Last updated on: May 12th, 2022

Hi there!

You’re looking at a multiple-choice question from QBank Prepper (the newest of four distinct learning formats available in Clinical Odyssey). Try it out, and have fun improving your clinical skills.

Dysrhythmias 3

An 18-year-old man is seen at a university clinic in South Florida for a pre-participation sports physical. He was on the cross-country track team in high school. He has been in good health, reports no symptoms, and denies recent travel out of the area. The physical examination is within normal limits. A routine electrocardiogram (ECG) is obtained and shows a heart rate of 58 and a PR interval of 300 milliseconds. The ECG is otherwise within normal limits.

Which of the following is the most likely cause of the prolonged P-R interval?

Want to continue practicing?

Subscribe to Clinical Odyssey today.
  • Enjoy unlimited access to 700+ learning modules.
  • Safely improve your skills, anytime and anywhere.
  • Get answers to your follow-up questions from practicing physicians.
Learn more ➜