Óscar Cano

Comparison of Effectiveness of Right Ventricular Septal Pacing Versus Right Ventricular Apical Pacing

Chronic right ventricular apical pacing (RVAP) has been associated with negative hemodynamic and clinical effects. The aim of the present study was to compare RVAP with right ventricular septal pacing (RVSP) in terms of echocardiographic features and clinical outcomes. A total of 93 patients without structural heart disease and with an indication for a permanent pacemaker were randomly assigned to receive a screw-in lead either in the RV apex (n = 46) or in the RV mid-septum (n = 47). The patients were divided into 3 subgroups according to the percentage of ventricular pacing: control group (n = 21, percentage of ventricular pacing < or =10%), RVAP group (n = 28), or RVSP group (n = 32; both latter groups had a percentage of ventricular pacing >10%). The RVAP group had more intraventricular dyssynchrony and a trend toward a worse left ventricular ejection fraction compared to the RVSP and control groups at 12 months of follow-up (maximal delay to peak systolic velocity between any of the 6 left ventricular basal segments was 57.8 +/- 38.2, 35.5 +/- 20.6, and 36.5 +/- 17.8 ms for RVAP, RVSP, and control group, respectively; p = 0.006; mean left ventricular ejection fraction 62.9 +/- 7.9%, 66.5 +/- 7.2%, and 66.6 +/- 7.2%, respectively, p = 0.14). Up to 48.1% of the RVAP patients showed significant intraventricular dyssynchrony compared to 19.4% of the RVSP patients and 23.8% of the controls (p = 0.04). However, no overt clinical benefits from RVSP were found. In conclusion, RVAP was associated with increased dyssynchrony compared to the RVSP and control patients. RVSP could represent an alternative pacing site in selected patients to reduce the harmful effects of traditional RVAP.

Cardiac magnetic resonance imaging at 1.5 T in patients with cardiac rhythm devices

AIMS Recent studies suggest that non-cardiac magnetic resonance imaging (MRI) scanning can be performed safely in selected cardiac rhythm device patients. However, little is known about the safety of performing specific cardiac MRI in this setting. We sought to determine the feasibility of cardiac MRI in patients with pacemakers (PMs) or implantable cardioverter-defibrillators (ICDs). METHODS AND RESULTS Thirty-eight patients underwent a total of 39 (8 ICDs and 31 PM) cardiac MRI examinations at 1.5 T using usual protocols without specific absorption rate (SAR) restrictions. Nine PM-dependent patients were included. All devices were interrogated before and immediately after MRI. During the scan, pacing mode was programmed to asynchronous for PM-dependent patients whereas ICDs were programmed to a monitor-only mode. All devices were functioning appropriately after cardiac MRI. Comparison of device parameters obtained before and immediately after MRI revealed no significant changes in pacing threshold, lead impedance, battery status, or sensing signal amplitude. Neither clinical events nor patient complaints were reported. Significant imaging artefacts were present on 11 of 39 scans (28.2%). These artefacts were significantly more frequent in ICDs (8 of 8, 100%) vs. PMs (3 of 31, 9.7%) (P < 0.001). Diagnostic questions were answered in 92.3% of the cases, with just three pronounced artefacts preventing an adequate diagnosis in three ICD patients. CONCLUSIONS Our results suggest that cardiac MRI may be performed safely in appropriately selected patients with close monitoring during the scan without limitation of peak SAR level using several precautionary measures. Image artefacts were more frequent in ICD patients.

Resonancia magnética nuclear en pacientes portadores de dispositivos de estimulación cardiaca

La resonancia magnetica esta actualmente contraindicada a los pacientes portadores de dispositivos de estimulacion cardiaca. Ante la necesidad de concretar los riesgos potenciales derivados de esta situacion, surgio este estudio. De forma prospectiva, se evaluaron parametros clinicos, electricos y tecnicos antes y despues de la realizacion de la prueba en 33 pacientes (5 desfibriladores automaticos implantables, 28 marcapasos), en los que se considero clinicamente indispensable realizarla. No se apreciaron complicaciones clinicas. Se detectaron dos casos de fallo temporal de telemetria, dos errores de deteccion durante la exploracion y una respuesta de seguridad en un marcapasos a frecuencia magnetica y salida maxima. No hubo limitaciones tecnicas en la adquisicion de imagenes ni alteraciones permanentes del funcionamiento de los dispositivos de estimulacion cardiaca.

Nuclear Magnetic Resonance Imaging in Patients With Cardiac Pacing Devices

Currently, nuclear magnetic resonance imaging is contraindicated in patients with a pacemaker or implantable cardioverter-defibrillator. This study was carried out because the potential risks in this situation need to be clearly defined. This prospective study evaluated clinical and electrical parameters before and after magnetic resonance imaging was performed in 33 patients (five with implantable cardioverter-defibrillators and 28 with pacemakers). In these patients, magnetic resonance imaging was considered clinically essential. There were no clinical complications. There was a temporary communication failure in two cases, sensing errors during imaging in two cases, and a safety signal was generated in one pacemaker at the maximum magnetic resonance frequency and output level. There were no technical restrictions on imaging nor were there any permanent changes in the performance of the cardiac pacing device.

Technical Reliability and Clinical Safety of a Remote Monitoring System for Antiarrhythmic Cardiac Devices

INTRODUCTION AND OBJECTIVES In recent years, physicians have experienced a huge increase in workload associated with cardiac devices. Remote monitoring enables these devices to be monitored at a distance and could reduce the number of hospital visits. The aim of this study was to assess the technical reliability and clinical safety of the Home MonitoringTM remote monitoring system (Biotronik GmbH, Germany). METHODS The study included 162 patients: 115 with pacemakers, 44 with implantable cardioverter-defibrillators (ICDs) and three with ICDs incorporating cardiac resynchronization therapy (CRT). Patients were followed up for a mean of 303+/-244 days. We compared the survival time free of event alerts in patients with pacemakers and in those with ICDs. The remote monitoring systems reliability was evaluated by comparing the data it transmitted with clinical observations made immediately afterwards. RESULTS The mean percentage of days monitored was 88.2%. The incidence of event alerts was higher in pacemaker than ICD patients (45% vs. 34%; P=.01). Event alerts preceded the following hospital visit by 76+/-47 days. In the ICD group, the data sent by the monitoring system were judged as true-positives in 42% of cases, as true-negatives in 57% and as false-positives in 1%. No false-negative was observed. In the ICD group, the remote monitoring system had a sensitivity of 100% and a specificity of 97% (positive predictive value 96%, negative predictive value 100%). CONCLUSIONS Remote monitoring was a reliable and safe method for following up patients with cardiac devices. Its routine use could enable the early detection of device malfunctions or arrhythmic events.

Initial Experience With a New Ablation Catheter Using Laser Energy for Electrical Pulmonary Vein Isolation

Life Support Organization Registry Report 2012. ASAIO J. 2013;59:202–10. 4. Haneya A, Philipp A, Diez C, Schopka S, Bein T, Zimmermann M, et al. A 5-year experience with cardiopulmonary resuscitation using extracorporeal life support in non-postcardiotomy patients with cardiac arrest. Resuscitation. 2012;83:1331–7. 5. Ariza-Solé A, Sánchez-Salado JC, Lorente-Tordera V, González-Costello J, Miralles-Cassina A, Cequier-Fillat A. Asistencia ventricular con membrana de oxigenación extracorpórea: una nueva alternativa al rescate del shock cardiogénico refractario. Rev Esp Cardiol. 2013;66:501–3. 6. Kirklin JK, Naftel DC, Stevenson LW, Kormos RL, Pagani FD, Miller MA, et al. INTERMACS database for durable devices for circulatory support: first annual report. J Heart Lung Transplant. 2008;27:1065–72.

Architecture for Development of WBES Based on Components and Agents

A new agents and components oriented architecture for the development of Web-based education systems (WBES) is presented. This architecture is based on the IEEE 1484 LTSA (learning technology system architecture) specification and the software development pattern of the intelligent reusable learning components object oriented (IRLCOO). IRLCOO are a special type of sharable content object (SCO) according to the sharable content object reference model (SCORM). SCORM is used to create reusable and interoperable learning content. The architecture, communication model (based on LMS API, Web services, AJAX, and Struts framework) and semantic Web platform (SWP) that are described in this paper are used to develop authoring and evaluation tools with the integration of a digital library

Improvement in Hemodynamics and Contractility With Multipoint Left Ventricular Pacing in Cardiac Resynchronization Therapy

a remaining relatives. No additional mutation was found in any of the other screened genes. The Table shows the results of the family study in affected (II:4, III:4, III:6 and IV:1) and nonaffected individuals (no additional family members were available for the study). Gene sequencing yielded the presence of the heterozygous ACTC1 mutation, not present in the National Center for Biotechnology list of single nucleotide polymorphisms in the ACTC1 gene. Although hundreds of variants have been identified in sarcomeric and desmosomal genes, only a few polymorphisms and < 30 mutations causing any kind of cardiomyopathy have been described in the ACTC1 gene, suggesting that changes in the ACTC1 gene are poorly tolerated. Actin is essential for cell morphology, adhesion, and migration. This novel variant alters a preserved amino acid residue (I289) in the protein, replacing a nonpolar (isoleucine) with another polar and noncharged (threonine) aminoacid, thus causing moderate modifications in the physicochemical properties related to the hydrophobicity, charge, polarity, and mass of the protein (Grantham distance 89 [0-215]). The prediction of in silico (SIFT [Sorting Intolerant from Tolerant], Polyphen-2, and Pmut) analyses neither confirmed nor ruled out its pathogenity (inconclusive results with low confidence). The preserved I289 amino acid residue maps to subdomain 3, important for the stability and polymerization of the actin filaments and next to the myosin binding site, possibly disrupted by the presence of the ACTC1 mutation. Furthermore, our ACTC1 mutation cosegregated perfectly with the LVNC phenotype, with a 100% penetrance in the individuals available for the study. We acknowledge that a more thorough genetic study could have included many other genes. Nonetheless, we considered it finished in terms of cost-effectiveness for three reasons: a) our results were consistent with a previous study linking LVNC and septal defects due to ACTC1 mutation; b) the variant strongly cosegregated with the phenotype, and c) the molecular consequences of the variant were considered probably pathogenic. Further functional information obtained from animal models may be valuable to confirm the causal role of the ACTC1 mutation. In summary, we offer the phenotypical description of a family with LVNC caused by the highly penetrant, novel, heterozygous ACTC1 mutation. Remarkably, in the literature this is the third ACTC1 mutation causing LVNC, and associated ostium secundum atrioseptal defect in some affected family members. J, d y.

Electrocardiogram–electrogram desynchronization while using radiofrequency wandless telemetry during implantation of an implantable cardioverter defibrillator

A 57-year-old man was referred for implantation of a dual-chamber implantable cardioverter defibrillator as secondary prevention of sudden cardiac death. During implantation, wandless telemetry was used to establish communication with the device. We describe an episode of electrocardiogram–electrogram desynchronization using this novel technology and discuss the possible clinical implications.

A misleading wide complex tachycardia with unusual features after carotid sinus pressure: what is the diagnosis?

Electrocardiographic differential diagnosis of a wide complex tachycardia (WCT) is challenging. During the last years different algorithms have tried to overcome these difficulties. The present article presents a case of a WCT in which traditional algorithms fail to give a definitive diagnosis that can be facilitated by a simple manoeuvre: carotid sinus pressure (CSP). An unusual response of the tachycardia after CSP is also discussed.