Assessment of Heart Rate Variability in Children with Mitral Valve Prolapse.

BACKGROUND: Mitral valve prolapse (MVP) is a heart valve anomaly with specific electrocardiographic findings and arrhythmia. A predominant sympathetic tone and diminished vagal activity have been reported especially in symptomatic MVP patients. OBJECTIVES: In the current study, we aim to review heart rate variability (HRV) parameters of MVP children in order to determine if there is an impaired autonomic regulation. METHODS: The data of children with MVP were retrospectively analyzed. Demographic characteristics, body mass index, symptomatology, MVP type and mitral regurgitation, MVP-related electrocardiographic changes, arrhythmia, and HRV parameters in 24-h Holter monitoring were recorded. HRV parameters of the control group were obtained from children applying for sport participation. Statistical significance limit was accepted as p < 0.05. RESULTS: 154 of the patients (74.8%) were girls, the median age was 13.58 ± 2.99 years. While MVP patients had shorter PR intervals, those who had syncope had longer PR intervals. Short PR distance may be a feature of MVP, long PR distance may be a condition associated with syncope with the underlying paroxysmal atrioventricular block. Moreover, the minimum heart rate was significantly lower in the MVP group compared to the control and there were no significant differences in terms of remaining parameters. The number of low LF values was higher in MVP patients than the control. Comparing HRV values of groups by gender, we found that overall HRV parameters were lower in girls with MVP while minimum, maximum, and average heart rate were lower in boys with MVP. CONCLUSION: Impaired HRV associated with MVP could be age, gender, and symptom related. In addition, low LF may indicate impaired baroreflex sensitivity in MVP patients.

Minimally invasive permanent pacemaker implantation immediately after birth: from delivery room to heart surgery.

INTRODUCTION: Congenital atrioventricular block is diagnosed in uterine life, at birth, or early in life. Atrioventricular blocks can be life threatening immediately at birth so urgent pacemaker implantation techniques are requested. Reasons can be cardiac or non-cardiac, but regardless of the reason, operations are challenging. We aimed to present technical procedure and operative results of pacemaker implantation in neonates. MATERIALS AND METHODS: Between June 2014 and February 2021, 10 neonates who had congenital atrioventricular block underwent surgical operation to implant permanent epicardial pacemaker by using minimally invasive technique. Six of the patients were female and four of them were male. Mean age was 4.3 days (0-11), while three of them were operated on the day of birth. Mean weight was 2533 g (1200-3300). RESULTS: Operations were achieved through subxiphoidal minimally skin incision. Epicardial 25 mm length dual leads were implanted on right ventricular surface and generators were fixed on the right (seven patients) or left (three patients) diaphragmatic surface by incising pleura. There were no complication, morbidity, and mortality related to surgery. CONCLUSION: Few studies have characterised the surgical outcomes following epicardial permanent pacemaker implantation in neonates. The surgical approach is attractive and compelling among professionals so we aimed to present the techniques and results in patients who required permanent pacemaker implantation in the first month of life.

Clinical characteristics of hypertrophic cardiomyopathy in children: An 8-year single center experience.

BACKGROUND: Hypertrophic cardiomyopathy (HCM) is the second most common pediatric cardiomyopathy. Although there is a large body of literature about HCM in adults, there is limited information on HCM in childhood. We evaluated various aspects of pediatric HCM patients treated at our center. METHODS: We identified 152 pediatric patients with HCM between October 2011 and October 2019. Clinical history, invasive (ICD, pacemaker, electrophysiologic study, catheter ablation therapy) and non-invasive (ECG, holter moniterization, echocardiography, cardiac MR, genetic study, medicam treatment) data were collected and evaluated. RESULTS: The mean ± standard deviation age of patients was 8.9 ± 5.7 years (1 month-18 years) and 67.8% were male. The most frequent clinical symptoms were murmur and palpitations. Three cases (2%) had aborted sudden death as the first manifestation of HCM. Of these patients, 120 (78.9%) had non-syndromic HCM and 32 (27.2%) had syndromic HCM. Asymmetric septal hypertrophy was common (48.3%) in the non-syndromic group, whereas concentric hypertrophy was common (56.2%) in syndromic group. Left ventricular outflow tract obstruction (LVOTO) occurred in 39 (25.6%) patients. Nine (5.9%) patients underwent electrophysiologic study and/or ablation and 16 patients underwent surgical intervention. Implantable cardioverter defibrillator (ICD) insertion was performed in 38 patients (26 transvenous, 12 epicardial). ICDs were inserted in three (7.9%) patients for secondary prevention; in the remaining patients (92.1%) the devices were placed for primary prevention. Mean SD follow-up time was 27.1 ± 22 months. Five (3.3%) patients died during the follow-up. No patient had heart transplantation or a long-term assistive device. CONCLUSION: The etiology of HCM is heterogeneous and present at any age. It is important to determine the timing of surgery and potential risks for sudden cardiac arrest. As most cases of HCM are familial, evaluation of family members at risk should be a routine component of clinical management.

Transcatheter radiofrequency pulmonary valve perforation in newborns with pulmonary atresia/intact ventricular septum: Echocardiographic predictors of biventricular circulation.

OBJECTIVE: We report a single-institute experience of neonatal transvenous radiofrequency pulmonary valve perforation for pulmonary atresia/intact ventricular septum, with echocardiographic predictors of biventricular circulation. METHODS: Data were reviewed retrospectively for all neonates who underwent primary transvenous pulmonary valve perforation for pulmonary atresia/intact ventricular septum between January 2008 and November 2018 at our institution. We compared patients who need systemic-to-pulmonary shunt or ductal stenting with patients who did not need. RESULTS: During the study period, 31 patients with pulmonary atresia/intact ventricular septum underwent successful radiofrequency pulmonary valve perforation and balloon dilation of the pulmonary valve. There was no procedure-related mortality. Sixteen patients (52%) needed systemic-to-pulmonary shunt or ductal stenting after initial procedure. Among the survivors (follow-up time of 1 to 11.5 years), 15 patients had a biventricular circulation and 6 patients had 1 and 1/2 ventricular circulation. Two patients are awaiting for Fontan operation. Both the TV/MV annulus ratio (>0.85) and tricuspid valve z-score (>-1) were found to be a good predictor of a biventricular outcome in our cohort. CONCLUSIONS: Percutaneous radiofrequency pulmonary valve perforation and balloon valvotomy is an effective and safe primary treatment strategy for neonates with pulmonary atresia/intact ventricular septum. Ductal stenting or systemic-to-pulmonary shunt may be required in the majority of patients who had smaller right heart components. Preselection of patients according to tricuspid valve z-score and TV/MV annulus ratio allows predicting biventricular circulation.

Tricuspid annular plane systolic excursion and mitral annular plane systolic excursion cardiac reference values in 1300 healthy children: Single-center results.

BACKGROUND: Tricuspid annular plane systolic excursion (TAPSE) and mitral annular plane systolic excursion (MAPSE) are two echocardiographic parameters which provide reliable information about the longitudinal myocardial functions of the right and left ventricles in both adult and pediatric population. The aim of this study was to determine the TAPSE and MAPSE reference values in healthy children aged 0-18 years. METHODS AND RESULTS: This prospective study included 1300 healthy children evaluated with two-dimensional echocardiography. In addition to routine echocardiographic examination, the right and left ventricular systolic functions were assessed by TAPSE and MAPSE measurements. Statistical analyses were carried out in the groups of subjects stratified according to age and body surface area. The mean and standard deviation values and z-scores of TAPSE and MAPSE were developed in each group. CONCLUSIONS: The determination of reference values for TAPSE and MAPSE in healthy children will be of guidance in the evaluation of both healthy children and those with congenital or acquired heart diseases in which the right and left ventricular systolic functions are affected. The reference values obtained will contribute to the clinical practice and the future studies.

A rare indication of permanent pacemaker implantation in children: congenital long QT syndrome.

Congenital Long QT Syndrome (LQTS) is a dangerous arrhythmic disorder that can be diagnosed in children with bradycardia. It is characterised by a prolonged QT interval and torsades de pointes that may cause sudden death. Long QT syndrome is an ion channelopathy with complex molecular and physiological infrastructure. Unlike the acquired type, congenital LQTS has a genetic inheritance and it may be diagnosed by syncope, stress in activity, cardiac dysfunction, sudden death or sometimes incidentally. Permanent pacemaker implantation is required for LQTS with resistant bradycardia even in children to resolve symptoms and avoid sudden death.

The Transjugular Approach: An Alternative Route to Improve Ablation Success in Right Anteriorly and Anterolaterally-Located Supraventricular Tachycardia Substrates in Children.

Catheter ablation via the femoral vein has been widely used in children. However, in certain conditions, an alternative vascular access is required for a successful ablation. Herein we reported that, accessory pathways (APs) and ectopic foci which reside right anterior and anterolateral to tricuspid valve orifice can be safely and effectively ablated with transjugular venous approach. Eleven procedures performed via the transjugular venous approach were reviewed retrospectively from the 355 electrophysiological procedures performed between March 2016 and November 2017. EnSite 3D electro-anatomic mapping and limited flouroscopy was used in all patients. The mean age of patients was 14.4 ± 2.9 years (12-18) and 6/11 (54.5%) were males. Seven of the patients had previous ablation procedures via the femoral vein approach and due to failure or recurrence the procedures had to be repeated. In these patients mean procedure time shortened from 196 ± 80 (105-280) to 111 ± 13 (96-125) min with the transjugular approach. 10/11 patients had APs, and one patient had focal atrial tachycardia. One of the APs was a Mahaim pathway. Ablation localisations were right anterior and right anterolateral in 8/11 and 3/11 patients respectively. The average fluoroscopy time was 3.38 ± 6.5 (0-15) min. All of the RF ablations via transjugular approach were successful (100%, 11/11). The mean follow-up period was 10.6 ± 1.1 (9-12) months. So far no recurrence has been observed. Right anterior and anterolateral regions are the most challenging areas in terms of catheter stabilization even when long sheaths are used during femoral route ablation. Ablation attempts in these regions have partial success, frequent recurrence, and high complication rates. This study revealed that transjugular approach seems as an effective alternative for those cases where transfemoral approach is unsuccessful for the ablation targets located in the right anterior and antero-lateral regions.

Evaluation of long-term cardiac side effects of anthracycline chemotherapy by conventional and non-conventional echocardiographic methods in childhood cancer survivors.

OBJECTIVE: Anthracycline chemotherapeutic agents carry the well-recognised risk of cardiac toxicity. The aim of this study was to determine the long-term effect of anthracycline chemotherapy on the biventricular function in childhood cancer survivors using tissue Doppler imaging and two-dimensional speckle tracking echocardiography. PATIENTS AND METHODS: The study included 45 survivors of childhood cancers and 50 healthy age-matched control patients. Cardiac function was prospectively studied with conventional echocardiography, tissue Doppler imaging, and speckle tracking echocardiography after completion of treatment. The same analysis was performed on matched controls. RESULTS: There was no difference in age, gender, height, and weight between the study and control groups. The mean anthracycline dose was 240 ± 106 mg/m2 and the mean remission duration was 8.2 ± 5 years (1-20 years) in the study group. Conventional echocardiography showed similar ejection fraction, shortening fraction, and left ventricle end-diastolic diameter in both groups. Mitral lateral and septal tissue Doppler imaging showed normal but according to control group relatively sub-normal systolic and diastolic function in patient group. The global longitudinal and circumferential strain and strain rates were significantly lower in the patient group compared to control group. Correlation analysis revealed a negative and significant correlation between total anthracycline dose and global longitudinal and circumferential strain and strain rates. CONCLUSION: Sub-clinical systolic and diastolic dysfunction may not be detected by conventional echocardiographic methods which are frequently used in daily practice. Sub-clinical systolic and diastolic dysfunction may be detected more sensitively by echocardiographic method such as speckle tracking echocardiography in childhood cancer survivors.

Ivabradine is an effective antiarrhythmic therapy for congenital junctional ectopic tachycardia-induced cardiomyopathy during infancy: Case studies.

Junctional ectopic tachycardia (JET) is a rare form of arrhythmia that is most commonly seen during infancy. JET is continuous and incessant, characterized by persistently high heart rates that may result in impaired cardiac function and tachycardia-induced cardiomyopathy. Despite the availability of multiple antiarrhythmic treatments, including flecainide and amiodarone, management of JET is generally very difficult. Catheter ablation has a high risk of atrioventricular block and it may require the placement of a pacemaker. Ivabradine, also known as a cardiac pacemaker cell inhibitor, is a new-generation antiarrhythmic used to treat sinus tachycardia and angina pectoris in adult patients. In this article, we present three cases of subjects with infantile congenital JET who were admitted to our clinic with a tachycardia-induced cardiomyopathy. The age of the subjects ranged from 52 days to 10 months. Although the cases of tachycardia could not be controlled by multiple antiarrhythmics, including a combination of amiodarone and flecainide combined with either propranolol or digoxin, they were rapidly converted into sinus rhythm with an ivabradine treatment of 0.1-0.2 mg/kg/day. No cardiac or other side effects were observed during ivabradine treatment, and left ventricular functions and rhythms improved within 24 hours. These three cases therefore provide hope that ivabradine may be a suitable standard initial treatment for congenital JET. However, additional research is needed to confirm the validity of these results in other circumstances.

Subclinical left ventricular systolic and diastolic dysfunction in type 1 diabetic children and adolescents with good metabolic control.

OBJECTIVE: Cardiac dysfunction is a well-known consequence of diabetes mellitus. This study was designed to assess whether type 1 diabetic children and adolescents with good metabolic control have early echocardiographic signs of subclinical left ventricular dysfunction and whether diabetes duration has any influence, using conventional and nonconventional echocardiographic tools. METHODS: A total of 100 patients with type 1 diabetes mellitus and 80 gender- and age-matched healthy controls were included. The cases underwent standard conventional transthoracic echocardiography, tissue Doppler imaging, and two-dimensional speckle tracking echocardiography. None of the diabetic patients had signs of renal, retinal, or neurological complications of the disease, and all were good metabolic control (mean HbA1c <7.5%). RESULTS: There was no difference among groups in relation to age, sex, body mass index, and blood pressure. Conventional echocardiographic parameters were similar between diabetic and nondiabetic subjects except increased mitral valve peak A-wave and significantly lower mitral E/A ratio in diabetics. Diabetic patients had more advanced diastolic dysfunction with TDI analysis. In the diabetic group, left ventricular global longitudinal, circumferential, and radial strain and strain rate were significantly lower compared with the controls. There was a positive correlation between diabetes duration and cardiac dysfunction. CONCLUSION: The results of this study showed that the diabetic children and adolescents with good metabolic control had diastolic dysfunction when assessed with either conventional or tissue Doppler echocardiography. Also diabetic patients had subclinical LV systolic dysfunction with a normal LVEF which can be detected with 2D speckle tracking echocardiography.

Sensitive Cardiac Troponins: Could They Be New Biomarkers in Pediatric Pulmonary Hypertension Due to Congenital Heart Disease?

To analyze the role of sensitive cardiac troponin I (scTnI) and high-sensitive troponin T (hscTnT) in the determination of myocardial injury caused by volume and pressure load due to pulmonary hypertension (PH) and to investigate if these markers may be useful in the management of PH in childhood. Twenty-eight patients with congenital heart disease (CHD) with left to right shunt and PH, 29 patients with CHD with left to right shunt but without PH, and 18 healthy children, in total 75 individuals, were included in the study. All cases were aged between 4 and 36 months. Echocardiographic evaluation was performed in all cases, and invasive hemodynamic investigation was performed in 33 cases. Blood samples were obtained from all cases, for the measurement of brain natriuretic peptide (BNP), pro-brain natriuretic peptide (pro-BNP), sensitive cardiac troponin I (scTnI), and high-sensitive troponin T (hscTnT) levels. The mean BNP, pro-BNP, scTnI, and hsTnT levels were statistically significantly higher in patients with PH than in the patients without PH (p < 0.001). A statistically significant positive correlation was determined between pulmonary artery systolic pressure and scTnI and hscTnT levels (r = 0.34 p = 0.01, r = 0.46 p < 0.001, respectively) levels. Pulmonary hypertension determined in congenital heart diseases triggers myocardial damage independently of increased volume or pressure load and resistance, occurring by disrupting the perfusion via increasing ventricular wall tension and the myocardial oxygen requirement. Serum scTnI and hscTnT levels may be helpful markers to determine the damage associated with PH in childhood.

Persistent left superior vena cava accompanying congenital heart disease in children: Experience of a tertiary care center.

BACKGROUND: This study focuses on determining concomitant persistent left superior vena cava (SVC) in patients with congenital heart disease (CHD). METHODS: Between 2005 and 2012, a total of 2.663 patients with CHD, 88 (3.3%) of whom were diagnosed with persistent left SVC, were evaluated retrospectively. The demographic characteristics of patients, clinical and radiographic findings, echocardiography, cardiac catheterization, and angiography results obtained from the patients' records were reviewed. RESULTS: The median age of the patients was 9.5 months, and 46 of the 88 (52.3%) patients were female. The most common concomitant CHD were ventricular septal defect, double outlet right ventricle (DORV), and tetralogy of Fallot (TOF). When the patients were compared according to their CHD, persistent left SVC frequency was significantly higher in those with DORV (P<.001), TOF (P=.04), patent ductus arteriosus (P=.01), and atrial septal defect (P=.03). Eighty-three of the 88 (94.3%) patients with persistent left SVC had right SVC, and 5 (5.7%) had absence of the right SVC. Twenty-seven of the 83 (32.5%) patients with double SVC had connected normal innominate vein. In all cases, right aortic arch association was seen in 14 (15.9%) patients. Eighty-four (95.4%) of the patients were diagnosed by echocardiography prior to catheter angiography. Persistent left SVC drained to the coronary sinus in all cases. CONCLUSION: Increased awareness about the association of certain CHD with persistent left SVC and a careful echocardiographic examination can facilitate the diagnosis of persistent left SVC. In addition, precise prior diagnosis of persistent left SVC can prevent complications during surgery.

Regression of symptomatic multiple cardiac rhabdomyomas associated with tuberous sclerosis complex in a newborn receiving everolimus.

UNLABELLED: Cardiac rhabdomyoma is the most common primary cardiac tumor, is considered to be a hamartoma of developing cardiac myocytes. Cardiac rhabdomyoma is associated with tuberous sclerosis complex (TSC) in 50-86% of cases. Mutations in TSC-1/TSC-2 genes result in increased mammalian target of rapamycin (mTOR) pathway activation responsible for the hamartomatous lesions of tuberous sclerosis complex. Therapy with mTOR inhibitors is currently under investigation as a treatment option for tumors associated with TSC. In this report we present a case with multiple symptomatic rhabdomyomas associated with tuberous sclerosis complex, deemed to be ineligible for surgical removal, treated with everolimus (mTOR inhibitor). CONCLUSION: As we observed in our patient, in cases with inoperable symptomatic rhabdomyomas associated with TSC, everolimus, an mTOR inhibitor, may be the treatment of choice, which should be confirmed with additional studies.

An evaluation of heart rate variability and its modifying factors in children with type 1 diabetes.

OBJECTIVE: To evaluate heart rate variability by Holter monitoring in type 1 diabetic children compared with a healthy control group and determine the factors modifying heart rate variability. METHODS: This was designed as a prospective study comparing 28 patients, diagnosed with type 1 diabetes and under follow-up, with 27 healthy control group subjects. RESULTS: The patients were aged 9.9 ± 4.2 years in the diabetic group, including 13 (46.5%) girls and 15 (53.5%) boys. The healthy control group comprised 20 (74%) girls and seven boys (26%) with an average age of 8.6 ± 3.7 years. The search for factors modifying heart rate variability yielded the following correlations: for the time-dependent variables, negative between age and both average and maximal heart rate (r = -0.263 and -0.460, respectively), negative between haemoglobin A1c and percentage of differences between adjacent RR intervals >50 ms, positive between diabetes duration and square root of the mean of the sum of squares of differences between adjacent NN intervals. The average heart rate and percentage of differences between adjacent RR intervals >50 ms was significantly higher in the girls than the boys in all groups. With regard to the frequency-dependent factors affecting heart rate variability, correlations were found between haemoglobin A1c level and both total power and very low frequency (r = -0.751 and -0.644) and between very low frequency and diabetes duration. CONCLUSION: A reduction in heart rate variability parameters was observed in type 1 diabetes mellitus patients who had a long disease duration or were poorly controlled, as compared with healthy controls.

Double outlet right ventricle with intact ventricular septum.

Double outlet right ventricle is a cardiac malformation in which both the aorta and pulmonary artery arise from the right ventricle. A double outlet right ventricle with intact ventricular septum is extremely rare. A nine-day-old boy born at 38 weeks with a birth weight of 3200 g was referred due to cyanosis and murmur. The history of the patient was nonsignificant. On the physical examination, oxygen saturation of the patient on room air was 84%, and cardiac activity and a 2/6 systolic murmur at the right sternal border were found. On electrocardiography, deep q's were determined in D2, D3, and aVF. On echocardiography, left atrial isomerism, dextrocardia, wide, high venosum atrial septal defect, double outlet right ventricle with intact ventricular septum, malposition of the great arteries, and moderate pulmonary stenosis were observed. Catheter angiography was performed for diagnostic confirmation. Herein, a newborn with cyanosis and murmur diagnosed as double outlet right ventricle with intact ventricular septum is reported.

Strain and strain rate echocardiography findings in children with asymptomatic congenital aortic stenosis.

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.

A Rare Case of Wolff-Parkinson-White Syndrome Associated with Right Atrial Aneurysm.

Wolff-Parkinson-White syndrome is rarely associated with a right atrial aneurysm. However, when such a condition occurs, it will be hard to manage since pre-excitation will be induced as long as the aneurysm persists. A 14-year-old female patient received emergency treatment for irregular wide QRS complex tachycardia in our center, and a pre-excitation pattern was then observed on the surface electrocardiogram. An initial electrophysiological study revealed a high-risk right posterior accessory pathway that was resistant to both radiofrequency and irrigated radiofrequency ablations. Subsequently, fluoroscopy showed that this was due to a right atrial aneurysm. Although successful ablation with irrigated radiofrequency was performed in the second procedure, the procedure was considered suboptimal due to the association of aneurysm. Accordingly, we initiated anti-thrombotic and anti-arrhythmic drug therapy. We decided to omit surgery and followed the case under medical treatment for 2 years without complications. Here, we report this rare coexistence and our treatment approach in detail.