Introduction: Chronotropic Incompetence (CI) is a sinus node disease variant. Rate responsive pacemakers (PM) are designed to simulate normal sinus node responsiveness and restore chronotropic competence.
Methods: We report our experience about the incidence of CI in a population of patients implanted with a not rate responsive PM. During the 2012 routine PM follow-up, 18 DDD PM patients (15 m, 3 f; age76±12 years) with battery status in Elective Replacement Indicator (ERI) were identified; they underwent telemetry detection of atrial pacing %, NYHA class, 6 minute walking test (6MWT) or atropine test, pharmacological history (44% was treated with beta-blockers). CI was defined by a sinus rate < 100 bpm at the 6MWT/atropine test, and an atrial pacing > 50%.
Results: In 10/18 patients (55%) a CI was identified (419+136 meters and 76.5+7.8 bpm sinus rate at 6MWT); they were reimplanted with a new DDDR PM; a single or a blended double sensor (accelerometer and/or minute ventilation) was activated.
Conclusions: : An appropriate CI detection at the elective PM replacement could improve the physiologic cardiac pacing with implementation of rate responsive algorithms.