Scenario: This is a preoperative screening 12-lead electrocardiogram (ECG) from a 68-year-old woman scheduled for an outpatient endoscopic procedure under deep propofol sedation. Her only significant medical conditions were obesity and hypertension managed with thiazide diuretics. After the ECG was interpreted, she was asked if she ever experienced symptoms including dizziness, and she reported that she had recently experienced episodes of dizziness but it had been an extremely hot summer so she thought she might be a little dehydrated.

Normal sinus rhythm at 75 beats per minute with 2 episodes of sinus node pause (see arrows).

The sinoatrial node is the dominate pacer in the heart, and sinoatrial node pauses fall under the category of sinus node dysfunction (SND). Although the pause is not long enough to generate an escape rhythm (3 or more beats from a latent or backup pacer such...

You do not currently have access to this content.