[Pseudoischemic T waves: a possible electrophysiologic mechanism].
An electrophysiologic study has been performed in 7 patients with giant stable inversion of the T waves in the precordial ECG leads and without any organic heart disease. The study was particularly directed to evaluate the specific properties of the conductive system. The main results of the study point out the presence of absolute (prolonged HV interval, delay of ventricular activation time) or relative (RRP of the left bundle branch greater than RRP of the right one) conduction delays already in basic conditions or occurring after ajmaline (1 mg/Kg iv). Moreover, repolarization normalized during repetitive high rate atrial extrastimuli in the beats where ventricular activation time shortened and not during regular pacing. On the other hand, repolarization worsened whenever an impairment of infra or intrahisian conduction occurred. During His bundle pacing an inversion of the T waves preceded a left bundle branch conduction delay. The present data make us to hypothesize that, in these patients with pseudoischemia, a delay of activation of the initial vectors of the QRS in the left side, by amplifying the electrical gradient between the 2 ventricles, can be the underlying mechanism causing the repolarization abnormalities.
Capucci
A
A
Istituto di Malattie dell'Apparato Cardiovascolare, Università degli Studi, Bologna.
Baroni
M
M
Boriani
G
G
Magnani
B
B
D000328:Adult; D000404:Ajmaline; D002036:Bundle of His / Q000503:physiopathology; D002037:Bundle-Branch Block / Q000503:physiopathology; D002304:Cardiac Pacing, Artificial; D003327:Coronary Disease / Q000503:physiopathology*; D003937:Diagnosis, Differential; D004562:Electrocardiography; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged
D000404:Ajmaline
Le onde T pseudoischemiche: un possibile meccanismo elettrofisiologico.