Limitation of the bandpass filter in preventing oversensing of pectoral myopotentials over the long-term follow-up.

A 60-year-old male experienced an inappropriate shock from an implantable cardioverter-defibrillator (ICD) because of oversensing of pectoral myopotentials. Battery depletion was also observed, and a generator change was performed. A single-chamber ICD (VENTAK PRIZM II 1860) was changed to a new ICD (INCEPTA VR F161). The myopotentials were clearly eliminated by the difference in the band pass filter (PRIZM; 21-171 Hz, INCEPTA; 20-85 Hz), but unfortunately, new noise was documented 4 years later. The utility of the bandpass filter for preventing oversensing of myopotentials was observed, but the limitation of its use for long-term follow-up was also indicated.