QT interval dynamics predict mortality in high-risk patients after myocardial infarction.
OBJECTIVE
The purpose of this study was to evaluate the prognostic properties of the QT/RR relationship in survivors of myocardial infarction with severe left ventricular dysfunction.


METHODS
The QT/RR interval slope was assessed from 24-h electrocardiographic recordings obtained from 241 patients representative of survivors of an acute myocardial infarction with an ejection fraction < or =35%. During a median follow-up of 752 days, 63 patients died.


RESULTS
In a multivariate analysis QT/RR at night-time was an independent predictor of all-cause mortality. A linear all-cause mortality predictor score was calculated from age, ejection fraction, QRS duration and QT/RR night, allowing identification of a high-risk one-third of the patients with a relative risk of death at 4.0.


CONCLUSIONS
This study demonstrates independent prognostic information of night-time QT/RR dynamics in patients at high risk after myocardial infarction. A linear predictor score calculated from age, ejection fraction, QRS duration and QT/RR night identifies a high-risk one-third of the patients with a 1-year mortality of 36% vs 9% in the remaining patients.
Hintze
Ulrik
U
Department of Cardiology, Odense University Hospital, Denmark. hintze@dadlnet.dk
Vach
Werner
W
Burchardt
Hans
H
Videbaek
Jørgen
J
Møller
Mogens
M
D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use; D000368:Aged; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000627:therapeutic use; D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use; D001145:Arrhythmias, Cardiac / Q000188:drug therapy / Q000453:epidemiology / Q000503:physiopathology; D015716:Electrocardiography, Ambulatory; D005260:Female; D005500:Follow-Up Studies; D006339:Heart Rate / Q000187:drug effects / Q000502:physiology; D006801:Humans; D008297:Male; D015999:Multivariate Analysis; D009203:Myocardial Infarction / Q000188:drug therapy / Q000453:epidemiology* / Q000503:physiopathology; D015588:Observer Variation; D010627:Phenethylamines / Q000627:therapeutic use; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012307:Risk Factors; D013449:Sulfonamides / Q000627:therapeutic use; D016019:Survival Analysis; D016896:Treatment Outcome; D018487:Ventricular Dysfunction, Left / Q000188:drug therapy / Q000453:epidemiology / Q000503:physiopathology
D000319:Adrenergic beta-Antagonists; D000806:Angiotensin-Converting Enzyme Inhibitors; D000889:Anti-Arrhythmia Agents; D010627:Phenethylamines; D013449:Sulfonamides; C063533:dofetilide