Cardiac magnetic resonance in arrhythmogenic cardiomyopathies

Over the past few years, the approach to the 'arrhythmic patient' has profoundly changed. An early clinical presentation of arrhythmia is often accompanied by non-specific symptoms and followed by inconclusive electrocardiographic findings. In this scenario, cardiac magnetic resonance (CMR) has been established as a clinical tool of fundamental importance for a correct prognostic stratification of the arrhythmic patient. This technique provides a high-spatial-resolution tomographic evaluation of the heart, which allows studying accurately the ventricular volumes, identifying even segmental kinetic anomalies and properly detecting diffuse or focal tissue alterations through an excellent tissue characterization, while depicting different patterns of fibrosis distribution, myocardial edema or fatty substitution. Through these capabilities, CMR has a pivotal role for the adequate management of the arrhythmic patient, allowing the identification of those phenotypic manifestations characteristic of structural heart diseases. Therefore, CMR provides valuable information to reclassify the patient within the wide spectrum of potentially arrhythmogenic heart diseases, the definition of which remains the major determinants for both an adequate treatment and a poor prognosis. The purpose of this review study was to focus on the role of CMR in the evaluation of the main cardiac clinical entities associated with arrhythmogenic phenomena and to present a brief debate on the main pathophysiological mechanisms involved in the arrhythmogenesis process.