PMCCPMCCPMCC

Search tips
Search criteria 

Advanced

 
Logo of brheartjLink to Publisher's site
 
Br Heart J. 1993 July; 70(1): 43–48.
PMCID: PMC1025227

QT interval variables from 24 hour electrocardiography and the two year risk of sudden death.

Abstract

OBJECTIVE--To study the effects of variability in the duration of the QT interval corrected for heart rate (QTc) on the occurrence of sudden death. DESIGN--Nested case-referent study. SUBJECTS--Cohort of 6693 consecutive patients who underwent 24 hour electrocardiography and were followed up for two years. Risk implications of QTc interval variables were studied in patients without evidence of cardiac dysfunction or of an intraventricular conduction defect (104 died suddenly and 201 patients were randomly drawn from the study cohort). MAIN OUTCOME MEASURES--Mean QTc interval duration and variation in QTc duration over time correlated with occurrence of sudden death. RESULTS--Patients with a prolonged mean QTc over 24 hours (> or = 440 ms) had a 2.3 times (95% confidence interval 1.3 to 4.5) higher risk of dying suddenly than patients with a normal mean QTc (400-440 ms); patients with a shortened mean QTc (< 400 ms) also had a higher risk (relative risk 2.4 (1.4 to 4.3)). Patients with low (< 20 ms) and high (> or = 25 ms) long term variation in QTc duration had an increased risk of dying suddenly compared with those with intermediate variation (20-25 ms) (relative risks 2.2 (1.2 to 4.2) and 2.3 (1.4 to 4.2) respectively). The relative risks for low and high short term variation were not significantly raised. CONCLUSIONS--A prolonged and a shortened mean QTc interval over 24 hours was associated with a more than twofold risk of sudden death compared with intermediate mean QTc values (400-440 ms). Neither short nor long term variability in QTc had a distinct relation with the risk of sudden death.

Full text

Full text is available as a scanned copy of the original print version. Get a printable copy (PDF file) of the complete article (1.0M), or click on a page image below to browse page by page. Links to PubMed are also available for Selected References.

Selected References

These references are in PubMed. This may not be the complete list of references from this article.
  • Kim SG. The management of patients with life-threatening ventricular tachyarrhythmias: programmed stimulation or Holter monitoring (either or both)? Circulation. 1987 Jul;76(1):1–5. [PubMed]
  • Kim SG. The management of patients with life-threatening ventricular tachyarrhythmias: programmed stimulation or Holter monitoring (either or both)? Circulation. 1987 Jul;76(1):1–5. [PubMed]
  • Schwartz PJ. Idiopathic long QT syndrome: progress and questions. Am Heart J. 1985 Feb;109(2):399–411. [PubMed]
  • Locati E, Schwartz PJ. Prognostic value of QT interval prolongation in post myocardial infarction patients. Eur Heart J. 1987 Mar;8 (Suppl A):121–126. [PubMed]
  • Algra A, Tijssen JG, Roelandt JR, Pool J, Lubsen J. QTc prolongation measured by standard 12-lead electrocardiography is an independent risk factor for sudden death due to cardiac arrest. Circulation. 1991 Jun;83(6):1888–1894. [PubMed]
  • WOOLF B. On estimating the relation between blood group and disease. Ann Hum Genet. 1955 Jun;19(4):251–253. [PubMed]
  • Puddu PE, Jouve R, Mariotti S, Giampaoli S, Lanti M, Reale A, Menotti A. Evaluation of 10 QT prediction formulas in 881 middle-aged men from the seven countries study: emphasis on the cubic root Fridericia's equation. J Electrocardiol. 1988 Aug;21(3):219–229. [PubMed]
  • Bragg-Remschel DA, Anderson CM, Winkle RA. Frequency response characteristics of ambulatory ECG monitoring systems and their implications for ST segment analysis. Am Heart J. 1982 Jan;103(1):20–31. [PubMed]
  • Rensma PL, Allessie MA, Lammers WJ, Bonke FI, Schalij MJ. Length of excitation wave and susceptibility to reentrant atrial arrhythmias in normal conscious dogs. Circ Res. 1988 Feb;62(2):395–410. [PubMed]
  • Schwartz PJ, Wolf S. QT interval prolongation as predictor of sudden death in patients with myocardial infarction. Circulation. 1978 Jun;57(6):1074–1077. [PubMed]

Articles from British Heart Journal are provided here courtesy of BMJ Group