EKG of the Week 2016-6-26

This EKG comes courtesy of our alumnus Dr. Ethan Cohen. (Ethan and Braden are running a close race on the number of EKG’s that make it into EKG of the week!!)

A 30 y/o female was in the water at the beach when she was struck by lightning.  She was initially in asystole.  Upon arrival to the ED she was in V-fib. Was defibrillated once with ROSC. She had a ferning pattern to her right anterior chest wall with an apparent exit wound to her middle finger. Initial labs revealed pH of 6.8, potassium 7, trop>14, lactic acid >15. Her EKG at the time of ROSC is attached here. 

1.       What pattern does the EKG demonstrate?

2.       How would you manage this patient?

ANSWER:

The EKG demonstrates a wide complex rhythm with absent P waves. This is consistent with a ventricular escape rhythm. However, the heart rate is 75 which is faster than expected for a ventricular escape rhythm. This is referred to as an “accelerated idioventricular rhythm”. 

The hyperkalemia should be treated with calcium. The rhythm itself should not be treated but should be monitored. The patient should be resuscitated for the lightning injury.

Lightning strike provides high voltage direct current injury of very brief duration. Patients can go into immediate cardiac arrest or can develop arrhythmias. EKG findings in patients struck by lightning can be varied. Patients with a direct hit can show ST elevations due to a current of injury, T wave inversions, PVC’s, and QT prolongation. Patients with a splash injury or ground current injury can have non-specific ST/T wave changes.

Remember that patients with lightning strike should be aggressively resuscitated. Lightning victims receive “reverse triage” and are classified as “immediate” even if they are in cardiac arrest.

This patient’s EKG findings can be due to the hyperkalemia or due to injury to the heart from the lightning strike (or both). The hyperkalemia should be treated with calcium. In this case it resulted in no change to the EKG.

This EKG appears to demonstrate a ventricular escape rhythm. However, the heart rate is 75 which is faster than expected for a ventricular escape rhythm. This is referred to as an “accelerated idioventricular rhythm”. This can be seen in patients who receive tPA or PCI after a STEMI for an occluded vessel. In this scenario, the accelerated idioventricular rhythm is considered a sign of successful reperfusion and is termed a “reperfusion arrhythmia”. Reperfusion arrhythmia can also occur after successful resuscitation from cardiac arrest. This is the likely cause in our patient.

(Lichtenberg et al. Cardiovascular Effects of Lightning Strikes. JACC 1993;21:531-6.)

(Paradis et al. Cardiac Arrest: The Science and Practice of Resuscitation Medicine. Cambridge University Press.)