The Rhythm Behind the Irregularity

ECG Weekly Workout with Dr. Amal Mattu

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HPI

A 69-year-old woman presenting with sepsis gets the following ECG for tachycardia while febrile and shivering. The baseline is poor, atrial activity is difficult to identify, and the computer interpretation reads atrial fibrillation. The diagnosis is then confirmed by the interpreting physician.

Before considering anticoagulation, review the ECG carefully and consider:

1. 1. Is the rhythm truly irregularly irregular? 
   2. Are the apparent pauses random or do they follow a reproducible pattern?
   3. What should be measured, and what alternative rhythm better explains this tracing?