Abstract 5691: Preliminary Experience With Noninvasive Electrocardiographic Imaging In Patients With Idiopathic Ventricular Tachycarda
Background: Localizing the origin of idiopathic ventricular tachycardia (VT) can be challenging. Electrocardiographic imaging (ECGI, CardioInsight) is a recently introduced technique that noninvasively produces electroanatomical epicardial (EPI) activation maps on a beat-to-beat basis. These data may be useful in planning and guiding catheter ablation.
Methods: Body surface potentials were acquired at 1 ms intervals during the cardiac cycle from 288 electrodes arranged in strips around the torso. EPI geometry and electrode position were registered by computed tomography. These data were combined by ECGI software to produce EPI electrograms and activation sequences. All pts underwent invasive mapping and ablation.
Results: Five pts (age 49±15 yrs) with a history of VT or frequent PVCs and no structural heart disease were studied. The origin of VT was determined by the successful ablation site: septal RV outflow tract, inferior tricuspid valve annulus, left sinus of valsalva (SOV), and right SOV (2 pts). In each pt the earliest activation site determined by ECGI corresponded to the successful ablation site. In one pt with right SOV origin, initial activation spread more rapidly to the superior right ventricle (RV) than to the left ventricle (LV), producing a LBBB QRS. In the other, circumferential spread of depolarization around the aortic root activated the LV prior to the RV (RBBB QRS, figure⇓).
Conclusions: ECGI appears to provide accurate information for localizing idiopathic VT. Understanding the patterns of global EPI activation may provide further insight into the utility and limitations of the standard 12 lead ECG for predicting VT origin.