Electrocardiographic Findings in Mortalities Due to Pure Methadone Toxicity

We aimed to evaluate electrocardiographic (ECG) abnormalities in mortalities due to pure methadone toxicity in ICU patients since methadone-related mortality may be due to cardiac complications even in acute toxicities. In a retrospective single-center study, files of all patients who had died with confirmed diagnosis of pure methadone toxicity between 2011 and 2016 were evaluated. Autopsy was performed in all cases. A cardiologist measured all ECG quantitative and qualitative indices. Fifty-one deaths were recorded. Forty-two dead patients were males. Median [IQR] age of the patients was 44 [30, 60] years. Of them, 38 (69%) were methadone-dependent and were significantly older than methadone-naïve patients (p = 0.008 and p = 0.001, respectively). ECG abnormalities were detected in all cases. ST-T abnormalities were found in 33 (64.7%) patients. Except longer PR interval in dependent patients (p = 0.017) and specific ST elevation in naïve cases (p = 0.008), other ECG indices were similar in two groups. No correlation was found between ST-T abnormalities and coronary disease in autopsy. ECG abnormalities irrelevant to coronary artery diseases are common in methadone-related mortalities. Methadone toxicity may affect myocardium and play a role in death. Further prospective studies to evaluate other cardiac indices in methadone-poisoned patients are recommended.