Open AccessSyncope in a patient with a dual‐chamber pacemaker: What is the possible mechanism?
Author(s) -
Koza Yavuzer,
Simsek Ziya,
Aydemir Selim,
Doğan Remziye
Publication year - 2017
Publication title -
journal of arrhythmia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.463
H-Index - 21
eISSN - 1883-2148
pISSN - 1880-4276
DOI - 10.1016/j.joa.2016.09.002
Subject(s) - medicine , cardiology , qrs complex , sick sinus syndrome , electrocardiography , heart rate , cardiac pacemaker , anesthesia , blood pressure
A 90-year-old woman with hypertension and a history of a dual-chamber, rate-modulated (DDDR) pacemaker implantation 9 years previously presented to the hospital with complaints of syncope, moderate shortness of breath, and a headache. She denied any other symptoms. Her vital signs were as follows: blood pressure, 110/80 mmHg; pulse, 35 beats/min (bpm); and respiratory rate, 18 breaths/min. One month before presentation, she had undergone pacemaker replacement due to battery depletion at another hospital. The electrocardiogram (ECG) on admission is shown in Fig. 1. Pacemaker interrogation showed the following parameters: programmed mode, DDDR with a base rate of 60 bpm; atrial impedance, 410Ω; ventricular impedance, 540Ω; atrial sensing threshold, 0.5 mV; ventricular sensing threshold, 2.0 mV; and battery voltage, 2.6 V. The paced and sensed atrioventricular intervals (AVIs) were 150 and 120 ms, respectively. The pacemaker was switched to AAI mode, and the corresponding ECG is shown in Fig. 2. What is your diagnosis?