Hyperkalemia
critical
Variant
The sine wave breaks down into ventricular fibrillation
Hyperkalemia
criticalHR75bpm
RR800msQT—
RR800msPR—QRS—QT—QTcF—
Pause, then click any lead to inspect itDraws the normal ECG in grey behind every lead. Shortcut: N.Hyperkalemia, ventricular fibrillation
The sine wave breaks down into ventricular fibrillation: cardiac arrest. Resuscitate as for any VF, and treat the potassium during the resuscitation.
On the trace
Try each step, then check it.
- Watch the first twelve seconds.
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The sine wave of the form before, regular at 120 per minute. - Watch it break down.
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From twelve seconds, the organised beats stop and the baseline turns into irregular waves of changing size and shape, with no QRS, no T and no two seconds alike. - Look at the readout.
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The rate and every interval show a dash: there are no beats left to count. - Check the size.
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Coarse: the waves are larger than 2 mm in lead II, at 4 to 8 per second.
Telling it apart
| Sine wave | Ventricular fibrillation | |
|---|---|---|
| Complexes | Regular, identical | None; chaotic, never repeating |
| Rate | 120 | Not measurable |
| Pulse | May still be present | None: cardiac arrest |
What it means
Cardiac arrest. Start CPR and defibrillate as for any ventricular fibrillation. Treat the potassium during the resuscitation: intravenous calcium, insulin with glucose, and consider sodium bicarbonate and dialysis during prolonged CPR. While the potassium stays high, defibrillation often fails to restore a lasting rhythm, and resuscitation is continued for longer than usual.
Full articleHyperkalemiaHow to recognise it, why it happens, what it means and what to do.