Identification of cavotricuspid isthmus voltage patterns in typical atrial flutter ablation.

Background: Electroanatomical mapping is an essential tool in the ablation of typical AFL. Objectives: To identify the existence of voltage patterns in the CTI voltage maps and their relevance for typical AFL ablation. Methods: A voltage map of the CTI was made prior to ablation, identifying the areas of maximum voltage and their location along the CTI, allowing classification into patterns according to their distribution. A stepwise ablation approach targeting the areas of maximum voltage was conducted. The ablation characteristics were compared based on the pattern obtained. Results: Two voltage patterns were identified, with differences in ablation time to bidirectional CTI block. No complications occurred. Conclusions: Voltage mapping identifies patterns in the CTI with implications for typical AFL ablation.

Cardiac magnetic resonance outperforms echocardiography to predict subsequent implantable cardioverter defibrillator therapies in ST-segment elevation myocardial infarction patients.

Background: Implantable cardioverter defibrillators (ICD) are effective as a primary prevention measure of ventricular tachyarrhythmias in patients with ST-segment elevation myocardial infarction (STEMI) and depressed left ventricular ejection fraction (LVEF). The implications of using cardiac magnetic resonance (CMR) instead of echocardiography (Echo) to assess LVEF prior to the indication of ICD in this setting are unknown. Materials and methods: We evaluated 52 STEMI patients (56.6 ± 11 years, 88.5% male) treated with ICD in primary prevention who underwent echocardiography and CMR prior to ICD implantation. ICD implantation was indicated based on the presence of heart failure and depressed LVEF (≤ 35%) by echocardiography, CMR, or both. Prediction of ICD therapies (ICD-T) during follow-up by echocardiography and CMR before ICD implantation was assessed. Results: Compared to echocardiography, LVEF was lower by cardiac CMR (30.2 ± 9% vs. 37.4 ± 7.6%, p < 0.001). LVEF ≤ 35% was detected in 24 patients (46.2%) by Echo and in 42 (80.7%) by CMR. During a mean follow-up of 6.1 ± 4.2 years, 10 patients received appropriate ICD-T (3.16 ICD-T per 100 person-years): 5 direct shocks to treat very fast ventricular tachycardia or ventricular fibrillation, 3 effective antitachycardia pacing (ATP) for treatment of ventricular tachycardia, and 2 ineffective ATP followed by shock to treat ventricular tachycardia. Echo-LVEF ≤ 35% correctly predicted ICD-T in 4/10 (40%) patients and CMR-LVEF ≤ 35% in 10/10 (100%) patients. CMR-LVEF improved on Echo-LVEF for predicting ICD-T (area under the curve: 0.76 vs. 0.48, p = 0.04). Conclusion: In STEMI patients treated with ICD, assessment of LVEF by CMR outperforms Echo-LVEF to predict the subsequent use of appropriate ICD therapies.

Cryoballoon Ablation for Persistent and Paroxysmal Atrial Fibrillation: Procedural Differences and Results from the Spanish Registry (RECABA).

Introduction: Cryoballoon ablation (CBA) has become a standard treatment for paroxysmal atrial fibrillation (PaAF) but limited data is available for outcomes in patients with persistent atrial fibrillation (PeAF). Methods: We analyzed the first 944 patients included in the Spanish Prospective Multi-center Observation Post-market Registry to compare characteristics and outcomes of patients undergoing CBA for PeAF versus PaAF. Results: A total of 944 patients (57.8 ± 10.4 years; 70.1% male) with AF (27.9% persistent) were prospectively included from 25 centers. PeAF patients were more likely to have structural heart disease (67.7 vs. 11.4%; p < 0.001) and left atrium dilation (72.6 vs. 43.3%; p < 0.001). CBA of PeAF was less likely to be performed under general anesthesia (10.7 vs. 22.2%; p < 0.001), with an arterial line (32.2 vs. 44.6%; p < 0.001) and assisted transeptal puncture (11.9 vs. 17.9%; p = 0.025). During an application, PeAF patients had a longer time to −30 °C (35.91 ± 14.20 vs. 34.93 ± 12.87 s; p = 0.021) and a colder balloon nadir temperature during vein isolation (−35.04 ± 9.58 vs. −33.61 ± 10.32 °C; p = 0.004), but received fewer bonus freeze applications (30.7 vs. 41.1%; p < 0.001). There were no differences in acute pulmonary vein isolation and procedure-related complications. Overall, 76.7% of patients were free from AF recurrences at 15-month follow-up (78.9% in PaAF vs. 70.9% in PeAF; p = 0.09). Conclusions: Patients with PeAF have a more diseased substrate, and CBA procedures performed in such patients were more simplified, although longer/colder freeze applications were often applied. The acute efficacy/safety profile of CBA was similar between PaAF and PeAF patients, but long-term results were better in PaAF patients.

Primary results of the Spanish Cryoballoon Ablation Registry: acute and long-term outcomes of the RECABA study.

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 < 0.001). Left atrium enlargement, female sex, non-PAF, and early recurrence were independent predictors of AF recurrence (p < 0.05). RECABA provides detailed insight into current dosing practices and demonstrates cryoablation is safe and effective in real-world use.ClinicalTrials.gov number: NCT02785991.

Predictores e impacto de la adopción de programación basada en la evidencia en la incidencia de terapias del desfibrilador automático implantable / Predictors of adoption and impact of evidence-based programming on the incidence of implantable cardioverter-defibrillator therapies

Introducción y objetivos El estudio ADVANCE III mostró una reducción de terapias del desfibrilador automático implantable (DAI) con el empleo de tiempos de detección de arritmia prolongados. Se describe la adopción y el impacto de dicha estrategia en la incidencia de terapias del DAI. Métodos Estudio observacional retrospectivo de pacientes con implante de DAI Medtronic (2005-2016) en un registro multicéntrico (UMBRELLA-NCT01561144). Se describe la evolución de la adopción de programación ADVANCE en relación con: publicación del estudio, implementación de una campaña de formación y publicación de un consenso de expertos. Se identificaron con regresión logística los predictores de la adopción. Se comparó la incidencia de terapias en pacientes con y sin programación ADVANCE estimando la razón de tasas de incidencia ajustada (RTIa) mediante regresión binomial negativa. Resultados Se incluyó a 3.528 pacientes. Se utilizó la estrategia ADVANCE en el 20% del total y el 44% al final del estudio. La adopción se incrementó tras publicarse el estudio ADVANCE, y en menor grado tras la campaña de formación y consenso de expertos. Predictores de la adopción: DAI con detección nominal 30/40 (ORa=4,4; IC95%, 3,5-5,4), implantador electrofisiólogo (ORa=1,7; IC95%, 1,4-2,2) y prevención secundaria (ORa=3,2; IC95%, 2,6-3,9). El implante de DAI bicameral (ORa=0,6; IC95%, 0,5-0,8) o tricameral (ORa=0,5; IC95%, 0,4-0,7) se asoció con menor adopción. La programación ADVANCE se asoció con reducción de terapias totales (RTIa=0,77; IC95%, 0,69-0,86) y choques inapropiados (RTIa=0,66; IC95%, 0,52-0,85). Conclusiones La adopción de la programación ADVANCE es poco amplia y puede mejorarse mediante una adecuada selección de los parámetros nominales. Emplearla se asocia con una reducción de las terapias del DAI. (AU)

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. ... (AU)

Predictors of adoption and impact of evidence-based programming on the incidence of implantable cardioverter-defibrillator therapies.

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.

Respuesta al ECG de octubre de 2020 / Response to ECG, October 2020

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ECG de octubre de 2020 / ECG, October 2020

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Respuesta al ECG de julio de 2020 / Response to ECG, July 2020

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Spectral Analysis and Mutual Information Estimation of Left and Right Intracardiac Electrograms during Ventricular Fibrillation.

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 IVTM (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.

ECG de julio de 2020 / ECG, July 2020

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Transient narrowing of a wide QRS tachycardia. What is the mechanism?

Electrocardiogram showing a regular wide QRS tachycardia with left branch block (LBBB) like in morphology at 200 beats per minute (bpm). During electrophysiology study, it suddenly gets narrow and faster. What is the mechanism of the switch from a broad complex to a narrow complex tachycardia?

Impact of dual-chamber pacing with closed loop stimulation on quality of life in patients with recurrent reflex vasovagal syncope: results of the SPAIN study.

AIMS: Reflex vasovagal syncope (VVS) is the most common cause of syncope and patients with recurrent episodes may severely impair quality of life (QoL). This pre-specified analysis evaluated whether the clinically significant reduction in syncope burden demonstrated by dual-chamber pacing with closed loop stimulation (DDD-CLS) reported in the SPAIN trial translates into improved QoL. METHODS AND RESULTS: Patients aged ≥40 years with ≥5 VVS episodes and cardioinhibitory response induced by head-up tilt testing were included. Patients were randomized 1:1 to active DDD-CLS pacing algorithm for 12 months followed by sham DDI mode for the remaining 12 months (Group A) or vice versa (Group B). QoL was assessed using the Short Form-36 (SF-36) health survey, Physical Component Score (PCS), and Mental Component Score (MCS) before randomization (baseline) and at 12- and 24-month follow-up. Fifty-four patients were enrolled from 11 participating centres. No significant carryover effect was detected for any variable, and the only period effect was observed in the vitality subdomain (P = 0.033). Mean SF-36 scores were higher in the DDD-CLS group vs. the DDI group for the eight subdomains and significantly different in physical role, bodily pain, and vitality (P < 0.05). The analysis of component summary scores indicated that DDD-CLS benefited both mental and physical components with significant differences in PCS when compared with the DDI group. CONCLUSION: Dual-chamber pacing with closed loop stimulation determined a significant and clinically relevant improvement in QoL across both mental and physical components in patients with recurrent VVS. REGISTRATION: Closed Loop Stimulation for Neuromediated Syncope (SPAIN Study); NCT01621464.

Diagnosis-to-ablation time in atrial fibrillation: A modifiable factor relevant to clinical outcome.

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.