This was contributed by one of our EM residents, Lauren Klein, with some editing by Smith.
An elderly male who missed dialysis presented to the emergency department complaining of 1 day of chest pain and shortness of breath at rest. Upon arrival to the ED, he was awake and well perfused and neurologically intact, and this ECG was obtained:
|What is it and how would you treat it?|
This is a very wide complex tachycardia with a sine wave morphology at a rate of about 160 and a QRS duration of about 220 ms. Hyperkalemia by itself can have exactly this morphology (sine wave), but should not be so fast. On the other hand, ventricular tachycardia is fast but rarely has such a sine wave morphology with such a super wide QRS. Thus, this is very likely ventricular tachycardia in the presence of hyperkalemia, especially as VT is a common complication of severe hyperkalemia.
Hyperkalemia with extreme tachycardia may be present without VT in severely ill patients, as in this case (this is worth a look). However, this patient is not extremely ill and it would be more common to have a heart rate like this one.
It would be appropriate to treat for both (use cardioversion and Calcium and Potassium shifting therapy).
Treatment of hyperkalemia will shorten the QRS duration of VT or of SVT with aberrancy.
Smith Comment: It would have probably worked very well to shock earlier. I would not use propofol for this, but would give a small dose of ketamine. I believe that intubation could have been avoided if cardioversion with ketamine had been done early.
VT or SVT with aberrancy? My friend from France, Pierre Taboulet, of e-cardiogram.com, makes the accurate point that the QRS morphology of the fast rhythm has the same RBBB configuration as the sinus rhythm, so that the fast rhythm was probably SVT with RBBB/LAFB aberrancy, extra wide due to the hyperkalemia. Thus, adenosine may well have worked!
Of note, the patient did have a baseline RBBB morphology, but, his QRS was not typically this wide. RBBB alone should have a QRS duration less than 170 ms (see this post).
Later, after more decline in the potassium, this ECG was recorded:
|Now the QRS is still shorter, at 157 ms, more typical of standard RBBB.|