[The diagnostic value of the rate-corrected QT interval in long-term type-1 diabetes mellitus]

Dtsch Med Wochenschr. 1996 Jun 21;121(25-26):819-22. doi: 10.1055/s-2008-1043072.
[Article in German]

Abstract

Objective: To assess the relationship between rate-corrected QT interval (QTc interval) and cardiac reflex tests in order to determine the value of QTc interval measurements in the diagnosis of diabetic cardiac autonomic neuropathy.

Investigations: The QTc interval was measured in the resting ECG of 97 type 1 diabetics (58 women, 39 men; mean age 35 +/- 12 years; duration of diabetes 18 +/- 10 years; HbA1c 7.8 +/- 1.8%). Age-related results were compared with five cardiac function tests (heart rate variation at rest and on forced breathing; 30/15 ratio of heart rate; Valsalva manoeuvre; orthostasis).

Results: The QTc interval was not prolonged ( < or = 440 ms) in 68 patients (70%), while in 29 (30%) it was prolonged ( > 440 ms). No significant differences regarding QTc interval were found between patients with autonomic cardiac neuropathy ( > or = 2 abnormal function tests) and those without ( < 2 abnormal function tests) (QTc interval 436 +/- 25 vs 426 +/- 19 ms). QTc intervals correlated with the coefficients of variation for heart rate variation at rest and on forced breathing and the 30/15 ratio of heart rate (p = 0.001; p = 0.001; p = 0.03), but not with the results of the Valsalva manoeuvre and the orthostasis test.

Conclusion: Prolongation of the QTc interval in longstanding type 1 diabetes does not provide a reliable indication of cardiac autonomic neuropathy and this measure cannot replace conventional reflex tests for its diagnosis.

Publication types

  • Comparative Study
  • English Abstract

MeSH terms

  • Adult
  • Chronic Disease
  • Diabetes Mellitus, Type 1 / complications
  • Diabetes Mellitus, Type 1 / diagnosis*
  • Diabetes Mellitus, Type 1 / physiopathology
  • Diabetic Neuropathies / diagnosis
  • Diabetic Neuropathies / etiology
  • Diabetic Neuropathies / physiopathology
  • Electrocardiography* / statistics & numerical data
  • Female
  • Heart Diseases / diagnosis
  • Heart Diseases / etiology
  • Heart Diseases / physiopathology
  • Heart Function Tests / methods
  • Heart Function Tests / statistics & numerical data
  • Heart Rate*
  • Humans
  • Male
  • Middle Aged
  • Statistics, Nonparametric