Registro español de desfibrilador automático implantable. XVIII informe oficial de la Asociación del Ritmo Cardiaco de la Sociedad Española de Cardiología (2021) / Spanish implantable cardioverter-defibrillator registry. 18th official report of the Heart Rhythm Association of the Spanish Society of Cardiology (2021)

Introducción y objetivos Se presentan los datos correspondientes a los implantes de desfibrilador automático implantable (DAI) en España en el año 2021. Métodos Los datos provienen de los centros implantadores, que cumplimentaron voluntariamente una hoja de recogida de datos durante el implante. Resultados En 2021 se recibieron 7.496 formularios de implante, frente a los 7.743 comunicadas por Eucomed (European Confederation of Medical Suppliers Associations), lo que implica que se han recogido datos del 96,8% de los dispositivos implantados en España. El cumplimiento osciló entre el 99,9% en el campo «nombre del hospital implantador» y el 8,9% en la variable «hospital de referencia». En 2021, 199 hospitales han participado en el registro, lo cual supera las cifras de los años previos en que el número de participantes osciló alrededor de 170 hospitales. La tasa total de implantes registrados fue 158/millón de habitantes (163 según Eucomed), lo que la sitúa como el año con mayor actividad. Sin embargo, el registro sigue mostrando diferencias importantes entre las comunidades autónomas y la tasa de implante más baja de todos los países europeos participantes en Eucomed. Conclusione El Registro español de desfibrilador automático implantable del año 2021 recoge un incremento en el número de implantes de DAI y refleja la recuperación de la actividad hospitalaria tras el impacto inicial de la pandemia por COVID-19 durante 2020. A pesar del incremento en el número total de implantes en España, este sigue siendo muy inferior a la media de la Unión Europea y persisten las diferencias entre las comunidades autónomas españolas (AU)

Introduction and objectives This article presents the data corresponding to implantable cardioverter-defibrillator (ICD) implantations in Spain in 2021. Methods The data were drawn from implanting centers, which voluntarily completed a data collection sheet during the procedure. Results In 2021, 7496 implant data sheets were received, compared with 7743 reported by Eucomed (European Confederation of Medical Suppliers Associations), indicating that data were collected from 96.8% of the devices implanted in Spain. Data completion ranged from 99.9% for “name of implanting hospital” to 8.9% for “implanting hospital”. In 2021, 199 hospitals participated in the registry, exceeding the figures of previous years, with around 170 participating hospitals. The total rate of registered implants was 158/million inhabitants (163 according to Eucomed), making 2021 the year with the highest activity. However, the registry continues to show significant differences among the various autonomous communities and the lowest implantation rate of all the European countries participating in Eucomed. Conclusions The Spanish implantable cardioverter-defibrillator registry for 2021 recorded an increase in the number of ICD implantations, reflecting the recovery of hospital activity after the initial impact of the COVID-19 pandemic in 2020. Although the total number of implants has increased in Spain, figures are still much lower than the European Union average, with differences persisting among Spanish autonomous communities (AU)

Transient entrainment of bundle-branch reentry by atrial and ventricular stimulation: elucidation of the tachycardia mechanism through analysis of the surface ECG.

BACKGROUND: Different responses to entrainment have been reported in relation to the pacing site of a variety of tachycardias. However, transient entrainment of bundle-branch reentrant tachycardia (BBRT) has not been investigated systematically. METHODS AND RESULTS: We attempted entrainment of 13 BBRTs in 9 patients by pacing first the right ventricle and then the right atrium. The initial pacing cycle length (CL) was 10 ms faster than the tachycardia CL. Subsequent pacing sequences were performed with 5- to 10-ms CL decrements until tachycardia termination or loss of postatropine 1:1 AV conduction. Both full ventricular-paced and AV-conducted QRS complex references were obtained during sinus rhythm pacing from the same sites and with similar CL as during entrainment. Transient entrainment was achieved by ventricular and atrial stimulation in 11 and 8 tachycardias, respectively. Constant fusion was always present during entrainment by ventricular stimulation. There was no change in the QRS complex (orthodromically concealed fusion) during entrainment by atrial stimulation in 6 of 6 tachycardias with left bundle-branch block morphology and in 1 of 2 tachycardias with right bundle-branch block morphology. CONCLUSIONS: BBRT, especially if it has a left bundle-branch block morphology, can be differentiated from other wide-QRS-complex tachycardia mechanisms through analysis of the ECGs recorded during tachycardia entrainment by atrial and ventricular stimulation. This diagnostic approach may be especially useful when it is difficult to record a stable or sufficiently sized His bundle electrogram or when spontaneous changes in the ventricular CL precede similar changes in the His bundle CL.

Bundle-branch reentry and the postpacing interval after entrainment by right ventricular apex stimulation: a new approach to elucidate the mechanism of wide-QRS-complex tachycardia with atrioventricular dissociation.

BACKGROUND: Diagnosis of bundle-branch reentry ventricular tachycardia (BBR-VT) by the standard approach is challenging, and this may lead to nonrecognition of this tachycardia mechanism. Because the postpacing interval (PPI) after entrainment has been correlated with the distance from the pacing site to the reentrant circuit, BBR-VT entrainment by pacing from the right ventricular apex (RVA) should result in a PPI similar to the tachycardia cycle length (TCL). This factor may differentiate BBR-VT from other mechanisms of wide-QRS-complex tachycardia with AV dissociation, such as myocardial reentrant VT (MR-VT) or AV nodal reentrant tachycardia (AVNRT), in which the circuit is usually located away from the RVA. METHODS AND RESULTS: Transient entrainment by RVA pacing was attempted in 18 consecutive BBR-VTs and finally achieved in 13. Results were compared with those found in 59 consecutive MR-VTs and 50 consecutive AVNRTs. The mean PPI-TCL difference was significantly (P:<0.0001) shorter in the BBR-VT group (9+/-11 ms) than in the MR-VT (109+/-48 ms) and the AVNRT (150+/-29 ms) groups. No BBR-VT showed a PPI-TCL >30 ms (range -12 to 24 ms). Except for 2 MR-VTs, no MR-VT (range 21 to 211 ms) or AVNRT (range 100 to 215 ms) showed a PPI-TCL <30 ms. CONCLUSIONS: A PPI-TCL >30 ms, after entrainment by RVA stimulation, makes BBR-VT unlikely. Conversely, a PPI-TCL <30 ms is suggestive of BBR-VT but should lead to further investigation by use of conventional criteria.

[The absence of interference between GSM mobile telephones and implantable defibrillators: an in-vivo study. Groupe Systèmes Mobiles]. / Ausencia de interferencia entre teléfonos móviles GSM y desfibriladores implantables: estudio in vivo.

INTRODUCTION AND OBJECTIVES: The electromagnetic field created by mobile telephones can cause pacemaker dysfunction. Although implantable cardioverter defibrillators are also susceptible to electromagnetic interference, few studies have addressed this issue and compatibility with the GSM mode has not been tested. This study was developed to detect possible "in vivo" interference between GSM mobile telephones and implantable cardioverter defibrillators. MATERIAL AND METHODS: The study group is composed of 30 patients with 8 different models of defibrillators. Twenty six had endocardial leads and 4 epicardial. Three GSM mobile phones were used: Siemens S3 COM and Motorola 6200 in all cases and Ericsson GA 318 in one. The tests were performed under continuous electrocardiographic monitoring. All therapies were deactivated and sensitivities were set to maximal parameters. The telephones were positioned in close contact to the defibrillator can and precordium, in two different angles. Three situations were evaluated: calling, established contact for 15 seconds and ringing. The protocol was repeated during pacing to assess the possibility of pacemaker mode inhibition. RESULTS: No cases of electromagnetic interference were observed. One patient presented non-sustained ventricular tachycardia episodes during the tests that were detected by the defibrillator. CONCLUSIONS: These results suggest that electromagnetic interference by GSM mobile phones are not a probable cause of implantable defibrillators dysfunction.

[Maze technique for the treatment of auricular fibrillation: initial experience]. / Técnica de MAZE para el tratamiento de la fibrilacion auricular: experiencia inicial.

INTRODUCTION AND OBJECTIVES: The MAZE procedure was developed as a surgical approach to the management of patients with atrial fibrillation refractory to medical treatment. This study seeks to identify the risk and benefits of adding the MAZE procedure in patients with atrial fibrillation undergoing surgery for underlying organic cardiac disorders. MATERIAL AND METHODS: Since november 1993, we have performed 10 interventions with the MAZE procedure, for the treatment of refractory atrial fibrillation. The indication to perform the technique was systemic embolism in 5 patients, contraindication for the anticoagulant treatment in two cases and no response to antiarrhythmic treatment in 5 cases. Two patients had more than one indication. In all the cases another surgical procedure was performed, 5 replacements of mitral valve, a mitral repair, one tricuspid repair and tree repairs of an atrial septal defect. RESULTS: Soon after surgery 9 patients were in sinus rhythm, and one in atrial fibrillation. Four patients needed atrial pacing during the first days. One patient required a pacemaker due to symptomatic sinus bradycardia. During the first 3 months, 4 patients had episodes of paroxysmal atrial fibrillation and flutter. One patient died suddenly one month after surgery. Seven patients have completed two years of follow-up, and are in stable sinus rhythm, in functional class I and free of antiarrhythmic drugs. All of them have echocardiographic evidence of mechanical activity in both atria. Left atrium had been reduced from 5.3 +/- 0.7 cm to 4.5 +/- 0.7 cm (p < 0.05). No patient has presented new embolic events. CONCLUSIONS: The MAZE procedure is a good choice in selected patients with atrial fibrillation refractory to medical treatment, or a precedent of systemic embolism. However, several problems can complicate the patient's course.

[Surgical treatment of atrial fibrillation]. / Tratamiento quirúrgico de la fibrilación auricular.

Atrial fibrillation is the most frequently found sustained arrhythmia. It increases the risk of thromboembolism and adversely affects cardiac performance because of loss of atrial kick. New surgical treatments of atrial fibrillation have been developed to ablate the origin of abnormal impulses on the atrium. The left atrial isolation and the corridor operation restores the regular rhythm, but do not reduce the risk of thromboembolism because the left atrium may continue to fibrillate. The maze operation has proven to be effective in both converting to sinus rhythm and regaining atrial contractility. However, this method is meticulous and time-consuming and takes more cardiac ischemic time, especially when other cardiac procedures are performed simultaneously.

Mechanisms of sustained ventricular tachycardia in myotonic dystrophy: implications for catheter ablation.

BACKGROUND: Ventricular arrhythmias have been documented and linked to the high incidence of sudden death seen in patients with myotonic dystrophy. However, their precise mechanism is unknown, and their definitive therapy remains to be established. METHODS AND RESULTS: We studied 6 consecutive patients with myotonic dystrophy and sustained ventricular tachycardia by means of cardiac electrophysiological testing. Particular attention was paid to establish whether bundle-branch reentry was the tachycardia mechanism, and when such was the case, radiofrequency catheter ablation of either the right or left bundle branch was performed. Clinical tachycardia was inducible in all patients and had a bundle-branch reentrant mechanism. In 1 patient, 2 other morphologies of sustained tachycardia were also inducible, neither of which had ever been clinically documented, and both had a bundle-branch reentrant mechanism. Ventricular tachycardia was no longer inducible after bundle-branch ablation, except for a nonclinically documented and nonsustained ventricular tachycardia in the only patient who had apparent structural heart disease. CONCLUSIONS: A high clinical suspicion of bundle-branch reentrant tachycardia is justified in patients with myotonic dystrophy who exhibit wide QRS complex tachycardia or tachycardia-related symptoms. Because catheter ablation will easily and effectively abolish bundle-branch reentrant tachycardia, myotonic dystrophy should always be considered in patients with sustained ventricular tachycardia. This is especially true if no apparent heart disease is found.

VDD pacing with single lead in a heart transplant recipient: case report.

Permanent pacemaker implantation is required in a large number of transplantation patients principally because of sinus node dysfunction of the donor atrium. The most suitable mode of pacing in these cases is still subject to controversy. We describe one case of a single lead system of VDD stimulation and sensing of the recipient atrial signal in a 32-year-old patient with posttransplant symptomatic sinus node dysfunction. Physiological adaptation of rate was achieved with recovery of normal receptor sinus node function.

Manejo de los pacientes con fibrilación auricular en los servicios de urgencias hospitalarios (actualización 2012) / Atrial fibrillation management in the hospital emergency department: 2012 update

La fibrilación auricular (FA) es la arritmia sostenida de mayor prevalencia en los servicios de urgencias (SHU), que presentan una frecuentación elevada y creciente en España. La FA es una enfermedad grave, que incrementa la mortalidad y asocia una relevante morbilidad e impacto en la calidad de vida de los pacientes y en el funcionamiento de los servicios sanitarios. La diversidad de aspectos clínicos a considerar y el elevado número de opciones terapéuticas posibles justifican la implementación de estrategias de actuación coordinadas entre los diversos profesionales implicados, con el fin de incrementar la adecuación del tratamiento y optimizar el uso de recursos. Este documento recoge las recomendaciones para el manejo de la FA, basadas en la evidencia disponible, y adaptadas a las especiales circunstancias de los SUH. En él se analizan con detalle las estrategias de tromboprofilaxis, control de frecuencia y control del ritmo, y los aspectos logísticos y diagnósticos relacionados (AU)

Atrial fibrillation is the most frecuently sustained arrhythmia managed in emergency departments, and accounts for a high and increasing prevalence in Spain. Atrial fibrillation is increases mortality, is associated with substantial complications and, therefore, has a relevant impact in running of the health care system. Management requires consideration of diverse clinical variables and a large number of possible therapeutic approaches, justifying action plans that coordinate the work of medical staff in the interest of providing appropriate care and optimizing resources. These evidence-based guidelines contain recommendations for managing atrial fibrillation in the special circumstances of hospital emergency departments. Stroke prohylaxis, rate control, rhtyhm control, and related diagnostic and logistic issues are discussed in detail (AU)