Appearance of Electrocardiographic Initial U‐Wave Inversion Dependent on Pressure‐Induced Early Diastolic Impairment in Patients with Hypertension

Abstract

Background: ECG U-wave inversion can be classified as initial and terminal U inversion according to the phasic relationship to positive U-wave deflection. Initial U inversion is occasionally observed in hypertensive patients while terminal U inversion frequently appears during severe myocardial ischemia. Hypothesis: The genesis of initial U inversion may be related to pressure-induced diastolic dysfunction. Methods: To clarify the genesis of initial U-wave inversion, we studied 11 consecutive hypertensive patients with both initial U inversion and impaired left ventricular early relaxation who were evaluated using Doppler echocardiography. Results: The U inversion disappeared during acute pressure lowering by sublingual administration of nitroglycerin. The U inversion also disappeared and relaxation improved significantly after chronic blood pressure lowering. Initial U inversion reappeared during a cold pressor test. Conclusion: The appearance of initial U inversion was dependent on the pressure-induced impaired left ventricular early relaxation in hypertensive patients.

Electrocardiographic Features of Left Ventricular Diastolic Dysfunction and Heart Failure With Preserved Ejection Fraction: A Systematic Review

“…The diastolic period, defined as the end of the T-wave until the onset of the QRS complex, comprised two studies (24,40).…”

The Double U Wave—Should the Electrocardiogram be Interpreted Echocardiographically?

“…The electrocardiographic deflection, which is sometimes seen at the end of ventricular repolarisation and which was named the U wave by Einthoven, is often seen in normal subjects, but is still of enigmatic origin. 1,2 The electrophysiological basis of U wave generation is still elusive with numerous cited hypotheses, 3,4 such as: repolarisation of the papillary muscles, 5 repolarisation of the Purkinje fibers outlasting that of the contracting myocardium, 6 prolonged repolarisation in cells of the mid-myocardium—the “M cells” 7 or it may be due to after-potentials, caused by mechanical forces in the ventricular wall with termination of mechanical systole—the “mechano-electrical feedback hypothesis”. 8…”