A discussion of the use of ECG as a diagnostic tool in assessing patients who are either non-responsive or unconscious upon admission. The case history of a 32-year old man admitted to an emergency department illustrates the significance of wide QRS complexes in a patient who had overdosed on tricylic antidepressants. The author states this type of drug hasa direct depressant effect on the myocardium & is particularly likely to cause conduction defects when taken in excessive doses. (NBB)