Utility of Holter electrocardiogram in iron-overloaded hemoglobinopathies.

Cardiac arrhythmias are among the leading causes of morbidity and mortality of transfusion-dependent, iron-overloaded beta-thalassemia patients. Routine screening with Holter electrocardiogram has been recommended; however, infrequent electrocardiographic changes limit its clinical usefulness. The purpose of this study was to determine the diagnostic yield of Holter electrocardiogram monitoring and its correlation with patient symptoms and disease status. A retrospective analysis was performed on 27 transfusion-dependent thalassemia patients who underwent cardiac questionnaire and Holter screening yearly, in addition to echocardiogram and quantitative iron-level determination. Four patients had clinically significant arrhythmias detected on Holter screening, while 2 patients developed severe cardiac complications secondary to arrhythmias within 1 year of follow-up of normal Holter screening. Early detection of cardiac events among transfusion-dependent thalassemia patients with Holter electrocardiography is not clinically effective. Other screening modalities, including the transtelephonic event recorder, should be evaluated in arrhythmia surveillance.