Enhancement of intracardiac navigation by new GPS-guided location system (MediGuide Technologies)

Abstract

Ventricular tachycardia in patients with structural heart disease is a clinical relevant arrhythmogenic disorder. Many of these patients require a combination of implantable cardioverter-defibrillator (ICD) for prevention of sudden cardiac death with antiarrhythmic medications to decrease the frequency of ventricular tachycardia (VT) episodes. However, ICD cannot prevent arrhythmia episodes and medication has only limited efficacy and in relevant number of patients it has to be discontinued due to multiple side effects. Severalreportsinthelastdecadehaveshownthatinpatientswith frequently recurrent ventricular arrhythmia episodes catheter ablation can be a highly effective therapy as an adjunct to ICD and/or medical treatment. In addition, the SMASH-VT and VTACH trials demonstrates, that prophylactic VT ablation results in a prolonged time to recurrence of VT in patients with stable VT, previous myocardial infarction, and reduced left ventricular ejection fraction. 1,2 According to this data it is hardlysurprising that, besides atrialfibrillation ablation, treatment of ventricular tachycardia is the next big frontier in the field of interventional therapy of cardiac arrhythmias. However, management of ventricular tachycardia is still challenging driven by a complex three-dimensional substrate. Successful treatment requires a comprehensive understanding and visualization of cardiac anatomy and electrical activation. Beside conventional fluoroscopy, 3-D electromagnetic mapping systems have been introduced to facilitate catheter navigation. Currently used techniques have some weaknesses. For instance, fluoroscopy provides only two-dimensional information, where it is difficult to repeatedly guide the catheter to the same area of interest. Thus, with prolonged procedures there is an increased X-ray exposure, adding risk for both the patient and the physician. One limitation of available 3-D-mapping system is failing to sufficiently compensate for respiratory, cardiac cycle, and patient movement and the limited integration on fluoroscopy. Recently, a new intracardiac navigation system (MediGuide TM System) was introduced to overcome this limitation and to merge the key benefits of fluoroscopy and 3-D-mapping system in a unique manner. In the following we are going to introduce this technology and present potential implications on interventional treatment of ventricular arrhythmias.