RESUMEN
Ventricular tachycardia is the most frequent cause of sudden cardiovascular death in patients with structural heart disease. Radiofrequency ablation is the treatment cornerstone in this population. Main mechanism for structural heart disease-related ventricular tachycardia is re-entry due to presence of slow conduction area within the scar tissue. Electroanatomical mapping with high density catheters can elucidate the presence of both scar (voltage maps) and slow conduction (activation maps). Despite the technological improvements recurrence rate after ventricular tachycardia ablation is high. Cardiac magnetic resonance has demonstrated to be useful to define the location of the scar tissue in endocardium, midmyocardium and/or epicardial region. Furthermore, recent studies have shown that cardiac magnetic resonance can analyse in detail the ventricular tachycardia substrate in terms of core scar and border zone tissue. This detailed tissue analysis has been proved to have good correlation with slow conduction areas and ventricular tachycardia isthmuses in electroanatomical maps. This review will provide a summary of the current role of cardiac magnetic resonance in different scenarios related with ventricular tachycardia in patients with structural heart disease, its limitations and the future perspectives.
RESUMEN
La resincronización cardiaca se ha consolidado en sus 10 años de vida como un tratamiento insustituible para determinados pacientes afectados de insuficiencia cardiaca refractaria. Este capítulo pretende transmitir algunos de los avances recientes y líneas de evolución que mantienen a este tipo de estimulación en permanente actualidad. Se revisan seguidamente los parámetros fisiopatológicos que justifican la mejora en la calidad de vida, disminución de las necesidades de tratamiento hospitalario y supervivencia logrados mediante la estimulación biventricular. También se aborda a los grupos de pacientes, fuera de las indicaciones establecidas en las guías de actuación internacionales, que son el centro de atención en importantes ensayos clínicos para ampliar la aplicación de esta terapia. Para optimizar la respuesta a la resincronización es preciso también una correcta planificación del implante incluida una cuidada estrategia de seguimiento y optimización en la programación del estimulador. Las indicaciones de resincronización se basan actualmente en determinados parámetros eléctricos y ecocardiográficos, se comentan también estos conceptos con especial énfasis en algunos datos de imagen que presumiblemente permitirán en un futuro próximo precisar la selección de pacientes y mejorar el porcentaje de respuestas al tratamiento de estimulación (AU)
In the ten years of its existence, cardiac resynchronization therapy has become established as an irreplaceable form of treatment in selected patients with refractory heart failure. This article presents a summary of recent advances and future trends which ensure that this type of pacing remains of continuing relevance. Thereafter, there is a review of the pathophysiologic factors that underlie the improvement in quality of life, the reduction in the need for hospitalization, and the increased survival brought about by biventricular pacing. There is also a discussion of the groups of patients who lie outside the indications listed in international guidelines and who are the focus of large clinical trials aimed at extending the applications of this type of therapy. To ensure an optimum response to resynchronization therapy, device implantation must be fully planned, there should be close follow-up, and device programming should be optimized. Currently, indications for resynchronization therapy are based on specific electrocardiographic and echocardiographic parameters. This article also contains a discussion of these parameters, with particular emphasis on imaging data that will enable more accurate patient selection in the near future, thereby increasing the response rate in cardiac pacing (AU)
