Objective-To determine the normal values of QT and QTc dispersion and the eVects of sinus arrhythmia on QT dispersion in healthy children. Patients and setting-The study was carried out in a university hospital on 372 local schoolchildren (200 male, 172 female), aged seven to 18 years. Methods-The QT and preceding RR intervals of at least one sinus beat were measured manually in a range of nine to 12 leads on standard 12 lead surface ECGs. The corrected QT interval was computed by the method of Bazett. Dispersion of QT and QTc were defined as (1) the diVerence between the maximum and minimum QT and QTc intervals occurring in any of the 12 leads (QTD and QTcD), (2) the standard deviation of the QT and QTc interval in the measurable leads (QT-SD and QTc-SD).Results-There was no significant diVerence in QT, QTc, and RR dispersion between girls and boys. Overall 53% of children had sinus arrhythmia. Although QTD and QT-SD were not aVected by sinus arrhythmia, both QTcD and QTc-SD were significantly greater in children with sinus arrhythmia than in those without (QTcD: 52.9 (17.4) v 40.9 (13.1); QTc-SD: 17.5 (5.9) v 13.2 (4.0); p < 0.001). Conclusions-As calculation of QTc dispersion is aVected by sinus arrhythmia, which is common in childhood, we suggest that QT dispersion should not be corrected for heart rate in children. (Heart 1998;80:77-79)

We demonstrated that LV Mass and cardiac output were reduced in proportion to decrease in body size in patients with PEM, and LV systolic and diastolic functions were preserved in atrophic hearts.

Although the incidence of ARF has decreased in the last decade, it still continues to be an important public health problem in Turkish pediatric population.

The aim of our study was to evaluate myocardial functions with strain/strain rate echocardiography in asymptomatic patients having congenital aortic stenosis (CAS) with normal cardiac functions as determined by conventional echocardiographic techniques and comparing them with those of healthy controls. A total of 58 patients with various degrees of isolated CAS and 52 healthy controls were enrolled in this study. Conventional and two-dimensional speckle tracking (2DSTE) echocardiography were performed. Global longitudinal strain (LS) (-23.1 ± 3.6 and -23.8 ± 4.7), and longitudinal strain rate (LSR) (-1.49 ± 0.32 and -1.76 ± 0.39) values were lower, whereas circumferential strain (CS) (-25.9 ± 4.7 and -22.8 ± 6.4) and circumferential strain rate (CSR) (-1.82 ± 0.46 and -1.69 ± 0.49) values were greater in the patient group than in the control subjects. The difference was significant for global LSR and CS (p < 0.05) values. Regional analysis showed lower LS values in the basal part of the left-ventricular (LV) free wall and lower LSR values in the basal parts of both of the septum and free wall in the patient group (p < 0.05). CS values in the anteroseptal, posterior, and inferior walls were significantly greater in the patients (p < 0.05). 2DSTE detects subtle alterations in myocardial function in asymptomatic children with CAS. Impairment of LV long-axis function occurred earlier and was more prominent in basal parts of the interventricular septum and the free wall of the left ventricle.

Cardiac involvement as pericarditis, myocarditis, and endocarditis is common in juvenile rheumatoid arthritis (JRA). Though there are many reports concerning systolic and diastolic functions of adults with rheumatoid arthritis, there are no studies on children with JRA. Thirty patients with JRA without any cardiac symptoms and 30 sex- and age-matched controls were included in the study. M-mode and pulsed-wave Doppler echocardiography were performed on each participant to assess the systolic and diastolic functions of the left ventricle. Left ventricular end-systolic diameter and volume were larger and ejection fraction and fractional shortening were decreased in the JRA group. Among the diastolic parameters, increased late flow velocity, decreased early flow velocity, and prolonged isovolumic relaxation time reflected an abnormal relaxation form of diastolic dysfunction. Mortality rate is increased in adults with rheumatoid arthritis, and ischemic heart disease is the leading cause of cardiovascular mortality. The abnormal relaxation form of diastolic dysfunction found in children with JRA is seen in ischemic heart disease. These children can therefore be candidates for ischemic heart disease in the future even though they are fully asymptomatic at present. In conclusion, children with JRA should be assessed for systolic and diastolic functions with serial echocardiography. In this way it may be possible to reduce the mortality and morbidity of the disease from cardiac causes.