Prognostic significance of negative U waves in the electrocardiogram in hypertension.

NEGATIVE U waves are usually preceded by negative T waves. It also seems that only secondarily inverted T waves are followed by inverted U waves. It was found by us, however, that the U wave was inverted in less than one half of the electrocardiograms that showed presumably secondary inversion of the T wave. The presence of an upright U wave in leads where the T wave was already inverted could be explained by the existence of a time lag between the inversion of the T wave and the inversion of the U wave in the evolution of a "left ventricular strain pattern." An isolectric U wave would probably signify a transitional phase preceding actual U wave inversion. Our previous clinical observations tended to support such a concept. If this assumption was correct and the occurrence of an inverted U wave was a late finding in 'left ventricular strain patterns," then an inverted U wave should be associated with clinical findings of more advanced disease of the left ventricle.