Ann Clin Toxicol | Volume 1, Issue 1 | Research Article | Open Access
Mahmoud LS* and Gihan BA
Department of Clinical Toxicology, Ain Shams University Poison Control Center, Ain Shams University Hospitals,
Egypt
*Correspondance to: Mahmoud LS
Fulltext PDFBackground: Carbon monoxide (CO) poisoning has a direct myocardial toxicity and arrhythmogenic potential. QT dispersion (QTd), calculated from 12 lead ECG, is an index of heterogeneity of ventricular repolarization which may contribute to ventricular arrhythmias. The objective of the present study was to investigate QTd in patients of all grades of acute CO poisoning and its possible relation to ventricular arrhythmias and carboxyhemoglobin level. 1.2.
Methods: A case-control study that included ten healthy non-smokers adult volunteers as control (Group I) in addition to thirty adult patients of both sexes suffering from acute CO poisoning admitted to Poison Control Center of Ain Shams University hospitals classified into three groups according to the symptoms and signs 9 Group II (mild toxicity) Group III (moderate toxicity) Group IV (severe toxicity)). Measurements: Carboxyhemoglobin (COHB) level and 12 lead ECG were recorded on admission and at the time of discharge from each patient. This was done only once for the control subjects. QTd was defined as the difference between the greatest and the least QT intervals in any of the 12 leads.
Results: Mean COHB levels were significantly high in all patients on admission compared to the control group. They were higher in group IV than group III followed by group II. COHB levels decreased significantly on discharge time in all groups. On admission, cQTd durations were significantly increased in all CO-poisoned patients compared to Control group. They were higher in group IV than group III followed by group II. In all the tested groups, cQTd durations decreased significantly on discharge when compared with on admission durations. The patients who developed ventricular arrhythmias in the form of bigeminy and premature ectopic beats were mostly from group IV, showed higher cQTd durations compared with patients without arrhythmias. Moreover, cQTd durations were higher in patients with ventricular bigeminy than patients with premature ectopic beats. No correlation was found between COHB levels and cQTd durations of group IV.
Conclusion: This study showed that cQTd reversibly increased in all patients with various grades of acute CO poisoning. Development of ventricular bigeminy and premature ectopic beats especially in patients with severe poisoning was associated with higher cQTd. No correlation was found between the levels of COHB and the cQTd durations in the severe poisoning group. So cQTd determination could provide a potentially simple, cheap, non-invasive method of measuring the underlying dispersion of ventricular excitability, thus improving the diagnostic accuracy in a routine clinical setting.
Poisoning; Carbon monoxide; Ventriculat arrhythmias; QT dispersion
Mahmoud LS, Gihan BA. Ventricular Arrhythmias in Patients with Acute Carbon Monoxide Poisoning are Associated with QT Dispersion. Ann Clin Toxicol. 2018; 1(1): 1002.