Clinical Course and Electrophysiological Characteristics of Permanent Junctional Reciprocating Tachycardia in Children

BACKGROUND

In this study, we aimed to evaluate the clinical aspects, electrophysiological studies, and ablation results of permanent junctional reciprocating tachycardia in children.

METHODS

The study comprised 29 pediatric patients diagnosed with permanent junctional reciprocating tachycardia between 2011 and 2021 in 2 pediatric electrophysiology centers. From the file records, the basic demographic characteristics of the patients, as well as electrocardiographic and echocardiographic findings, were acquired retrospectively. The medical treatment and responses of the patients throughout follow-up, as well as the electrophysiological study and ablation data of the patients who had electrophysiological study, were assessed.

RESULTS

The mean age at diagnosis of the patients was 3.13 ± 4.43 (0-18) years and the mean weight was 18.22 ± 19.68 (3.8-94) kg. Eighteen patients (62.1%) were girls. Eleven patients (38%) developed tachycardia-induced cardiomyopathy. Tachycardia was incessant in 15 patients (51.7%). In total, 22 patients required 26 ablation procedures. Tachycardia-induced cardiomyopathy and multidrug-resistant tachycardia were the most prevalent indications for ablation. The right posteroseptal pathway was detected in 18 patients (81.8%). The acute procedure success rate was 100% (22/22). The recurrence rate was 18% (4/22) and 3 of them underwent successful ablation again. The overall success percentage was 95.4% (21/22). None of the patients had any complications. The mean follow-up period was 4.39 ± 3.05 years.

CONCLUSION

Although permanent junctional reciprocating tachycardia is uncommon, it is often persistent, resistant to medical treatment, and associated with a substantial risk of tachycardia-induced cardiomyopathy. Catheter ablation can be performed on these patients at any age, with minimal risk of complications and a high success rate. It is crucial to keep monitor of the patients' recurrence.

Functional evaluation of the tachycardia patient-derived iPSC cardiomyocytes carrying a novel pathogenic SCN5A variant

Tachycardia is characterized by high beating rates that can lead to life-threatening fibrillations. Mutations in several ion-channel genes were implicated with tachycardia; however, the complex genetic contributors and their modes of action are still unclear. Here, we investigated the influence of an SCN5A gene variant on tachycardia phenotype by deriving patient-specific iPSCs and cardiomyocytes (iPSC-CM). Two tachycardia patients were genetically analyzed and revealed to inherit a heterozygous p.F1465L variant in the SCN5A gene. Gene expression and immunocytochemical analysis in iPSC-CMs generated from patients did not show any significant changes in mRNA levels of SCN5A or gross NaV1.5 cellular mislocalization, compared to healthy-derived iPSC-CMs. Electrophysiological and contraction imaging analysis in patient iPSC-CMs revealed intermittent fibrillation-like states, occasional arrhythmic events, and sustained high-paced contractions that could be selectively reduced by flecainide treatment. The patch-clamp analysis demonstrated a negative shift in the voltage-dependent activation at the patient-derived iPSC-CMs compared to the healthy control line, suggestive of a gain-of-function activity associated with the SCN5A^+/p.F1465L variant. Our patient-derived iPSC-CM model recapitulated the clinically relevant characteristics of tachycardia associated with a novel pathogenic SCN5A^+/p.F1465L variant leading to altered Na⁺ channel kinetics as the likely mechanism underlying high excitability and tachycardia phenotype.

Current Strategies for the Management of Anomalous Origin of Coronary Arteries from the Pulmonary Artery

INTRODUCTION

The coronary arteries, which have to originate from the aorta, may sometimes rise from the pulmonary artery. This study evaluated clinical and diagnostic findings, treatment methods, and follow up of cases with anomalous coronary arteries arising from the pulmonary artery.

PATIENTS AND METHODS

Eight patients with the diagnosis of anomalous left coronary artery from the pulmonary artery (ALCAPA) (N = 6) and anomalous right coronary artery from the pulmonary artery (ARCAPA) (N = 2), between January 2014 and January 2020 from a single center university hospital, were included in the study. Data from patients' demographic characteristics, electrocardiography, echocardiography, angiographic findings, operation, hospitalization, and follow up were evaluated.

RESULTS

The study included eight patients (six females and two males) - six patients with ALCAPA and two with ARCAPA. The ages of the patients ranged between 3-135 (average: 53.25) months. The median body weight was calculated as 17.4 kg. Severe mitral valve insufficiency was detected in two patients and two other patients had a moderate degree of mitral insufficiency on echocardiography. Ejection fractions ranged between 16-74%. One patient had perimembranous malalignment large ventricular septal defect with pulmonary stenosis. Operative techniques were Takeuchi procedure (three patients), direct implantation (four patients), and left internal thoracic artery to left main coronary artery bypass (one patient). Mechanical cardiac support was not required in the postoperative period. Mortality did not occur. Mitral insufficiency and ejection fractions improved following correction of the coronary anatomy.

CONCLUSION

It is important to diagnose the ALCAPA or ARCAPA, where the coronary artery originates from the pulmonary artery. Patients should be treated before congestive heart failure and fatal complications occur. Surgical correction should be planned regardless of symptom status, even though some of patients reach adulthood with an increased number of collaterals.

[Electrophysiological properties of asymptomatic children and adolescents with the Wolff-Parkinson-White electrocardiographic pattern]

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.

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.

Electroanatomic mapping-guided catheter ablation of atrial tachycardia in children with limited/zero fluoroscopy

INTRODUCTION

Atrial tachycardia (AT) is an uncommon cause of supraventricular tachycardia in children and it is often resistant to medical therapy. Catheter ablation can be curative in children with AT. However, experience of ablation of pediatric AT is still very limited. The aim of this study, which is the largest series from a single center, was to assess the efficacy and safety of ablation of AT using an electroanatomical-mapping system.

METHODS

It was a retrospective review of 39 children with AT who underwent catheter ablation procedure using the EnSite Velocity system (St. Jude Medical, St. Paul, MN, USA) between July 2012 and April 2017.

RESULTS

The mean patient age was 13.32 ± 6.82 years. The location of AT was right sided in 25 and left sided in 13, and both sides in one patient. The mean procedure time was 184.23 ± 60.19 min. Fluoroscopy was not used in 25 of 39 patients. The mean fluoroscopy time in the remaining patients was 5.53 ± 5.22 min. Radiofrequency (RF) ablation was used in 22, cryoablation was used in 10, and both RF and cryoablation were used in seven. Acute success was achieved in 34 patients (87.2%). During a mean follow-up of 51.35 ± 12.62 months, AT recurred in five patients. These patients underwent second ablation procedures and four of them were successful. Final success was achieved in 33 out of 39 patients (84.6%). There were no complications except for one patient who had an uneventful pericardial needle injury during transseptal puncture without effusion.

CONCLUSIONS

Catheter ablation of AT in children can be performed safely and effectively with a limited fluoroscopy using electroanatomical mapping systems.

Comparison of 6-mm Versus 8-mm-Tip Cryoablation Catheter for the Treatment of Atrioventricular Nodal Reentrant Tachycardia in Children: A Prospective Study

Due to its safety profile, cryoablation (Cryo) for atrioventricular nodal reentrant tachycardia (AVNRT) is more commonly preferred over radiofrequency (RF) ablation in children in recent years. Recent studies demonstrated high long-term success rates comparable to radiofrequency ablation. The aim of this prospective study was to compare the efficacy and safety of an 8-mm-tip versus 6-mm-tip Cryo catheter in the treatment of AVNRT in children. A total of 125 consecutive patients over 10 years of age with AVNRT were included. EnSite system (St. JudeMedical, St Paul, MN, USA) was used to reduce or eliminate fluoroscopy. The acute procedural success was 100% in both groups. The prodecure duration for the 8-mm-tip group was shorter (151.6 ± 63.2 vs. 126.6 ± 36.7 min, p < 0.01, respectively). Fluoroscopy was used in only 7 patients. The mean follow-up duration was 14.6 ± 8.4 months (median 13.5 months, min. 3 months and max. 27 months). The recurrence rate for AVNRT was also comparable between the two groups (6-mm tip: 9.6 vs. 8-mm tip: 8%). Cryo of AVNRT is a safe and effective procedure with comparable acute and mid-term follow-up success rates using 6-mm and 8-mm-tip catheters in children. In addition, procedure duration is shorter with an 8-mm-tip Cryo catheter.

Successful ablation of coexistent Mahaim tachycardia and right posterior accessory pathway in a patient with Ebstein's anomaly

The atriofascicular accessory pathway (AP), known as the Mahaim pathway, is a rare form of pre-excitation, comprising less than 3% of all APs. Mahaim AP is characterized by decremental, anterograde-only conduction, and antidromic tachycardia with left bundle branch morphology. Prevalence of Mahaim AP in Ebstein's anomaly is significantly high. In addition, combination of Wolff-Parkinson-White (WPW) syndrome and Mahaim AP in patients with Ebstein's anomaly has been reported. Presently described is the coexistence of Mahaim AP and manifest WPW syndrome in a patient with Ebstein's anomaly, who was successfully ablated without fluoroscopy.

Cryoablation with an 8-mm-Tip Catheter for Right-Sided Accessory Pathways in Children

BACKGROUND

Cryoablation is increasingly utilized in children because of its safety profile. Recently, larger catheter tips have been more widely used to improve long-term success rates. The aim of this study was to assess the safety and efficacy of 8-mm-tip catheters for cryoablation of right-sided accessory pathways (APs) in children.

METHODS

Electrophysiological procedures were performed using the EnSite™ system (St. Jude Medical Inc., St. Paul, MN, USA).

RESULTS

Between July 2010 and July 2014, 54 patients (mean age: 13.1 ± 3.7 years) underwent cryoablation using an 8-mm-tip catheter. In 18 of 54 (33%) patients where an 8-mm-tip catheter was the first-choice catheter, the success rate was 18 of 18 (100%). There was a history of previous failed attempts or recurrence with radiofrequency ablation and/or 6-mm-tip cryoablation in 36 of 54 (67%) patients. The success rate in these patients was 24 of 36 (67%). No fluoroscopy was used in 34 of 54 procedures. The recurrence rate was six of 42 (14%) during a mean follow-up period of 32 ± 15 months. In one patient, transient atrioventricular block occurred.

CONCLUSIONS

Cryoablation with an 8-mm-tip catheter for right-sided APs in children who weigh over 40 kg appears to be safe and acutely effective in cases where conventional ablation methods fail and also as a first choice for ablation procedure. However, the recurrence rate still seems to be high.

Catecholaminergic Polymorphic Ventricular Tachycardia: A Rare Cause of Cardiac Arrest Following Blunt Chest Trauma

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an electrophysiological disorder of a physically normal heart that occurs in children when the body is subjected to intense emotional or physical stress that causes adrenergic discharge. This troubling disease can be sporadic (spontaneous) or familial (genetic/inherited). Unfortunately, its associated ventricular tachycardia may cause sudden death, so early diagnosis of CPVT is very important. Treatment modalities include medical treatment, implantation of a cardioverter defibrillator, or surgical sympatectomy; but the implantable cardioverter defibrillator (ICD) should be the first choice in patients with a history of cardiac arrest. We herein present the case of a patient diagnosed with CPVT after a successful cardiopulmonary resuscitation triggered by blunt chest trauma. We implanted an implantable cardioverter defibrillator and started oral B-blocker treatment. During the course of follow-up, flecainide was added to his treatment depending on the patient's status regarding recurrent ICD shock. The patient has now continued follow-up without recurrent ICD shock since flecainide treatment was initiated. In conclusion, in patients with syncope and sudden cardiac arrest secondary to physical stress or blunt chest trauma, CPVT should be considered and an implantable cardioverter defibrillator must be implanted. Additionally, flecainide theraphy should be considered to decrease recurrent ICD shock.

KEY WORDS

Blunt chest trauma; Cardiac arrest; CPVT.

Using a Cardiac Event Recorder in Children with Potentially Arrhythmia-Related Symptoms

BACKGROUND

In this study, we reported our experience with the use of cardiac event recorders in pediatric patients.

METHODS

We evaluated 583 patients fitted with an event recorder (15-30 days) between March 2010 and November 2014 at our clinic. Excluded from the study were 117 patients with no recorded events and six with records contaminated by electrocardiogram artifacts. All of the patients received electrocardiograms, Holter monitoring, and echocardiography before the cardiac event recording.

RESULTS

The patient sample consisted of 460 patients (64% female). The mean age was 12.8 ± 4.1 years. The median number of recorded events was 7. The indications included palpitations in 336 (73%) patients, syncope in 27 (6%) patients, and chest pain and palpitations in 97 (21%) patients. Whereas 64 patients (14%) had structural heart disease according to echocardiographic examination, the remaining patients had normal echocardiographic examination results. The most frequent cardiac comorbidities were mitral valve prolapse (6%), operated tetralogy of Fallot (1.5%), and complicated congenital heart diseases with single ventricle physiology (1%). The recorded events were sinus tachycardia in 113 (25%) patients, supraventricular tachycardia in 35 (8%) patients, ventricular extrasystole in 20 (4%) patients, supraventricular extrasystole in nine (2%) patients, and ventricular tachycardia in two (0.4%) patients. Based on the event recorder and follow-up electrocardiogram findings, 46 patients received an electrophysiology study/ablation. The symptom-rhythm correlation was 39%.

CONCLUSION

In the presence of possible arrhythmia-related symptoms in children, a cardiac event recorder can be considered a useful primary diagnostic method. More research on this topic is needed.

Effects of atomoxetine on heart rhythm in children and adolescents

BACKGROUND

The aim of this study was to examine the effects of atomoxetine on heart rhythm using 12-lead electrocardiography (ECG) and 24 h Holter monitoring.

METHODS

Children and adolescents who were diagnosed with attention deficit-hyperactivity disorder according to DSM-IV-TR were referred to a pediatric cardiology clinic for cardiologic examination before and after 4 or 5 weeks of atomoxetine treatment. Cardiac examination, complete blood count, biochemistry, thyroid function tests, 12-lead ECG and 24 h Holter monitoring were performed routinely in all patients. Each subject underwent 24 h Holter ECG monitoring before atomoxetine was started and after 4 or 5 weeks of effective dose atomoxetine treatment.

RESULTS

Forty-one patients were included in this prospective study. No statistically significant change was found in QT, QTc or QT interval dispersion or blood pressure before and after 4 or 5 weeks of atomoxetine treatment. There was a statistically significant increase in heart rate (both during the day and at night) and QRS duration, and a statistically significant decrease in P wave dispersion. Three patients had rhythm disturbances. All of these three patients were asymptomatic and none of these arrhythmias reached clinical significance.

CONCLUSION

Atomoxetine did not cause significant changes in ECG or Holter variables. In two patients, who had undiagnosed subclinical extrasystoles, extra beats were increased after 4th week of treatment, but still remained clinically insignificant. Before and after atomoxetine treatment, listening to the heart sounds for a longer time, may help clinicians to notice an extra beat. If an extra beat is identified then 24 Holter monitoring is recommended.

The use of flecainide in critical neonates and infants with incessant supraventricular tachycardias

OBJECTIVE

This study aimed to evaluate the efficacy of flecainide therapy in neonates and infants with drug resistant incessant supraventricular tachycardia.

METHODS

The study included 11 neonates and infants who received medical and/or ablation therapy between January 2010 and December 2013. Mean patient age and weight were 101.6 ± 96 days and 5.3 ± 1.9 kg respectively. Of the 12 patients, 5 underwent ablation between January 2010 and December 2011, and 6 were treated medically between January 2012 and December 2013. Mean follow-up time was 18 months (6 months-4 years).

RESULTS

The antiarrhythmic agent flecainide only became available in Turkey in 2012, and the most noteworthy point was its addition to the therapy administered prior to ablation (adenosine, esmolol-propranolol, propafenone, amiodarone and cardioversion). In all 6 patients admitted between January 2012 and December 2013, refractory SVT was successfully treated with the administration of a triple therapy regimen of esmolol-propranolol, amiodarone and flecainide. One patient with myocarditis developed an atrial flutter complicated by a concealed accessory pathway and was put on extracorporeal membrane oxygenation (ECMO) support due to cardiopulmonary failure. The SVT was terminated, but the patient died on the fifteenth day of ECMO support. One patient with recurrent tachycardia, who had previously undergone ablation for a complex cardiac anomaly and Wolf-Parkinson-White syndrome, was treated with ablation again. No recurrence of tachycardia was observed in any of the other 9 patients.

CONCLUSION

It appears that the use of propranolol-esmolol and amiodarone combined with flecainide in the medical treatment of drug-resistant SVT may reduce the need for ablation in critical neonates and infants.

Cardiac Interventions in Pregnant Patients without Fluoroscopy

INTRODUCTION

Cardiac interventions with fluoroscopy during pregnancy carry significant risks for the fetus. This report reviews three pregnant patients: two of them requiring pacemaker implantation and one underwent diagnostic cardiac catheterization without fluoroscopy.

METHODS

The cases were performed using EnSite system (St. Jude Medical Inc., MN, USA) guidance. The necessary cardiac structure geometries were reconstructed with a deflectable quadripolar electrophysiology catheter without fluoroscopy. In two cases, pacemaker leads were connected to the EnSite system for navigation and fixation of leads. In the third case, long sheaths and electrophysiology catheters were used to access the right ventricle and pulmonary artery. Transthoracic echocardiography was also used in all three cases.

RESULTS

A 31-year-old woman at 8-week pregnancy was admitted with ventricular septal defect and significant pulmonary hypertension. The patient underwent catheterization to assess for the risk of continuation of pregnancy. There was partial reactivity, it was decided not to terminate the pregnancy, and an uneventful delivery was succeeded at 35 weeks of gestation without complications. The rest of the two pregnant patients were a 28-year-old pregnant woman at 14 weeks of gestation and a 40-year-old woman at 12-week gestation. Both of them presented with symptomatic complete AV block. A single-chamber pacemaker was implanted in the first one, and a dual-chamber pacemaker was implanted in the latter. Pregnancy continued in both without complications.

CONCLUSION

Successful cardiac catheterization and pacemaker implantation can be performed safely in selected pregnant patients using an electroanatomic mapping system guidance without fluoroscopy.

Evaluation rhythm problems in unexplained syncope etiology with implantable loop recorder

BACKGROUND

Syncope is a frequent complaint in children and adolescents and may be a significant sign of serious pathology. Although patient history, family history, and physical examination are sufficient to reach a diagnosis in most cases of syncope, the cause of syncope still cannot be determined after initial investigation in one-third to half of all patients. The aim of this study was to evaluate the diagnostic yield of implantable loop recorder (ILR) in children with unexplained syncope.

METHODS

A retrospective review was carried out of clinical data, indications, findings, and a final management strategy in patients who underwent ILR implantation.

RESULTS

A total of 12 patients with a mean age of 9.4 ± 4.5 years underwent ILR (Reveal Plus; Medtronic) implantation. ILR implantation indication was syncope in all of the patients. Family history, routine cardiac assessment, including resting 12-lead electrocardiogram, transthoracic echocardiography, 24 h Holter recording, and event recorder findings, were normal with the exception of one patient with (previously corrected) tetralogy of Fallot. After an average of 20 months (range, 1-36 months), six patients developed symptoms. ILR memory showed torsades de pointes-ventricular fibrillation (n = 3), catecholaminergic polymorphic ventricular tachycardia (n = 1), asystole and ventricular tachycardia (n = 1), and normal sinus rhythm (n = 1). At the time of writing six patients were still in follow up with no symptoms after an average of 25.2 months.

CONCLUSION

Implantable loop recorder plays an important role in the diagnosis of life-threatening arrhythmias in which syncope is otherwise unexplained. ILR implantation should be remembered in children whose symptoms are strongly correlated with rhythm disturbances.

Electroanatomic mapping guided cryoablation of Mahaim pathways in children with limited fluoroscopy exposure

BACKGROUND

The presence of Mahaim accessory pathways (MAP) with anterograde decremental conduction is a disorder that leads to antidromic atrioventricular reentrant tachycardia. There are rare reports of cryoablation use in MAP. This study aims at sharing our experience with using cryoablation to treat MAP in children.

METHODS

Electrophysiology study and catheter ablation were performed in 14 patients diagnosed with Mahaim tachycardia between January 2010 and December 2013. Cryoablation was used in nine of the cases. A three-dimensional navigation system with surface electrode patches (EnSite System, St. Jude Medical Inc., St. Paul, MN, USA) was used for all procedures.

RESULTS

The patients (two girls and seven boys) had a median age of 11.5 years (8-18 years) and a median weight of 67 kg (31-80 kg). Mahaim conduction was localized in the right posterolateral (n = 4), right lateral region (n = 2), right posteroseptal (n = 1), right anterolateral (n = 1), and right anterior (n = 1). A pathway potential was noted in six of nine cases at the tricuspid annulus. Catheter choices and acute success rates were as follows: cryoablation in four (three of four successful), radiofrequency catheter ablation (RFA) and cryoablation in five (successful in four of five). No fluoroscopy was used in six of nine patients. The mean procedure duration was 249 ± 90 minutes. No major complications were observed. The final long-term success rate for cryoablation was seven of nine (78%).

CONCLUSIONS

Cryoablation can be used as a reliable and effective alternative to RFA in the treatment of Mahaim accessory conduction pathways in children. Prospective comparative studies are necessary in order to further evaluate the long-term efficacy of this method.

Successful cryoablation of Mahaim tachycardia in a child with Ebstein's anomaly

Mahaim fibers with decremental atrioventricular (AV) node-like conduction properties comprise less than 3 % of accessory pathways. Radiofrequency ablation of right atriofascicular pathways guided by a distinct Mahaim potential detected at the anterolateral to posterolateral tricuspid annulus or in the right ventricular free wall is a safe and highly effective treatment method. The case report presents a 16-year-old boy with Ebstein's anomaly and symptomatic wide complex tachyarrhythmia. The electrophysiologic study and the entire ablation procedure were performed using a three-dimensional mapping system (EnSite Velocity; St. Jude Medical Inc., St. Paul, MN, USA). No fluoroscopy was used during the procedure. Electrophysiologic evaluation demonstrated typical atrioventricular nodal reentrant tachycardia and Mahaim tachycardia with a wide QRS and a left bundle branch block pattern. After Mahaim potential was located at the lateral tricuspid annulus, successful cryoablation was performed with an 8-mm-tip catheter followed by slow pathway ablation to eliminate typical atrioventricular nodal reentrant tachycardia. Cryoablation with an 8-mm-tip catheter can be an alternative treatment option for children with Mahaim tachycardia.

Percutaneous closure of large VSD using a home-made fenestrated atrial septal occluder in 18-year-old with pulmonary hypertension

Background

Hemodynamically significant muscular ventricular septal defects in children after the infantile period are a rare occurrence and ideal for transcatheter closure. In cases of severe concomitant pulmonary hypertension, it may be necessary to fenestrate the device. In this report, we present an 18-year old patient with a large mid-trabecular ventricular septal defect and severe pulmonary hypertension that underwent percutaneous closure of the defect with a home-made fenestrated atrial septal occluder.

Case presentation

An 18-year-old female patient referred to us with complaints of dyspnea (NYHA score of 2–3). Physical examination revealed an apical rumble and a harsh second heart sound. Echocardiographic examination revealed a large mid-trabecular ventricular septal defect with bidirectional shunt and the widest diameter measuring 22 mm on 2D echocardiography. Left and right heart cavities were enlarged. Before and after the vasoreactivity test performed during cardiac catheterization, average aortic pressure was 65 → 86 mmHg, average pulmonary artery pressure: 58 → 73 mmHg, Qp/Qs: 1.6 → 3.2, PVR: 4.6 → 4.3 Wood/U/m² and PVR/SVR: 0.5 → 0.2. On left-ventricular angiocardiogram, the largest end-diastolic defect diameter was 21 mm. The closure procedure was performed with transthoracic echocardiographic guidance, using a 24 mm Cera septal occluder and a 14 F sheath dilator to make a 4.5-5 mm opening. Measured immediately after the procedure and during cardiac catheterization one month later, average aortic pressure was 75 → 75 mmHg, average pulmonary artery pressure: 66 → 30 mmHg, Qp/Qs 1.5 → 1.4, PVR: 4.4 → 2.9 Wood/U/m² and PVR/SVR: 0.4 → 0.2. Transthoracic echocardiographic examination performed 24 hours after the procedure showed a max 35–40 mmHg gradient between the left and right ventricles through the fenestration. After the procedure, we observed sporadic early ventricular systoles and a nodal rhythm disorder that started after approximately 12 hours and spontaneously reverted to normal 9 days later.

Conclusion

In patients with large ventricular septal defects, large atrial septal occluders may be used. In cases with risk of pulmonary vascular disease, a safer option would be to close the defect using a manually fenestrated device.

Effects of carvedilol therapy on cardiac autonomic control, QT dispersion, and ventricular arrhythmias in children with dilated cardiomyopathy

BACKGROUND

The purpose of this study was to examine the effects of carvedilol therapy on autonomic control of the heart and QT-interval dispersion (QTd) among children with idiopathic dilated cardiomyopathy (DCM) whose symptoms were not adequately controlled with standard congestive heart failure therapy.

MATERIAL AND METHODS

Patients with DCM who were treated with carvedilol were enrolled in the study. All patients had undergone carvedilol therapy in addition to standard therapy for at least 6 months. Clinical, echocardiographic, and electrocardiographic parameters, and 24-h Holter records of patients were retrospectively evaluated before and after carvedilol treatment.

RESULTS

A total 34 patients (mean age: 7.4 ± 4.3 years) with DCM were analyzed in the study. The median follow-up period was 9.5 months. After the 6 months of carvedilol therapy the clinical score significantly improved, left ventricular ejection fraction (LVEF) and fractional shortening (LVFS) significantly increased, and left ventricle end-diastolic dimensions and end-systolic dimensions significantly decreased. There were statistically significant increases in mean SDNN, SDANN, rMSSD, and pNN50 (p = 0.002, p = 0.001, p = 0.008, and p = 0.026, respectively). After the carvedilol therapy, SDNN was correlated with the clinical score, heart rate, LVEF, LVFS, and total premature ventricular contractions (PVCs). In addition, rMSSD and pNN50 were correlated with heart rate, LVEF and LVFS. A significant reduction was observed in QTc-minimum, QTc-maximum, and QTd values (434.9 ± 40.7 vs. 416.1 ± 36.5, 497.8 ± 43.6 vs. 456.3 ± 41.7, 58.6 ± 17.1 vs. 49.3 ± 15.6; p < 0.001, p = 0.001, and p = 0.008, respectively). QTd was significantly related to PVCs (r = 0.62, p = 0.02).

CONCLUSIONS

We conclude that the addition of carvedilol to standard therapy can improve clinical symptoms and heart rate variability, and reduce in arrhythmia markers in children with DCM.

Subxiphoid approach to epicardial implantation of implantable cardioverter defibrillators in children

BACKGROUND

Epicardial implantation of implantable cardioverter defibrillators (ICDs) is considered in the presence of intracardiac shunt, venous access issue, or small body size. We report our experience with epicardial ICD coil implantation using a minimally invasive method.

METHODS

Nine patients who underwent epicardial ICD implantation were included. The median age was 7.4 years (3.9-9.6 years) and the median weight was 15 kg (12-24 kg). Diagnosis at the time of implantation included long QT syndrome (n = 5), catecholaminergic polymorphic ventricular tachycardia (n = 2), hypertrophic cardiomyopathy (n = 1), and fast monomorphic ventricular tachycardia (n = 1). The minimally invasive method involved a subxiphoid incision to place the epicardial pacing leads. The ICD coil was placed in the transverse sinus in four patients using an access path posterior to the heart. The second approach involved a path anterior to the heart to reach the epicardial location posterior to the left atrial appendage in the five remaining patients. No fluoroscopy was used in either approach. The median defibrillation threshold (DFT) at implantation was 7.5 J.

RESULTS

Lower DFTs were observed in the anterior approach (10 J vs 5 J). Appropriate ICD shocks were observed in three patients during the median 18-month follow-up period (0.3-28 months). No inappropriate shocks were noted. One patient developed pericardial tamponade 39 days after the procedure and was surgically drained.

CONCLUSIONS

Minimally invasive epicardial ICD coil implantation in children with low DFT values is possible. The anterior implantation approach appears superior to the posterior approach.

Cryoablation of anteroseptal accessory pathways in children with limited fluoroscopy exposure

Due to its safety profile, cryoablation is used increasingly in pediatric patients, especially for septal arrhythmia substrates. Recent advances in electroanatomical-mapping technologies have resulted in a decrease or complete elimination of fluoroscopy exposure during catheter ablation procedures. The aim of this study was to assess the efficacy and safety of cryoablation of anteroseptal accessory pathways (APs) using electroanatomical-mapping system guidance with limited fluoroscopy exposure. A total of 24 patients underwent cryoablation of anteroseptal APs between July 2010 and April 2012. Cryomapping was performed with a 6 mm-tip catheter at -30 °C before the lesions were delivered. An 8 mm-tip catheter was used in one patient. The EnSite system (St. Jude Medical, St Paul, MN) was used in all procedures. The mean age was 11.9 ± 4.3 years. Acute success rate was 95.8 % (23 of 24). The mean procedure and cryoablation durations were 168 ± 58 min and 1,463 ± 525 s, respectively. Limited fluoroscopy was used only in 7 patients, and the mean fluoroscopy time was 1.7 ± 1.8 min (range 0.1-4 min) in these patients. Recurrence was noted in 2 patients (8.7 %) who underwent a second successful cryoablation procedure. The patient who underwent a failed attempt during the first procedure was successfully treated with a repeat procedure. The resultant long-term success rate was 100 % at a mean follow-up period of 14.2 ± 7.7 months. There were no complications except for transient atrioventricular block in one patient. Cryoablation of anteroseptal APs can be performed effectively and safely in children using a limited fluoroscopic approach with the help of electroanatomical-mapping systems.

Successful cryoablation of atrioventricular nodal reentrant tachycardia and coexisting accessory pathways without fluoroscopy

We report the case of a 14-year-old boy patient admitted to our outpatient clinic with palpitations and documented supraventricular tachycardia. Electrophysiological study and ablation were planned. In the electrophysiological study, two tachycardias with different cycle lengths and morphologies were induced. After elimination of the slow pathway, left posterior accessory pathway was detected and successfully ablated. Another pathway was detected following that ablation. Due to the slow retrograde conduction of this pathway, diltiazem infusion was started to uncover the accessory pathway. The second accessory pathway was at the left posteroseptal region and was successfully ablated. After a 30-minute waiting period, no tachycardia was induced. In addition, no fluoroscopy was used during the procedure.

Idiopathic ventricular arrhythmias detected by an implantable loop recorder in a child with exercise-induced syncope

Syncope is common in the general population. Despite extensive evaluation, including tilt-table testing and electrophysiologic studies, approximately 30% of cases of recurrent syncope remain unexplained. An implantable loop recorder can be used for diagnosis when recurrent syncope has an idiopathic cause. We present the case of a 9-year-old boy who had a history of recurrent, exercise-induced syncope. Results of physical examination and noninvasive diagnostic testing were inconclusive, and an electrophysiologic study revealed no inducible supraventricular or ventricular arrhythmias. Sixteen months after an implantable loop recorder was placed, the patient had a syncopal episode while swimming in a pool. Cardiopulmonary resuscitation was performed, and data from the loop recorder revealed polymorphic ventricular tachycardia and ventricular fibrillation. A cardioverter-defibrillator was subsequently implanted. Implantable loop recorders can play an important role in the diagnosis of life-threatening arrhythmias in children whose syncope is otherwise unexplained.

Combined resection and radiofrequency ablation of rhabdomyoma in a child with sustained ventricular tachycardia

Cardiac rhabdomyoma is a benign tumor of the heart in childhood and can be associated with life-threatening arrhythmia. In this report, we present the case of a 2-year-old male with right ventricular rhabdomyoma, who was admitted with syncope that was associated with episodes of sustained ventricular tachycardia. The patient underwent combined surgical resection and radiofrequency ablation of the tumor. There was no recurrence of ventricular tachycardia after surgery.

Percutaneous embolization of a caroticoazygous fistula with the Amplatzer Vascular Plug 1

We present the case of a five-year-old boy with a caroticoazygous fistula, which is an extremely rare congenital vascular malformation. The patient also had patent ductus arteriosus, a common cause of continuous murmur. The murmur continued despite successful coil embolization of the ductus. Repeated catheter-angiography revealed a large caroticoazygous fistula. The fistula was successfully embolized using the Amplatzer(®) Vascular Plug 1. Transcatheter occlusion of caroticoazygous fistula was performed easily, safely, and efficiently with a vascular plug.

Levoatriocardinal vein with normal intracardiac anatomy and pulmonary venous return

Levoatriocardinal vein (LACV) is characterized by an abnormal connection between pulmonary and systemic venous return. This extremely rare cardiac malformation is usually associated with left-sided obstructive lesions including mitral atresia, hypoplastic left-heart syndrome, and abnormal pulmonary venous connection. Patients may have low systemic cardiac output and pulmonary venous obstruction symptoms. In this manuscript, we report a case with LACV and normal pulmonary venous return with absence of any intracardiac pathology. LACV was demonstrated with echocardiography, angiography, and computed tomography. Surgical correction was made successfully.

Giant tumor of the right atrium in infancy

Cardiac hemangiomas can occur at any age, but they are extremely rare when they occur early after birth. We describe the case of a 5-month-old infant who had a giant right atrial capillary hemangioma associated with massive pericardial effusion. The tumor was incidentally diagnosed during routine clinical follow-up. The hemangioma was removed successfully under cardiopulmonary bypass, and the patient's postoperative course was uneventful. The occurrence of giant capillary hemangioma in infancy represents an unusual event in the relevant literature. Herein, we discuss the clinical features and surgical management of this rare primary tumor of infancy.

Cheatham-Platinum stent for native and recurrent aortic coarctation in children and adults: immediate and early follow-up results

OBJECTIVE

To present our institutional experience of endovascular Cheatham-Platinum stent implantation in children and adults with native and recurrent aortic coarctation.

METHODS

Between August 2007 and November 2009, 45 patients had aortic coarctation treated with 47 stents implantation. We preferred primarily stent implantation in adult patient with coarctation, in children more than five years-old it is preferred in cases of aneurysm, subatretic or blind coarctation and coarctation with patent ductus arteriosus or in restenosis. Files of stent-implanted patients were retrospectively analyzed in terms of patients' demographic features, echocardiographic and angiographic findings both before and after procedure. Patients were grouped as Group 1: native coarctation and Group 2: recoarctation developed after either surgery or balloon angioplasty. Findings of the cases' were compared using paired and unpaired Student's t, Mann-Whitney U and Chi-square tests.

RESULTS

Sixteen covered and 31 bare totally 47 balloon expandable stents were implanted in 45 patients. The mean follow up duration was 12.1 ± 7.1, median 11 months (2-29 months). There was no procedure related death. In two patients two stents were implanted in tandem. While the coarctation of the aorta was native in 26 patients (functionally interrupted aortic arch in one), recoarctation was detected in 7 patients after surgery, in 8 patients after balloon angioplasty, in 4 patients both after surgery and balloon angioplasty. One patient had functionally interrupted aortic arch perforated with guide wire and then covered stent implanted. The mean age 12.2 ± 5.9 years (5-33 years) and mean body mass index was 21 ± 3.7 kg/m2 (14.8-31 kg/m2). Considering all cases, a statistically significant decrease in both the invasive and echocardiographic gradients (p<0.001 for both) and statistically significant increase in lesion diameter (p<0.001) were detected. The decrease in invasive and echocardiographic gradients and increase in lesion diameter is statistically significant in each group also (p<0.001, <0.001 and <0.001 for both groups, respectively). Before the procedure, the invasive gradient was significantly higher and the lesion diameter was significantly lower in group I than in group II (p=0.002 and p=0.005, respectively). Also the percentage of decrease in gradient and increase in diameter was statistically higher in group 1 than in group 2 (p=0.04 and p=0.04).

CONCLUSION

Our early and short- term follow-up results indicate that stent implantation is safe and very effective in reducing coarctation gradient and increasing lesion diameter both in native coarctation and recoarctation.

[Our medium-term results with aortic balloon valvuloplasty and factors affecting development of aortic regurgitation]

OBJECTIVE

The objective of this study was to assess medium-term results of aortic balloon valvuloplasty (ABV) in congenital aortic stenosis and to determine factors affecting development of aortic regurgitation (AR).

METHODS

Between September 2003 and January 2010, 114 ABV procedures performed on 97 patients analyzed retrospectively. Patients were evaluated in terms of transvalvular gradients before and after procedure, development of new aortic insufficiency or increase in the current insufficiency and factors affecting the procedural success and development of aortic insufficiency. In addition, follow up results were also evaluated in terms of restenosis and increase or decrease of aortic regurgitation. Student's t-test, ANOVA for repeated measurements, linear discriminant and Kaplan-Meier survival analyses were used for statistical analysis.

RESULTS

The mean age was 6.63±6.33 year (2 days-21 years). Mean follow-up was 32.6±25.1 months (1 to 75 months). Thirty-seven patients were infant (<1 year) and 18 of them were newborn. The peak systolic pressure gradient decreased from 77.2±24.9 mmHg to 28.5±12.9 mmHg (p=0.0001). Eighty-two procedures were optimal, 29 suboptimal and 3 were unsuccessful. AR developed in totally 53 patients, 16 of them were significant degree. Balloon /annulus ratio and the percentage of reduction in gradient was meaningfully higher in patients with significant aortic regurgitation (p=0.02 and p=0.03, respectively). Infants show more significant AR (9/37, 24%) in comparison with bigger patients (7/77, 9%) (p=0.02). Four patients died after procedure at intensive care unit, three of them were newborn.

CONCLUSION

ABV is safe and effective palliative method for the treatment of congenital aortic stenosis. AR, which was the most common complication, incidence was increased in infancy and was related with high balloon/annulus ratio and high reduction in gradient.

[Radionuclide evaluation of lung perfusion after transcatheter closure of patent ductus arteriosus: analysis of frequently used two different types of coils]

OBJECTIVE

Impaired left lung perfusion (LLP) has been described after transcatheter closure of the patent ductus arteriosus (PDA). In this study, we aimed to evaluate lung perfusion scans (LPSs) following occlusion of PDA with two frequently used coils: Cook detachable coil and Gianturco coil.

METHODS

A prospective study of 89 patients who underwent PDA occlusion using the Cook coils in 49 and the Gianturco coils in 40, was conducted. LPSs were performed after a median period of 18 months. The relationships between the LPSs and continuous variables were assessed by Pearson correlation analysis and the cut-off value of the best correlated parameters to predict abnormal LPSs obtained by the Receiver Operating Characteristic (ROC) analysis.

RESULTS

Decreased left lung perfusion (LLP) was found in 13 patients including 10 after using Cook coils and 3 after using Gianturco coils (p=0.077). LLP values were significantly correlated with the loops deployed at the pulmonary side, coil/ductal diameter ratio and number of coils deployed (p=0.002, p=0.006 and p=0.009, respectively). Number of loops deployed at the pulmonary side >1.4 (specificity 77%, sensitivity 85%, area under the ROC curve 0.804, 95%CI 0.661-0.947, p<0.001) and first coil/ductal diameter ratio >1.85 (specificity 70%, sensitivity 77%, area under the ROC curve 0.747, 95%CI 0.423-0.790, p<0.005) were the best discriminative cut-off values of decreased LLP.

CONCLUSION

Impaired LLP may appear following transcatheter closure of PDA with either Cook detachable coils or Gianturco coils. This situation may be complicated with loops deployed at the pulmonary side, the use of relatively large size of coil with respect to the ductal diameter and the use of multiple coils.

Anomalous origin of one pulmonary artery branch from the ascending aorta: experience of our center

OBJECTIVES

Anomalous origin of one pulmonary artery branch from the aorta in the presence of separate aortic and pulmonary valves is a rare but important entity necessitating early diagnosis and surgery to prevent irreversible vascular pulmonary disease. We evaluated our experience with seven infants having this anomaly.

STUDY DESIGN

Between December 2003 and 2009, a total of seven infants (2 girls, 5 boys, age range 4 days to 84 days) were diagnosed as having anomalous origin of one pulmonary artery branch from the aorta. Clinical records were reviewed for clinical features, operative procedures, and postoperative follow-up.

RESULTS

Common symptoms were dyspnea, tachypnea, and poor feeding. All the cases were diagnosed by echocardiography. The right pulmonary artery in six cases and the left pulmonary artery in one case originated from the ascending aorta. In addition, three patients had patent ductus arteriosus (PDA), five patients had patent foramen ovale, and one patient had interruption of the aortic arch and aortopulmonary window. All patients underwent surgical re-implantation of the anomalous pulmonary artery branch to the pulmonary trunk. Associated surgical procedures included PDA ligation in three patients, and total repair of interrupted aortic arch and aortopulmonary window in one patient. There were no in-hospital deaths. Two patients had prolonged intubation (10 and 16 days). All patients were discharged in good clinical condition. During a follow-up period ranging from two months to six years, only one patient developed stenosis at the site of anastomosis.

CONCLUSION

Prompt diagnosis at infancy, improved surgical technique, and good patient care decrease mortality and morbidity associated with anomalous origin of the pulmonary artery from the aorta.

The effect of low-carbohydrate diet on left ventricular diastolic function in obese children

BACKGROUND

This study was conducted to evaluate left ventricle (LV) functions using conventional and tissue Doppler imaging in childhood obesity and to identify the effects of diet on LV diastolic functions.

METHODS

Conventional and tissue Doppler echocardiographic measurements were compared in 34 obese children and 24 age- and gender-matched lean controls. Fasting plasma glucose, insulin and homeostatic model assessment of insulin resistance levels were also obtained. Thirty-one of the obese children were subjected to a low-carbohydrate diet and their follow-up measurements were obtained after 6 months.

RESULTS

Left atrial diameter, LV mass and LV mass index were higher in obese children than in lean controls. Lateral mitral myocardial early diastolic (E(m)) and peak E(m)/myocardial late diastolic (A(m)) were lower, and mitral E/E(m) and lateral mitral myocardial isovolumetric relaxation time were higher in obese subjects than in lean controls. Insulin and homeostatic model assessment of insulin resistance levels were higher in obese patients and decreased significantly after diet. After diet therapy, lateral mitral E(m) and peak E(m)/A(m), were increased, mitral E/E(m) and myocardial isovolumetric relaxation time were decreased.

CONCLUSIONS

Obesity predisposes children to increased preload reserve, left ventricular subclinical diastolic dysfunction and deterioration in diastolic filling. Weight reduction with a low-carbohydrate diet seems to be associated with significant improvement in LV diastolic function and a decrease in diastolic filling, as well as causing reversal in insulin resistance seen in obese children.

Double outlet right ventricle and aortopulmonary window in a patient with Cornelia de Lange syndrome: a novel association

We report a patient with Cornelia de Lange syndrome with congenital cardiac malformation; double outlet right ventricle and aortopulmonary window. This is the first report describing this combination of findings for Cornelia de Lange syndrome. Behalf of this report, the pathogenesis of congenital heart disease in Cornelia de Lange syndrome was also revisited.

Supracoronary myotomy for myocardial bridges in the setting of hypertrophic cardiomyopathy: off-pump experience

Myocardial bridges (MB) are rarely observed but well known pathology of the major epicardial coronary arteries which are embedded in the overlying myocardial tissue. It is most frequently found in young patients with hypertrophic cardiomyopathy (HCM). Myocardial bridges are associated with myocardial ischemia and infarction, cardiac arrhythmias and sudden death. The present case series report the outcomes of three symptomatic patients with hypertrophic cardiomyopathy who underwent myocardial muscle debridges. They were operated using beating heart technique without cardiopulmonary bypass. The authors conclude that off-pump supracoronary muscle myotomy is a feasible treatment modality in the young age group with non-obstructive hypertrophic cardiomyopathy.

Cardiac functions in children with coeliac disease during follow-up: insights from tissue Doppler imaging

BACKGROUND

The identification of a coeliac disease in patients with idiopathic dilated cardiomyopathy raises critical questions on the relationship between the two entities. But cardiac functions have not been studied in patients with coeliac disease. The present study was undertaken to assess cardiac functions by Tissue Doppler Echocardiography in patient with coeliac disease.

METHODS

We studied 45 clinically stable patients; twenty-five patients with positive serum IgA Antiendomysial Antibody levels (Group 1), twenty patients with negative serum IgA Antiendomysial Antibody levels (Group 2) at the time of echocardiographic study. Control group consisted of 30 healthy children free of any disease.

RESULTS

Myocardial systolic wave velocity of the mitral annulus was significantly lower (p<0.001), myocardial precontraction and contraction time were slightly longer in Group 2 when compared control group (p=0.015, p=0.044, respectively). There was a negative correlation between the serum IgA Antiendomysial Antibody levels titers and myocardial systolic wave levels of all patients included in the study (r = -0.633; p<0.001). A myocardial systolic wave velocity of <8.9 cm/s had a 92% sensitivity and 80% specificity in predicting serum IgA Antiendomysial Antibody levels positive patients.

CONCLUSIONS

We detected subclinical systolic dysfunction of the left ventricle in children with coeliac disease in whom serum IgA Antiendomysial Antibody reactivity is prominent. Tissue Doppler echocardiography provides a quantifiable indicator useful for cardiac monitoring of disease during follow up.