Effect of Elimination of Noisy ECG Leads on the Noninvasive Localization of the Focus of Premature Ventricular Complexes

High frequency of the premature ventricular complexes (PVCs) can lead to the development of the left ventricular dysfunction. Preoperative noninvasive localization of the PVC focus can decrease the time of the invasive electrophysiological study and improve the success rate of the radiofrequency ablation. Body surface potential (BSP) maps, patient-specific inhomogeneous torso model and inverse solution in terms of single dipole model were used for noninvasive localization of the PVC focus in five patients. BSP maps were computed for the initial 20 ms time interval of the ventricular activation (QRS complex in the ECG) from five selected PVCs in each patient. The inhomogeneous torso model included surfaces of torso, lungs, heart cavities and outflow tracts. To investigate whether the exclusion of the noisy ECG leads improves the accuracy of the inverse solution, the leads with the signal-to-noise ratio (SNR) less than the defined threshold value were excluded from the inverse computations. Four levels of the SNR were defined: 10, 20, 30, 40 dB. Locations of the PVC foci were computed by the inverse solution and compared with the catheter positions during successful radiofrequency ablation performed within invasive electrophysiological study. Removal of noisy ECG leads did not improve the PVC localization when the noisy ECG leads were located in left anterior torso region.