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.

Molecular Approach of Hereditary Arrhythmias, Long QT Syndrome, and Arrhythmogenic Right Ventricular Cardiomyopathy.

BACKGROUND: Hereditary cardiac arrhythmias result from mutations in various genes encoding ion channels. One major channelopathy is long QT syndrome, which has excel- lent genetic and clinical heterogeneity. Arrhythmogenic right ventricular cardiomyopa- thy, another hereditary arrhythmia type, also shows high genetic heterogeneity and variable expressivity. Next-generation sequencing is an effective tool to reveal the dis- ease's underlying genetic etiology. METHODS: In this study, we performed clinical exome sequencing or gene panel including cardiac arrhythmia and cardiomyopathy-associated genes by next-generation sequenc-ing in 13 unrelated patients. RESULTS: Five pathogenic or likely pathogenic mutations, including three novel mutations, were found in the total cases. CONCLUSION: This research shows a strong genetic heterogeneity in the disease. In addi- tion, the study revealed that patients with QT interval prolongation on electrocardio- gram might also have mutations in genes that are not associated with long QT syndrome, such as MYLK2 and DSG2. Therefore, our data helped expand the molecular scope of long QT syndrome. It is necessary to study with a broad perspective to elucidate the underly- ing molecular etiology in patients with hereditary cardiac arrhythmias.

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.

Cryoablation with an 8-mm tip catheter for typical AVNRT in children: a single center 5-year experience.

BACKGROUND: In children with typical atrioventricular nodal reentrant tachycardia (tAVNRT), cryoablation is preferred over radiofrequency ablation (RFA) because of its safety profile and acceptable long-term success rates. In this study, we have assessed the utility of 8-mm tip cryocatheters for tAVNRT ablation in our center. METHODS: All pediatric AVNRT patients who underwent cryoablation with an 8-mm tip cryocatheter in our center between 2013 and 2018 were included. EnSite™ (St. Jude Medical Inc., St. Paul, MN, USA) was used in all patients. RESULTS: A total of 120 patients (64 females, 53%) were included in this study, and the mean age was 13.9 years with a standard deviation of 2.5 years. Eleven patients (9.1%) had structural heart disease, and 12 patients (10%) had additional arrhythmia substrate. The mean number of effective cryolesions was 8 with a standard deviation of 2.3. Fluoroscopy was used in three patients (2.5%). There were minor complications in only four patients (3.3%)-transient first-degree atrioventricular block or transient incomplete right bundle branch block. Acute success rate of cryoablation was 108/120 (90%). In twelve patients, cryoablation was suboptimal, or it failed. The procedure was completed successfully with RFA in the same session in ten patients. Overall acute success rate of ablation (Cryo ± RFA) was 98.5%. During a mean follow-up period of 24.6 months with a standard deviation of 11.3 months, three patients had recurrence (2.5%). Time between the beginning of the effective cryolesion and termination of AVNRT was found associated with acute success of cryoablation (p = 0.013). CONCLUSIONS: Cryoablation of AVNRT with an 8-mm tip catheter in children appears to be safe, with an acceptable acute success rate and a low recurrence rate. A faster termination of AVNRT during the cryolesion, slowing down before ending with atrioventricular block, is a good indicator for acute success.

Aortic cusp ablation for premature ventricular contractions and ventricular tachycardia in children: a 5-year single-center experience.

PURPOSE: Aortic cusps might be the source of supraventricular or ventricular arrhythmias. For many years, aortic cusp ablation has been widely used to treat premature ventricular contractions (PVCs) and ventricular tachycardia (VT). However, the data on the outcomes of this procedure in children are limited. The study aimed to convey or describe our own aortic cusp ablation experiences in children and, thus, contribute to the literature. METHODS: The focus was pediatric cases of ventricular arrhythmia in which the origin of the PVCs was ablated above the Valsalva. The sample comprised patients who underwent aortic cusp ablation between 2013 and 2018. The demographic characteristics, noninvasive test results, procedure details, and follow-up results for the patients were noted. RESULTS: The 3D EnSite Precision cardiac mapping system and limited fluoroscopy were used. A total of 26 procedures were performed on 22 patients. The mean age was 14.4 ± 3.0 (9-19) years, and the mean weight was 57.3 ± 17.5 (27-99) kg. The mean follow-up period after the first presentation was 38.6 ± 22.9 (3-72) months. There were significant differences in the values of the transition index, V2S/V3R, IIR/IIIR, aVRS/aVLS ratio, and QRS polarity in I at various locations. The most common ablation site was the left coronary cusp (LCC). Radio frequency (RF) ablation, cryoablation, and irrigated RF ablation were found to be effective energy sources in 15, 4, and 3 patients, respectively. Patients who underwent ablation at the LCC-right coronary cusp (RCC) commissure were more likely to present with only VT and to experience worsening symptoms. Twelve patients had previously undergone ablation of the right ventricular outflow tract (RVOT). Ablation in the RVOT had been previously performed in all the patients who eventually underwent ablation at the RCC and the LCC-RCC commissure. CONCLUSION: Aortic cusp ablation can be safely performed in children. The careful evaluation of previous noninvasive tests provides important data for determining the location. There might be significant differences in the signs and requirements on the basis of the locations during mapping and ablation.

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.

Successful left coronary cusp cryoablation in an adolescent with premature ventricular extrasystoles-associated cardiomyopathy.

Ventricular arrhythmias arising from coronary cusps are not uncommon. However, the mapping and ablation of outflow tract ventricular arrhythmias originating from aortic cusps can be challenging. Radiofrequency ablation of this area can cause rare but serious complications. This was a report of a 17-year-old male patient with very frequent, nonsustained ventricular tachycardia attacks and premature ventricular contraction-induced cardiomyopathy. The origin of the ventricular arrhythmia was determined to be the left coronary cusp, and the patient was treated successfully with cryoablation. In high-risk areas, cryoablation is an effective and safe alternative method.

Clinical features and arrhythmic complications of patients with pediatric-onset arrhythmogenic right ventricular dysplasia.

OBJECTIVE: Arrhythmogenic right ventricular dysplasia (ARVD) is a myocardial genetic disease that occurs primarily in the right ventricle. Patients with ARVD may present with severe ventricular arrhythmias, syncope, and cardiac arrest. The purpose of this study is to evaluate the clinical features and arrhythmic complications of patients with pediatric-onset ARVD. METHODS: Patients diagnosed with ARVD between January 2010 and January 2019 were included in this study. RESULTS: A total of 19 patients with ARVD were evaluated. Of them, 15 patients were male, and their mean age was 12±4 years. The most common symptoms were palpitations (n=6), syncope (n=4), and heart failure symptoms (n=2). Five patients were asymptomatic. Thirteen patients had an epsilon wave; all patients ≥14 years had a T wave inversion in V1-3. Premature ventricular contractions (PVCs) were observed in 15 patients, and ventricular tachycardia (VT) was observed in 9 patients. All patients underwent cardiac magnetic resonance imaging (MRI). Echocardiography and cardiac MRI of two patients were normal at the time of admission; patients were in the concealed phase, and the diagnosis was made by ECG, Holter monitoring, and genetic findings. We administered a beta-blocker in all patients. Two patients underwent an electrophysiological study and ablation because of PVC/VT. An implantable cardiac defibrillator was implanted in 8 patients. The mean follow-up period was 21.5±11 months. Two patients were deceased with incessant VT and heart failure, and one patient was deceased with multiorgan dysfunction after biventricular assist device implantation (n=3). CONCLUSION: Diagnosis of pediatric-onset ARVD might be much more difficult in children. Sudden cardiac death might be prevented in the early period by raising the awareness of physicians about the disorder. Prevention of sudden death with implantable cardiac defibrillators is crucial in the management of these patients. It should be kept in mind that children with structurally normal hearts may present with an earlier concealed phase and can be diagnosed with ARVD.

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.

Symptomatic Fetal-Type Cardiac Rhabdomyoma.

Rhabdomyomas are the most common primary cardiac tumors, especially seen during early periods of childhood. Fetaltype rhabdomyoma is a benign tumor described almost always in extracardiac locations. Although the natural history of the cardiac rhabdomyoma is to regress, the behaviour of the fetal-type rhabdomyomas when present in the heart is unknown with respect to its infrequency. Herein, we report a hemodynamically unstable female neonate with a single large intra-cardiac mass unresponsive to medical treatment, who underwent surgery. The neonate could not survive the operation due to ventricular fibrillation. The mass was diagnosed as fetal-type cardiac rhabdomyoma on autopsy.

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.

Ventricular non-compaction in children: clinical characteristics and course.

Isolated left ventricular non-compaction (LVNC) is a rare cardiomyopathy characterized by prominent trabeculations and deep intratrabecular recesses. In this study, we aimed to identify the clinical characteristics of children with ventricular non-compaction and determine the factors affecting prognosis. We retrospectively evaluated 29 children with LVNC followed at Dr. Sami Ulus Children Hospital Pediatric Cardiology Department from December 2004 to November 2009. There were 13 females (45%) and 16 males (55%) and the mean age at presentation was 4.8±4.6 years (one month-15 years). Although there was no statistical significance; early presentation age and high left ventricular end-diastolic diameter at the diagnosis were associated with poorer prognosis.