Cardiac damage in carbon monoxide poisoning

Background

Cardiac dysfunction including arrhythmias and myocardial ischemia have often been reported in carbon monoxide poisoning. An appropriate diagnostic approach is crucial to assess carbon monoxide (CO) cardiac damage. QT dispersion (QTd) is a measure of inhomogeneous repolarization and is used as an indicator of arrhythmogenicity.

Objectives

The aim of the present prospective study was to evaluate the relationship between the patients' age and QT dispersion of the surface ECG in carbon monoxide poisoning.

Methods

Carbon monoxide intoxication was confirmed in 40 patients by arterial blood gas analysis. Patients were subdivided into two groups according to age < 35 years (Group I) or age> 35 years (Group II). QT dispersion was measured by surface electrocardiogram and Bazzet's formula was used to correct the QTd for heart rate (QTcd). Measurements of QT intervals were calculated at admission and in 24-hour and 72-hour ECGs (after admission).

Results

There were no significant differences between Group I and Group II with regard to gender and carboxyhemoglobin levels. On admission, the QTd, QTc, and QTcd intervals in Group I were significantly increased compared with Group II, but not the QT interval. There were no significant differences in QT interval measurements between Group I and Group II 72 hours after admission.

Conclusion

Although QT dispersion increased in patients with CO poisoning, age-related increases in QTd in the absence of QT interval prolongation may address this group as high risk.

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