Relationship between the Trace Elements and Abnormal Electrocardiogram in Bed-ridden Patients

Sudden death has been reported in patients with low serum copper level, however its mechanism has not been fully clarified. Imbalance of trace elements including copper may affect the electrophysiological aspects of the conduction systems of the ventricle. QT dispersion (QTd equals maximal minus minimal QT interval) and JT dispersion (JTd equals maximal minus minimal JT interval) on a standard ECG has been shown to reflect severe cardiac arrhythmia and with abnormal ventricular repolarization. We investigated the QTd, JTd and QTc (heart rate-corrected QT interval) in the ECGs of 24 bed-ridden state patients aged 78.1±13.5 years and 11 controls aged 49.6±9.8 years. QTd and JTd and QTc intervals were determined by using cardiofaxV ECAPS 12 (Nihon Kohden). Serum levels of copper, zinc, total protein and albumin were also measured in bed-ridden patients. QTd, JTd and QTc prolongation were significantly correlated with the level of serum copper, but not with the level of serum zinc, total protein or albumin. The incidence of QTd, JTd and QTc prolongation was higher in the patients with low level of serum copper than in those with normal level of it. These findings suggest that the cardiac autonomic dysfunction is related to the level of serum copper, and that it may predispose such patients to cardiac disorders including sudden cardiac death.