Electrocardiographic alterations in acute tricyclic antidepressant intoxication and its clinical implications

Abstract

Introduction: The acute poisoning by tricyclic antidepressants is common in emergency rooms. Abnormalities in 12-lead electrocardiogram (ECG) are associated with this type of poisoning, with diagnostic and prognostic implications. The ECG may have incremental value especially in situations of altered consciousness, seizures or heart rhythm disturbances associated. Objective: To review the electrocardiographic changes described in tricyclic antidepressant poisoning and to establish their prognostic implications in the management of this condition. Methods: Bibliographic search in MEDLINE (PubMed) limited to articles published between 1980 and 2010 in English, using key words (tricyclic antidepressant overdose OR tricyclic antidepressant intoxication OR tricyclic antidepressant poisoning OR tricyclic antidepressant ingestion AND electrocardiography). Of the 133 articles identified, 44 were selected for review. Results: We identified prevalent as changes with diagnostic power in descending order the following findings: deviation of 40 ms terminal of QRS to the right of the frontal plane (from 61.0 to 83.0%), sinus tachycardia (40.7 to 57.7 %), QTc prolongation (8.2 to 53.0%), ratio R / S in aVR> 0.7 (28.8 to 32.9%), prolongation of QRS (8.2 to 21.3% ) and Brugada-pattern, the evidence is sparse, but suggestive of a greater chance of seizures and hypotension. Conclusion: The ECG is an instrument easily performed in the emergency room, providing diagnostic and prognostic information for poisoning by tricyclic and should be performed in all patients with suspicion of intoxication