This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via Google Scholar Google Scholar Articles by SURAWICZ, B. Articles by BELLET, S. Search for Related Content PubMed PubMed Citation Articles by SURAWICZ, B. Articles by BELLET, S.

(Circulation. 1957;15:90.)
© 1957 American Heart Association, Inc.

---

XII. Polarity and Amplitude of the U Wave of the Electrocardiogram in Relation to that of the T Wave

BORYS SURAWICZ M.D.¹; ROBERT L. KEMP M.D.¹; SAMUEL BELLET M.D.¹

¹ From the Division of Cardiology of the Philadelphia General Hospital, Philadelphia, Pa.

The ratio of the amplitude of the QRS complex to the amplitude of the U wave varies in different leads of the same electrocardiogram. In the majority of electrocardiograms, the U wave has the same polarity as the T wave and the ratio of the U wave and T wave amplitude is relatively constant in all leads. The tallest positive U wave is usually observed in the area of leads V₂ to V₄. The deepest negative U wave is usually observed in the area of leads V₅ to V₆. Secondary changes of the T wave are very frequently accompanied by similar changes of the U wave. T-wave changes caused by myocardial infarction and digitalis are usually not accompanied by changes of the polarity of the U wave.

The electrocardiograms of 297 cases of hypertension were divided into 6 groups on the basis of the relationship between the polarity of the T wave and the U wave. Both waves were positive in all precordial leads in 48.1 per cent of the cases. Negative U waves were found in 21.8 per cent of the cases and these were predominantly in the leads with negative T waves. A negative T wave in the left precordial leads was accompanied most frequently by a negative, less frequently by an isoelectric, and least frequently by a positive, U wave. An inverted U wave in the presence of an upright T wave was found in only 2.8 per cent of the cases. A change from a negative to a positive or isoelectric U wave was observed after slowing of the heart rate, a drop in blood pressure, and nitroglycerin administration.