RESUMEN
A 69-year-old man received epicardial pacing leads for complete atrioventricular block that occurred during a mechanical tricuspid valve replacement procedure. During follow-up, the patient reported intermittent episodes of dizziness and bradycardia. Remote transmissions and device interrogations failed to elucidate the cause of his symptoms. A continuous ambulatory electrocardiogram (ECG) monitor was used as an alternative diagnostic tool. Multiple pauses were detected by the monitor and, upon review, these events were deemed to be due to the intermittent loss of capture by the epicardial lead. Once this diagnosis was made and the malfunctioning lead was replaced, the patient's symptoms resolved. This case highlights the novel use of a continuous ambulatory ECG monitor in diagnosing intermittent loss of capture, which was not detected by remote monitoring or device interrogations.