Original Article Cardiol Young 2006; 16: 141–146 © Cambridge University Press ISSN 1047-9511 doi: 10.1017/S1047951106000060 A CUTE RHEUMATIC FEVER REMAINS A SERIOUS problem for public health which is common in developing countries. Rheumatic valvar heart disease, an important sequel to rheumatic fever, remains the most common acquired cardiac disease worldwide. 1,2 One of the most characteristic distur- bances of conduction in acute rheumatic fever is first- degree heart block. Prolongation of the PR interval relative to the heart rate is a nonspecific finding, present in more than one-third of the patients. The PR interval usually returns to normal after the disease becomes inactive, and this can occur with or without carditis. Low-voltage QRS complexes, and changes in the ST segments, may be found in the presence of pericarditis and pericardial effusion. 3 A measurement that may be useful in this context, and one that has been identified as a marker of electrical myocardial instability, is the variation in the duration of the QT interval between the leads, so-called QT dispersion. Such dispersion reflects variations in the repolariza- tion in different regions of the myocardium. These result from reentrant mechanisms due to the exis- tence of areas of slow conduction. 4,5 The dispersion has been measured in electrocardiograms obtained in various clinical populations, ranging from healthy volunteers 6,7 to patients with the long QT syn- drome, 8 survivors of acute myocardial infarction, 9 and patients with hypertrophic 10 and dilated car- diomyopathies, 11 as well as many other well defined groups. 4,12,13 The extent of QT dispersion in patients with acute rheumatic fever, however, has not yet, to the best of our knowledge, been elucidated. In this study, therefore, we have analyzed prospectively the varia- tions of the QT dispersion in the surface electrocar- diogram of children with acute rheumatic fever. QT dispersion in acute rheumatic fever Tugcin Bora Polat, Yalim Yalcin, Celal Akdeniz, Cenap Zeybek, Abdullah Erdem, Ahmet Celebi Department of Pediatric Cardiology, Dr Siyami Ersek Thoracic and Cardiovascular Surgery Hospital, Istanbul, Turkey Abstract Background: Disturbances of conduction are well known in the setting of acute rheumatic fever. The aim of this study is to investigate the QT dispersion as seen in the surface electrocardiogram of children with acute rheumatic fever. Methods: QT dispersion was quantitatively evaluated in 88 children with acute rheu- matic fever. Patients were divided into two groups based on the absence or presence of carditis. As a control group, we studied 36 healthy children free of any disease, and matched for age with both groups. Repeat echocardiographic examinations were routinely scheduled in all patients at 3 months after the initial attack to study the evolution of valvar lesions. Results: The mean QT dispersion was significantly higher in children with rheumatic carditis. But there was no statistical difference between children without carditis and normal chil- dren. Among the children with carditis, the mean dispersion was higher in those with significant valvar regur- gitation. Dispersion of greater than 55 milliseconds had a sensitivity of 85%, and specificity of 70%, in predicting rheumatic carditis, while a value of 65 milliseconds or greater had sensitivity of 81% specificity of 85% in predicting severe valvar lesions in acute rheumatic carditis. At follow-up examination, a clear reduc- tion on the QT dispersion was the main finding, reflecting an electrophysiological improvement. Conclusions: These observations suggest that QT dispersion is increased in association with cardiac involvement in children with acute rheumatic fever. Keywords: Electrocardiography; carditis; Jones, criterions Correspondence to: Tugcin Bora Polat, Mehmetcik Cad. Tokkal Apt. No: 53/13, Fulya-Istanbul, Turkey. Tel: +212 212 32 62; Fax: +212 311 32 45; E-mail: tugcin75@mynet.com Accepted for publication 19 September 2005