[Skip to Navigation]
Access to paid content on this site is currently suspended due to excessive activity being detected from your IP address Please contact the publisher to request reinstatement.
August 1965

T-P Phenomenon: An Electrocardiographic Clue to Unsuspected Alkalosis

Author Affiliations


From the Minneapolis Veterans Administration Hospital and the Department of Medicine, University of Minnesota. Chief, Cardiovascular Section, Veterans Administration Hospital and Associate Professor, Department of Medicine, University of Minnesota.

Arch Intern Med. 1965;116(2):220-227. doi:10.1001/archinte.1965.03870020060013

IN THE COURSE of examining the charts of many alcoholic patients, an unusual electrocardiographic pattern was frequently observed which had two main features: (1) sinus tachycardia, and (2) relative prolongation of the QT interval (QTc), which in most cases was actually due to relative prolongation of the ST segment. Thus, the delayed T wave is closely followed by the next P wave, or the P wave may even begin on the downstroke of a T wave (Fig 1), and since this double peak strikes the eye at first glance it has been called T-P approximation or simply T-P. These changes which are illustrated best in leads II, III, AVF, and left precordial leads, have been found to be a reliable indicator of metabolic, respiratory, or mixed alkalosis. Since the electrocardiogram is usually obtained early in the course of a diagnostic survey, it has been helpful in directing attention to