PSEUDO-OVERSENSING OF THE T-WAVE BY AN IMPLANTABLE CARDIOVERTER-DEFIBRILLATOR - A NONCLINICAL PROBLEM

Two patients are described who had pseudo-over-sensing of T waves duri ng follow-up testing of the Medtronic PCD. Each patient exhibited appr opriate T wave sensing following closely coupled spontaneous (QRS comp lexes to subthreshold stimuli without having T wave sensing following sensed or paced complexes. One patient also revealed T wave sensing fo llowing fusion beats. The occurrence of T wave sensing in these unique clinical situations was due to the auto-adjusting sensitivity thresho ld function used by the PCD. Recognition of this normal sensing functi on will prevent inappropriate reprogramming of the sensitivity or post pace refractory period, interventions that could potentially lead to v entricular tachyarrhythmia undersensing.