Clinical Significance of the Negative U Wave in Electrocardiogram

In this examination the clinical significance of negative U wave was investigated in relation to age, sex, blood pressure, clinical diagnosis and other changes in ECG. 1) The incidence of negative U wave showed a marked increase in both sexes in age groups over 40 years of age and it increased rapidly as their age progressed. 2) The incidence of negative U wave increased remarkably both above 160mmHg systolic pressure and above 90mmHg diastolic pressure, and above these pressures it increased gradually as systolic and diastolic pressure became elevated. Namely, it increased remarkably in those patients who were clinically regarded as hypertensive. 3) The U wave inversion was frequently detected in the ECG of LVS, LBBB, myocardial infarction, myocardial damage and coronary insufficiency. 4) The U wave inversion was observed in leads V5 and V6 in remarkable high incidence ; in addition, the ST depression of more than 0.1 mV or T inversion in these leads were frequently accompanied by the U wave inversion. 5) Regarding clinical diagnosis, the appearance of negative U wave was closely connected with hypertensive diseases, myocardial infarction, angina pectoris, valvular diseases and congenital heart diseases. 6) U wave inversion was found twice as frequently among hypertensive patients whose condition was complicated by cardiac, cerebral or renal lesions, as among those with hypertension alone or associated with other diseases. 7) U wave inversion as an isolated abnormality was correlated considerably with hypertensive diseases or asymptomatic coronary sclerosis. 8) We should emphasize that in atypical anginal complaint associated with insignificant changes in ST segment or T waves the transient U wave inversion may be regarded as a reliable criterion of acute coronary insufficiency.