Prognostic significance of inverse spatial QRS-T angle circadian pattern in myocardial infarction survivors.
BACKGROUND
We investigated the predictive value of the spatial QRS-T angle (QRSTA) circadian variation in myocardial infarction (MI) patients.


METHODS
Analyzing 24-hour recordings (SEER MC, GE Marquette) from 151 MI patients (age 63 +/- 12.7), the QRSTA was computed in derived XYZ leads. QRS-T angle values were compared between daytime and night time. The end point was cardiac death or life-threatening ventricular arrhythmia in 1 year.


RESULTS
Overall, QRSTA was slightly higher during the day vs. the night (91 degrees vs. 87 degrees, P = .005). However, 33.8% of the patients showed an inverse diurnal QRSTA variation (higher values at night), which was correlated to the outcome (P = .001, odds ratio 6.7). In multivariate analysis, after entering all factors exhibiting univariate trend towards significance, inverse QRSTA circadian pattern remained significant (P = .036).


CONCLUSIONS
Inverse QRSTA circadian pattern was found to be associated with adverse outcome (22.4%) in MI patients, whereas a normal pattern was associated (96%) with a favorable outcome.
Giannopoulos
Georgios
G
1st Department of Cardiology, University of Athens Medical School, Hippokration Hospital, Athens, Greece.
Dilaveris
Polychronis
P
Batchvarov
Velislav
V
Synetos
Andreas
A
Hnatkova
Katerina
K
Gatzoulis
Konstantinos
K
Malik
Marek
M
Stefanadis
Christodoulos
C
D002940:Circadian Rhythm; D004562:Electrocardiography / Q000379:methods*; D005260:Female; D006115:Greece / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis* / Q000401:mortality* / Q000503:physiopathology; D011379:Prognosis; D015203:Reproducibility of Results; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D012680:Sensitivity and Specificity; D016019:Survival Analysis; D015996:Survival Rate; D017741:Survivors