Magnetic resonance imaging and radiofrequency ablations.

Cardiac MRI has evolved one of the major imaging technologies in cardiology. Increasingly MRI has also been used for electrophysiological applications. Anatomically based procedures such as the circumferential pulmonary vein ablation emphasized the importance of including the individual's cardiac anatomy in a tailored ablation approach. Today, many centers routinely perform pre-ablation imaging to identify left atrial anatomy. Three-dimensional reconstructions based on MRI are frequently integrated in clinical mapping systems to provide cardiac anatomy during the ablation procedure. Similarly, MRI is a clinically very valuable tool in assessing potential ablation complications such as pulmonary vein stenosis. New innovative use of MRI is likely to occur in three areas over the next several years. During ventricular tachycardia ablations volume rendering/fusion imaging will enable a detailed three-dimensional substrate evaluation and provide supplementary scar characterization using a combination of different imaging approaches. With the ongoing technical improvements real-time MRI will likely emerge as a stand-alone clinical modality to directly guide catheter ablation procedures. The advent of stronger field strength MRI, faster imaging protocols, and improved gating techniques will allow accurate peri- and post-procedural visualization of ablation lesions. These developments should result in shorter procedure times and decreased complications rates. Ultimately, they will enable the development of novel ablation strategies and expand the current indications for electrophysiological ablations.