The relationship between serum ferritin levels and electrocardiogram characteristics in acutely ill patients

Cardiac arrhythmias are common comorbidities among acutely ill patients admitted to hospitals. An abnormal iron metabolism may contribute to the abnormalities in the conduction and propagation of action potentials through myocardium.

To determine whether serum indexes of iron metabolism correlate with electrocardiogram (ECG) changes.

In the present retrospective, pilot chart review, serum levels of iron, ferritin, Na(+), K(+), Mg(2+), Ca(2+) and total iron-binding capacity in 77 hospitalized patients with acute illness were correlated with ECG variables.

The serum ferritin level correlated strongly (r=0.49) with QT/QTs interval. There were three subjects with QT prolongation (longer than 450 ms) within the high serum ferritin (576 ng/mL or greater) group versus subjects with low ferritin. Multiple regression analysis showed that serum ferritin level and serum iron level contributed to the variance in the QT/QTs prolongation. No other correlation between the studied serum markers and ECG characteristics were found.

The present study suggests that serum ferritin and iron levels affect the QT interval in a variety of medical conditions, possibly contributing to the emergence of fatal cardiac arrhythmias.