Question

identify this rhythm

normal sinus
sinus rhythm with 1st degree block
sinus tachycardia with 2nd degree block
sinus bradycardia

Explanation:

Analyze the heart rate and rhythm regularity

The R-R intervals are regular, and the heart rate is approximately 75 beats per minute (within the normal range of 60–100 bpm).

Evaluate P waves and PR interval

Each QRS complex is preceded by a single, upright P wave, indicating a sinus origin. However, the PR interval is consistently prolonged, measuring approximately 0.32 seconds (8 small boxes), which exceeds the normal limit of 0.20 seconds.

Determine the cardiac rhythm

A regular sinus rhythm with a constant, prolonged PR interval (\(>0.20\) seconds) and a 1:1 P-to-QRS conduction ratio defines a sinus rhythm with a first-degree atrioventricular (AV) block.

Answer:

• Normal Sinus
• Sinus rhythm with 1st degree block (Correct answer)
• Sinus Tachycardia with 2nd degree block
• Sinus Bradycardia