the only accepted strategy in the prevention of SCD. So far, genetic testing has a limited role in risk assessment and management of the individual patient. This review aims to summarize these criticisms and to refine the current indications of ICD implantation in patients with cardiomyopathies and major channelopathies.
    Reviews on Recent Clinical Trials 04/2015; 10(2). · 1.07 Impact Factor
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    ABSTRACT: Rivaroxaban is a once-daily oral anticoagulant currently marketed for the prevention of stroke and systemic embolism in patients with non-valvular atrial fibrillation. This indication is largely based on the results of the ROCKET-AF trial. Although these results are robust, studies performed in clinical practice are necessary to confirm these data in real-life patients. These studies have shown rates of stroke and bleeding similar to that found in ROCKET-AF. As an anticoagulant, attention should be paid to making a correct prescription of rivaroxaban, particularly in fragile patients, to reduce the risk of bleeding. In addition, a number of studies have shown that rivaroxaban is cost-effective in clinical practice. Moreover, rivaroxaban is a good alternative to warfarin in patients undergoing elective cardioversion or atrial fibrillation ablation.
    Expert Review of Cardiovascular Therapy 04/2015; 13(4):341-53. DOI:10.1586/14779072.2015.1026259
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    ABSTRACT: Experimental and clinical data demonstrate that atrial fibrillation (AF) maintenance in animals and groups of patients depends on localized reentrant sources localized primarily to the pulmonary veins (PVs) and the left atrium(LA) posterior wall in paroxysmal AF but elsewhere, including the right atrium (RA), in persistent AF. Moreover, AF can be eliminated by directly ablating AF-driving sources or "rotors," that exhibit high-frequency, periodic activity. The RADAR-AF randomized trial demonstrated that an ablation procedure based on a more target-specific strategy aimed at eliminating high frequency sites responsible for AF maintenance is as efficacious as and safer than empirically isolating all the PVs. In contrast to the standard ECG, global atrial noninvasive frequency analysis allows non-invasive identification of high-frequency sources before the arrival at the electrophysiology laboratory for ablation. Body surface potential map (BSPM) replicates the endocardial distribution of DFs with localization of the highest DF (HDF) and can identify small areas containing the high-frequency sources. Overall, BSPM had a sensitivity of 75% and specificity of 100% for capturing intracardiac EGMs as having LARA DF gradient. However, raw BSPM data analysis of AF patterns of activity showed incomplete and instable reentrant patterns of activation. Thus, we developed an analysis approach whereby a narrow band-pass filtering allowed selecting the electrical activity projected on the torso at the HDF, which stabilized the projection of rotors that potentially drive AF on the surface. Consequently, driving reentrant patterns ("rotors") with spatiotemporal stability during >70% of the AF time could be observed noninvasibly after HDF-filtering. Moreover, computer simulations found that the combination of BSPM phase mapping with DF analysis enabled the discrimination of true rotational patterns even during the most complex AF. Altogether, these studies show that the combination of DF analysis with phase maps of HDF-filtered surface ECG recordings allows noninvasive localization of atrial reentries during AF and further a physiologically-based rationale for personalized diagnosis and treatment of patients with AF.
    Cardiac electrophysiology clinics 03/2015; 7(1):59-69. DOI:10.1016/j.ccep.2014.11.002
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    ABSTRACT: Empiric circumferential pulmonary vein isolation (CPVI) has become the therapy of choice for drug-refractory atrial fibrillation (AF). Although results are suboptimal, it is unknown whether mechanistically-based strategies targeting AF drivers are superior. This study sought to determine the efficacy and safety of localized high-frequency source ablation (HFSA) compared with CPVI in patients with drug-refractory AF. This prospective, multicenter, single-blinded study of 232 patients (age 53 ± 10 years, 186 males) randomized those with paroxysmal AF (n = 115) to CPVI or HFSA-only (noninferiority design) and those with persistent AF (n = 117) to CPVI or a combined ablation approach (CPVI + HFSA, superiority design). The primary endpoint was freedom from AF at 6 months post-first ablation procedure. Secondary endpoints included freedom from atrial tachyarrhythmias (AT) at 6 and 12 months, periprocedural complications, overall adverse events, and quality of life. In paroxysmal AF, HFSA failed to achieve noninferiority at 6 months after a single procedure but, after redo procedures, was noninferior to CPVI at 12 months for freedom from AF and AF/AT. Serious adverse events were significantly reduced in the HFSA group versus CPVI patients (p = 0.02). In persistent AF, there were no significant differences between treatment groups for primary and secondary endpoints, but CPVI + HFSA trended toward more serious adverse events. In paroxysmal AF, HFSA failed to achieve noninferiority at 6 months but was noninferior to CPVI at 1 year in achieving freedom of AF/AT and a lower incidence of severe adverse events. In persistent AF, CPVI + HFSA offered no incremental value. (Radiofrequency Ablation of Drivers of Atrial Fibrillation [RADAR-AF]; NCT00674401). Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.
    Journal of the American College of Cardiology 12/2014; 64(23). DOI:10.1016/j.jacc.2014.09.053 · 15.34 Impact Factor
  • Cardiac electrophysiology clinics 12/2014;
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    ABSTRACT: Atrial fibrillation (AF) results in a remodeling of the electrical and structural characteristics of the cardiac tissue which dramatically reduces the efficacy of pharmacological and catheter-based ablation therapies. Recent experimental and clinical results have demonstrated that the complexity of the fibrillatory process significantly differs in paroxysmal versus persistent AF; however, the lack of appropriate research models of remodeled atrial tissue precludes the elucidation of the underlying AF mechanisms and the identification of appropriated therapeutic targets. Here, we summarize the different research models used to date, highlighting the lessons learned from them and pointing to the new doors that should be open for the development of innovative treatments for AF.
    Expert Review of Cardiovascular Therapy 11/2014; DOI:10.1586/14779072.2015.986465
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    ABSTRACT: Ventricular fibrillation is routinely induced during implantable-cardioverter defibrillator insertion to assess defibrillator performance, but this strategy is experiencing a progressive decline.
  • Revista Espanola de Cardiologia 08/2014; 67(8). DOI:10.1016/j.rec.2014.03.016 · 3.34 Impact Factor
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    ABSTRACT: Introduction: The role of tissue remodeling in the reentrant activity during atrial fibrillation (AF) is not well understood. The aim of this study is to evaluate in an in-vitro model of AF the role of tissue remodeling in the mechanisms of perpetuation of this arrhythmia. Methods: HL-1 cultures were obtained for early stage (6.1 ± 1.3 days in culture, N=10) and late stage (11.7 ± 0.5 days in culture, N=8) AF. Bright field images together with optical calcium mapping (Rhod-2AM staining) were obtained for evaluating remodeling and electrophysiological characteristics of cell cultures. Results: The number of singularity points per square centimeter at baseline was significantly higher in the late stage group (i.e. 0.43±0.19 vs. 1.12±0.14 PS/cm2, p <0.01) and showed an inverse correlation with the degree of homogeneity in the corresponding bright field microscopy images (R2=0.78, p <0.01) (Fig.1). These results demonstrate that the electrical complexity in the dish increased with the culture time. Rotor dynamics (i.e. curvature and rotor movement) were significantly correlated with the amount of PSs in the cultures (R2=0.86 and R2=0.79 respectively, Fig. 1). Conclusion: Early and late stage HL-1 cell cultures present different degrees of electrophysiological complexity. Dynamics of functional reentries may be the main responsible for the increased complexity of remodeled cell cultures.
    Cardiovascular Research 07/2014; 103(suppl 1):S20. DOI:10.1093/cvr/cvu082.55 · 5.81 Impact Factor
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    ABSTRACT: BACKGROUND Ablation is an effective therapy in patients with atrial fibrillation (AF) in which an electrical driver can be identified. OBJECTIVE The aim of this study was to present and discuss a novel and strictly noninvasive approach to map and identify atrial regions responsible for AF perpetuation. METHODS Surface potential recordings of 14 patients with AF were recorded using a 67-lead recording system. Singularity points (SPs) were identified in surface phase maps after band-pass filtering at the highest dominant frequency (H DE). Mathematical models of combined atria and torso were constructed and used to investigate the ability of surface phase maps to estimate rotor activity in the atrial wall. RESULTS The simulations show that surface SPs originate at atrial SPs, but not all atrial SPs are reflected at the surface. Stable SPs were found in AF signals during 8.3% +/- 5.7% vs 73.1% +/- 16.8% of the time in unfiltered vs HDF-filtered patient data, respectively (P < .01). The average duration of each rotational pattern was also Lower in unfiltered than in HDF-filtered AF signals (160 +/- 43 ms vs 342 +/- 138 ms; P < .01), resulting in 2.8 +/- 0.7 rotations per rotor. Band-pass filtering reduced the apparent meandering of surface HDF rotors by reducing the effect of the atrial electrical activity occurring at different frequencies. Torso surface SPs representing HDF rotors during AF were reflected at specific areas corresponding to the fastest atrial location. CONCLUSION Phase analysis of surface potential signals after HDF filtering during AF shows reentrant drivers localized to either the left atrium or the right atrium, helping in localizing ablation targets.
    Heart rhythm: the official journal of the Heart Rhythm Society 05/2014; 11(9). DOI:10.1016/j.hrthm.2014.05.013 · 4.92 Impact Factor
  • Revista Espa de Cardiologia 03/2014; 67(8). DOI:10.1016/j.recesp.2013.10.029 · 3.34 Impact Factor
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    ABSTRACT: Background Ablation is an effective therapy in atrial fibrillation (AF) patients in which an electrical driver can be identified. Objective The aim of this study is to present and discuss a novel and strictly non-invasive approach to map and identify atrial regions responsible for AF perpetuation. Methods Surface potential recordings of 14 patients with AF were recorded using a 67-lead recording system. Singularity points (SPs) were identified in surface phase maps after band-pass filtering at the highest dominant frequency (HDF). Mathematical models of combined atria and torso were constructed and used to investigate the ability of surface phase maps to estimate rotor activity in the atrial wall. Results The simulations show that surface SPs originate at atrial SPs, but not all atrial SPs are reflected at the surface. Stable SPs were found in AF signals during 8.3±5.7% vs. 73.1±16.8% of the time in unfiltered vs. HDF-filtered patient data respectively (p<0.01). The average duration of each rotational pattern was also lower in unfiltered than in HDF-filtered AF signals (160±43 vs. 342±138 ms, p<0.01) resulting in 2.8±0.7 rotations per rotor. Band-pass filtering reduced the apparent meandering of surface HDF rotors by reducing the effect of the atrial electrical activity taking place at different frequencies. Torso surface SPs representing HDF rotors during AF were reflected at specific areas corresponding to the fastest atrial location. Conclusion Phase analysis of surface potential signals after HDF-filtering during AF shows reentrant drivers localized to either the LA or RA, helping in localizing ablation targets.
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    ABSTRACT: The aim of this study is to evaluate the safety and feasibility of using the Amigo Remote Catheter System (RCS) in arrhythmia ablation procedures. Because Amigo allows the physician to operate all catheter function outside of the radiation field, operator exposure time was also evaluated. This is a nonrandomized, prospective clinical trial conducted at 1 site (identifier: NCT01834872). The study prospectively enrolled 50 consecutive patients (mean age 59 ± 15 years, 72% men) with any type of arrhythmia (23 atrial fibrillation ablation, 12 common atrial flutters, 10 patients with other supraventricular tachycardia, 4 ventricular tachycardia, and 1 patient with palpitations with no arrhythmia induced) referred for catheter ablation, in which we used RCS. Fifty matched ablation procedures (mean age 57 ± 14 years, 70% men) performed during the same time period, without RCS, were enrolled into the control group. Acute ablation success was 96% with RCS and 98% in the manual group. In only 2 cases, the physician switched to manual ablation (1 ventricular tachycardia and 1 accessory pathway) to complete the procedure. There were no complications related to the use of RCS. No differences were observed in total procedure time, total fluoroscopy time, or total radiofrequency delivery compared with the manual group. In procedures performed with RCS, the operator's fluoroscopy exposure time was reduced by 68 ± 16%. In conclusion, arrhythmia ablation with RCS is safe and feasible. Furthermore, it significantly reduces operator's exposure to radiation.
    The American journal of cardiology 12/2013; 113(5). DOI:10.1016/j.amjcard.2013.11.030 · 3.43 Impact Factor
  • Circulation Arrhythmia and Electrophysiology 12/2013; 6(6):e80-e84. DOI:10.1161/CIRCEP.113.000430 · 5.42 Impact Factor
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    ABSTRACT: Radiofrequency ablation (RFCA) of septal accessory pathway (SAPs) locations is associated with a significant rate of first procedure failures and complications. Several single-center studies suggest that cryothermal ablation might be a safer alternative. The purpose of our study was to systematically review the available literature, including the nonpublished experience of our center, and to compare the safety and efficacy of RFCA vs cryoablation of SAPs. We conducted an electronic search in MEDLINE guided by key terms. In addition, manual review of editorials, review articles, textbooks, and guidelines was undertaken. The search was restricted to studies in humans and publication dates between January 1991 and December 2012. We recorded patient numbers, demographics, procedural data, outcome data, and procedural complications. A random effects meta-analysis model was performed using Stata (version 10.1, StataCorp, College Station, TX). Of the 927 articles screened, 128 were selected for detailed review and 55 were finally retained for analysis: 35 reported RFCA between 1991 and 2012, 20 articles reported cryoablation between 2002 and 2012. Of them, 24 studies referred totally or partially to pediatric patients. Additionally, we included our single-center experience of 118 consecutive SAPs undergoing cryoablation. Overall, 3775 patients constitute our study population: 3328 in the RFCA cohort and 447 in the cryoablation cohort. Efficacy outcomes consistently favored RFCA compared to cryoablation. Acute procedural success rate of cryoablation was 84% (95% confidence interval [CI] 78%-88%) vs RFCA 90% (95% CI 87%-92%). Recurrence rate of cryoablation was 21% (95% CI 18%-26%) vs RFCA 11% (95% CI 10%-12%). Long-term success rate after multiple ablation procedures of cryoablation was 73% (95% CI 63%-81%) vs RFCA 90% (95% CI 86%-93%). There were no reported cases of persistent AV block with cryoablation compared to 2.8% (95% CI 2.2%-3.5%) with RFCA. Studies of RFCA for treatment of SAPs report higher efficacy rates than do studies using cryoablation. However, the excellent safety profile of cryoablation makes it the energy of choice in high-risk SAP ablation, particularly in young individuals.
    Heart rhythm: the official journal of the Heart Rhythm Society 11/2013; 10(11):1753-4. DOI:10.1016/j.hrthm.2013.09.050 · 4.92 Impact Factor
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    ABSTRACT: BACKGROUND: In patients with organic intraventricular conduction defects (IVCDs), (1) QRS morphology during sinus rhythm frequently meets ventricular tachycardia (VT) morphological criteria and (2) there are further rate-related changes in QRS morphology. OBJECTIVE: To search for the best morphological criteria in this context. METHODS: We prospectively studied 69 patients, in sinus rhythm, with QRS duration >/=120 ms. Continuous rapid atrial pacing (RAP) trains were introduced at increasing rates in order to mimic supraventricular tachycardia. We analyzed the specificity of VT criteria during RAP. Finally, we used the criteria with a specificity of >/=0.9 in a "test sample" of 53 patients with preexisting IVCD and wide complex tachycardia to confirm their validity. RESULTS: Only 10 of the 20 analyzed criteria had a specificity of >/=0.9 during RAP at the highest rate. The specificity of these 10 criteria was confirmed in the test sample. The best accuracy to diagnose VT was obtained: for an isolated criterion: "R-wave peak time (RWPT) >/=50 ms at lead II" (specificity = 0.97; sensitivity = 0.67); for an algorithm: the combination of 2 criteria "RWPT >/=50 ms at lead II" and "absence of RS patterns in precordial leads" (specificity = 0.97; sensitivity = 0.88). CONCLUSIONS: In patients with IVCD, (1) specificity of most VT criteria is low during RAP, suggesting a limited applicability of many of these criteria in case they develop supraventricular tachycardia, and (2) the superior accuracy to diagnose VT was observed with "RWPT >/=50 ms at lead II" and for an algorithm with the combination of "RWPT >/=50 ms at lead II" and "absence of RS patterns in precordial leads."
    Circulation 09/2013; 10(9-9):1393-401. DOI:10.1016/j.hrthm.2013.07.006 · 14.95 Impact Factor
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    ABSTRACT: AIMS: Pulmonary vein ganglia (PVG) are targets for atrial fibrillation ablation. However, the functional relevance of PVG to the normal heart rhythm remains unclear. Our aim was to investigate whether PVG can modulate sinoatrial node (SAN) function.Methods and Results49 C57BL and 7 Connexin40(+/EGFP) mice were studied. We used tyrosine-hydroxylase (TH) and choline-acetyltransferase (ChAT) immunofluorescence labeling to characterize adrenergic and cholinergic neural elements. PVG projected postganglionic nerves to the SAN which entered the SAN as an extensive, mesh-like neural network. PVG neurons were adrenergic, cholinergic and biphenotypic. Histochemical characterization of 2 human embryonic hearts showed similarities between mouse and human neuroanatomy: direct neural communications between PVG and SAN. In Langendorff-perfused mouse hearts PVG were stimulated using 200-2000&emsp14;ms trains of pulses (300&emsp14;µs, 400&emsp14;µA, 200&emsp14;Hz). PVG stimulation caused an initial heart rate (HR) slowing (36±9%) followed by acceleration. PVG stimulation in the presence of propranolol caused HR slowing (43±13%) that was sustained over 20 beats. PVG stimulation with atropine progressively increased HR. Time-course effects were enhanced with 1000 and 2000&emsp14;ms trains (P<0.05 vs 200&emsp14;ms). In optical mapping PVG stimulation shifted the origin of SAN discharges. In 5 paroxysmal AF patients undergoing PV ablation, application of radiofrequency energy to the PVG area during sinus rhythm produced a decrease in heart rate similar to that observed in isolated mouse hearts. CONCLUSIONS: PVG have functional and anatomical biphenotypic characteristics. They can have significant effects on the electrophysiological control of the SAN.
    Cardiovascular Research 04/2013; DOI:10.1093/cvr/cvt081 · 5.81 Impact Factor

Publication Stats

1k Citations
425.03 Total Impact Points

Institutions

  • 2004–2015
    • Hospital General Universitario Gregorio Marañón
      • Department of Cardiology
      Madrid, Madrid, Spain
  • 2014
    • Instituto de Investigación Sanitaria Gregorio Marañón
      Madrid, Madrid, Spain
  • 2013
    • University Foundation San Pablo CEU
      Madrid, Madrid, Spain
  • 2009
    • Complutense University of Madrid
      • Departamento de Medicina
      Madrid, Madrid, Spain
  • 2007
    • University Carlos III de Madrid
      Getafe, Madrid, Spain
  • 2006
    • State University of New York Upstate Medical University
      • Department of Pharmacology
      Syracuse, NY, United States
  • 2000
    • Consorcio Hospital General Universitario de Valencia
      • Departamento de Cardiología
      Valencia, Valencia, Spain