QT-interval abnormalities in hypertrophic cardiomyopathy

Clin Cardiol. 1992 Oct;15(10):739-42. doi: 10.1002/clc.4960151010.


To examine whether QTc and QTc dispersion across the leads of a surface electrocardiogram (ECG) are different in patients with hypertrophic cardiomyopathy (HCM) compared with normal subjects, we measured QT and calculated QTc in all 12 leads of a surface ECG in 24 patients with HCM and in 20 age- and sex-matched normal control subjects. Maximal QTc was prolonged in HCM patients (465 +/- 24 ms) compared with controls (410 +/- 20 ms) (p < 0.001). QTc dispersion defined as the difference of maximum-minimum QTc was also greater in HCM patients (71 +/- 21 ms) compared with normals (35 +/- 11 ms) (p < 0.001). A correlation was found between the degree of left ventricular hypertrophy expressed by the maximal wall thickness and maximal QTc (r = 0.48, p < 0.02). However, QTc dispersion did not correlate with maximal wall thickness. Thus, patients with HCM show a prolonged QTc (> 440 ms) and increased QTc dispersion compared with normal subjects. In addition, the degree of left ventricular hypertrophy correlates with maximal QTc. The presence of a prolonged QT with increased regional dispersion may be associated with the occurrence of serious ventricular arrhythmia and sudden death in HCM.

MeSH terms

  • Adult
  • Arrhythmias, Cardiac / diagnosis*
  • Arrhythmias, Cardiac / etiology*
  • Cardiomyopathy, Hypertrophic / complications*
  • Cardiomyopathy, Hypertrophic / diagnostic imaging
  • Death, Sudden, Cardiac / epidemiology
  • Echocardiography
  • Electrocardiography*
  • Female
  • Humans
  • Male
  • Risk Factors
  • Tachycardia, Ventricular / epidemiology