RESUMO
UNLABELLED: The aim of this paper is to report major cardiovascular complications related to intoxication due to tricyclic antidepressants (TCA) and related drugs, especially the stabilizing membrane effect (SME) and Brugada syndrome, and identify risk factors related to cardiac toxicity. POPULATION AND METHODS: A retrospective study (35 months), including all adult patients admitted for an isolated intoxication by a TCA or a related drug. The statistical analysis of clinical signs and history as well as ECG abnormalities included parameters recorded in emergency rooms. RESULTS: 65 patients without underlying cardiovascular history were retrieved (mean age 30 + 12 years). The intoxication was intentional in all cases, and the mean estimated taken dosage (ETD) was at 749 + 436 mg. Amitriptyline was the most common drug (66%) followed by clomipramine (29%). The cardiovascular examination noted a tachycardia in 63% of cases (mean HR - 108 + 13 bpm), followed by hypotension (SBP = 80 + 40 mmHg) in 11% of cases. The ECG showed a sinus tachycardia (63%), a PR prolongation (>200 ms) in 28% of cases, a MSE (15.4%) and a type-I aspect of Brugada syndrome (15.4%). The analysis of influence of ETD on HR showed a linear relationship, with the equation HR = 82.276 + 0.039 EDT (mg) (R2=0.138, p=0.001). Analyzing the influence of type of drug on ECG abnormalities revealed a more tachycardia effect of amitryptiline vs. clomipramine (p=0.047). CONCLUSION: Tachycardia is a frequent sign of intoxication, which can be expressed by a linear function depending on ETD. The MSE is more frequently noted with amitriptyline. The clinical aspect of type-I Brugada syndrome is as frequent as the MSE but does not seem prognostic. It is unclear whether it is related to an isolated electrical aspect or it hides a genetic mutation.