To the Editor.
—In an article in the July 1979 Archives (139:790-794), Hall et al reported their data concerning the ventricular repolarization changes observed after minoxidil therapy. These authors, in agreement with others,1 described the abnormalities of the T waves, studying all the cases as a single group, without separating the patients who had normal ECGs (positive T waves in I, aVL, and V3 through V6) from those who had abnormal ones (negative or flattened T waves in the same leads).We studied 19 patients with hypertension who were treated with minoxidil. Nine of the patients had normal ECGs and ten had abnormal ones (left ventricular hypertrophy or signs of ischemic heart disease). The ECG changes of the two groups differed, although the average dosage of minoxidil was similar in both. In the latter group, the T waves showed a slightly reduced negativity after minoxidil treatment was