Sixty-eight cases of tricyclic antidepressive (TCA) poisoning are discussed. Cardiac arrest occurred in 8 patients, preceded by minor ECG-abnormalities. Five patients died. All cardiac arrests arose within the first 24 h after TCA ingestion. Fifty-seven patients developed ECG-abnormalities, of which 84% began within the first 6 h after TCA ingestion. ECG-abnormalities and other symptoms (respiratory arrest, coma, convulsion and hypotension) often occurred in the same patients. Treatment is described, and cardiac monitoring for at least the first 24 h is recommended. In cases of severe cardiac (ECG) abnormalities, monitoring is recommended until no ECG abnormalities are observed for at least 12 h.

In conclusion, the unrestricted use of TCA is cautioned against, since TCA must be regarded as potentially cardiotoxic.