Electrocardiographic artifact: Cardioversion with paralytics?

Electrocardiograph artifacts are known to occur in uncontrolled muscle activity, classically in seizures. With the use of therapeutic hypothermia in post cardiac arrest patients in modern ICUs, occurrence of EKG artifact is common due to shivering in patients.

We present a 52-year-old admitted to the intensive care unit post cardiac arrest secondary to cyclobenzaprine overdose been treated with therapeutic hypothermia for cerebral protection. Within 5 h of cooling, his cardiac monitor started to show persistent wide complex tachycardia with a rate of more than 300/min. It was decided to give loading dose of amiodarone. Before starting amiodarone it was seen that the arterial line showed a normal waveform with a rate of 70/min and BP of 140/70 mm Hg. The paradoxical waveform was presumptively attributed to shivering of patient. Patient was paralyzed with vecuronium and the cardiac monitor changed to normal sinus rhythm with a rate of 70/min almost immediately.

Arrhythmias are unique among transient pathologies because even in the absence of symptoms and other clinical correlations, they often lead to intensive investigations and treatments. When artifacts mimic arrhythmias, these tests are unnecessary and can be potentially dangerous.