The rate-corrected Q-T interval (Q-Tc) was measured in 273 children with congenital complete heart block. Fifty-nine had prolonged Q-Tc and 50 of these had symptoms. All 10 with isolated complete heart block, prolonged Q-Tc and bundle branch block had symptoms. The ventricular rate (VR) was significantly lower in patients with prolonged Q-Tc than in their age-matched controls. The outcome is worse for children with low VR and long Q-Tc than for those with low VR and normal Q-Tc. In 11 children a prolonged Q-Tc preceded symptoms by more than 1 month. This suggests that prolonged Q-Tc in children with congenital complete heart block can be of prognostic significance.
Key wordsCongenital complete heart block Q-T interval Bundle branch block
Unable to display preview. Download preview PDF.
- 2.Bazett HC (1920) An analysis of the time-relations of electrocardiograms.Heart 7:353–370Google Scholar
- 5.Esscher E, Michaëlsson M: Bloqueo A-V completo congenito In Diagnostico y tratamiento de las arritmias cardiacas (Bayes A, Cosin J, eds). Barcelona, Doyma, 1978, p 618–624Google Scholar
- 6.Kissin M, Schwarzschild MM, Bakst H (1948) Nomogram for rate correction of QT interval in electrocardiogram.Am Heart J 35:990–992Google Scholar
- 8.Lepeschkin E: Physiologic basis of the U wave. InAdvances in Electrocardiography (Schlant RC, Hurst JW, eds). New York, London: Grune & Stratton, 1972, p 437Google Scholar
- 9.Michaëlsson M, Engle MA (1972) Congenital complete heart block. An international study of the natural history.Cardiovasc Clin 4:86–101Google Scholar
- 10.Michaëlsson M, Swiderski J (1967) High degree atrioventricular block in children.Proc Ass Europ Paediatr Cardiol III:44–49Google Scholar
- 11.New York Heart Association: Nomenclature and criteria for diagnosis of disease of the heart and great vessels/the criteria committee of the New York Heart Association. Boston, Little Brown, 1973, p 232Google Scholar
- 15.Taussig HB: Congenital malformations of the heart. Vol II Specific malformations. Cambridge, Mass, Harvard University Press, 1960, p 1002Google Scholar
- 16.White PD, Mudd SG (1929) Observations on the effect of various factors on the duration of the electrical systole of the heart as indicated by the length of the QT interval of the electrocardiogram.J Clin Invest 7:387–435Google Scholar
- 17.Yater WM, Lyon JA, McNabb PE (1933) Congenital heart block.JAMA 100:1831–1837A0946014 00007 CS-SPJRNPDF [HEADSUP]Google Scholar