MRI-guided ablation of wide complex tachycardia in a univentricular heart

Noninvasive Radioablation of Ventricular Tachycardia

Ventricular tachycardia (VT) occurs most commonly in the presence of structural heart disease or myocardial scarring from prior infarction. It is associated with increased mortality, especially when it results in cardiac arrest outside of a hospital. When not due to reversible causes (such as acute ischemia/infarction), placement of an implantable cardioverter-defibrillator for prevention of future sudden death is indicated. The current standard of care for recurrent VT is medical management with antiarrhythmic agents followed by invasive catheter ablation for VT that persists despite appropriate medical therapy. Stereotactic arrhythmia radioablation (STAR) is a novel, noninvasive method of treating VT that has been shown to reduce VT burden for patients who are refractory to medical therapy and/or catheter ablation, or who are unable to tolerate catheter ablation. STAR is the term applied to the use of stereotactic body radiation therapy for the treatment of arrhythmogenic cardiac tissue and requires collaboration between an electrophysiologist and a radiation oncologist. The process involves identification of VT substrate through a combination of electroanatomic mapping and diagnostic imaging (computed tomography, magnetic resonance imaging, positron emission tomography) followed by carefully guided radiation therapy. In this article, we review currently available literature describing the utilization, efficacy, safety profile, and potential future applications of STAR for the management of VT.

Magnetic Resonance Imaging-Guided Cardiac Interventions

Performing intraoperative cardiovascular procedures inside an MR imaging scanner can potentially provide substantial advantage in clinical outcomes by reducing the risk and increasing the success rate relative to the way such procedures are performed today, in which the primary surgical guidance is provided by X-ray fluoroscopy, by electromagnetically tracked intraoperative devices, and by ultrasound. Both noninvasive and invasive cardiologists are becoming increasingly familiar with the capabilities of MR imaging for providing anatomic and physiologic information that is unequaled by other modalities. As a result, researchers began performing animal (preclinical) interventions in the cardiovascular system in the early 1990s.