Final answer:
The statement regarding the ST segment being isoelectric or less than 1 mm above or below the isoelectric line in the limb leads is true, as the ST segment should normally be flat indicating uniform ventricular repolarization.
Step-by-step explanation:
The statement that in the limb leads, the ST segment is normally isoelectric, or less than 1 mm above or below the isoelectric line is true. In a typical electrocardiogram (ECG), the ST segment represents the period between ventricular depolarization and repolarization. It is expected to be isoelectric, meaning it should appear as a flat line, as this indicates that the ventricles are in a state of uniform repolarization. Changes in the ST segment's elevation or depression can be significant for various cardiac conditions such as ischemia or myocardial infarction, which may alter the homogeneity of repolarization.