A system and method provide immediate monitoring of a physiological function, such as ECG, of a subject before, during, or after application of an electric shock intended to temporarily incapacitate the subject. The electric shock may be delivered via at least one electrode ballistically implanted into the subject's skin. Systems and methods may further include performing time domain and/or frequency domain analysis of the results of monitoring, recording results of monitoring and/or analysis, and preventing follow-on shocks, or altering energy characterizing parameters of follow-on electric shocks so as to lessen the risk of injury to the subject, such as cardiac malfunction.