Case 21 — ECGs

ECG leads I, II, III recorded simultaneously at 25 mm/sec, 10 mm/mV. Heart rate approximately 230-240 bpm. Rhythm is fast, supraventricular, and irregular with no identifiable P waves — consistent with atrial fibrillation.
Leads I, II, III (25 mm/s). Fast, irregular supraventricular rhythm with no P waves.
Same leads recorded at 50 mm/sec showing atrial fibrillation plus premature ventricular complexes (PVCs) — wide, bizarre QRS complexes interspersed with the supraventricular complexes.
Same leads (50 mm/s). Atrial fibrillation with PVCs also visible.

Quiz

1. What is the primary rhythm abnormality in the top trace?

2. What additional rhythm abnormality is present in the second trace?

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