Tayfun Uçar

Myocardial Tissue Velocities in Neonates

Background: Tissue Doppler echocardiography (TDE) has been applied to the children age group; however, myocardial tissue velocities of neonates have been reported by few researchers. Methods: Myocardial velocities along the longitudinal axis of the left ventricle were measured in two groups: 50 term neonates within 5 days after birth and 54 healthy children by TDE. Sample volumes were placed in mitral lateral annulus (MLA), mitral medial annulus (MMA), and in the basal and middle parts of the left ventricular lateral wall (LVLW) and interventricular septum (IVS). Results: The highest myocardial velocities were obtained from MLA. In all segments, the mean systolic velocity (Sw) was found significantly lower than the mean early diastolic (Ew) and atrial systolic velocities (Aw) (P < 0.0001). The mean Aw was the dominant component in the MMA and were significantly higher than Ew (P < 0.001). The mean Ew/Aw in the MMA and MLA increased significantly while replacing the Doppler beam from base to apex. TDE indexes of neonates, except Aw obtained from MLA and MMA, were significantly lower than that of children group (P < 0.0001 and P < 0.0001, respectively). The mean E/Ew ratio of the left ventricle in neonates was found to be significantly higher than that found in children group (P < 0.0001). Conclusion: In neonates, the diastolic and systolic myocardial velocities of the left ventricle were significantly lower than those measured in the children group. Decreased myocardial tissue values of neonates might be reflecting the immaturity of neonatal myocardium.

PLATELET AGGREGATION IN TERM AND PRETERM NEWBORNS

The platelets of newborns have a hyporeactive period. This period, during which the platelet count is normal but their functions are deficient, is called transient platelet hyporeactivity of newborns. The platelet functions and their normalizing process of term and preterm neonates are investigated. Twenty term and 20 preterm (gestational age <37 weeks) newborns were enrolled in the study. Twenty-eight healthy children aged 2 months to 3 years old participated in the study as the control group. Healthy newborns were followed for 15 days after birth longitudinally in 3 periods: period 1 (0–4 days), period 2 (5–9 days), period 3 (10–15 days). Aggregation studies were performed from whole blood samples. Whole blood aggregation was measured by the impedance method. Transient hyporeactivity of platelets was found in term and preterm groups, and there was no difference between term and preterms. Platelets of newborns gained their normal functions at postnatal 10–14 days. The results show that hyporeactivity of platelets during the first 9 days of life is physiological and transient.

The Effect of p.Arg25Cys Alteration in NKX2-5 on Conotruncal Heart Anomalies: Mutation or Polymorphism?

Heterozygous mutations in the NKX2-5 gene of patients with various congenital heart defects have been reported. Most of the congenital heart defects associated with the mutations in the NKX2-5 gene are conotruncal heart anomalies, primarily the tetralogy of Fallot. In this study, the authors screened 72 Turkish children with conotruncal heart anomalies and 185 healthy control subjects to find the NKX2-5 alterations. They found one previously documented NKX2-5 missense alteration, heterozygous c.73C>T (p.Arg25Cys), in a 10-year-old boy with tetralogy of Fallot. The same heterozygous alteration was found also in the patient’s healthy father and in two unrelated persons in the healthy control group. The current study shows for the first time the presence of p.Arg25Cys in healthy control subjects other than African Americans. These results show that no genetic support exists for the pathogenecity of this alteration, although a previous in vitro study and theoretical predictions suggest a structural/functional difference in the altered protein region.

Antistreptococcal Response is Exaggerated in Children with Familial Mediterranean Fever

Abstract: Familial Mediterranean fever (FMF) is an autosomal recessive disorder. Although the pathogenesis of the disease is not yet completely understood, enhanced acute-phase responsiveness is considered to be one of the most important mechanisms. The presence of high levels of antistreptolysin O (ASO) antibodies and streptococcus-associated diseases, such as acute poststreptococcal glomerulonephritis (AGN) and acute rheumatic fever (ARF), has been reported in patients with FMF. In order to better understand the effect of FMF on antistreptococcal antibody response, we measured ASO and antideoxyribonuclease B (anti-DNAse B) levels in patients with FMF and compared them with those in healthy controls. The study consisted of two parts. In the first step, antistreptococcal antibody levels were analysed in 44 patients with FMF and 165 healthy children who had no history or clinical evidence of upper respiratory tract infection (URTI) for the last 4 months. In the second step, antistreptococcal antibody levels were measured in 15 patients with FMF and 22 healthy controls in response to documented group A β-haemolytic streptococcal pharyngitis. In the first part of the study, ASO and anti-DNAse B levels in patients with FMF were found to be significantly higher than those in healthy controls (P<0.001). In the second part, ASO and anti-DNAse B titres were found to be significantly higher in patients with FMF than in controls (P<0.001 and <0.05, respectively) 4 weeks after a positive throat culture. We concluded that patients with FMF have an exaggerated response to streptococcal antigens and might be prone to poststreptococcal non-suppurative complications, such as ARF.

Global left-ventricular function by tissue Doppler imaging in pediatric dialysis patients

Cardiovascular abnormalities are observed in most children with end-stage renal disease (ESRD). The aim of this study was evaluation of left-ventricular (LV) myocardial performance using tissue-Doppler imaging (TDI) in patients with ESRD. Twenty-five patients with ESRD and 25 healthy gender- and age-matched control subjects were assessed with conventional M-mode echocardiography, pulsed-wave Doppler (PWD), and TDI. Myocardial Performance Index (MPI) and LV mass index (LVMI) were calculated. MPI and conventional echo-Doppler indices were compared in the ESRD and control groups. Significant differences were present in the mean systolic and diastolic blood pressure (BP) between children with ESRD and healthy children (p = 0.007 and p < 0.001, respectively). The mean LVMI was significantly greater in the patient group (p < 0.001). The tissue-Doppler MPI of patients was significantly higher than that in healthy children (p < 0.001). LVMI was significantly correlated with systolic and diastolic BP. MPI obtained by TDI was significantly correlated with LVMI. Our study confirms that LV dysfunction is present in patients with ESRD and hypertension is an important risk factor.

Hypertension and left ventricular hypertrophy in pediatric peritoneal dialysis patients: ambulatory blood pressure monitoring and echocardiographic evaluation.

Background: Hypertension is a frequent complication of end-stage renal disease and left ventricular hypertrophy (LVH) is common in patients with poorly controlled hypertension. The aim of this study was to evaluate hypertension in pediatric peritoneal dialysis (PD) patients, to compare casual and ambulatory blood pressure (BP) measurements and to evaluate the impact of BP parameters on LVH. Methods: The study comprised 25 PD patients (9 M, 16 F; mean age 14.14 ± 3.32 years) that have been followed in outpatient clinics. Medical records were reviewed for demographic features; casual BP measurements, ambulatory blood pressure monitoring (ABPM) and echocardiographic evaluation were applied to all patients. Results: The mean 24-hour and daytime systolic blood pressure (SBP) values were found to be higher than casual SBP (p < 0.001). Significant difference was present in the frequency of hypertension between casual SBP (32%) and the mean daytime SBP (56%) (p < 0.05). Nighttime systolic hypertension was detected in 14 (56%) and diastolic hypertension in 16 (64%) patients. Elevated daytime SBP load and DBP load were detected in 64 and 76% of the patients, respectively. Elevated nighttime SBP load and DBP load were detected in 72% of the patients. Seventeen (68%) patients had attenuated dipping for SBP. The mean left ventricular mass index (LVMI) was 52.65 ± 18.17 g/m2.7 and 13 (52%) patients had LVH. LVMI was significantly correlated with casual BP measurements and the majority of ABPM parameters. Conclusion: The majority of pediatric PD patients had BP abnormalities in which severity was most accurately assessed with ABPM. Casual BP and majority of ABPM parameters were found to be significantly correlated with LVMI. Ambulatory blood pressure monitoring should be performed in all pediatric PD patients.

Bilateral Coronary Artery Dilatation and Supravalvular Pulmonary Stenosis in a Child with Noonan Syndrome

Noonan syndrome is the second most frequent congenital malformation syndrome, after Down syndrome, associated with cardiovascular abnormalities. The most prevalent cardiovascular abnormalities in Noonan syndrome are pulmonary stenosis and hypertrophic cardiomyopathy. We report the case of a 12-year-old girl with Noonan syndrome who had multiple cardiovascular abnormalities, including extensive bilateral coronary artery dilatation, valvular and supravalvular pulmonary stenosis, atrial septal defect, and mitral valve prolapse. Both coronary artery dilatation and supravalvular pulmonary stenosis, although rarely reported, are abnormalities of the cardiovascular system that may occur in Noonan syndrome.

Congenital absence of portal vein associated with nodular regenerative hyperplasia of the liver and pulmonary hypertension

We present a 15-year-old girl with congenital absence of the portal vein, pulmonary arterial hypertension and multiple liver lesions proven to be nodular regenerative hyperplasia with biopsy. Ultrasonography, computed tomography, and magnetic resonance imaging findings of the liver lesions and Type I portosystemic shunt are presented.

Acremonium spp. peritonitis in an infant

Fungal peritonitis is a rare but serious complication in children on peritoneal dialysis. Clinical presentation of fungal peritonitis is similar to bacterial peritonitis and Candida spp. are the most common agent. Fungal peritonitis has been usually associated with high morbidity, mortality and its treatment is difficult. In this report, we present an infant with Acremonium spp. peritonitis. A 7‐month‐old boy with Down syndrome, congenital heart disease, pulmonary hypertension and congestive heart failure required peritoneal dialysis for his persistent pulmonary oedema and symptomatic hyponatremia. Acremonium spp. peritonitis developed while he was on extended spectrum antibiotics and fluconazole. The patient was successfully treated with peritoneal dialysis catheter removal and liposomal amphotericin B. The case was presented to draw attention to a rare cause of peritonitis –Acremonium spp. – in a paediatric patient.

Management of patent ductus arteriosus in preterm infants: clinical judgment might be a fair option

Abstract Objective: The objective of this study was to find out the percentage of preterm infants that needed treatment for patent ductus arteriosus (PDA), when treatment decision was based on clinical signs and symptoms, besides echocardiographic findings. Methods: Daily echocardiographic evaluation was conducted in 39 preterms ≤296/7 weeks’ gestation. Patients with ductus arteriosus were closely followed-up for clinical symptoms of PDA for treatment decision until ductus arteriosus was closed either spontaneously or by treatment. Results: PDA was found in 25 (64%) infants. Mean gestational age and birth weight (BW) of the patients with PDA were 27.8 ± 1.2 and 998 ± 221 g, respectively. PDA closed spontaneously or had minimal ductal shunting before any signs and symptoms attributable to PDA were observed in 16 (41%) infants. Mean ductus size/BW ratio and mean left atrial/aortic root ratio were significantly higher in 9 (23%) symptomatic patients (2.06 ± 0.75 versus 1.32 ± 0.75 mm, p = 0.012 and 1.31 ± 0.52 versus 1.19 ± 0.2 mm, p = 0.043, respectively). PDA closure was observed after the first dose of ibuprofen in six of nine patients. Conclusion: Correlation of clinical signs with echocardiographic findings for the decision of PDA treatment can be appropriate to prevent unnecessary medical treatments.