Delayed-Enhancement: Aportando su contribución en el área de la Electrofisiologia Invasiva.

Robert S. Oakes, et al, realmente nos muestra la utilidad tan valiosa de la técnica de realce tardío en los pacientes con Fibrilación Atrial. Barbela y colaboradores en el 2005 realizaron una revisión del tema y exponian que :La fibrilación auricular es la arritmia cardíaca sostenida más frecuente. Afecta a 0,6% de la población, y a 6% y 8% de los sujetos mayores de 60 y 80 años, respectivamente. Los pacientes con fibrilación auricular tienen una morbilidad cinco veces mayor (incluyendo cardiomiopatía dilatada e insuficiencia cardíaca congestiva) y el doble de mortalidad que los que tienen ritmo sinusal. Además de la importancia del remodelamiento auricular que tiene dos componentes uno eléctrico y el otro anatómico, los cuales son dos puntos importantes para el manejo de la terapéutica, que pudiera ser quirurgico o por ablación con radiofrecuencia. De ahí la importancia del aporte de la RMC con sus nuevas técnicas para ayudar al manejo, no solo terapéutico si no también para determinar el pronostico de los pacientes con dicha patología.

Detection and Quantification of Left Atrial Structural Remodeling With Delayed-Enhancement Magnetic Resonance Imaging in Patients With Atrial Fibrillation
Robert S. Oakes, BS; Troy J. Badger, MD; Eugene G. Kholmovski, PhD; Nazem Akoum, MD; Nathan S. Burgon, BS; Eric N. Fish; Joshua J.E. Blauer, BS;Swati N. Rao; Edward V.R. DiBella, PhD; Nathan M. Segerson, MD; Marcos Daccarett, MD;Jessiciah Windfelder, NP; Christopher J. McGann, MD; Dennis Parker, PhD;Rob S. MacLeod, PhD; Nassir F. Marrouche, MD

Background—Atrial fibrillation (AF) is associated with diffuse left atrial fibrosis and a reduction in endocardial voltage.These changes are indicators of AF severity and appear to be predictors of treatment outcome. In this study, we reportthe utility of delayed-enhancement magnetic resonance imaging (DE-MRI) in detecting abnormal atrial tissue before radiofrequency ablation and in predicting procedural outcome.
Methods and Results—Eighty-one patients presenting for pulmonary vein antrum isolation for treatment of AF underwent 3-dimensional DE-MRI of the left atrium before the ablation. Six healthy volunteers also were scanned. DE-MRI imageswere manually segmented to isolate the left atrium, and custom software was implemented to quantify the spatial extent of delayed enhancement, which was then compared with the regions of low voltage from electroanatomic maps fromthe pulmonary vein antrum isolation procedure. Patients were assessed for AF recurrence at least 6 months afterpulmonary vein antrum isolation, with an average follow-up of 9.6
3.7 months (range, 6 to 19 months). On the basis of the extent of preablation enhancement, 43 patients were classified as having minimal enhancement (averageenhancement, 8.0
4.2%), 30 as having moderate enhancement (21.3
5.8%), and 8 as having extensive enhancement (50.1
15.4%). The rate of AF recurrence was 6 patients (14.0%) with minimal enhancement, 13 (43.3%) with moderate enhancement, and 6 (75%) with extensive enhancement (P0.001).
Conclusions—DE-MRI provides a noninvasive means of assessing left atrial myocardial tissue in patients suffering from AF and might provide insight into the progress of the disease. Preablation DE-MRI holds promise for predicting responders to AF ablation and may provide a metric of overall disease progression. (Circulation. 2009;119:1758-1767.)