Pro-arrhythmia in atrial fibrillation suppression pacing algorithms.

Atrial overdrive pacing algorithms have been partially effective in controlling atrial fibrillation (AF). A 76-year-old man with history of a cardiomyopathy and paroxysmal AF underwent implant of a dual-chamber ICD. After enabling preferential pacing (PP) algorithms, marked control of his AF was demonstrated, but with inappropriate ICD shocks secondary to a typical AV nodal re-entrant tachycardia. After successful slow pathway modification, no further episodes were documented with suppression of his AF burden with PP algorithms enabled.