A stimulus artifact suppressor for esophageal pacing studies: design and clinical testing

The design, implementation, and clinical testing of an electronic circuit called a stimulus artifact suppressor (SAS) which eliminates the large stimulator-induced pacing artifacts from the standard 12-lead electrocardiogram (ECG) during esophageal pacing without affecting the ECG signal integrity is described. The SAS consists of (1) a battery-operated blanking pulse generator synchronized to logic pulses from the esophageal stimulator and variable in duration from 0 to 100 ms; (2) a blanking circuit driven by the pulse generator to blank the pacing artifact from the 12-lead ECG, (3) an optical isolation circuitry to electrically isolate the SAS circuitry from the simulator circuitry, and (4) input defibrillation protection circuitry. Test results showing the SAS utility in improving the ECG recording quality and interpretation during esophageal pacing are presented