One can either use calculated sums of the amplitudes of QRS complexes of all 12 leads, or the 6 limb leads, or only leads I and II ... ECG along these lines in the care of patients with CHF will ...

In a “normal” electrocardiogram (ECG), the transition of the QRS axis in the precordial leads ... is “early,” occurring at or before lead V 3, whereas “clockwise rotation” is a variant ...