Negative U wave during percutaneous transluminal coronary angioplasty.
To clarify the clinical significance of the negative U wave during acute myocardial ischemia, the appearance of the U wave and ST-segment elevation on electrocardiography during percutaneous transluminal coronary angioplasty (PTCA) of the left anterior descending artery (LAD group: 11 patients) or right coronary artery (RCA group: 18 patients) was studied. During PTCA, U-wave inversion (newly developed negative U wave, and increased negativity of the pre-existing negative U wave) was observed in 37 (90%) of 41 patients in the LAD group and in 16 (89%) of 18 patients in the RCA group. The incidence of ST-segment elevation was similar to that of U-wave inversion; however, U-wave inversion appeared before detectable ST-segment elevation in 20 patients (49%) in the LAD group and in 4 patients (22%) in the RCA group. Moreover, U-wave inversion was observed frequently in a wider range of leads than ST-segment elevation. These results suggest that the U wave is a more sensitive indicator of myocardial ischemia than ST-segment elevation in some patients, and that a negative U wave may be produced by a different mechanism than that which produces ST-segment deviation, although both are related to myocardial ischemia.
Yano
H
H
Department of Cardiology, Komatsushima Red Cross Hospital, Tokushima, Japan.
Hiasa
Y
Y
Aihara
T
T
Nakaya
Y
Y
Mori
H
H
D015906:Angioplasty, Balloon, Coronary; D002404:Catheterization; D002933:Cineradiography; D017023:Coronary Angiography; D003327:Coronary Disease / Q000503:physiopathology; D003331:Coronary Vessels / Q000503:physiopathology; D004562:Electrocardiography / Q000295:instrumentation / Q000379:methods; D004566:Electrodes; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D012680:Sensitivity and Specificity