Shocked by 120 volts hand to hand: when an electrician should get an ECG
An electrician on Reddit's r/electricians took a quarter-second, 120-volt hit while his other hand was on a grounded HVAC cabinet and asked whether to go to the ER. An emergency physician and hospital studies point to one ECG the same day, and no long monitoring if it is normal and there are no symptoms.
The path is what makes the question fair. With one hand on a live conductor and the other on grounded metal, current crosses the chest. Troy Madsen, an emergency physician at University of Utah Health, names that pattern, a shock felt in one hand while the other holds metal, as a higher-risk case, along with standing in water and a history of heart rhythm trouble. His advice for any household-voltage shock is to go to the ER for an EKG. If it comes back normal, staff may keep the patient on a heart monitor for a short while. He put the odds of being fine at about 98%.
Hospital data point the same way. A 2020 study in Frontiers in Medicine of 239 electrical injury patients in Vienna and Ludwigshafen found no deaths among low-voltage cases and no rhythm problem that needed drugs or a procedure. Of 90 patients with no symptoms, two developed ECG changes, both harmless slow heart rates. A 2023 Czech review of 333 cases over 23 years, published in Clinical Research in Cardiology, found that every dangerous arrhythmia appeared right after the shock and none showed up hours later.
The Frontiers authors recommend that even low-voltage patients get a 12-lead ECG, an exam and blood work for cardiac enzymes, including high-sensitivity troponin. They cite the European Resuscitation Council's reasons to keep someone on a monitor: earlier heart or lung disease, passing out, cardiac arrest, an abnormal ECG, or burns and other tissue damage. Chest pain or abnormal blood results move the patient onto the standard cardiac workup.
Both studies conclude that a patient with no symptoms, no prior heart disease and a normal first ECG can go home without extended monitoring.
Why it matters: Most electricians take a 120-volt bite at some point. After a hand-to-hand or hand-to-ground shock, one ECG the same day settles the question. Burns, chest pain or a blackout call for longer monitoring.
Sources
- ER or Not: I Electrocuted Myself!University of Utah Health, Oct 16, 2018
- International Multi-Center Analysis of In-hospital Morbidity and Mortality of Low-Voltage Electrical InjuriesFrontiers in Medicine, Nov 11, 2020
- Arrhythmias and laboratory abnormalities after an electrical accident: a single-center, retrospective study of 333 casesClinical Research in Cardiology (Springer), Aug 1, 2023