Electrophysiologic abnormalities of heart in iron deficiency anemia. Effect of iron therapy

55 patients with iron deficiency anemia (IDA) and 55 age- and sex-matched control subjects were given exercise test on a treadmill to observe the effect on ST segment of the electrocardiogram. 14 IDA patients showed significant ST segment depression compared to only 1 in the control group, the difference being highly significant (p less than 0.001). Test was repeated 2-3 days later in 12 IDA cases and it showed significant ST depression as on previous occasions showing the reproducibility of the results. 11 of these patients received total dose i.v. iron-dextran and the exercise test was repeated 2-3 days later before any significant rise in the hemoglobin level; in 10 cases there was no significant ST segment depression. Response to iron therapy was highly significant (p less than 0.003). Correction of electrophysiological abnormalities of the heart in IDA patients by iron therapy, before the rise of hemoglobin, may be the result of the effect of iron at the tissue level.