Intrapericardial cardiosphere-derived cells hinder epicardial dense scar expansion and promote electrical homogeneity in a porcine post-infarction model.

The arrhythmic substrate of ventricular tachycardias in many structural heart diseases is located in the epicardium, often resulting in poor outcomes with currently available therapies. Cardiosphere-derived cells (CDCs) have been shown to modify myocardial scarring. A total of 19 Large White pigs were infarcted by occlusion of the mid-left anterior descending coronary artery for 150 min. Baseline cardiac magnetic resonance (CMR) imaging with late gadolinium enhancement sequences was obtained 4 weeks post-infarction and pigs were randomized to a treatment group (intrapericardial administration of 300,000 allogeneic CDCs/kg), (n = 10) and to a control group (n = 9). A second CMR and high-density endocardial electroanatomical mapping were performed at 16 weeks post-infarction. After the electrophysiological study, pigs were sacrificed and epicardial optical mapping and histological studies of the heterogeneous tissue of the endocardial and epicardial scars were performed. In comparison with control conditions, intrapericardial CDCs reduced the growth of epicardial dense scar and epicardial electrical heterogeneity. The relative differences in conduction velocity and action potential duration between healthy myocardium and heterogeneous tissue were significantly smaller in the CDC-treated group than in the control group. The lower electrical heterogeneity coincides with heterogeneous tissue with less fibrosis, better cardiomyocyte viability, and a greater quantity and better polarity of connexin 43. At the endocardial level, no differences were detected between groups. Intrapericardial CDCs produce anatomical and functional changes in the epicardial arrhythmic substrate, which could have an anti-arrhythmic effect.

Wide QRS Complex Arrhythmia with Alternating QRS Morphology: What Is the Mechanism?

A 75-year-old man was admitted due to an electrical storm with appropriate recurrent implantable cardioverter defibrillator (ICD) discharges. The patient had had an extensive anterolateral myocardial infarction with associated severe left ventricular dysfunction 10 years earlier (left ventricular ejection fraction, 25%), and an ICD was placed 9 years before admission for primary prevention of sudden cardiac death. A first invasive study induced up to five ventricular tachycardias and an extensive endocardial substrate ablation was performed. Despite intravenous ß-blockers, general anesthesia and procainamide infusion, the patient continued to have recurrent episodes of very slow sustained ventricular tachycardia with a right bundle branch block pattern. In a subsequent invasive study, no mid-diastolic activity was found despite careful mapping during the induced clinical ventricular tachycardia and ablation attempts inside the apical endocardial scar were unsuccessful. A percutaneous epicardial approach with navigation system support (EnSite PrecisionTM Cardiac Mapping System v. 2.0, St. Jude Medical, St. Paul, MN, USA) without antiarrhythmic infusion was planned. A wide QRS complex rhythm with alternating QRS morphology was readily induced by epicardial ventricular pacing trains (Fig. 1, top) that elicited both arrhythmia QRS patterns with very long stimulus QRS intervals (Fig. 1, bottom). What is the possible mechanism of this arrhythmia? Do we need further pacing maneuvers during the arrhythmia to localize critical sites at which ablation pulses can predictably be successful?

Seguridad del implante ambulatorio de desfibrilador automático implantable / Safety of outpatient implantation of the implantable cardioverter-defibrillator

Introducción y objetivos. Es importante desarrollar estrategias que reduzcan los costes sanitarios y mejoren la atención de los pacientes. El objetivo de nuestro estudio es analizar la seguridad del implante ambulatorio de desfibriladores automáticos implantables. Métodos. Se estudió retrospectivamente a 401 pacientes consecutivos a los que se implantó un desfibrilador automático implantable entre 2007 y 2012. Se comparó la tasa de complicaciones relacionadas con la intervención de los 232 (58%) pacientes cuyo implante se programó como ambulatorio frente a los 169 (42%) intervenidos durante ingreso hospitalario. Resultados. La media de edad era 62 ± 14 años; 336 (84%) pacientes eran varones. Los pacientes ambulatorios tuvieron, en comparación con los hospitalizados, menor fracción de eyección del ventrículo izquierdo y mayor porcentaje de indicación por prevención primaria de muerte súbita. Sólo 21 pacientes (9%) del grupo ambulatorio requirieron ingreso hospitalario. La tasa de complicaciones hasta el tercer mes tras el implante fue similar en los dos grupos (el 6,0% en ambulatorios frente al 5,3% en ingresados; p = 0,763). En el análisis multivariable, solo el tratamiento anticoagulante previo se relacionó con la presencia de complicaciones (odds ratio = 3,2; intervalo de confianza del 95%, 1,4-7,4; p < 0,01), principalmente por un incremento en la tasa de hematomas de la bolsa del dispositivo. Cada implante ambulatorio supuso un ahorro de 735 euros. Conclusiones. El implante ambulatorio de desfibrilador automático implantable es seguro y reduce los costes. En pacientes con tratamiento anticoagulante crónico, se incrementa el riesgo de complicaciones, por lo que debería recomendarse un control específico (AU)

Introduction and objectives. Strategies are needed to reduce health care costs and improve patient care. The objective of our study was to analyze the safety of outpatient implantation of cardioverter-defibrillators. Methods. A retrospective study was conducted in 401 consecutive patients who received an implantable cardioverter-defibrillator between 2007 and 2012. The rate of intervention-related complications was compared between 232 patients (58%) whose implantation was performed in the outpatient setting and 169 patients (42%) whose intervention was performed in the inpatient setting. Results. The mean age (standard deviation) of the patients was 62 (14) years; 336 (84%) were male. Outpatients had lower left ventricular ejection fraction and a higher percentage had an indication for primary prevention of sudden death, compared to inpatients. Only 21 outpatients (9%) required subsequent hospitalization. The rate of complications until the third month postimplantation was similar for outpatients (6.0%) and inpatients (5.3%); P = .763. In multivariate analysis, only previous anticoagulant therapy was related to the presence of complications (odds ratio = 3.2; 95% confidence interval, 1.4-7.4; P < .01), mainly due to an increased rate of pocket hematomas. Each outpatient implantation saved approximately €735. Conclusions. Outpatient implantation of implantable cardioverter-defibrillators is safe and reduces costs. Close observation is recommended for patients receiving chronic anticoagulation therapy due to an increased risk of complications (AU)

Safety of Outpatient Implantation of the Implantable Cardioverter-defibrillator.

INTRODUCTION AND OBJECTIVES: Strategies are needed to reduce health care costs and improve patient care. The objective of our study was to analyze the safety of outpatient implantation of cardioverter-defibrillators. METHODS: A retrospective study was conducted in 401 consecutive patients who received an implantable cardioverter-defibrillator between 2007 and 2012. The rate of intervention-related complications was compared between 232 patients (58%) whose implantation was performed in the outpatient setting and 169 patients (42%) whose intervention was performed in the inpatient setting. RESULTS: The mean age (standard deviation) of the patients was 62 (14) years; 336 (84%) were male. Outpatients had lower left ventricular ejection fraction and a higher percentage had an indication for primary prevention of sudden death, compared to inpatients. Only 21 outpatients (9%) required subsequent hospitalization. The rate of complications until the third month postimplantation was similar for outpatients (6.0%) and inpatients (5.3%); P = .763. In multivariate analysis, only previous anticoagulant therapy was related to the presence of complications (odds ratio = 3.2; 95% confidence interval, 1.4-7.4; P < .01), mainly due to an increased rate of pocket hematomas. Each outpatient implantation saved approximately €735. CONCLUSIONS: Outpatient implantation of implantable cardioverter-defibrillators is safe and reduces costs. Close observation is recommended for patients receiving chronic anticoagulation therapy due to an increased risk of complications.

[Update on arrhythmias and cardiac electrophysiology]. / Actualización en arritmias y electrofisiología cardiaca.

This article contains a review of the most important developments in clinical arrhythmology and interventional cardiac electrophysiology that have been reported during the past year. Special emphasis has been placed on clinical conditions that are most prevalent in the general population as well as on progress that has been achieved using the main therapeutic approaches, whether pharmacologic or interventional.

Actualización en arritmias y electrofisiología cardiaca / Update on arrhythmias and cardiac electrophysiology

En el presente artículo se revisan las novedades más relevantes relacionadas con la arritmología clínica y la electrofisiología cardiaca intervencionista que han sido publicadas este último año. Se realiza especial énfasis en las entidades clínicas de mayor prevalencia en la población general, así como en los avances obtenidos en las principales terapias tanto farmacológicas como intervencionistas (AU)

This article contains a review of the most important developments in clinical arrhythmology and interventional cardiac electrophysiology that have been reported during the past year. Special emphasis has been placed on clinical conditions that are most prevalent in the general population as well as on progress that has been achieved using the main therapeutic approaches, whether pharmacologic or interventional (AU)

[Torsades de pointes during methadone treatment]. / Torsade de pointes durante el tratamiento con metadona.

Methadone is a synthetic opioid that has been used successfully to treat heroin addiction and chronic pain. It is usually well tolerated and has few side effects. Recently, an association with torsade de pointes has been reported. We present 4 cases of torsade de pointes during methadone treatment.

Torsade de pointes durante el tratamiento con metadona / Torsades de pointes during methadone treatment

La metadona es un opioide sintético que, con frecuencia, se utiliza para el tratamiento de la adicción a la heroína y el dolor crónico. En general es bien tolerada y tiene escasos efectos secundarios, aunque recientemente han surgido dudas respecto de su seguridad. Presentamos 4 casos de torsade de pointes en posible relación con tratamiento con metadona

Methadone is a synthetic opioid that has been used successfully to treat heroin addiction and chronic pain. It is usually well tolerated and has few side effects. Recently, an association with torsade de pointes has been reported. We present 4 cases of torsade de pointes during methadone treatment

[Treatment of patients with ventricular preexcitation]. / Tratamiento de los pacientes con preexcitación ventricular.

Ventricular preexcitation, due to an accessory pathway that creates an electrical connection between the atria with the ventricles, can provide a substrate for a variety of arrhythmogenic syndromes, from paroxysmal AV junctional tachycardia, to the facilitation or aggravation of atrial tachyarrhythmias that can lead to sudden death. However, statistics show that the most frequent situation is for the individual to remain asymptomatic throughout his or her life. In the asymptomatic individual, population-based studies with very long follow-up periods indicate that the risk of sudden death is minimal. Acute therapy for tachyarrhythmias is based on adenosine/verapamil for regular, narrow-QRS tachycardias and procainamide/electrical cardioversion for preexcited tachyarrhythmias. Chronic pharmacologic therapy with antiarrhythmic drugs is not recommended because its efficacy is not well proven and its risk of side effects can be considerable. In symptomatic patients, the treatment of choice is catheter ablation, with an efficacy of 93%, a complication rate of 1% and a mortality rate of 1 per thousand. Whether catheter ablation should be recommended for asymptomatic individuals remains controversial. The authors recommend that these individuals should be followed with regular clinical evaluation, and that catheter ablation should be advised only for those who become symptomatic.

Indicación de desfibrilador automático implantable después de angioplastia coronaria transluminal percutánea primaria / Indication of the automatic implantable defibrillator after primary percutaneous transluminal coronary angioplasty

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Automatic discrimination between supraventricular and ventricular tachycardia using a multilayer perceptron in implantable cardioverter defibrillators.

The morphological analysis of implantable cardioverter defibrillator (ICD) stored electrograms (EGM) using a multilayer perceptron (MLP) has been proposed for discrimination between supraventricular and ventricular arrhythmias. However, a reliable estimation of the accuracy of MLP methods is lacking. The aim of the study was to compare the morphology and spectrum-based MLP with more conventional morphology-based algorithms in a large series of ICD-stored episodes of arrhythmia. One set of ICD-stored electrograms was used for control and training purposes and a second one, consisting of spontaneous episodes in patients with dual chamber ICDs, for validation of the MLP performance. The correlation waveform analysis (CWA) and the EGM width criterion were compared with MLP methods. Bootstrap resampling techniques were used to extract the relevant information in the MLP training. The morphology-based MLP achieved better discrimination than any other method, with areas under the receiver operating characteristic (ROC) curve (tolerance intervals): 0.96 (0.81, 0.96) for MLP, 0.91 (0.77, 0.94) for CWA, and 0.68 (0.49, 0.78) for EGM width in the validation set. A specificity of 73.0% was obtained at 95% sensitivity, compared with 38.1% and 55.1% using CWA and EGM width criteria, respectively. In contrast, the generalization capabilities of spectral-based MLP methods are poor, showing a lower area under the ROC curve in the validation set. Time-domain MLP techniques may be useful for the morphological analysis of the intracardiac EGM signal stored by ICD devices. When properly trained and validated, these methods perform better than other commonly used morphological criteria for discrimination between supraventricular and ventricular arrhythmias.