QT interval prolongation during carbon monoxide poisoning is a predictor of late cardiac and neurological complications

Background: Carbon monoxide (CO) poisoning late complications and deaths are mainly associated with myocardia and central nervous system damage. The aim of this study was to examine how serum carboxyhemoglobin levels relate to acute QT interval prolongation (QTc) on electrocardiograms, delayed cardiac syndrome (DCS), delayed neuropsychiatric issues (DNS), and death in acute carbon monoxide poisoning. Methods: In this retrospective analysis, 1924 patients who presented to the emergency department with a preliminary diagnosis of CO poisoning between 2018 and 2023 were included in the study. Patients’ QTc, serum carboxyhemoglobin, and late complications of CO poisoning were recorded. Additionally, DNS, DCS, and 30-day and one-year mortality rates were assessed. Results: The mean (standard deviation) age of the 1924 patients included in the study was 45 (14.7) years, and 837 (43.5%) were female. Troponin I was 0.3 (0.6) ng/dL, glucose was 125.1 (37.0) mg/dL, and the mean carboxyhemoglobin was 31.0 (10.5%) (p < 0.001). The QTc was 404.4 (38.3) ms in the group without complications of CO poisoning, 494.9 (23.9) ms in the DCS group, 481.2 (16.3) ms in the DNS group, and 497.0 (15.4) ms in the patients who died (p < 0.001). All-cause 30-day mortality rate was 127 (6.6%) (p = 0.006), while the 180-day mortality rate was 179 (9.3%). At a multivariate regression analysis, the QTc was an independent predictor of late complications and mortality due to CO poisoning, (p < 0.001). The ability to correctly identify DCS, DNS, and death in patients with a prolonged QTc was 90.3–92.7 (Area Under Curve (AUC): 0.93, 95% CI: 0.91–0.95), 89.6–90.8 (AUC: 0.87, 95% CI: 0.85–0.89), and 94.1–96.4 (AUC: 0.94, 95% CI: 0.92–0.95), respectively (p < 0.001). Conclusions: QTc in the acute phase of carbon monoxide poisoning may be an important in predicting late cardiac complications and neuropsychiatric sequelae.

Carbon monoxide poisoning; Emergency department; Cardiac complications; Neuropsychiatric sequelae; QT interval prolongation

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