A hangover does not preclude ECG testing but I suspect any individual that’s hungover will also probably have a rapid heartbeat because one of the reasons that one feels hungover after alcohol is because of vasodilatation. The blood vessels in the body vasodilate and cause the headache. If the whole body is vasodilated, the heart rate will be faster so the only thing that the cardiologist may notice is that the heart’s beating faster than it should be beating but it won’t prevent the diagnosis of long QT, of Wolff-Parkinson-White if someone’s hungover and neither will it mask these diagnoses.
