1. (A) Atrial (RA) and ventricular (RV) electrograms from unipolar DDD pacemaker during atrial fibrillation (AF). AF appears as rapid atrial depolarizations (AS). The upper rate limit and postventricular atrial refractory period of the pacemaker determine the rate at which the pacemaker stimulates the ventricle (VP). (B,C) Heart rate over 24 hours from memory of DDD pacemaker. (B) Sinus node incompetence during amiodarone therapy for paroxysmal atrial fibrillation. (C) Rate variation after activation of rate response. Patient reported improved exercise tolerance.
Source: Chapter 59. Surgical Implantation of Pacemakers and Automatic Defibrillators, Cardiac Surgery in the Adult, 4e
Citation: Cohn LH. Cardiac Surgery in the Adult, 4e; 2012 Available at: Accessed: January 15, 2018
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