75 year-old male, known since 15 years with ischemic heart disease with multiple percutaneous coronary interventions, LVEF 30% with narrow QRS-complexes, implanted in 2012 with a Boston Incepta F162 ICD for primary prevention. Programmation: VT zone 180-220 bpm, VF zone >220 bpm. RYTHMIQ "on" (AAI 60/min + backup VVI).
April 2016: VF initiated by PVC > short-cycle/long-cycle > VF > 1 succesful shock.
The long diastole may have been provoked by the AAI/RYTHMIQ mode which is designed to avoid RV pacing. The patient was stimulated Ap 30%, Vp 2% of the time. We reprogrammed to DDD mode with a long AV-interval with the goal to not capture the RV too much.
[originally published on the French forum 05-09-2016, by DR X Harlé, GCS CARDIOLOGIE BAYONNE LAFOURCADE.]