A 79-year-old woman was admitted to the emergency department because of respiratory tract infection and several near-syncopes due to intermittent third-degree AV block (Fig. 1). She had a medical history of known paroxysmal atrial fibrillation without left ventricular dysfunction, and chronic mental depression treated by oral flecainide and nortriptyline, respectively.
Fig. 1
ECG at presentation showing third-degree AV block
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An underlying respiratory tract infection (C-reactive protein 150 mg/l) with a right lower lobe infiltrate was discovered on X-ray. A temporary pacemaker lead was placed and the patient was admitted to the cardiac care unit. Flecainide and nortriptyline were stopped at admission. Over the next hours, the AV block disappeared and the following subsequent electrocardiograms were recorded (Figs. 2 and 3).
Fig. 2
ECG 2 h after presentation
Fig. 3
ECG 3 h after presentation
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