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Cryoablation is safe and effective for the treatment of atrial fibrillation (AF) in controlled clinical trials, but contemporary real-world usage and outcomes are limited. The Report of the Spanish Cryoballoon Ablation Registry (RECABA) was designed to evaluate acute and 12-month outcomes of cryoballoon ablation for the treatment of AF in Spain. Patients from 27 Spanish centers were prospectively enrolled. Patients were treated with cryoballoon ablation and managed according to standard of care protocols at each center. The primary endpoint was ≥ 30 s freedom from AF at 12-month after a 3-month blanking period. Secondary endpoints included a description of patient characteristics, cryoablation procedural strategy and safety, and predictors of efficacy. In total, 1742 patients (71.4% PAF, 68.8% male, mean age 58.02 ± 10.40 years, 76.1% overweight or obese, CHA2DS2-VASc index 1.40 ± 1.28) were enrolled. Patients received 7.2 ± 2.67 cryo-applications. PV potentials could be detected in 61% of the PVs during ablation, with a mean time to block of 52.9 ± 37.02 s. Acute PVI was observed in 97% of PVs with 75.8% isolated with the first cryo-application. Mean procedural time was 113 ± 41 min. Acute complications occurred in 4.4% of the cases. With follow-up in 1628 patients, AF-free survival was 78.5% (PAF: 80.6% vs PersAF 73.3%; p ClinicalTrials.gov number: NCT02785991.

Background Cryoablation is safe and effective for the treatment of atrial fibrillation (AF) in controlled clinical trials, but contemporary real-world usage and outcomes are limited. Objectives The Report of the Spanish Cryoballoon Ablation Registry (RECABA) was designed to evaluate acute and 12-month outcomes of cryoballoon ablation for the treatment of AF in Spain. Methods Patients from 27 Spanish centers were prospectively enrolled. Patients were treated with cryoballoon ablation and managed according to standard of care protocols at each center. Theprimary endpoint was ≥ 30 sec freedom from AF at 12-mo after a 3-mo blanking period. Secondary endpoints included a description of patient characteristics, cryoablation procedural strategy and safety, and predictors of efficacy. Results In total, 1742 patients (71.4% PAF, 68.8% male, mean age 58.02 ± 10.40 years, 76.1% overweight or obese, CHA2DS2-VASc index 1.40 ± 1.28) were enrolled. Patients received 7.2 ± 2.67 cryoapplications. PV potentials could be detected in 61% of the PVs during ablation, with a mean time to block of 52.9 ± 37.02 seconds. Acute PVI was observed in 97% of PVs with 75.8% isolated with the first cryoapplication. Mean procedural time was 113 ± 41 minutes. Acute complications occurred in 4.4% of the cases21. With follow-up in 1628 patients, AF-free survival was 78.5% (PAF: 80.6% vs PersAF 73.3%; p

INTRODUCTION AND OBJECTIVES: The ADVANCE III trial showed that a delayed-detection strategy reduces implantable cardioverter-defibrillator (ICD) therapies. Here, we describe the adherence to and predictors of ADVANCE adoption and compare ICD therapy rates between patients with and without ADVANCE programming. METHODS: This observational retrospective study analyzed patients implanted with Medtronic ICDs included from 2005 to 2016 in a Spanish national multicenter registry (UMBRELLA database; ClinicalTrials.gov, NCT01561144). Changes in ADVANCE programming adoption were described in relation to a) publication of the ADVANCE trial, b) implementation of an "ADVANCE awareness" campaign, and c) publication of an expert consensus statement. Multivariate logistic regression identified predictors of adoption. Therapy incidence rates were compared between groups by estimating the adjusted incidence rate ratio (aIRR) using negative binomial regression. RESULTS: A total of 3528 patients were included. An ADVANCE strategy was used in 20% overall and in 44% at the end of the study. ADVANCE III adoption increased after trial publication, with less growth after an "ADVANCE awareness" campaign and after expert consensus statement publication. Predictors of ADVANCE adoption were as follows: ICD device with a nominal number of intervals to detect 30/40 (aOR, 4.4; 95%CI, 3.5-5.4), implantation by an electrophysiologist (aOR, 1.7; 95%CI, 1.4-2.2), and secondary prevention (aOR, 3.2; 95%CI, 2.6-3.9). Dual-chamber ICDs (aOR, 0.6; 95%CI, 0.5-0.8) and cardiac resynchronization-defibrillators (aOR, 0.5; 95%CI, 0.4-0.7) were associated with lower adoption. ADVANCE programming was associated with reduced total therapy burden (aIRR, 0.77; 95%CI, 0.69-0.86) and fewer inappropriate shocks (aIRR, 0.66; 95%CI, 0.52-0.85). CONCLUSIONS: ADVANCE adoption remains modest and can be improved through evidence-driven selection of nominal ICD settings. ADVANCE programming is associated with reduced therapy rates in real-world ICD recipients.

Aims Atrial fibrillation (AF) recurrence after pulmonary vein isolation (PVI) is usually associated to conduction gaps in pulmonary veins (PVs). Our objective was to characterize gaps in patients with recurrences after a first radiofrequency (RF) or cryoballoon (CB) PVI procedure, using a high-density mapping (HDM) system. Methods and results Fifty patients with AF recurrence after a first PVI procedure (pre-RF 25 patients; pre-CB 25 patients) were included at two centres. Activation map (AM) and voltage map (VM) of the left atrium and PVs were built using the HDM Rhythmia® system. Superior PVs were reconnected more frequently in both groups. Right PVs were reconnected more frequently in pre-RF patients. Pre-RF patients had more reconnected veins than pre-CB patients (mean ± standard deviation: 3.00 ± 0.96 vs. 1.88 ± 1.13; P

Background Pacing in vasovagal syncope remains controversial. Objectives The authors evaluated dual-chamber pacing with closed loop stimulation (DDD-CLS) in patients with cardioinhibitory vasovagal syncope. Methods This randomized, double-blind, controlled study included Canadian and Spanish patients age ≥40 years, with high burden syncope (≥5 episodes, ≥2 episodes in the past year), and a cardioinhibitory head-up tilt test (bradycardia 3 s). Patients were randomized to either DDD-CLS pacing for 12 months followed by sham DDI mode pacing at 30 pulses/min for 12 months (group A), or sham DDI mode for 12 months followed by DDD-CLS pacing for 12 months (group B). Patients in both arms crossed-over after 12 months of follow-up or when a maximum of 3 syncopal episodes occurred within 1 month. Results A total of 46 patients completed the protocol; 22 were men (47.8%), and mean age was 56.30 ± 10.63 years. The mean number of previous syncopal episodes was 12 (range 9 to 20). The proportion of patients with ≥50% reduction in the number of syncopal episodes was 72% (95% confidence interval [CI]: 47% to 90%) with DDD-CLS compared with 28% (95% CI: 9.7% to 53.5%) with sham DDI mode (p = 0.017). A total of 4 patients (8.7%) had events during DDD-CLS and 21 (45.7%) during sham DDI (hazard ratio: 6.7; 95% CI: 2.3 to 19.8). Kaplan-Meier curve was significantly different between groups in time to first syncope: 29.2 months (95% CI: 15.3 to 29.2 months) versus 9.3 months (95% CI: 6.21 months, NA; p Conclusions DDD-CLS pacing significantly reduced syncope burden and time to first recurrence by 7-fold, prolonging time to first syncope recurrence in patients age ≥40 years with head-up tilt test–induced vasovagal syncope compared with sham pacing. (Closed Loop Stimulation for Neuromediated Syncope [SPAIN Study]; NCT01621464)

Background Reflex vasovagal syncope (VVS) is one of the most common causes of syncope and, when recurrent, can have devastating consequences on the quality of life of patients despite pharmacological interventions. The closed loop stimulation (CLS) pacing algorithm converts, during an incipient VVS, variations in right intracardiac impedance into heart rate adaptation. The study SPAIN was the first randomized, double-blind trial robustly showing a strong reduction in syncopal recurrence in patients paced with dual-chamber (DDD)-CLS. (NCT01621464). Purpose To evaluate whether the differences observed in the SPAIN study regarding syncope burden and time to recurrence translate into improvements on quality of life. Methods This study analysed quality of life data from the SPAIN study: a randomized, prospective, double-blind, multicenter trial conducted in 10 Spanish and 1 Canadian centers. Ethics Committee approval was obtained at each participating center. Patients aged ≥40 years, with ≥5 VVS episodes and cardioinhibitory response to head-up tilt testing were included. After implant, patients were randomized 1:1 to active DDD-CLS mode for 12 months followed by sham DDI mode for the remaining 12 months or vice-versa. Quality of life was assessed via the Short Form-36 (SF-36) health survey before randomization (baseline), and at 12- and 24-month follow-up. The change in quality of life during the entire follow-up relative to baseline was compared between each pacing mode (DDD-CLS vs. DDI). Results Fifty-four patients were enrolled with a mean age of 56.3±10.6 years and a median of 12 syncopal episodes before randomization. Median SF-36 scores greatly increased from baseline in the DDD-CLS group across the 8 domains, whereas the response was variable in the DDI group. Comparing both pacing algorithms, median SF-36 scores were higher in the DDD-CLS group, with differences reaching statistical significance for “physical role” and “vitality” domains (p-value =0.006 and 0.014, respectively). Pacing sequence or treatment period did not significantly influence the response (p-value >0.05 for all the domains). Conclusions We demonstrated the beneficial effect of this physiological pacing algorithm on the quality of life of patients, as evidenced by the improvement in all the domains of the SF-36 when stimulated in DDD-CLS as compared to the sham DDI mode.

Syncope results from sudden, transient, global cerebral hypoperfusion. Neurally mediated syncope, orthostatic hypotension, arrhythmic and cardiac syncope, and steal syndromes are the main pathophysiological forms of syncope. This chapter focuses on the treatment of neurally mediated syncope and orthostatic syncope, since other forms of syncope are reviewed elsewhere. In neurally mediated and orthostatic syncope, patient education and non-pharmacological measures are the mainstay of treatment, although benefits of pharmacological treatment are not so evident.

Introduction Recurrences after atrial fibrillation (AF) ablation are still common. Among the reported clinical and imaging predictors of recurrences, diagnosis-to-ablation time (DAT) has been defined as a predictor of ablation outcome in single-center studies. We aimed to validate DAT in a multicenter real-life cohort. Methods This was a multicenter study including consecutive patients undergoing first paroxysmal and persistent AF ablation with radiofrequency or cryoballoon catheters during 2013. Cox proportional hazard regression models were performed to identify predictors of recurrence. Results In total, 309 patients were included across nine centers (71% men, 57 ± 10 years old, 46% with hypertension, and 66% with CHA2 DS2 -VASc ≤ 1). Most patients had paroxysmal AF (67%) and underwent radiofrequency ablation (68%) with a median DAT of 51 (43) months. Patients with DAT ≤ 1 year (16.6%) were less likely to have repeat procedures (4% vs 18%; P = .017). The adjusted proportional hazards Cox model identified hypertension (P = .005), heart failure (P = .011), nonparoxysmal AF (P = .038), DAT > 1 year (P = .007), and LA diameter (P = .026) as independent predictors for AF recurrence. DAT > 1 year was the only modifiable factor independently associated with recurrence (HR 4.2 [95% CI, 1.5-11.9]) CONCLUSION: Diagnosis-to-ablation time is a modifiable factor independently associated with recurrent arrhythmia and repeat ablation after first AF ablation. An early intervention strategy during the first year from AF diagnosis might improve outcomes.

Ventricular fibrillation (VF) signals are characterized by highly volatile and erratic electrical impulses, the analysis of which is difficult given the complex behavior of the heart rhythms in the left (LV) and right ventricles (RV), as sometimes shown in intracardiac recorded Electrograms (EGM). However, there are few studies that analyze VF in humans according to the simultaneous behavior of heart signals in the two ventricles. The objective of this work was to perform a spectral and a non-linear analysis of the recordings of 22 patients with Congestive Heart Failure (CHF) and clinical indication for a cardiac resynchronization device, simultaneously obtained in LV and RV during induced VF in patients with a Biventricular Implantable Cardioverter Defibrillator (BICD) Contak Renewal IV(TM) (Boston Sci.). The Fourier Transform was used to identify the spectral content of the first six seconds of signals recorded in the RV and LV simultaneously. In addition, measurements that were based on Information Theory were scrutinized, including Entropy and Mutual Information. The results showed that in most patients the spectral envelopes of the EGM sources of RV and LV were complex, different, and with several frequency peaks. In addition, the Dominant Frequency (DF) in the LV was higher than in the RV, while the Organization Index (OI) had the opposite trend. The entropy measurements were more regular in the RV than in the LV, thus supporting the spectral findings. We can conclude that basic stochastic processing techniques should be scrutinized with caution and from basic to elaborated techniques, but they can provide us with useful information on the biosignals from both ventricles during VF.

Background Inappropriate shocks (IS) continue to have a major negative impact on patients implanted with defibrillators. Objective The purpose of this study was to assess IS reduction with the PARAD+ discrimination algorithm in a general population implanted for primary or secondary prevention. Methods ISIS-ICD (Inappropriate Shock Reduction wIth PARAD+ Rhythm DiScrimination–Implantable Cardioverter Defibrillator) was a 2-year international, interventional study in patients implanted with a dual implantable cardioverter-defibrillator (ICD) or triple-chamber defibrillator (cardiac resynchronization therapy–defibrillator [CRT-D]) featuring PARAD+. IS (shocks not delivered for ventricular tachycardia or fibrillation) were independently adjudicated. The primary endpoint was percentage of IS-free patients at 24 months. Primary and worst-case analyses of annual incidence rates of patients with ≥1 IS, overall and per defibrillator type, were conducted. Results In total, 1013 patients (80.7% male; age 67.1 ± 11.4 years; 68%/30%/2% primary/secondary/other indication) were enrolled and followed for a median of 552 days (interquartile range 354; 725). Of 993 analyzed patients programmed with PARAD+, 14 had ≥1 IS, corresponding to a percentage free from IS of 98.1% (95% confidence interval [CI] 96.8%– 98.9%). Annual incidence rates (per 100 person-years) of patients with IS were 1.0 (95% CI 0.59–1.69) and 2.1 (95% CI 1.46–3.02) in the primary and worst-case analyses, respectively. In ICD patients, rates were 1.2 (95% CI 0.68–2.23) and 2.3 (95% CI 1.47–3.53), and in CRT-D patients 0.59 (95% CI 0.19–1.83) and 1.8 (95% CI 0.93–3.44) per 100 person-years. Conclusion The annual rate of defibrillator patients with IS using the enhanced PARAD+ discrimination algorithm alone ranged from 1.0 to 2.1 per 100 person-years in a general population implanted for primary or secondary prevention.

Background— Epicardial ablation has shown improvement in clinical outcomes of patients with ischemic heart disease (IHD) after ventricular tachycardia (VT) ablation. However, usually epicardial access is only performed when endocardial ablation has failed. Our aim was to compare the efficacy of endocardial+epicardial ablation versus only endocardial ablation in the first procedure in patients with IHD. Methods and Results— Fifty-three patients with IHD, referred for a first VT ablation to our institution, from 2012 to 2014, were included. They were divided in 2 groups according to enrollment time: from May 2013, we started to systematically perform endo-epicardial access (Epi-Group) as first-line approach in consecutive patients with IHD (n=15). Patients who underwent only an endocardial VT ablation in their first procedure (Endo-Group) included patients with previous cardiac surgery and the historical (before May 2013; n=35). All late-potentials in the scar zone were eliminated, and if VT was tolerated, critical isthmuses were also approached. The end point was the noninducibility of any VT. During a median follow-up of 15±10 months, the combined end point (hospital or emergency admission because of a ventricular tachycardia or reablation) occurred in 14 patients of the Endo-group and in one patient in the Epi-group (event-free survival curves by Grey-test, P =0.03). Ventricular arrhythmia recurrences occurred in 16 and in 3 patients in the Endo and Epi-Group, respectively (Grey-test, P =0.2). Conclusions— A combined endocardial–epicardial ablation approach for initial VT ablation was associated with fewer readmissions for VT and repeat ablations. Further studies are warranted.

Background: The implantable loop recorder (ILR) is a useful tool for diagnosis of syncope or palpitations. Its easy use and safety have extended its use to secondary hospitals (those without an Electrophysiology Lab). The aim of the study was to compare results between secondary and tertiary hospitals. Methods: National prospective and multicenter registry of patients with an ILR inserted for clinical reasons. Data were collected in an online database. The follow-up ended when the first diagnostic clinical event occurred, or 1 year after implantation. Data were analyzed according to the center of reference; hospitals with Electrophysiology Lab were considered Tertiary Hospi­tals, while those hospitals without a lab were considered Secondary Hospitals. Results: Seven hundred and forty-three patients (413 [55.6%] men; 65 ± 16 year-old): 655 (88.2%) from Tertiary Centers (TC) and 88 (11.8%) from Secondary Centers (SC). No differences in clinical characteristics between both groups were found. The electrophysi­ologic study and the tilt table test were conducted more frequently in Tertiary Centers. Fol­low-up was conducted for 680 (91.5%) patients: 91% in TC and 94% in SC. There was a higher rate of final diagnosis among SC patients (55.4% vs. 30.8%; p < 0.001). Tertiary Hospital patients showed a trend towards a higher rate of neurally mediated events (20% vs. 4%), while bradyarrhythmias were more frequent in SC (74% vs. 60%; p = 0.055). The rate of deaths and adverse events was similar in both populations. Conclusions: Patients with an ILR in SC and TC have differences in terms of the use of complementary tests, but not in clinical characteristics. There was a higher rate of diagnosis in Secondary Hospital patients.

Aims: Left atrial (LA) remodelling is a key determinant of atrial fibrillation (AF) ablation outcome. Optimal methods to assess this process are scarce. LA sphericity is a shape-based parameter shown to be independently associated to procedural success. In a multicentre study, we aimed to test the feasibility of assessing LA sphericity and evaluate its capability to predict procedural outcomes. Methods and results: This study included consecutive patients undergoing first AF ablation during 2013. A 3D model of the LA chamber, excluding pulmonary veins and LA appendage, was used to quantify LA volume (LAV) and LA sphericity (≥82.1% was considered spherical LA). In total, 243 patients were included across 9 centres (71% men, aged 56 ± 10 years, 44% with hypertension and 76% CHA2DS2-VASc ≤ 1). Most patients had paroxysmal AF (66%) and underwent radiofrequency ablation (60%). Mean LA diameter (LAD), LAV, and LA sphericity were 42 ± 6 mm, 100 ± 33 mL, and 82.6 ± 3.5%, respectively. Adjusted Cox models identified paroxysmal AF [hazard ratio (HR 0.54, P = 0.032)] and LA sphericity (HR 1.87, P = 0.035) as independent predictors for AF recurrence. A combined clinical-imaging score [Left Atrial Geometry and Outcome (LAGO)] including five items (AF phenotype, structural heart disease, CHA2DS2-VASc ≤ 1, LAD, and LA sphericity) classified patients at low (≤2 points) and high risk (≥3 points) of procedural failure (35% vs. 82% recurrence at 3-year follow-up, respectively; HR 3.10, P

Background The optimal dosage of cryotherapy during cryoballoon ablation of pulmonary veins is still unclear. This trial tested the noninferiority of a novel, individualized, cryotherapy-dosing strategy for each vein. Methods and Results This prospective, randomized, multicenter, noninferiority study included 140 patients with paroxysmal atrial fibrillation, which was refractory to antiarrhythmic drugs. Patients were randomly assigned to a conventional strategy of 180-second cryoballoon applications per vein with a bonus freeze (control group, n=70) or to a shorter-time application protocol, with 1 application that lasted the time required for electric block time to effect plus 60- and a 120-second freeze bonus (study group, n=70). Patients were followed with a long-term monitoring system of 30 days. At 1-year follow-up, no difference was observed in terms of free atrial fibrillation-recurrence rates: 79.4% in control versus 78.3% in study group (Δ=1.15%; 90% confidence interval, −10.33% to 12.63%; P =0.869). Time to effect was detected in 72.1% of veins. The control and study groups had similar mean number of applications per patient (9.6±2 versus 9.9±2.4; P =0.76). Compared with controls, the study group had a significantly shorter cryotherapy time (28.3±7 versus 19.4±4.3 minutes; P P P Conclusions The new time-to-effect–based cryotherapy dosage protocol led to shorter cryotherapy and procedure times, with equal safety, and similar acute and 1-year follow-up results, compared with the conventional approach. Clinical Trial Registration URL: https://clinicaltrials.gov . Unique identifier: NCT02789358.

Pacing in vasovagal syncope remains controversial.The authors evaluated dual-chamber pacing with closed loop stimulation (DDD-CLS) in patients with cardioinhibitory vasovagal syncope.This randomized, double-blind, controlled study included Canadian and Spanish patients age ≥40 years, with high burden syncope (≥5 episodes, ≥2 episodes in the past year), and a cardioinhibitory head-up tilt test (bradycardia 40 beats/min for 10 s or asystole3 s). Patients were randomized to either DDD-CLS pacing for 12 months followed by sham DDI mode pacing at 30 pulses/min for 12 months (group A), or sham DDI mode for 12 months followed by DDD-CLS pacing for 12 months (group B). Patients in both arms crossed-over after 12 months of follow-up or when a maximum of 3 syncopal episodes occurred within 1 month.A total of 46 patients completed the protocol; 22 were men (47.8%), and mean age was 56.30 ± 10.63 years. The mean number of previous syncopal episodes was 12 (range 9 to 20). The proportion of patients with ≥50% reduction in the number of syncopal episodes was 72% (95% confidence interval [CI]: 47% to 90%) with DDD-CLS compared with 28% (95% CI: 9.7% to 53.5%) with sham DDI mode (p = 0.017). A total of 4 patients (8.7%) had events during DDD-CLS and 21 (45.7%) during sham DDI (hazard ratio: 6.7; 95% CI: 2.3 to 19.8). Kaplan-Meier curve was significantly different between groups in time to first syncope: 29.2 months (95% CI: 15.3 to 29.2 months) versus 9.3 months (95% CI: 6.21 months, NA; p 0.016); odds ratio: 0.11 (95% CI: 0.03 to 0.37; p 0.0001).DDD-CLS pacing significantly reduced syncope burden and time to first recurrence by 7-fold, prolonging time to first syncope recurrence in patients age ≥40 years with head-up tilt test-induced vasovagal syncope compared with sham pacing. (Closed Loop Stimulation for Neuromediated Syncope [SPAIN Study]; NCT01621464).

Objetivo: Las recomendaciones para la extracción completa de la bolsa de dispositivos implantables por problemas locales han cambiado. Analizamos la evolución entre 2002 y 2010 de los pacientes que requirieron una intervención por una complicación local en nuestro centro. Métodos: Ochenta y tres pacientes tuvieron un problema local de la bolsa que se clasificó según integridad de la piel: 1. Íntegra y 2. Abierta, y el tipo de intervención realizada: 1. Conservadora, 2. Extracción parcial y 3. Extracción completa. El objetivo primario fue la necesidad de reintervención posterior y la de extracción total durante el seguimiento. Resultados: El grupo de pacientes con extracción completa presentó una menor tasa de reintervención durante el seguimiento medio de 1,000 días comparado con los otros 2 grupos (6.7 vs. 57.7 y 43.8%, p < 0.01). La extracción parcial y la actitud conservadora mostraron una evolución parecida con una tasa de extracción completa final del 25% y del 37.5%. Se observó una incidencia de endocarditis del 8.4%; todos con antecedente de extracción parcial o actitud conservadora. Conclusiones: Las complicaciones de la bolsa, independientemente de la integridad de la piel, tratadas conservadoramente o con extracción parcial se asocian a alta tasa de reintervenciones, necesidad de extracción completa y evolución a endocarditis.

Background— Infarct size (IS) determined by cardiac magnetic resonance (CMR) has proven an additional value, on top of left ventricular ejection fraction (LVEF), in prediction of adverse arrhythmic cardiac events (AACEs) in chronic ischemic heart disease. Its value soon after an acute ST-segment–elevation myocardial infarction remains unknown. Our aim was to determine whether early CMR can improve AACE risk prediction after acute ST-segment–elevation myocardial infarction. Methods and Results— Patients admitted for a first noncomplicated ST-segment–elevation myocardial infarction were prospectively followed up. A total of 440 patients were included. All of them underwent CMR 1 week after admission. CMR-derived LVEF and IS (grams per meter squared) were quantified. AACEs included postdischarge sudden death, sustained ventricular tachycardia, and ventricular fibrillation either documented on ECG or recorded via an implantable cardioverter-defibrillator. Within a median follow-up of 2 years, 11 AACEs (2.5%) were detected: 5 sudden deaths (1.1%) and 6 spontaneous ventricular tachycardia/ventricular fibrillation. In the whole group, AACEs associated with more depressed LVEF (adjusted hazard ratio [95% confidence interval], 0.90 [0.83–0.97]; P P =0.01). According to the corresponding area under the receiver operating characteristic curve, LVEF ≤36% and IS ≥23.5 g/m 2 best predicted AACEs. The vast majority of AACEs (10/11) occurred in patients with simultaneous depressed LVEF ≤36% and IS ≥23.5 g/m 2 (n=39). Conclusions— In the era of reperfusion therapies, occurrence of AACEs in patients with an in-hospital noncomplicated first ST-segment–elevation myocardial infarction is low. In this setting, assessment of an early CMR-derived IS could be useful for further optimization of AACE risk prediction.

Cryoballoon ablation of the pulmonary veins (CAPV) is a new technique that could have similar results to radiofrequency procedures, but with fewer complications. We analyzed the outcomes and safety of this technique in a consecutive cohort of patients with atrial fibrillation (AF). A total of 63 patients with paroxysmal (n = 40) or persistent (n = 23) AF were studied. Patient follow-up was performed at 3 months and then every 6 months with 72-h continuous electrocardiographic recordings. A total of 262 pulmonary veins were treated; 60.3 % of the cases presented normal pulmonary vein drainage with 4 pulmonary veins, and 23.8 % of the cases presented a common left-sided antrum. Complete isolation of all veins was achieved in 95.2 % of cases with 10.3 ± 2.8 (mean ± standard deviation) applications per patient. Transient right phrenic nerve injury was the most common complication (4.7 %). Median follow-up was 5.5 months. The probability of being free of recurrence at 1 and 2 years was, respectively, 86.2 and 72.2 % for paroxysmal AF and 49 and 36.4 % for persistent AF (P = 0.012). Patients with structural heart disease experienced recurrence more often than patients with a normal heart (62.5 versus 24.5 %; P = 0.03). CAPV appears to be a safe and effective procedure for the treatment of patients with AF, particularly those with paroxysmal AF and no structural heart disease.

Background— The occurrence of ventricular tachyarrhythmias seems to follow circadian, daily, and seasonal distributions. Our aim is to identify potential temporal patterns of electrical storm (ES), in which a cluster of ventricular tachycardias or ventricular fibrillation, negatively affects short- and long-term survival. Methods and Results— The TEMPEST study (Circannual Pattern and Temperature-Related Incidence of Electrical Storm) is a patient-level, pooled analysis of previously published data sets. Study selection criteria included diagnosis of ES, absence of acute coronary syndrome as the arrhythmic trigger, and ≥10 patients included. At the end of the selection and collection processes, 5 centers had the data set from their article pooled into the present registry. Temperature data and sunrise and sunset hours were retrieved from Weather Underground, the largest weather database available online. Total sample included 246 patients presenting with ES (221 men; age: 65±9 years). Each ES episode included a median of 7 ventricular tachycardia/ventricular fibrillation episodes. Fifty-nine percent of patients experienced ES during daytime hours ( P P P =0.003). Conclusions— ES incidence is not homogenous over time but seems to have a clustered pattern, with a higher incidence during daytime hours and working days. ES is associated with an increase in monthly temperature variation. Clinical Trial Registration— https://www.crd.york.ac.uk . Unique identifier: CRD42013003744.

Aims The implantation of an implantable loop recorder (ILR) leads to the diagnosis in about 35% of patients with syncope of unknown origin. Information on outcome of patients in whom a diagnosis is not reached during the lifetime of the device is scarce. The aim of our study is to determine the outcome of these patients in terms of syncope recurrence and survival. Methods and results An ILR was implanted to 97 patients with syncope of unknown origin. Patients were classified in groups A and B depending on their high or low risk, respectively, of having arrhythmic syncope. Diagnosis had not been reached in 60 patients (62%) when the ILR battery reached end operational life. Five patients were lost to follow up. During a median follow-up of 48 months after ILR explantation (interquartile range 36–56), 22 patients (40%) had recurrence of syncope (32% in group A vs. 48% in group B, P = 0.3). Syncopes with no neurally mediated profile were more frequent in group A (18 vs. 0%, P = 0.05) and neurally mediated profile syncopes were more frequent in group B (44 vs. 11%, P = 0.007). Five patients died, four of them in group A and 1 in group B ( P = 0.4). No sudden or cardiac deaths were detected during follow-up. All deaths were due to non-cardiac causes. Conclusion Recurrent syncope is common in patients in whom a diagnosis is not established after the full battery life of an ILR. The prognosis of these patients seems to be good, without observed sudden or cardiac death.

Aims Electrical storm (ES) is a life-threatening condition that predicts bad prognosis. Treatment includes antiarrhythmic drugs (AAD) and catheter ablation (CA). The present study aims to retrospectively compare prognosis in terms of survival and ES recurrence in 52 consecutive patients experiencing a first ES episode. Methods and results Patients were admitted from 1995 to 2011 and treated for ES by conservative therapy (pharmacological, 29 patients) or by CA (23 patients), according to the physician's preference and time of occurrence, i.e. conservative treatments were more frequently administered during the first years of the study, as catheter ablation became more frequent as the years passed by. After a median follow-up of 28 months, no differences either in survival (32% vs. 29% P = 0.8) or in ES recurrence (38% in ablated vs. 57% in non-ablated patients, P = 0.29) were observed between groups. Low left ventricle ejection fraction (LVEF) was the only variable associated with ES recurrence in ablated patients. When including patients with LVEF > 25%, ES recurrence was significantly lower in ablated patients (24 months estimated risk of ES recurrence was 21% vs. 62% in ablated and non-ablated patients, respectively); however, no benefit in survival was observed. Conclusion Our data suggest that in most patients, especially those with an LVEF > 25%, catheter ablation following a first ES episode, decreases the risk of ES recurrence, without increasing survival.

Resumen Introduccion y objetivos El objetivo del estudio es evaluar la utilidad de un protocolo diagnostico escalonado mediante estudio electrofisiologico (EEF) y registrador de eventos implantable (REI) en pacientes con sincope y bloqueo de rama (BR). Metodos Se realizo un EEF con provocacion farmacologica con procainamida en 85 pacientes consecutivos remitidos por sincope y BR tras una evaluacion inicial no diagnostica. En aquellos sin indicacion de desfibrilador implantable, se implanto un REI. Se realizo seguimiento hasta el diagnostico o el agotamiento de la bateria del dispositivo. Resultados El EEF fue diagnostico en 36 pacientes (42%); el mecanismo mas frecuente fue el bloqueo auriculoventricular (BAV) paroxistico (n = 27), seguido por la taquicardia ventricular (TV) (n = 6). Todos los pacientes con TV tuvieron cardiopatia estructural y mayor prevalencia de BR izquierda. Se implanto un REI a 38 pacientes, y se alcanzo un diagnostico en 13 (34%); el BAV paroxistico fue el mas frecuente (n = 10). La mediana de seguimiento hasta el diagnostico de BAV paroxistico mediante el REI fue 97 dias (intervalo intercuartilo, 60-117 dias). El BAV paroxistico fue mas frecuente en los pacientes con BR derecha y PR prolongado y/o desviacion del eje. No se observaron TV o muertes arritmicas durante el seguimiento. Conclusiones En pacientes con sincope y BR, la etiologia principal esta representada por el BAV paroxistico, seguido por la TV. El uso escalonado del EEF y del REI en los casos negativos permite alcanzar un rendimiento diagnostico alto y con seguridad, dado que la TV suele identificarse durante el EEF.

La ablacion transcateter, especialmente con energia de radiofrecuencia, ha sido el avance mas significativo de la arritmologia y uno de los de mayor impacto global en la cardiologia de los ultimos 25 anos. Su introduccion clinica en 1982 para la interrupcion de la conduccion auriculoventricular se siguio, a principios de los noventa, de la demostracion amplia de su eficacia en el tratamiento curativo de pacientes con vias accesorias y en pacientes con taquicardias por reentrada nodal. Posteriormente se anadieron el aleteo auricular, las taquicardias auriculares y las taquicardias ventriculares idiopaticas. El abordaje de las taquicardias ventriculares asociadas a cardiopatia estructural permite en muchos casos el control total de la arritmia, mientras que en cualquier caso puede utilizarse como parte de una terapia hibrida, junto con los farmacos y los dispositivos implantables. Por ultimo, las tecnicas de ablacion de la fibrilacion auricular, en pleno desarrollo, han venido a completar una oferta terapeutica que el cardiologo clinico puede y debe ofrecer a los pacientes con arritmias.

Aims The efficacy of preventive pacing algorithms (PPA) and anti-tachycardia pacing (ATP) in reducing atrial fibrillation (AF) burden remains controversial. The aim of this study was to assess whether ATP on top of PPA decreases AF burden. Methods and results A series of 199 consecutive patients, with conventional indications for pacing, and documented AF, received a DDDR (rate adaptive dual chamber pacemaker) pacemaker with ATP capabilities (AT 500 Medtronic). After 3 months of conventional DDDR pacing at 70 b.p.m., AF burden was analysed. If patients had >30 min/week of AF, they were randomized to PPA or to PPA+ATP for 3 months (period 1). They were then crossed to the alternative therapy (period 2) and followed three additional months with a 1-month wash out period in-between. A group of 85 patients were randomized. Mean age 68 ± 8 years, 61% men. Both groups showed a significant decrease in AF burden at the end of period 1 (64 and 81%, respectively). Conclusions Atrial pacing with PPA decreases AF burden in patients with pacing indication. We did not observe a further decrease in AF burden or in the number of episodes when adding ATP on top of PPA.

Los marcapasos, para generar los impulsos electricos y alimentar sus circuitos, precisan de una fuente de energia, que en la actualidad es una pila de litio-yodo, de capacidad limitada aunque su carga sea tres veces mayor por unidad de volumen que la disponible en las baterias empleadas hace 30 anos. A continuacion se exponen aspectos tecnicos basicos cuyo conocimiento es necesario para obtener un bajo consumo de energia y de este modo prolongar la vida util de los generadores. La programacion de la energia del impulso permite reducir el consumo, por lo que es fundamental obtener un optimo umbral de estimulacion, que en gran parte depende de la interfase electrodo-endocardio. Tambien se revisan los automatismos de respuesta en frecuencia, deteccion y reduccion de la estimulacion ventricular innecesaria, asi como la digitalizacion de las senales intracardiacas.

Introduction and objectives. The best therapeutic approach for persistent atrial fibrillation has yet to be defined. Our aim was to investigate the effects of cardioversion in unselected patients with persistent atrial fibrillation who were treated according to a strict protocol involving pretreatment, cardioversion, and follow-up. Methods. Consecutive patients with persistent atrial fibrillation of at least 1 months’ duration were included prospectively in a cardioversion protocol that involved standard antiarrhythmic pretreatment, with amiodarone being offered first, and follow-up. Results. The study included 295 patients, 87.5% of whom were taking the antiarrhythmic drug amiodarone. Sinus rhythm was restored in 92.5%, with pharmacologic cardioversion occurring in 9.5%. The recurrence rate was 33.5% in the first month and 54.9% by month 12. Antiarrhythmic treatment had to be modified in 10.8% of patients. Independent risk factors for recurrence during the first year after cardioversion were an atrial fibrillation duration greater than 1 year, previous cardioversion, and left ventricular dilatation. A simple risk scoring system was able to differentiate between subgroups of patients with a low, intermediate or high risk of recurrence in the first year after cardioversion. Conclusions. Sinus rhythm was maintained for 1 year after effective cardioversion in 45.1% of patients who received homogeneous antiarrhythmic pretreatment. There were few side effects. Recurrence can be predicted using clinical variables such as left ventricular dilatation, arrhythmia duration, and previous cardioversion.

Background: The diagnostic significance of a tilt table test (TTT) in patients with a suspected arrhythmic etiology for syncope and negative electrophysiologic study (EPS) has not been previously assessed comparing the TTT results with the findings of prolonged monitoring using an implantable loop recorder (ILR). We sought to assess the diagnostic yielding of TTT in patients with suspected arrhythmic syncope and negative EPS. Methods and Results: In 81 patients with suspected arrhythmic etiology for syncope and negative EPS, TTT was performed and an ILR implanted regardless the results of TTT. TTT was positive in 38 patients. During follow-up, syncope or presyncope recurred in 32 patients (39.5%). No differences were found in recurrence rates in patients with positive and negative TTT (31.5% vs 46.5%, P = ns). According to rhythm registered during ILR activation, mechanisms of syncopal events were classified as: arrhythmic (atrioventricular [AV] block and ventricular tachycardia; n = 18), neurally mediated (sinus bradycardia and sinus pause; n = 9), and indeterminate (normal sinus rhythm; n = 5). There was no statistical association between the results of TTT and the mechanism of syncope. Conclusions: In patients with a suspected arrhythmic etiology for syncope and a negative EPS, TTT is of little value to predict the mechanism of syncope and the ILR implantation seems to be a useful and safe diagnostic strategy.