[Paediatric echocardiography in clinical practice. 2012 Recommendations of the Echocardiography Working Group of the Polish Cardiac Society]

Echocardiography has become the primary imaging tool in the diagnosis and assessment of cardiological disorders in children. The purposes of this paper are to describe indications for paediatric echocardiography, define optimal instrumentation and laboratory setup for paediatric echocardiographic examinations and establish a baseline list of recommended measurements to be performed in a complete pediatric echocardiogram.

Age-and sex-dependent mRNA expression of KCNQ1 and HERG in patients with long QT syndrome type 1 and 2

INTRODUCTION

The main goal of this study was to examine the patient age and sex dependent expression of KCNQ1 and HERG genes that encode potassium channels responsible for the occurrence of long QT syndrome (LQTS).

MATERIAL AND METHODS

The study enrolled 43 families whose members suffered from LQTS type 1 (LQTS1) or 2 (LQTS2) or were healthy. The study attempted to prove that β-actin is a good endogenous control when determining the expression of the studied genes. Examination of gene expression was achieved with quantitative real-time PCR (QRT-PCR). Expression of the investigated genes was inferred from the analysis of the number of mRNA copies per 1 μg total RNA isolated from whole blood.

RESULTS

Significantly lower KCNQ1 and KCNH2 mRNA levels in healthy females than healthy males were observed (p = 0.032; p = 0.02). In male patients both transcripts were expressed at a lower level (p = 0.0084; p = 0.035). The comparison of transcriptional activity of KCNQ1 and KCNH2 in healthy adults and children revealed higher KCNQ1 and lower KCNH2 mRNA levels in healthy adults (p = 0.033; p = 0.04), higher KCNQ1 and lower KCNH2 mRNA levels in adult patients below 55 years old than in adults over 55 years old (p=0.036; p = 0.044), and significantly higher KCNQ1 and lower KCNH2 mRNA levels in adult patients (over 55 years) than in paediatric patients (below 15 years) (p=0.047; p = 0.08).

CONCLUSIONS

The results support the hypothesis that KCNQ1 and HERG gene expression is influenced by age and gender in human patients with long QT syndrome and in healthy subjects.

Expression of genes KCNQ1 and HERG encoding potassium ion channels Ikr, Iks in long QT syndrome

BACKGROUND

The KCNQ1 and HERG genes mutations are responsible for specific types of congenital long QT syndrome (LQT).

AIM

To examine the expression of KCNQ1 and HERG genes that encode potassium channels (rapid and slow) responsible for the occurrence of particular types of LQT syndrome. The study also attempted to prove that beta-actin is a good endogenous control when determining the expression of the studied genes.

METHODS

The study enrolled six families whose members suffered from either LQT1 or LQT2, or were healthy. Examination of gene expression was achieved with quantitative PCR (QRT-PCR). Expression of the investigated genes was inferred from the analysis of the number of mRNA copies per 1 mg total RNA isolated from whole blood. On the basis of KCNQ1 gene expression profile, the presence of, or absence of, LQT1 could be confirmed.

RESULTS AND CONCLUSIONS

The study revealed a statistically significant difference (p = 0.031) between the number of KCNQ1 gene copies in patients and healthy controls. On the basis of HERG (KCNH2) gene expression profile, patients with LQT2 cannot be unequivocally differentiated from healthy subjects (p = 0.37).

The diagnosis, clinical course and follow-up of children with cardiac tumours - a single-centre experience

BACKGROUND

Rhabdomyoma is the most frequent primary cardiac tumour in children (about 50% of all cardiac neoplasms in this population). Fibroma, myxoma, teratoma and haemangioma are less frequent.

AIM

To investigate the clinical presentation, diagnosis and follow-up of children diagnosed with cardiac tumours in our department between 1993 and 2008.

METHODS

In the 15-year review we found 9 cases of cardiac tumours, confirmed in echo scan in every case and pathomorphologically in 5 out of 9 cases.

RESULTS

Cardiac tumours were found in six boys and three girls, usually in the neonatal period. Cardiac murmur was the most common clinical symptom (4 cases). Two children were symptom-free. Out of the remaining children, two had circulatory failure and one had arrhythmia. Five children were operated on: three cases of rhabdomyoma, one fibroma and one teratoma. In 3 children who did not undergo surgery, the most probable diagnosis was rhabdomyoma. The follow-up (possible in 8 out of 9 cases, mean 7 years) showed that six children developed regularly and in two cases neurological abnormalities appeared.

CONCLUSIONS

In this series, primary cardiac tumours presented as murmurs or circulatory failure. Most children needed surgery. In most cases, pathomorphology revealed rhabdomyoma. Follow-up showed regular development in six out of nine cases.

N-terminal prohormone brain natriuretic peptide-proBNP levels in ventricular arrhythmias in children

BACKGROUND

Ventricular arrhythmias are the most common consequences of structural and functional heart diseases, but cases with no evident pathology are also observed. A parameter indicating asymptomatic circulatory failure could support decisions related to possible treatment of ventricular arrhythmias.

HYPOTHESIS

The study objective was the evaluation of N-terminal prohormone brain natriuretic peptide (NT-proBNP) levels in children with ventricular arrhythmias and an attempt to determine if this parameter may be used for diagnosis and prognosis of ventricular arrhythmias.

MATERIAL AND METHODS

The study population was comprised of 36 children age 5 to 17.5 years old with idiopathic ventricular arrhythmias (Group B) graded mild or potentially malignant; 29 patients with mild ventricular arrhythmias were included into Group B1; and 7 patients with potentially malignant cases into Group B2. In all the patients, NT-proBNP assays were performed.

RESULTS

The NT-proBNP levels in Groups B, B1, B2 and the control group (Group K) were as follows: 41.5 +/- 15.1 pg/mL, 35.5 +/- 18.5 pg/mL, 66.3 +/- 24.9 pg/mL and 31.5 +/- 15.1 pg/mL, respectively. Between the groups with and without arrhythmias (Group B vs Group K), no statistically significant differences in NT-proBNP levels were found. However, markedly higher NT-proBNP levels were shown in the children with potentially malignant arrhythmias (Group B2) compared to the patients with mild arrhythmias (B1) and the control group (Group K).

CONCLUSIONS

The level of NT-proBNP increases with the severity of ventricular arrhythmia. NT-proBNP assays can be helpful for diagnosing and grading the severity of ventricular arrhythmias.

Electrocardiographic abnormalities in young athletes with mitral valve prolapse

BACKGROUND

Mitral valve prolapse (MVP) is the most common primary valvular abnormality in a young population. In some individuals, MVP is silent or associated with palpitations, dizziness, chest pain, and abnormal electrocardiogram (ECG) repolarization with or without ventricular arrhythmias.

HYPOTHESIS

The aim of the present study was to assess the occurrence of the clinical and electrocardiographic abnormalities in young athletes with silent MVP.

METHODS

A group of 10 children, who have been sport training intensively, with preparticipation silent MVP were examined for symptoms and/or ECG abnormalities. The diagnosis of MVP was made by echocardiography.

RESULTS

Three athletes were asymptomatic at initial presentation. The other 7 athletes presented with symptoms. The QTc intervals > 440 msec were recorded in 2 athletes (1 with syncope). Abnormal ECG repolarization was found in 7 athletes (4 athletes were symptomatic and 3 were asymptomatic). A large variety of T-waves was registered in athletes who presented with symptoms. In asymptomatic athletes, the tall and flat T-waves were recorded.

CONCLUSIONS

Young athletes with MVP are often predisposed to electrocardiographic abnormalities of ventricular repolarization, which requires annual cardiologic evaluation.

[The new diagnostic tool - congenital heart diseases and the great arteries imaging using multislice computed tomography - case presentations]

Multislice computed tomography is an imaging method of internal organs including heart and vessels with the use of X-ray. The indications for computed tomography of the heart include also congenital heart diseases and the evaluation of the great arteries. Ultrasonography is a method of choice in heart evaluation. The authors show the possibilities of modern multislice computed tomography in congenital heart diseases imaging based on their own material.

Challenges of Diagnosis of Long-QT Syndrome in Children

We describe the clinical and genetic characteristics of the family, in which the diagnosis of LQT1 had been made. The electrocardiogram (ECG) characteristics of this patient indicated the likelihood of LQTS1. Polymorphic ventricular extrasystolies and episodes of polymorphic non-sustained ventricular tachycardia were confirmed by Holter ECG monitoring. On the exertional electrocardiogram polymorphic ventricular tachycardia (torsade de pointes) was recorded. Direct sequencing of both DNA strands revealed the absence of mutations or polymorphisms in the KCNQ1, HERG, and SCN5A genes.

Arrhythmogenic right ventricular dysplasia:clinical study

Arrhythmogenic right ventricular dysplasia (ARVD) is a complex arrhythmogenic cardiomyopathy, characterized by a partial or total replacement of the right ventricular myocytes by fatty and fibrous tissue. In this study, we present a case of ARVD in 17 year old girl, who was admitted to the hospital after syncope with ventricular arrhythmia. The echocardiography did not demonstrate structural cardiac abnormalities but the magnetic resonance recently showed thinning of the right ventricular wall. The girl was treated with the lidocaine, amiodarone and next, after radiofrequency catheter ablation she was receiving metoprolol. The girl has remained asymptomatic for four years of follow-up.

[Diagnostic problems with long QT syndrome in 5-year-old boy]

The authors described the case of 5-year-old boy, in whom a proper diagnosis was established after 19 months. In differential diagnosis, epileptic, tetanic and conversion seizures were taken into consideration.

[Syncope in children]

Syncope is a very common problem during childhood presenting to emergency departments. It generates a great deal of anxiety among children and their parents because of the fear that syncope are at risk for sudden death. Neurocardiogenic (vaso-vagal) syncope are the most common, while cardiac type are rare. The vaso-vagal syncope are secondary to irregularities in an autonomic reflex resulting in an abnormal relaxation of the blood vessels. This is non-life threatening form of syncope in differ cardiac type that can be very dangerous. In cardiac syncope causes can be secondary to obstruction to blood flow (Tetralogy of Fallot, cardiomyopathies, aortic stenosis), heart rhythm abnormalities (WPW, L-QTS, A-V block) as well as ischemic heart disease secondary to an anomalous coronary artery. The cardiac syncope are rare (6%) but the most inconvenient because they can be life-threatening.

[Vasovagal syncope--diagnostic difficulties in adolescents]

Consciousness disturbances in adolescents may be caused by different reasons. Among them, cardiologic and neurological backgrounds should be considered. The most important diagnostic tests the vasovagal syncopes are: tilt-table test, brain oxygenation measurement, routine and extended elektroencephalography. Performing of these examinations simultaneously may help in determining cause of symptoms. Our patient serves us as an example.

[Selected birth outcomes as prognostic determinants of hypertension in children]

BACKGROUND

About 5-15% of children suffer from hypertension. The influence of maturity and the physical development of newborns on primary hypertension has been recently underlined.

AIM

The aim of the study was to estimate the importance of low birth weight (< 10 percentiles--2500 g), low birth length (< 10 percentiles--50 cm), low Apgar score (< 4 points), prematurity (< 37 Hbd) in the developmental of hypertension in children.

METHODS

The project was conducted retrospectively in a group of 197 children with primary hypertension (aged 15.4 +/- 1.9) and 119 healthy children (aged 12.9 +/- 3.1) as the control group. The statistical analysis was performed with Epilnfo 6.0 procedures.

RESULTS

Male sex, overweight and family history of hypertension increased the risk of hypertension in a statistically significant way and the adequate estimated odds ratios were: OR = 3.69 (95% CI: 2.20-6.19), OR = 22.76 (95% CI: 6.61-94.12), OR = 21.87 (95% CI: 6.27-91.1). No influence of low birth weight, low birth length, low Apgar score and prematurity on primary hypertension was observed.

CONCLUSION

The results suggest that the role of low birth weight, low birth length, low Apgar score and prematurity in the development of hypertension in children is arguable. It also suggests the necessity to conduct epidemiologic surveys in more frequent groups of children.

[Implantation of cardiac pacemaker in children, author's experiences]

Cardiac pacemaker was implanted as a therapeutic method for children with atrio-ventricular block, sick sinus syndrome, LQT syndrome, cardio-depressive syncope. Twenty six children (aged 1-17) underwent pacemaker implantation or exchange of pacemaker and electrode. In nineteen cases cardiac peacemaker was implanted in the endocardial system; in the next seven cases epicardial system was required. The difference between the implantations depended on patient's age and the character of the disease. The single chamber peacemaker was implanted in twenty children, dual-chamber in six patients. There were no visible complications in follow up observation and constant heart stimulation can be considered as a safe way of children's severe bradycardia treatment.

[Late recognition of Kawasaki disease--difficulties in diagnosis]

Authors describe the case of 4 years old girl with Down syndrome, who was operated due to common atrio-ventricular canal and persistent Botalli's duct. Intermittent total atrio-ventricular block (without significant bradycardia) has been observed one year later and considered as a late postoperative block requiring no treatment. Kawasaki disease was diagnosed because of the presence of 4 out of 6 leading symptoms appearing in typical chronology (fever, mouth and throat inflammation, conjunctivitis, erythema with subsequent desquamation of skin on palms and feet). ECG revealed total atrio-ventricular block, however with significant bradycardia. ECHO showed aneurysms in both coronary arteries. Standard treatment of Kawasaki disease was administered (immunoglobulins, acetylsalicylic acid) and orciprenalin due to described cardiac block. Pacemaker was implanted because of bradycardia. The literature review showed that the treatment with immunoglobulins and aspirin can reduce the risk of coronary aneurysms development. On the other hand, identification of patients at risk coronary aneurysms development is not possible on the ground of biochemical blood analysis and physical signs. Thus, all the patients stricken should be treated with described above costly drugs (immunoglobulins). Finally, the algorithm of procedures in patients with coronary aneurysms was presented.

[Arterial hypertension among children and teenagers in the Upper Silesia]

Nowadays arterial hypertension is more frequently observed among children and teenagers then it used to be earlier. Arterial hypertension and obesity are more and more often the main sources of atherosclerosis. The purpose of this work was to assess the patients with the arterial hypertension treated in the Department of Pediatric Cardiology in Katowice in 2003. Patients' age, family history of hypertension, family background and parents' education were taken into consideration. Birth weight, BMI factor, all the sufferings reported by patients, blood pressure measurements results, ABPM, EKG parameters, ECHO+ Doppler parameters, exercise test results, fundus of the eye examination, laboratory investigation results, were also analyzed. Our results show that a positive family history is a very important factor in the development of arterial hypertension among children (44.7%). In our patients' cases the most frequent clinical symptoms are tachycardia (68%) and obesity (59.2%). In conclusion, children and teenagers with hypertension should be successfully treated and those with positive family history of hypertension should be taken under primary prevention in order to decrease the risk of cardiovascular complications.

[The significance of cardiac symptoms in patients referred to pediatric cardiology outpatient clinics]

OBJECTIVE

To determine the significance of cardiac symptoms in patients referred to paediatric cardiology outpatient clinics.

MATERIAL AND METHODS

All patients above l month of age referred to paediatric cardiac outpatient clinics between 01-Apr-2004 and 31-Dec-2004. Data was collected prospectively in Internet data base. Patients were divided into 3 groups: patients referred by paediatricians to regional paediatric cardiology outpatient clinic (group 1, N=3383), patients referred to Academic Paediatric Cardiac outpatient clinics by paediatricians (group 2, N= 7461) and by cardiologists (group 2a, N=793).

RESULTS

Average age of patients was 6.4 +/- 5.8 years. The most common reasons for referral included cardiac murmur, chest pain, syncope, earlier diagnosed congenital heart disease (CHD). The proportion of patients referred by cardiologists and paediatricians because of murmur was 30% vs 56%, arrhythmia 12.6% vs 8% and CHD 44% vs 8%. The percentage of the significant cardiac pathology in all groups (l/ 2/ 2a) was 38/35/76; in patients with chest pain -- 9/18/0; with syncope -- 56/70/80; with murmur -- 19/21/43; with CHD -- 68/69/93 and with arrhythmia -- 57/80/92.

CONCLUSIONS

l. There were no significant differences between patients referred by paediatricians from regional and academic outpatient cardiology clinics. 2. Isolated cardiac symptoms such as chest pain, cardiac murmur and syncope were caused by significant cardiac pathology only in about 1/5 cases. 3. Cardiac murmur was the most common reason for referral to cardiac outpatient clinic in younger patients, in older group syncope and arrhythmia were more frequent.