During rhythm evaluation of an ECG, which findings should you look for?

• A. Both premature beats and ST segment changes
• B. Elevated ST segments
• C. Depressed ST segments
• D. P wave abnormalities

Answer: (A)

During rhythm evaluation, you’re looking for both disruptions to the regular cadence and signs of ischemia that show up on the tracing. Premature beats are early impulses that interrupt the normal rhythm—think premature atrial or ventricular contractions. They alter the cadence, sometimes with a different morphology or a compensatory pause afterward, which is why they’re important to spot when assessing rhythm. ST segment changes, whether elevation or depression, signal myocardial ischemia or injury and provide essential context about the heart’s current state, which can affect rhythm and overall stability. Because rhythm assessment isn’t just about timing of beats but also about what those beats reveal about heart health, noting both premature beats and ST segment deviations gives a complete picture of rhythm status and underlying pathology.