Evaluation of serial QT dispersion in patients with first non-Q-wave myocardial infarction: relation to the severity of underlying coronary artery disease.
BACKGROUND
Increased QT dispersion (QTD) has been correlated with ventricular arrhythmias. Recent reports suggest that it may serve as a marker of the severity of underlying coronary artery disease (CAD).


OBJECTIVE
The aim of this study was to examine in-hospital changes of QTD and their possible correlation with the severity of underlying CAD in patients with first non-Q-wave myocardial infarction.


METHODS
In 62 patients we estimated QTD, precordial QTD, as well as their values corrected for heart rate on Days 3 and 7 after admission. The severity of underlying ischemic burden was estimated by means of the number of diseased vessels as well as by the jeopardy score.


RESULTS
On Day 3, patients with jeopardy score > or = 6 exhibited greater QTD, corrected QTD, precordial QTD, and corrected precordial QTD (p = 0.001, p = 0.003, p = 0.02, p = 0.036, respectively); patients with multivessel disease had greater QTD (p = 0.007). On Day 7, patients with jeopardy score > or = 6 and multivessel disease exhibited greater QTD, corrected QTD, precordial QTD, and corrected precordial QTD (p < 0.001 for all). Multiple regression analysis revealed a jeopardy score of > or = 6 as the most significant independent predictor for QTD variables. From Days 3 to 7, only patients with none or one diseased vessel orjeopardy score < 6 had shortened QTD (p = 0.01 and p = 0.015, respectively) and corrected QTD (p < 0.001 for both).


CONCLUSIONS
In patients with first non-Q-wave myocardial infarction, QTD variables and their in-hospital changes reflect the severity of underlying CAD.
Lyras
T G
TG
Cardiology Department, Athens General Hospital G. Gennimatas, Athens, Greece. tglyras@ath.forthnet.gr
Papapanagiotou
V A
VA
Foukarakis
M G
MG
Panou
F K
FK
Skampas
N D
ND
Lakoumentas
J A
JA
Priftis
C V
CV
Zacharoulis
A A
AA
D017023:Coronary Angiography; D003327:Coronary Disease / Q000175:diagnosis* / Q000503:physiopathology; D004562:Electrocardiography; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000503:physiopathology*; D012044:Regression Analysis; D012720:Severity of Illness Index; D013997:Time Factors