Rule Out / Past cases / Atrial fibrillation
Rule Out case #7 · GentleAtrial fibrillation: a six-clue practice case
Read the clues in order and name the diagnosis as early as you can. Clues move from the patient’s story to the classic findings.
Play it as a game firstGuess before each clue unlocks, then share your score.The clues
Clue 1: A 72-year-old man has noticed his heart "fluttering" for 2 days.
Clue 2: He feels lightheaded and short of breath when walking his dog.
Clue 3: He has high blood pressure and drinks a few beers most nights.
Clue 4: His pulse feels irregularly irregular.
Clue 5: His heart rate is 128.
Clue 6: The ECG shows no P waves and irregular narrow QRS complexes.
Show the diagnosis and takeaways
Diagnosis
Atrial fibrillation
What gives it away
- An irregularly irregular pulse with no P waves on ECG is the signature of atrial fibrillation.
- The big danger is stroke from clots that form in the left atrium; CHA₂DS₂-VASc guides anticoagulation.
- Management means controlling rate or rhythm and preventing stroke.
Ran as Rule Out #7 (Saturday, October 24, 2026).
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