Effects of ischemia on QT dispersion during spontaneous anginal episodes.
Myocardial ischemia induced by pacing, angioplasty, or stress results in a significant increase in QT dispersion (QTd = QT maximum - QT minimum). This study investigated the effects of ischemia on QTd and the rate-corrected QTd (QT(c)d) during spontaneous anginal episodes in patients with coronary artery disease (CAD). Ninety-five patients with CAD and typical angina pectoris and 15 control subjects complaining of anginalike symptoms were studied. QTd and QT(c)d were calculated from 12-lead surface electrocardiograms recorded during and after the relief of pain. QTd and QT(c)d were significantly higher during the anginal episode (84+/-31 ms and 98+/-51 ms) compared to the painless conditions (69+/-24 ms and 71+/-24 ms) (P = .003 and P = .001 for QTd and QT(c)d, respectively) only in the 57 CAD patients who had a history of an old previous myocardial infarction. QTd and QT(c)d are significantly increased during spontaneous angina in patients with documented CAD and history of previous myocardial infarction.
Dilaveris
P
P
State and University Department of Cardiology, Hippokration Hospital, Athens, Greece.
Andrikopuolos
G
G
Metaxas
G
G
Richter
D
D
Avgeropoulou
C
C
Androulakis
A
A
Gialafos
E
E
Michaelides
A
A
Toutouzas
P
P
Gialafos
J
J
D000787:Angina Pectoris / Q000175:diagnosis / Q000503:physiopathology*; D016022:Case-Control Studies; D004562:Electrocardiography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000175:diagnosis / Q000503:physiopathology*; D015588:Observer Variation