A Method For Removing Pacing Artifacts From Ultra-High-Frequency Electrocardiograms

Cardiac resynchronization therapy (CRT) is an effective treatment for heart-failure patients with ventricular dyssynchrony. Analysis of ultra-high frequencies in ECG (UHFECG) has been shown to provide precise identification for the selection of CRT recipients, but the use of UHFECG for CRT optimization is limited due to the fact that UHFECG activity is buried under pacemaker stimuli. While removing the rising edge of a stimulus is quite straightforward, the localization and removal of the end of the post-stimulus recharge phase is more complicated due to its very low amplitude and interference with depolarization signals in QRS onset. 12-lead 5 kHz ECG during a 3-10 minute rest period was measured in 19 patients. We detected artifacts as 1.6-ms-long segments with high energy at frequencies of 1400-1900 Hz. We removed the area around the detected peaks in the time domain. Detection of artifacts, the stimulating pulse and the end of the recharge phase was evaluated against manually annotated marks with sensitivity and specificity of 0.98 and 0.97.