Effect of Multielectrode Versus Point-by-Point Mapping on Recurrence of Ventricular Tachycardia in Ischemic Heart Disease

Overview

VT ablation is a frequently performed intervention in patients with symptomatic ventricular tachycardia, electrical storm due to monomorphic VT and appropriate ICD shocks, primarily aiming at reducing the burden of complaints, and ICD shocks. The recommendations for its use were described in the ESC guideline for ventricular arrhythmias and the prevention of sudden cardiac death. To visualize the arrhythmogenic substrate leading to ventricular tachycardia complex mapping techniques are currently used in clinical routine, including conventional Point-by-Point mapping or Multielectrode Mapping. The latter is associated with shorter Mapping and overall procedure times, while maintaining the same primary endpoint of the procedure itself. The aim of this trial is to validate, whether the reduction of mapping and procedure time is associated with a comparable long-term outcome compared with conventional Point-by-Point mapping.

Catheter Ablation in Patient with VT and ischemic heart disease has shown a beneficial effect in terms of VT Recurrence and Quality of life. The short-term outcome of catheter Ablation in Patients with this particular disease is good, but VT recurrence during long-term follow up is as high as 50-70%. An integral Part of the Ablation procedure is the substance guided Mapping for localisation of low Voltage areas, late diastolic or fractioned potentials, as possible substrate for VT maintenance. These diastolic pathways, which represent slow conducting myocardium, are the major prerequisites for Reentry and thus for ventricular tachycardia. Commonly these diastolic pathways are found in myocardial scar after infarction. Cardiac MRI can help to visualize these scars. In Patients with non-ischemic cardiomyopathy, the physician has to rely on intraprocedural Mapping and localisation of pathologic signals mentioned above. In the last few years, the use of Multielectrode Mapping catheters becomes more and more part of complex EP procedures, mainly due to a high spatio temporal resolution, thereby reducing the overall Mapping time while maintaining the same primary endpoint of VT-non-inducibility compared to Point-by-Point Mapping. There is growing evidence, that Multielectrode Mapping is associated with lesser mapping and procedure time, while generating more elecatroanatomical points (and thus more information regarding the arrhythmogenic substrate, responsible for VT maintenance). Currently there is considerable uncertainty as to whether the reduced mapping and procedure time of Multielectrode Mapping will have an effect on the recurrence of ventricular tachycardia. Procedure time of catheter ablation in patients with scar mediated ventricular tachycardia is directly correlated to hospital mortality. Yet there are no prospective studies, which evaluate the effect of the aforementioned Mapping systems in the recurrence of ventricular tachycardia in comparison to conventional mapping techniques. The objective of the trial is to demonstrate that Multielectrode Mapping in patients with ventricular tachycardia with structural (on inflammatory) is not inferior to conventional Mapping techniques with respect to VT Recurrence.