. Farzad Gheshlaghi, . Mozhgan Karbalayi Mehrizi, . Ahmad Yaraghi, . Ali Mohammad Sabzghabaee, . Forough Soltaninejad, . Nastaran Eizadi-Mood
Abstract Objective: Tricyclic antidepressant (TCA) poisoning is among highly prevalent and potentially
dangerous toxicities. ST‑T changes are observed in the electrocardiogram (ECG) of most
of TCA poisoned patients. We aimed to study ST‑T segment changes in TCA toxicity and
its probable relationship with other ECG findings.
Methods: This retrospective study was carried out in Noor and Ali Asghar University
Hospital, Isfahan (Iran) in 2012. Patients with TCA toxicity based on the patients’ history
who had not consumed any cardio-active drugs and did not have a past medical history of
cardiovascular disease in the recent 5 years, were randomly selected and investigated. Their
demographic and medical data on admission including ECG, age, sex, type and amount of
ingested TCA, poisoning severity score, QRS changes, QT interval, heart axis position and
R‑wave were all recorded. ST‑T changes and their relation with other ECG parameters have
been determined using statistical analysis.
Findings: Medical records of 272 patients were analyzed. In symptomatic patients, ST change
prevalence was 40.8% and T change prevalence was 9.5%. In asymptomatic patients, the
frequency of ST and T changes were 4.8% and 0.8%, respectively (P < 0.05). The most common
ST and T changes in baseline (on admission) ECG were non‑significant elevation (15.4%),
significant elevation (11%) in pre‑cordial leads, and T‑wave flattening (6.6%). A statistically
significant correlation was documented between ST segment changes with QRS and R‑wave
in aVR. The correlation between T‑wave changes and R‑wave in aVR lead was also significant.
Conclusion: ST‑T changes in TCA poisoned patients are more prevalent in symptomatic
patients. Obviously for a more definite conclusion, it is necessary to design a prospective study
with the control group. This may facilitate a better understanding of ST‑T segment changes.