en Comparative evaluation of Wide QRS Interval and R Changes in Avr Lead in Predicting Severe Complications of Tricyclic Antidepressant Poisoning عمومى General پژوهشي Research <span style="font-weight: bold">Background:</span> Tricyclic antidepressants (TCAS) Poisoning is the most common poisoning in the Poisoning Emergency Department of Noor Hospital, Isfahan, Iran. The objective of this study was to compare QRS interval duration with RaVR³3mm and R/SaVR³ 0.7 in predicting: serious complications of acute TCA toxicity. <br><span style="font-weight: bold">Methods and Materials:</span> This study was descriptive – analytic and prospective cohort. TCA poisoned patients (155 cases) were evaluated in the Emergency Department of Noor Hospital, Isfahan. On admission time, ECG and ABGs were done. Data were analyzed by SPSS Software, using t – students and chi- square tests. <br> <span style="font-weight: bold">Results:</span> The ECG results showed that frequency of RaVR³3mm , R/SaVR³ 0.7 , QRS³0.1(s), QT> 0.48(s) , Right axis deviation and arrhythmia were 5.2% ,12.9% , 37.4% , 8.38% , 12.4% and 4.5 % respectively. There was a significant relationship between widening of QRS with arrhythmia RaVR³3mm with tachycardia and delirium and R/SaVR³ 0.7 with delirium, seizure, tachycardia, hypotension and arrhythmia. QRS interval duration (61.5% -85.7%) was found to be a more sensitive indicator of toxicity than the R/SaVR ³ 0.7 (27.1% -30.7%) and RaVR>3mm (7.6% -14.2%). The positive prodective values (PPV) of ECG parameters for TCA toxicity for R/SaVR ³0.7 (20%) was more than RaVR³3mm (12.5%) and widening QRS (10.3%). <br><span style="font-weight: bold">Conclusion: </span>Specific ECG parameters such as R/SaVR, QRS interval duration and height of the R wave in lead aVR can be useful parameters in assessing and predicting cardiac and CNS complication of TCA toxicity. Tricyclic Antidepressants, Widening QRS Toxicity, RaVR Modifications. Tricyclic Antidepressants, Widening QRS Toxicity, RaVR Modifications. 2 2 http://ijt.arakmu.ac.ir/browse.php?a_code=A-10-2-60&slc_lang=en&sid=1 Farzad Gheshlaghi فرزاد قشلاقی Gheshlaghi@med.mui.ac.ir 10031947532846003458 10031947532846003458 Yes Department of Anesthesiology, School of medicine, Isfahan University of Medical Sciences, Isfahan, Iran Department of Anesthesiology, School of medicine, Isfahan University of Medical Sciences, Isfahan, Iran Nastaran Ezadi Mood نسترن ایزدی مود 10031947532846003459 10031947532846003459 No Department of Anesthesiology, School of medicine, Isfahan University of Medical Sciences, Isfahan, Iran Department of Anesthesiology, School of medicine, Isfahan University of Medical Sciences, Isfahan, Iran