Previous studies have evaluated left ventricular dimensions in children using two-dimensional echocardiography, but there is little information on gender differences and on the longitudinal development of the dimensions of the left ventricle. Our objective was to assess, by two-dimensional echocardiography, the normal size of the left ventricular end-diastolic dimension (LVDd) in children, its differences by sex, and the rate of its development using height, weight, and body surface area as indices. The study group consisted of 437 patients (264 males, 173 females) with a history of Kawasaki disease but with no coronary artery lesions, as determined by repeated echocardiographic and other examinations. A total of 1595 examinations were done over an average of 6.7 years. The increase in LVDd was significantly more rapid in (1) children below 2 years of age than in older children of either sex and (2) in males who were 11 and 12 years old than in males who were 10 years old. Significant gender differences were observed in the increase in LVDd by all indices (p < 0.001).

Adolescent↗

PubMedDate not supplied

Measurement and validity of the ventilatory threshold in patients with congenital heart disease.

The purpose of the present study was to measure oxygen uptake (VO2) at the ventilatory threshold (VT) in patients with congenital heart disease using a progressive exercise protocol on a treadmill and to evaluate the validity and feasibility of this procedure. Eight control subjects and seventeen patients performed a maximal exercise test with breath-by-breath measurement of ventilation and gas exchange variables. VT(VE) was determined by the change in the ventilatory equivalent for VO2 and carbon dioxide output, VT(V-sl) by the V-slope method, and the lactate threshold (LT) by the change in blood lactate concentration; these parameters were determined in 100%, 88%, and 96% of subjects, respectively. The interobserver error among three evaluators was not significant, and LT was correlated with each VT (r = 0.97, 0.92; p = 0.0001) and with peak VO2 (r = 0.91; p = 0.0001). The VTs were correlated with each other when expressed as milliliter per minute and milliliters per kilogram per minute. It was concluded that a progressive exercise protocol on a treadmill was a feasible procedure for determining the VTs in most individuals and that VTs were valid, useful parameters for evaluating submaximal exercise tolerance in patients with congenital heart disease.

Adolescent↗

PubMedDate not supplied

Incidence of stenotic lesions predicted by acute phase changes in coronary arterial diameter during Kawasaki disease.

To clarify the incidence of stenotic lesions according to the coronary arterial diameter in the acute phase. we investigated 190 patients with coronary arterial lesions who underwent an initial coronary angiogram (CAG) less than 100 days after the onset of Kawasaki disease. The largest diameters of the major branches were measured in the initial CAGs. The diameter of the large group was > or = 8.0 mm, that of the medium group was > or = 6.0 mm but < 8.0 mm, and that of the small group was > or = 4.0 mm but < 6.0 mm. There were 121 patients in the large group, 85 in the medium group, 77 in the small group. We investigated the stenotic lesions in the follow-up CAGs and evaluated the incidence of stenotic lesions in each group by the Kaplan-Meier method. The mean interval from the initial CAGs to the latest CAG was 97 months. The incidence of stenosis at 5, 10, and 15 years in the large group was 44, 62, and 74%, respectively. In the medium group the corresponding values were 6, 20, 58%, respectively. None of the patients in the small group developed stenotic lesions. Dilatation of more than 6.0 mm produces a high probability of irreversible change in the coronary arterial wall, leading to subsequent stenotic lesions.

Adolescent↗

PubMedDate not supplied

Responses of plasma norepinephrine and heart rate during exercise in patients after Fontan operation and patients with residual right ventricular outflow tract obstruction after definitive reconstruction.

To determine the exercise responses of patients with congenital heart disease, 20 patients-5 who had undergone a right ventricular outflow tract reconstruction (group R; age, 15 +/- 2 years), eight who had undergone a Fontan operation (group F; age, 13 +/- 2 years), and seven who had a history of Kawasaki disease (group C; age, 15 +/- 1 years)-performed a treadmill exercise test. Patients of group R had a significant residual right ventricular outflow obstruction. Oxygen uptake (VO2), heart rate (HR), and plasma norepinephrine (NE) concentrations were measured at rest, during warm-up, at ventilatory threshold (VT), and at peak exercise. Exercise capacity was determined as a percentage of the predicted normal peak VO2 (%pVO2). The %pVO2 for groups R and F was 65 +/- 10 and 56 +/- 11, respectively. Peak HR for groups R and F was 171 +/- 4 and 155 +/- 5, which were lower than the HR for group C (p < 0.001). Although NE concentrations at rest, during warm-up, and at VT were significantly greater in groups R and F (p < 0.05), there were no significant differences in the NE concentrations at peak exercise. Peak HR correlated with %pVO2 (p < 0.001). The ratio of the increase in HR to NE from rest to VT was significantly lower in groups R and F than in group C (p < 0.001) and correlated with %pVO2 (r = 0.80; p < 0. 001). These data suggest that sympathetic nervous activity in groups R and F is increased at rest and during mild to moderate exercises, and reduced sinus node sensitivity to NE may be partly responsible for the abnormal HR response during exercise of patients with uncorrected congenital heart disease.

Adolescent↗

PubMedDate not supplied

The relation between right ventricular function and left ventricular morphology in hypoplastic left heart syndrome: angiographic and pathological studies.

Cases of hypoplastic left heart syndrome (HLHS) were studied angiographically in 18 patients and pathologically in 22 patients. They were divided into three subgroups according to the morphological features of the left heart: mitral atresia with aortic atresia (MA/AA), mitral stenosis with aortic atresia (MS/AA) and mitral stenosis with severe aortic stenosis (MS/AS). Patients with MS/AA had a significantly lower right ventricular end-diastolic volume index and more hypokinesis of the right ventricular posterior wall than those with MA/AA. MS/AA not only increased the thickness of the left ventricular posterior wall and interventricular septum but also increased endocardial thickness compared with MA/AA. Myocardial histology revealed more frequent abnormal findings such as myocardial necrosis, calcification and interstitial fibrosis in the mitral stenosis groups (i.e., MS/AA and MS/AS) than in MA/AA. Right ventricular function appeared to be greatly influenced by left heart structure. The presence of larger left ventricular muscle bulk and frequent myocardial damage seen in MS/AA seems disadvantageous to right ventricular end-diastolic volume and right ventricular wall motion.

Analysis of Variance↗