QT dispersion as a risk factor for sudden cardiac death and fatal myocardial infarction in a coronary risk population.
OBJECTIVE
To test in a prospective study the hypothesis that increased QT dispersion in resting 12-lead ECG is a predictor of sudden cardiac death.


METHODS
A nested case-control study during a mean (SD) follow up time of 6.5 (2.8) years.


METHODS
A prospective, placebo controlled, coronary prevention trial with gemfibrozil among dyslipidaemic middle aged men in primary (occupational) health care units: the Helsinki heart study.


METHODS
24 victims of fatal myocardial infarction, 48 victims of sudden cardiac death without acute myocardial infarction, and their matched controls.


METHODS
QT dispersion in baseline and pre-event electrocardiograms.


RESULTS
At study baseline, QT dispersion was similar in all victims and controls. When estimated from the pre-event ECG on average 14 months before death, the risk of sudden cardiac death in the highest QTPEAK (up to the peak of the T wave) dispersion tertile (> or = 50 ms) was 6.2-fold (95% confidence interval 1.7 to 23.5) compared with the risk in the lowest tertile (< or = 30 ms), and 4.9-fold (1.2 to 19.5) after adjustment for the presence of left ventricular hypertrophy, while QTPEAK dispersion could not predict fatal myocardial infarction. QTEND dispersion (up to the end of the T wave) in pre-event ECGs could not discriminate victims of either sudden cardiac death or fatal myocardial infarction from their matched controls.


CONCLUSIONS
In middle aged men with a normal conventional QT interval in 12-lead resting ECG, increased QTPEAK dispersion is an independent risk factor for sudden cardiac death, but not for fatal myocardial infarction.
Mänttäri
M
M
Department of Medicine, Helsinki University, Finland.
Oikarinen
L
L
Manninen
V
V
Viitasalo
M
M
D000328:Adult; D016022:Case-Control Studies; D016757:Death, Sudden, Cardiac / Q000517:prevention & control*; D004562:Electrocardiography; D015248:Gemfibrozil / Q000627:therapeutic use; D006339:Heart Rate; D006801:Humans; D000960:Hypolipidemic Agents / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000401:mortality / Q000503:physiopathology* / Q000517:prevention & control; D015588:Observer Variation; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012044:Regression Analysis; D012307:Risk Factors
D000960:Hypolipidemic Agents; D015248:Gemfibrozil