Arrhythmias

Electric shocks can cause fatal arrhythmias; in fact, 85% of fatal electrocution is secondary to arrhythmias. The most common arrhythmia in lightning injuries is asystole, while VF is more likely in lower current manmade electro-current shocks. Different arrhythmias, including atrial arrhythmias, V-Tach and ectopic beats can occur but are less likely to be immediately fatal. These arrhythmias can even occur up to 2 weeks after the event. Of note, a similar current of 20 uA can both cause asystole when directly applied to cardiac tissue as well as cause defibrillation.

Neural damage

It is commonly assumed that electric shock is most likely to cause immediate damage to the nervous system. However, the myelin sheath, which is high in fats and insulation, actually protects the nervous system from immediate damage.

Cardiac damage

Electric shock can cause direct injury to the cardiac tissue. Damage includes burns that can cause infarcts and even cardiac rupture to the damaged area. The damage usually occurs more inferiorly, which can be demonstrated with ECG change primarily in the inferior leads.

ECG changes

Following electric shock injury, there can be lasting damage to the heart. Unfortunately, the normalization of ECG changes does not guarantee complete recovery. Patients may need a follow-up echocardiogram or myocardial perfusion imaging to evaluate for lasting myocardial damage. Additionally, the adrenergic excess, including hypertension, can cause cardiac damage. Some other factors that can help predict long-term damage include the length of time of the current exposure as well as the pathway to the heart. A pathway from superior to inferior to the heart is associated with outcome.  On the other hand, injury from lightning, while potentially causing a range of arrhythmias, is more likely to resolve with normal cardiac function.