Case series of neonatal hypocalcemia due to pseudohypoparathyroidism

Four children; all between 10-40 days of age, were admitted with multiple episodes of multifocal seizure. After admission blood investigation was carried out and they were found to have hypocalcemia, hyperphosphatemia; kidney function tests were normal. Serum parathyroid hormone was highly elevated and serum magnesium level was found to be normal in these patients. The infants did not have any other features of pseudohypoparathyroidism. The seizure was initially resistant to intravenous calcium therapy and later responded to oral calcitriol and calcium therapy. The diagnosis of pseudohypoparathyroidism was made according to biochemical investigations. The infants were symptom-free during follow-up and the biochemistry reports were also normalized. One of the infants was also suffering from neonatal hepatitis, due to CMV infection.     

Gonadal dysfunction due to cis-platinum

Gonadal function was studied in 15 patients 12 pubertal or postpubertal, and three prepubertal, who had been treated during childhood for nonmetastatic osteosarcoma of the long bones by chemotherapy regimens that included cis-platinum and adriamycin. Of seven postpubertal female patients assessed (mean age at diagnosis 16.5 years), three were amenorrhoeic and showed evidence of ovarian damage with raised gonadotrophin levels and a low serum oestradiol concentration. One patient who had regular periods had a raised luteal-phase follicle-stimulating hormone (FSH) concentration suggestive of gonadal dysfunction. Severe oligospermia or reduced testicular volumes in the presence of raised gonadotrophin levels were observed in three of the five pubertal males (mean age at diagnosis 13.25 years). A reliable assessment of gonadal function was not possible in three male patients who remained prepubertal at the time of study. The median total dose of cis-platinum received by those patients with gonadal damage (median dose, 490 mg) was significantly higher than in those patients with normal gonadal function (median dose, 300 mg) (P = 0.01). In the boys the damage to the testes was primarily directed at the germinal epithelium. Leydig cell function was intact and the males progressed spontaneously through puberty. In the girls, unlike the boys, there was evidence of reversibility of gonadal damage with time. This is the first study to show gonadal dysfunction due to cis-platinum and adriamycin therapy in childhood.     

Myocardial dysfunction in birth asphyxia

Evidence of myocardial dysfunction was present in all the 50 newborns who had suffered from moderate and severe birth asphyxia. Myocardial status were dependent on the degree of asphyxia. In 10 newborns who suffered from moderate asphyxia, myocardial status was as follows: respiratory distress in eight (80%) cardiac murmur in two (20%), cardiomegaly on X-ray was present in three (30%) and ischemic changes in form of ST, T changes in ECG in all. Shock and CHF were absent. Of 40 cases of severe birth asphyxia features observed were shock in four (100%) CHF in nine (22.5%) respiratory distress in 40 (100%) cardiac murmur in 30 (100%) ischemic changes inform of ST depression, abnormal Q and T waves in 40 (100%) cardiomegaly in 28 (70%). Early diagnosis and treatment of these cases reduced mortality in moderate asphyxia to zero and in severe asphyxia to 40% in the present study.     

Myocardial dysfunction in hypothyroid children

Eleven children with primary hypothyroidism were studied by echocardiography. Eight patients had pericardial effusion. Systolic time intervals (preejection period-ejection time ratio and left ventricular isovolumic contraction time) were suggestive of abnormal myocardial function. Asymmetric septal hypertrophy without left ventricular out-flow obstruction (ventricular septal-left ventricular posterior wall diastolic thickness ratio, greater than 1.3) was present in two hypothyroid children. After full replacement therapy, these cardiac abnormalities reversed to normal. Our data suggest that the myopericardial response to hypothyroidism in children is similar to that seen in adults.     

Myocardial dysfunction in group B streptococcal shock

A rabbit model of group B Streptococcal (GBS) shock was used to determine if myocardial dysfunction contributes to GBS shock and, if so, to ascertain if prostaglandins modulate this dysfunction. The infusion of heat-killed GBS (group I) produced a dramatic decrease in the first derivative of left ventricular pressure with respect to time (LVdP/dt) from baseline values (p less than 0.05). LVdP/dt remained stable in rabbits pretreated with indomethacin (group II) and in saline-infused control rabbits (group III), and was significantly different at 30 min from LVdP/dt in group I (p less than 0.05). Values for group I mean arterial pressure, cardiac output, pulmonary vascular resistance, and heart rate and for pH and pO2 after GBS infusion were all significantly different from baseline values and from postinfusion values for groups II and III (p less than 0.05). Systemic vascular resistance and left ventricular end diastolic pressure did not change significantly in any group at any time interval. These results indicate a primary role for myocardial dysfunction in the pathogenesis of GBS shock, and suggest strongly that prostaglandins modulate GBS-induced myocardial dysfunction.     

Myocardial dysfunction in children with acute meningococcemia

Acute meningococcemia is frequently associated with cardiovascular collapse of uncertain cause. Review of the records of 12 consecutive children revealed clinical evidence of myocardial dysfunction in six (50%). Subsequently myocardial function was prospectively assessed clinically and echocardiographically in 12 children. Seven (58%) of the 12 children had echocardiographic evidence of myocardial dysfunction as defined by a depressed left ventricular shortening fraction (LVSF). The mean LVSF in these seven children was 0.25 +/- 0.03, as compared with the mean LVSF of 0.39 +/- 0.7 in the remaining children. The LVSF estimate of myocardial function strongly correlated with cardiac output as measured by standard thermodilution (r = 0.98, P less than 0.01). Acute meningococcemia was not fatal in those children without evidence of myocardial dysfunction. In contrast, three of the seven children with evidence of myocardial dysfunction died. In four children, echocardiographic evidence of left ventricular dysfunction preceded cardiovascular collapse and clinical recognition of myocardial dysfunction. In children with an initially low LVSF, recovery of LVSF was associated with survival. Children with acute meningococcemia may have impaired myocardial function as indicated by depressed LVSF, resulting in low cardiac output despite normal intravascular volume. Thus, in addition to restoring intravascular volume, knowledge of the status of myocardial function may help direct therapy toward optimizing myocardial contractility.     

Myocardial hypertrophy and dysfunction in maternal diabetes

Diabetes in pregnancy, both pre-gestational and gestational, is a frequent cause of fetal myocardial hypertrophy, partly due to fetal hyperinsulinism. In fetal life, cardiac function may be impaired, especially during diastole, as a result of decreased left ventricular distensibility and altered left atrial dynamics secondary to myocardial hypertrophy. In neonates, the hypertrophy is a transient disorder, with spontaneous regression of the increased myocardial thickness during the first months of life. Nevertheless, cardiac hypertrophy may be associated with neonatal cardiomegaly and respiratory distress secondary to poor left ventricular compliance. The development of a number of new echocardiographic parameters discussed in this article, and primarily based on the pathophysiological consequences of myocardial hypertrophy, highlight an area of research priority: the assessment of diastolic function in fetuses of diabetic mothers with (and without) myocardial hypertrophy. A score for grading the severity of fetal diastolic dysfunction in these fetuses is proposed.