Woman Blacks Out Repeatedly, Doesn’t Remember Doing So

ANSWER

The ECG shows marked sinus bradycardia with a four-second pause consistent with sinus arrest. This may be due to conduction disease within the sinus node and may be exacerbated by use of β-blockers or calcium-channel blockers, or by hypothyroidism.

The patient’s episodes of near-syncope coincided with sinus arrest on telemetry monitoring. She underwent implantation of a dual-chamber permanent pacemaker and resumed all previous activities without issue.