Transient second-degree high-grade atrioventricular block caused by myocarditis.

Myocarditis is an inflammatory disease of the heart muscle that most commonly occurs after infectious diseases in childhood. The clinical picture of acute myocarditis ranges from asymptomatic infection to fulminant heart failure and sudden death (1). Most of the patients may present with nonspecific symptoms such as respiratory distress, chest pain, nausea, and vomiting (2). While rhythm abnormalities such as ventricular and supraventricular rhythm disorders can be observed in these patients, various degrees of atrioventricular blocks may rarely develop (3). In this article, we aimed to present a patient who developed second-degree, high-grade atrioventricular block after myocarditis and recovered completely after treatment.

Transcatheter Ventricular Septal Defect Closure with Lifetech™ Konar-MF Occluder in Infants Under 10 kg with Only Using Venous Access.

Transcatheter closure of VSD remains a complex procedure in infants with technical challenges and carries the risk of significant complications, due to its complex anatomical morphology and closed proximity to the atrioventricular valves and the conduction system. In this article, we presented transcatheter VSD closure in infants under 10 kg using the Lifetech Konar-MF device via only venous route without TEE guidance and arterial access. Between January 2021 and May 2023, a total of 34 patients weighing less than 10 kg who underwent transcatheter VSD closure antegradely with Lifetech™ Konar-Multifunctional (MF) occluder were included in the study. The mean age of the patients was 8.1 (3.5-35) months. Average weight was 6.5 kg (range 4.5-10 kg). VSD was perimembranous in 27 patients (79.4%). Successful device placement was achieved in all 34 patients. However, device embolization occurred in three patients. One of the patients was successfully implanted with a one size larger device, the surgical closure was performed other two cases. TR occurred in seven patients (20.6%) after releasing devices. None of the patients developed complete heart block. Right bundle branch block developed in two patients. Residual shunt was observed in 9 patients (six small, two moderate, and one large). During follow-up, residual shunt disappeared in six of these patients and only mild residual shunt remained in the other four patients which have not required any further intervention. Transcatheter closure of VSD with Lifetech Konar-MF device is safe and effective in infants less than 10 kg via only venous access with a high success rate and low complication rate. In these patients, transcatheter VSD closure can be performed by excluding the risk of complications that may occur due to AV loop formation, arterial intervention, endotracheal intubation and TEE use.

Successful catheter ablation of the accessory pathway in an unusual location in a 13-year-old girl with a coronary sinus diverticulum and Wolff-Parkinson-White syndrome.

Wolff-Parkinson-White syndrome is a congenital cardiac pre-excitation syndrome that is effectively treated by ablating the accessory pathway. However, accessory pathways located in the posteroseptal region can sometimes be challenging. In this paper, we present the successful ablation of the epicardial posteroseptal accessory pathway through the middle cardiac vein in a 13-year-old girl with a coronary sinus diverticulum and Wolff-Parkinson-White syndrome, after unsuccessful ablation attempts at different locations. If the ablation procedure fails, the possibility of the posteroseptal pathway should be kept in mind, and coronary sinus angiography should be performed. In cases with a coronary sinus diverticulum where ablation is not successful, other coronary sinus structures, for example, the middle cardiac vein should be considered as potential accessory pathways.

A rare complication after radiofrequency catheter ablation in an adolescent case: skin burn.

Radiofrequency catheter ablation is a preferred treatment method for cardiac arrhythmias in children due to its high success rate and low complication risk. We present an adolescent patient who underwent radiofrequency catheter ablation for Wolff-Parkinson-White syndrome and developed a skin burn at the site of the electrode patch. Skin burns can catastrophic consequences, especially in patients with life-threatening arrhythmias; therefore, clinicians should be aware of this complication.

Adaptation of adult right ventricular scoring systems to pediatric patients undergoing continuous LVAD implantation: Feasible or not?

PURPOSE: The aim of this study is to investigate the efficacy of adaptation of right ventricular (RV) risk scores used in adult patients to pediatric age group undergoing LVAD implantation. METHODS: Twenty-two pediatric patients who underwent LVAD implantation were retrospectively reviewed from January 2014 to September 2018. Preoperative patient characteristics, hemodynamic parameters, and echocardiographic data were collected. Adult RV risk scores were calculated for all patients. Effects of all the parameters on RV function were also investigated. Study endpoints were RVF and in-hospital mortality. RESULTS: Eleven (50%) of 22 patients were male. The mean age of the patients was 13.4 ± 3.8 years. The mean body surface area of the patients was 1.4 ± 0.4 m2. In five patients BiVAD implantation was performed. Of these five BiVAD patients two underwent successful heart transplant; two weaned from temporary RVAD and last patient died due to multi-organ failure. Four patients showed signs of early RVF; one patient was transplanted successfully while on medical support. Three patients developing RVF did not respond medical therapy necessitating ECMO and died in the early postoperative period. All risk scores and potential predictive factors were evaluated individually and in combination of several parameters. No significant predictor for RVF in pediatric patients that underwent LVAD implantation was found (p > 0.05). CONCLUSION: Neither an adult risk score nor a predictive factor was successful in predicting RVF, alone or in combination due to limited number of patients and events. Large further investigations are needed to identify the predictors or scoring system in pediatric population.

A Nine-year-old Boy with Renovascular Hypertension: Knowing Where to Look.

Renal artery entrapment (RAE) by hypertrophic diaphragmatic crura is an extremely rare cause of renovascular hypertension (RVH). Here, we report the case of a 9-year-old boy diagnosed with RVH caused by right RAE by a hypertrophic diaphragmatic crus and successfully managed with close medical monitoring. Diagnosis of this entity is easily overlooked if the optimal views are not obtained during imaging, which depends on a high index of suspicion. We would like to remind clinicians to keep this rare condition in mind when evaluating children with RVH.

The Relationship between Arterial Elasticity Parameters of Ascending Aorta, Abdominal Aorta and Carotid Arteries with Carotid Intima Media Thickness in Children with Bicuspid Aortic Valve.

BACKGROUND: Bicuspid aortic valve is a congenital cardiac malformation that affects not only the valve and ascending aorta but also the abdominal aorta and large central arter-ies like carotid arteries by damaging the elasticity of the vessel resulting in increased stiffness and reduced distensibility. Deterioration of aortic compliance disturbs functions of the left ventricle and triggers atherosclerosis determined with carotid intima-media thickness. The aim of this study was to assess the effect of the bicuspid aortic valve on the elastic properties of these parts of the arterial system in children. METHODS: Thirty-four children with bicuspid aortic valves with normal valvular functions or mild valvular dysfunction and a control group of 34 individuals with tricuspid aortic valves were included in the study. Echocardiographic measurements of the left ventri- cle, ascending aorta, and ultrasonographic measurements of the abdominal aorta and carotid arteries were performed, and elasticity indexes were calculated. RESULTS: The bicuspid aortic valve group had higher stiffness and lower distensibility in ascending aorta, abdominal aorta, and carotid arteries with higher carotid intima- media thickness values than the tricuspid aortic valve group. Aortic valvular z scores and ascending aorta and abdominal aorta stiffness were higher in patients with bicus- pid aortic valves irrespective of valvular functions than in controls. Valvular dysfunction affected stiffness in carotid arteries. Dilatation of ascending aorta increased stiffness in the abdominal aorta. Distensibility was lower in ascending aorta and left carotid artery, with increased carotid intima-media thickness independent from ascending aorta dila- tation. Stiffness of abdominal aorta revealed a positive correlation with the stiffness of the ascending aorta and the carotid arteries (P < .05, for all). CONCLUSIONS: Elasticity indexes of children with bicuspid aortic valves were impaired in ascending aorta, abdominal aorta, and carotid arteries with an increase in carotid intima-media thickness.

Transitioning from Radiofrequency Ablation to Cryoablation for Treatment of Pediatric Atrioventricular Nodal Reentrant Tachycardia: A Single Tertiary Center Experience.

Catheter ablation of the slow pathway is the recommended treatment for atrioventricular nodal reentrant tachycardia (AVNRT) in children. Both radiofrequency ablation (RF) and cryoablation (CA) have been used for this purpose. In this report, we describe our experience during the transition period from RF to CA for the treatment of pediatric AVNRT. Between January 2012 and August 2021, a retrospective evaluation was conducted of the clinical features, procedural outcomes, and follow-ups of pediatric AVNRT patients who underwent catheter ablation at a pediatric electrophysiology center. The catheter ablation outcomes of 89 pediatric AVNRT patients were evaluated: 29 patients were ablated using RF (RF group) and 60 patients were ablated using CA (CA group). No significant difference was found between the groups in terms of gender, age, weight, and success and recurrence rates. The procedure duration and total lesion numbers were statistically significantly lower in the RF group compared with the CA group (86.67 ± 45.8 and 156.1 ± 37.7 min; p = 0.01, 4 [3-6] and p < 0.01, 8 [7-9] lesions, respectively). Catheter ablation was successful in all patients. There were no permanent complete atrioventricular blocks in both groups. A total of six patients (6.8%) developed recurrences. The cryoablation of pediatric AVNRT is a safe and effective procedure with comparable acute and mid-term follow-up success rates compared with RF, even during a period of transition from RF to CA.

Assessment of Cardiac Arrhythmic Risk in Children With Covid-19 Infection.

Coronavirus disease of 2019 (COVID-19) is a cause of significant morbidity and mortality worldwide. Although COVID-19 clinical manifestations are mainly respiratory, major cardiac complications are being reported. The mechanism of cardiac injury and arrhythmias is unclear. Also, drugs currently used to treat the COVID-19 may prolong the QT interval and may have a proarrhythmic propensity. The study aims to investigate the effects of COVID-19 infection with asymptomatic and mild symptoms on trans-myocardial repolarization parameters in children without treatment. A total of 105 COVID-19 patients were compared with 40 healthy children. The patient and control group data were compared by calculating the QT interval, corrected QT (QTc), QT dispersion (QTd), QTc dispersion (QTcd), Tp-e, Tp-e dispersion, Tp-e/QT ratio, and Tp-e/QTc ratio on the 12-lead surface electrocardiogram. The mean age was determined as 11.2 ± 0.3 years in the patient group, and 10.8 ± 2.1 years in the control group. In the COVID-19 group, QTd, QTcd, Tp-e, Tp-e dispersion, Tp-e/QT ratio and Tp-e/QTc ratio were statistically higher than the control group. The ventricular repolarization was impaired even in asymptomatic children with COVID-19 infection. These results suggest the need to further assess the long terms risks of prolonged QT dispersion in the setting of COVID-19 infection.

[Electrophysiological properties of asymptomatic children and adolescents with the Wolff-Parkinson-White electrocardiographic pattern]. / Wolff-Parkinson-White elektrokardiyografik paterni olan asemptomatik çocuk ve ergenlerin elektrofizyolojik özellikleri.

OBJECTIVE: Optimal management in asymptomatic children and adolescents with the Wolff-Parkinson-White (WPW) electrocardiographic pattern is still debatable. The aim of this retrospective study was to evaluate the electrophysiological properties of asymptomatic children and adolescents with WPW. METHODS: The medical records and procedural data of asymptomatic children and adolescents with the WPW electrocardiographic pattern who underwent invasive electrophysiological study (EPS) and catheter ablation between April 2012 and April 2018 were evaluated. RESULTS: In all, 149 consecutive, asymptomatic children and adolescents with WPW who underwent EPS were retrospectively investigated. In 39 (26.2%) of the patients, a shortest pre-excited R-R interval of ≤250 ms during atrial fibrillation or an accessory pathway effective refractory period of ≤270 ms was found. A total of 39 patients with high-risk antegrade conduction and 45 patients with inducible orthodromic atrioventricular re-entrant tachycardia underwent catheter ablation. In addition, 14 patients underwent catheter ablation due to family preference. CONCLUSION: High-risk antegrade conduction properties are exhibited by more than one-quarter of asymptomatic children and adolescents with WPW. Ablation should be considered as a first-line therapy in asymptomatic children and adolescents with high-risk WPW.

The evaluation of right ventricular systolic function in patients with repaired Tetralogy of Fallot by conventional echocardiographic methods and speckle tracking echocardiography: Compared with the gold standard cardiac mangenetic resonance.

BACKGROUND: Right ventricular (RV) function is one of the important prognostic factors in patients with repaired Tetralogy of Fallot (TOF). We aimed to assess RV function by conventional echocardiography and two-dimensional speckle tracking echocardiography (2D-STE) in patients with repaired TOF. METHODS: Twenty-seven (male 17) adolescents and young adult patients (mean age 22.7 ± 6.7 years) operated on for TOF and age- and gender-matched healthy controls were included. RV systolic function in both groups were evaluated by fractional area change (FAC), tricuspid annular plane systolic excursion (TAPSE), RV myocardial performance index (RVMPI) and tricuspid annular peak systolic velocity by pulsed tissue Doppler (tricuspid S'), and also RV global longitudinal strain (RV GLS) obtained from STE. These results were compared with RV ejection fraction (RVEF) measured by cardiac magnetic resonance imaging (CMRI) performed within 3 months in patient group. RESULTS: Systolic RVGLS values were significantly lower in patients compared to controls (-17.4 ± 3.1% vs -25.6 ± 3%). Among the echocardiographic parameters, RVGLS had the best correlation with RV EF derived from CMRI (r: -.6). By receiver operating characteristics analysis (ROC), an RV GLS cutoff value of -17.4% had 75% sensitivity and 68.4% specificity in identifying RVEF <45% with an area under curve 0.743 (P < .05). The intra- and inter-observer agreement for RV GLS was excellent. CONCLUSION: RVGLS is an easy, effective, feasible, and reproducible tool in the evaluation of RV systolic function. So, RVGLS measurement by STE may be one of the routine echocardiographic parameters in the evaluation of RV systolic function in patients with repaired TOF.

Catheter ablation of left posterior fascicular ventricular tachycardia in children with limited fluoroscopy exposure.

INTRODUCTION: Catheter ablation of left posterior fascicular ventricular tachycardia in the pediatric population remains challenging, and most studies about this topic have been conducted on adult patients. This study aimed to assess the clinical presentation features and outcomes of catheter ablations performed using limited fluoroscopy with three-dimensional electroanatomic mapping system guidance in a pediatric left posterior fascicular ventricular tachycardia patient group. METHODS: A total of 20 consecutive patients undergoing left posterior fascicular ventricular tachycardia ablation at a single tertiary centre were enrolled. All children with left posterior fascicular ventricular tachycardia underwent electrophysiological studies using the EnSite NavX system guidance. Ablations were performed during the sinus rhythm based on the Purkinje potentials in all patients. RESULTS: The mean patient age was 12.7 years (range 2-16), and the mean patient weight was 51 kg (range 11-84). The mean procedure and median fluoroscopy times were 143.1 minutes and 3.4 minutes, respectively. No fluoroscopy was used in three patients. Acute success was achieved in 19 patients (95%). During a mean follow-up of 38.6 ± 19.35 months, left posterior fascicular ventricular tachycardia recurred in four patients (20%). Repeat ablations were performed successfully in those patients who developed recurrences. No complications were seen. CONCLUSIONS: Catheter ablation of left posterior fascicular ventricular tachycardia in children can be performed safely and effectively with low fluoroscopy exposure using a three-dimensional electroanatomic mapping system.

Unusual ventricular entrainment response: What is the mechanism?

Entrainment is an important tool for the diagnosis and location of reentry. The usefulness of this maneuver requires that, prior to cessation of ventricular pacing, the atrial rate accelerates to the ventricular pacing rate. Moreover, it is important to verify the continuation of the tachycardia following cessation of entrainment. The recognizing the last entrained atrial beat is utmost important to avoid erroneous A-A-V labeling.

Tp-e interval and Tp-e/QT ratio in clinically stable pediatric heart transplant recipients.

OBJECTIVE: A study of the T wave peak-to-end (Tp-e) interval, the Tp-e/QT ratio, and the Tp-e/QTc ratio in pediatric heart transplant recipients (HTRs), a group which has a higher risk of sudden cardiac death than the normal population, has not previously been reported. The aim of this study was to assess alterations in ventricular repolarization using the Tp-e interval, Tp-e/ QT ratio, and Tp-e/QTc ratio in clinically stable pediatric HTRs. METHODS: A total of 13 clinically stable HTRs, 13 patients who had undergone cardiac surgery (CS) under cardiopulmonary bypass, and 16 healthy controls under 18 years of age were retrospectively evaluated. RESULTS: No significant differences were observed between the HTR, CS, and control groups in terms of QTc, JTc interval, and T wave amplitude (p>0.05). The Tp-e interval (p=0.001), Tp-e/QT ratio (p<0.001), and Tp-e/QTc ratio (p=0.001) were significantly higher in the HTR group compared with the CS and normal control participants. CONCLUSION: The Tp-e interval, Tp-e/QT ratio, and Tp-e/QTc ratio were elevated in stable HTRs compared with the normal and CS groups.

Transseptal Puncture for Catheter Ablation in Children.

Transseptal puncture (TP) is used in pediatric patients to access the left atrium in left-sided arrhythmia catheter ablation. Performing this procedure can be difficult and risky, especially in small children. In this study, we aimed to evaluate the safety and feasibility of TPs in children ≤ 30 kg. Between April 2012 and April 2018, a retrospective evaluation was conducted of the clinical features, procedural outcomes, and follow-ups of ≤ 30 kg pediatric patients who required TPs for left-sided ablations at a pediatric electrophysiology center in which a three-dimensional mapping system was routinely used. A total of 45 pediatric patients who were ≤ 30 kg, underwent TPs: 10 patients ≤ 20 kg (Group 1) and 35 patients > 20 kg and ≤ 30 kg (Group 2). The TP success rate was 97.8%. The median procedure and fluoroscopy times were 120 min and 5.43 min, respectively. One patient developed self-limited pericardial effusion during the procedure; however, there were no incidences of cardiac tamponade. There was no significant difference between the two groups in terms of the procedure time and fluoroscopy time, and pericardial effusion was only observed in Group 2. TPs are safe and feasible in small children. These procedures can be performed with low complication rates in children weighing ≤ 30 kg.

Catheter ablation for supraventricular tachycardia in children ≤ 20 kg using an electroanatomical system.

PURPOSE: Catheter ablation is the only choice of treatment in some small children with medically refractory supraventricular tachycardia (SVT). Electroanatomical mapping systems (EMS) are more commonly utilized in electrophysiological procedures in recent years, which resulted in a significant decrease in fluoroscopy exposure. The potential benefit of EMS in small children has not been studied. Therefore, we investigated the outcomes of children undergoing catheter ablation weighing ≤ 20 kg using an electroanatomical mapping system. METHODS: This study evaluated the outcomes, characteristics, and follow-ups of children ≤ 20 kg who underwent SVT ablations between April 2012 and April 2018 in a pediatric electrophysiology center where EMS were routinely used. RESULTS: In a 6-year period, 1129 children underwent SVT catheter ablation under EMS guidance at our institution. A total of 84 of them were weighing ≤ 20 kg. The acute success rate was 97.6% in 85 tachycardia substrates. No fluoroscopy was used in 58 of the patients, while a median of 5 (4-14) min of fluoroscopy was used in the remaining 26 patients. Recurrences were seen in 4 patients (4.8%) at a mean follow-up of 3.89 ± 2.08 years. Five patients developed non-vital complications (2 right bundle block and 3 temporary complete block that spontaneously resolved during the procedure). CONCLUSIONS: The outcome of catheter ablation with the guidance of EMS for the treatment of SVT in small children is favorable. Fluoroscopy exposure can be decreased and even eliminated in most patients.

High incidence of co-existing factors significantly modifying the phenotype in patients with Fabry disease.

Fabry disease results from deficiency of the lysosomal enzyme alpha-galactosidase A. The families of 11 index cases were screened by enzyme and molecular assays. Further clinical and laboratory investigations were carried out in all cases. Including 33 new patients, a total of 28 females (Age 25,82 ±â€¯12,1 Range 8-46) and 16 males (Age 24,56 ±â€¯15,04 Range 2-48) were investigated. Ten different disease-causing variants were found two of them being novel. One patient had co-existing familial mediteranian fever, one had celiac disease and three had rheumatological disorders. Lipoprotein (a) levels were elevated in 17,6%, homocysteine in 22,2%, total and low density cholesterol in 12% and antithrombin 3 levels were elevated in 13,3%. One patient was found to be heterozygous for prothrombin p.G20210A disease-causing variant (5,8%) and two for factor V Leiden disease-causing variant (11,7%). Anticardiolipin IgM antibody was found to be positive in 11,7%. The patients with abnormal cranial imaging were also noticed to have additional risk factors for thrombosis. This study provides the largest data about Fabry patients from Turkey and implies that co-existing risk factors unrelated to Fabry Disease have significant association with the presence of clinical symptoms in females and might cause an early and severe clinical course in males.

Electroanatomic mapping-guided pediatric catheter ablation with limited/zero fluoroscopy.

OBJECTIVE: The use of fluoroscopy in pediatric catheter ablation has decreased because of mapping systems. In this study, we present the efficiency and reliability of the electroanatomic mapping system in nonfluoroscopic pediatric catheter ablation. METHODS: The medical records of patients aged <18 years who underwent ablation between November 2016 and April 2018 were evaluated. Fluoroscopy was not used in cases involving ablation of right sided-arrhythmia foci. Fluoroscopy was used only for trans-septal puncture or retroaortic approach/coronary angiography. RESULTS: A total of 76 patients underwent catheter ablation for 78 supraventricular and ventricular tachyarrhythmia substrates under the guidance of EnSite Velocity system. Fluoroscopy was used in only 14 (18.4%) of these substrates. The mean fluoroscopy duration in these 14 procedures was 5.4±3.15 min. No complications were noted, except a temporary right bundle branch block in one patient and pericardial effusion in another following cryoablation. The acute success rate in achieving complete elimination of arrhythmia substrates was 97.4% (76/78). The recurrence rate was 5.1% (4/78) at follow-up. CONCLUSION: Fluoroscopy can be completely eliminated in most pediatric catheter ablation procedures with the use of mapping systems by achieving high acute success rates and acceptable low complication rates.