Magnetic resonance imaging in patients with cardiac implantable electronic devices: A prospective study.

BACKGROUND: The number of patients with cardiac implantable electronic devices in whom magnetic resonance imaging (MRI) is indicated is constantly increasing. The potential risk of electromagnetic interference has limited its use and it is still contraindicated by the Food and Drug Administration in some cases. The aim of this study is to evaluate the safety and efficacy of MRI in these patients. METHODS: A prospective registry comprising patients with a pacemaker (PM) or implantable cardioverter-defibrillator (ICD), MRI-conditional or not, who were candidates for MRI (at 1.5 T) with no suitable alternative diagnostic technique. All devices were programmed before the procedure and patients were monitored throughout the test. Clinical, electrical, and technical parameters were evaluated before and after MRI. RESULTS: 147 MRI examinations (132 PM and 15 ICD) were performed. There were no clinical events or significant differences in the electrical parameters of the leads after MRI. A variation in the impedance of the ventricular leads was detected, although the difference was not clinically relevant. In one patient with a PM, a failure in release of the safety impulse was detected in the auto-threshold test, although the threshold was correctly determined. In 11 of the 17 thoracic MRIs, image artifacts were detected, preventing the diagnosis in two of them. CONCLUSIONS: In patients with cardiac implantable electronic devices, MRIs performed under a specific protocol has been shown to be safe in the short term even in the thoracic region, as well as interpretable in most cases.

Temas de actualidad en arritmias y estimulación cardiaca / Update in cardiac arrhythmias and pacing

En este trabajo se comentan los principales avances en arritmias y estimulación cardiaca aparecidos entre 2013 y 2014 seleccionados como más relevantes. Se revisan especialmente las publicaciones referidas al tratamiento intervencionista de la fibrilación auricular y de las arritmias ventriculares, y los avances en estimulación cardiaca y desfibrilador automático implantable, con mención especial al paciente mayor (AU)

This article discusses the main advances in cardiac arrhythmias and pacing published between 2013 and2014. Special attention is given to the interventional treatment of atrial fibrillation and ventricular arrhythmias, and on advances in cardiac pacing and implantable cardioverter defibrillators, with particular reference to the elderly patient (AU)

Update in cardiac arrhythmias and pacing.

This article discusses the main advances in cardiac arrhythmias and pacing published between 2013 and 2014. Special attention is given to the interventional treatment of atrial fibrillation and ventricular arrhythmias, and on advances in cardiac pacing and implantable cardioverter defibrillators, with particular reference to the elderly patient.

Differences in the yield of the implantable loop recorder between secondary and tertiary centers.

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.

Implantable loop recorder allows an etiologic diagnosis in one-third of patients. Results of the Spanish reveal registry.

BACKGROUND: The implantable loop recorder (ILR) is a useful tool for diagnosing paroxysmal conditions potentially related to arrhythmias. Most investigations have focused on selected clinical studies or high-volume centers. The aim of this study was to evaluate the indications and outcomes of the ILR in real clinical practice. METHODS AND RESULTS: This was a prospective, multicenter registry of patients undergoing ILR implantation for clinical indications (April 2006-December 2008). Clinical characteristics (symptoms, arrhythmias, treatments) were recorded in a database. Follow-up data at 1 year or after the occurrence of the first episode were also recorded. Total enrollment: 743 patients (male, 413, 55.6%; 64.9 ± 16 years); 228 (30.7%) had structural heart disease (SHD), and 183 (24.6%), bundle branch block (BBB). Recurrent syncope (76.4%) was the most common indication for implantation. Complete follow-up was obtained for 680 patients (91.5%). Three hundred and twenty-five patients (48%) presented 414 events, with a final diagnosis in 230 patients (70.8% of patients with events; 33.1% of patients with follow-up). Syncope secondary to bradyarrhythmia was the most frequent diagnosis. Similar rates of final diagnoses were noted in subgroups of SHD, BBB and normal heart. Regarding the cause of implantation, higher event rates were registered among patients with recurrent syncope. CONCLUSIONS: One-third of patients obtained a final diagnosis with the ILR, independent of the baseline characteristics. Only the cause of implantation provided different rates of final diagnosis.

[Progress in cardiac pacing]. / Novedades en estimulación cardiaca.

This review summarizes recent scientific developments in ambulatory monitoring and its legal implications in appropriately selected patients. It also considers how new cardiac pacing devices can be used in the clinical monitoring of atrial fibrillation, sleep apnea and, in transplant patients, heart failure and transplant rejection. In addition, the system of accreditation for cardiac pacing services in Spain is outlined, with a focus on process development and quality indicators. Finally, the scientific articles on cardiac pacing that made the greatest impact in 2007 are summarized.

Efectos de la estimulación cardiaca convencional. Estimulación en sitios alternativos / Effect of conventional cardiac pacing. Alternative pacing sites

Desde la primera publicación del abordaje transvenoso para la implantación de marcapasos en 1959, el ápex del ventrículo derecho ha sido el sitio tradicional de estimulación por ser de fácil acceso y proporcionar estabilidad a largo plazo y umbrales crónicos de estimulación óptimos. La estimulación en orejuela derecha y ápex de ventrículo derecho ha permitido establecer una frecuencia cardiaca estable y lograr la sincronía auriculoventricular, dos de los objetivos principales de la estimulación eléctrica extrínseca; sin embargo, con ello no se ha conseguido lograr un patrón de activación y sincronía fisiológicos. Múltiples estudios publicados en los últimos años han puesto de manifiesto los efectos perjudiciales de la estimulación convencional, tanto funcionales como estructurales, con las consiguientes morbilidad y mortalidad. De ahí el interés surgido en la búsqueda de sitios alternativos de estimulación que permitan obtener despolarización y contracción miocárdica fisiológicas. En este capítulo se plantea la posibilidad de estimulación auricular en sitios alternativos, con el objetivo fundamental de prevenir las arritmias auriculares. Se revisan, asimismo de forma pormenorizada, las evidencias demostradas hasta el momento acerca de los efectos hemodinámicos y funcionales de la estimulación en tracto de salida de ventrículo derecho, así como su influencia en la duración del QRS y su correlación con la función ventricular. Finalmente, se desarrolla la estimulación permanente del haz de His, con las ventajas que supone la activación ventricular vía sistema específico de conducción (AU)

Since the appearance of the first publication on the transvenous approach to pacemaker implantation in 1959, the apex of the right ventricle has been the conventional site for pacing because it is readily accessible, it provides long-term stability, and the chronic pacing threshold is optimal. Pacing in the right atrial appendage and the ventricular apex enables the heart rate to be stabilized and atrioventricular synchrony to be established, two of the main objectives of extrinsic electrical pacing. However, it does not lead to the establishment of physiologic activation and synchrony patterns. Numerous studies published over the past few years have demonstrated the deleterious effects, both functional and structural, of conventional pacing, and its associated morbidity and mortality. These findings have triggered a search for alternative pacing sites that would enable more physiologic myocardial depolarization and contraction to be achieved. This article discusses the possibility of using alternative atrial pacing sites, with the fundamental aim of preventing atrial arrhythmia. In addition, it also contains a detailed review of the evidence published to date on the hemodynamic and functional effects of right ventricular outflow tract pacing, its influence on the QRS duration, and its correlation with ventricular function. Finally, there is a discussion of permanent His bundle pacing, and the possible advantages associated with ventricular activation via this particular conduction system (AU)

Consenso sobre la terapia de Resincronización Cardíaca / Spanish Society of Cardiology Cardiac Resynchronization Working Group Consensus on Indications for, Programing of and Follow-Up Resynchronization Devices

Dentro del arsenal terapéutico de la insuficiencia cardíaca, la resincronización cardíaca cada vez está adquiriendo un papel más importante como coadyuvante del tratamiento médico. Se ha demostrado ampliamente que en los pacientes con insuficiencia cardíaca avanzada y bloqueo de rama izquierda, la estimulación biventricular produce una mejoría hemodinámica y clínica, así como un remodelado inverso del ventrículo izquierdo. Algunos estudios sugieren también una disminución de la mortalidad. Sin embargo, es una terapia costosa y compleja que no está libre de complicaciones y con un porcentaje de pacientes que no mejoran. Por ello, para su correcta aplicación es necesaria una colaboración multidisciplinaria. El Grupo de Trabajo de Resincronización Cardíaca de la Sociedad Española de Cardiología ha redactado el presente documento de consenso con especial interés por exponer las indicaciones de esta terapia, así como la correcta selección de los dispositivos y su adecuada técnica de implante y seguimiento (AU)

Cardiac resynchronization is an increasingly important therapeutic option for a subgroup of patients with heart failure. It has been shown that biventricular pacing produces significant hemodynamic and clinical improvements and results in left ventricular remodeling in patients with severe heart failure and left bundle branch block. Some studies also indicate that cardiovascular mortality is decreased. However, this form of treatment is expensive and complex, it is not free of complications, and there are a significant number of non-responders. Therefore, multidisciplinary collaboration is necessary if it is to be used correctly. The Spanish Society of Cardiology Cardiac Resynchronization Working Group has produced this consensus document with the aim of establishing current indications for therapy, and ensuring that device selection is appropriate and that implantation and follow-up are carried out correctly (AU)