Automatic measurement of corrected QT interval in Holter recordings: comparison of its dynamic behavior in patients after myocardial infarction with and without life-threatening arrhythmias.
This study was designed to determine the value of automatic corrected QT-interval measurement in Holter tapes in patients after myocardial infarction as a marker of life-threatening ventricular arrhythmias. We compared the corrected QT interval, automatically measured in 24-hour Holter recordings, in two groups of patients after myocardial infarction: group I was composed of 14 patients admitted consecutively to our hospital for documented sustained ventricular tachycardia or out-of-hospital cardiac arrest. Group II consisted of 28 patients with previous myocardial infarction with characteristics similar to those of group I, but without malignant ventricular arrhythmias in the follow-up. The global mean 24-hour corrected QT interval was longer in group I (425 +/- 20 msec) than in those patients after myocardial infarction without arrhythmias (group II) (405 +/- 17 msec; p < 0.01). Furthermore, a significant proportion of patients of group I (seven of 14) exhibited more peaks of corrected QT longer than 500 msec compared with patients of group II (two of 28; p < 0.005). A circadian rhythm of corrected QT peaks was observed in group I, having a significantly higher incidence from 11 PM to 11 AM (p < 0.05). We conclude that automatic corrected QT-interval measurement on Holter electrocardiogram is now available and feasible. Our results suggest that this is a marker for risk assessment of life-threatening ventricular arrhythmias. Large-scale trials are needed to confirm these results and to determine the predictive value of this technique for risk stratification.
Homs
E
E
Department of Cardiology and Cardiac Surgery, Hospital de la Santa Creu i Sant Pau, Universitat Autónoma de Barcelona, Spain.
Martí
V
V
offndo
J
J
Laguna
P
P
Viñolas
X
X
Caminal
P
P
Elosua
R
R
Bayés de Luna
A
A
D000465:Algorithms; D001145:Arrhythmias, Cardiac / Q000175:diagnosis* / Q000209:etiology; D016022:Case-Control Studies; D016757:Death, Sudden, Cardiac / Q000209:etiology*; D015716:Electrocardiography, Ambulatory / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000150:complications / Q000503:physiopathology*; D011237:Predictive Value of Tests; D011379:Prognosis; D018570:Risk Assessment; D012307:Risk Factors; D012815:Signal Processing, Computer-Assisted; D017180:Tachycardia, Ventricular / Q000209:etiology / Q000503:physiopathology*