Ventricular Arrhythmias In Children Research Articles

Effectiveness of Radiofrequency Catheter Ablation of Outflow Tract Ventricular Arrhythmias in Children and Adolescents

Outflow tract ventricular arrhythmias (OTVAs) are common in children; however, experience is limited on their radiofrequency catheter ablation (RFCA). The purpose of this study was to assess the outcomes of mapping and ablation of pediatric OTVAs and to evaluate the role of ECG algorithms in distinguishing the origin of OTVAs. We compared retrospectively collected single-center data on 92 consecutive pediatric patients (58 male; age, 8.2±2.9 [range 3.6-18] years) who underwent RFCA for OTVAs from 2009 to 2015. Two independent and blinded observers analyzed ECG data. Of these children, 69 (75%) were of RVOT origin. RFCA was given up in 1 case, and the acute success rate was 92.3% (84/91), the 1-year follow-up recurrence rate was 8.3% (7/84) and the complications of the procedure were 2.2% (2/92). And 3D versus 2D mapping-guided RFCA was associated with significantly (p<0.05) higher acute success rate (96.1% [49/51] vs. 87.5% [35/40]), and lower X-ray exposure (742.5±323.1 vs. 1432.3±605.5mGycm2) and 1-year recurrence rate (4.1% [2/49] vs. 14.3% [5/35]). The positive predictive value of four types of ECG algorithms used in adults for LVOT origin was only 47.7-65.4%. In these cases, four identified as RVOT origin and two identified as LVOT origin by ECG underwent successful ablation on the other side of outflow tract finally. And these six children who underwent successful RFCA in both sides of outflow tract had no follow-up recurrence. OTVAs in children originate mostly from RVOT. RFCA can be used for ablation of pediatric OTVAs effectively and safely. In some cases, successful RFCA should be ablated in both sides of outflow tract. ECG-based prediction of OTVA origin as used in adults is limited in children.

Lower spatial QRS-T angle rules out sustained ventricular arrhythmias in children with hypertrophic cardiomyopathy.

Corrected QT interval and spatial peaks QRS-T angles were retrospectively assessed in 133 paediatric hypertrophic cardiomyopathy patients (12.4±6.6 years) with versus without ventricular arrhythmias of 30 seconds or longer. Significance, positive/negative predictive values, and odds ratios were calculated based on receiver operating characteristic curve cut-off values. In total, 10 patients with ventricular arrhythmias were identified. Although the corrected QT interval did not differentiate those with versus without ventricular arrhythmias, the spatial peaks QRS-T angle did (151.4±19.0 versus 116.8±42.6 degrees, respectively, p<0.001). At an optimal cut-off value (124.1 degrees), the positive and negative predictive values of the spatial peaks QRS-T angle were 15.4 and 100.0%, respectively, with an odds ratio of 25.9 (95% CI 1.5-452.2). In children with hypertrophic cardiomyopathy, the spatial peaks QRS-T angle is associated with ventricular arrhythmia burden with high negative predictive value and odds ratio.

Efficacy of radiofrequency catheter ablation of outflow tract ventricular arrhythmias in children

To explore the features of outflow tract ventricular arrhythmias (OTVA) in children and evaluate the efficacy and experiences of radiofrequency catheter ablation (RFCA). Data were collected and analyzed on 53 consecutive pediatric patients who underwent RFCA for OTVA from January 2012 to July 2015 in the First Hospital of Tsinghua University. These children included 34 male and 19 female, whose average age was (8±3) years and body weight was (33±13) kg. All the children met the indication criteria for RFCA of OTVA in children. Data were analyzed about the onset age, the forms and ablation efficacy and strategies of OTVA. The average age of onset was (8±4) years. Of these children, 68% (36/53) had frequent premature ventricular complex which was the main arrhythmia pattern.The proportion of 66%(35/53) were of right ventricular outflow tract (RVOT). The vast majority of RVOT ventricular arrhythmias originates from myocardium with in the first 1 cm beneath the pulmonary valve(89%, 31/35) or the septal region(77%, 27/35). The total acute success rate was 98%(52/53), the recurrence rate on follow-up was 10% (5/52) and the complications of the procedure was 2%(1/53). The X-ray exposure dose was(743±323) mGay·cm(2). However, for 6 of the children RFCA on both sides of outflow tract was necessary for success. OTVA in children originates mostly from RVOT. RFCA can be used for ablation of pediatric OTVA effectively and safely. In some cases, successful RFCA should be performed on both sides of outflow tract.

Possibilities of Radionuclide-Tomo-Ventriculorgraphy with Labeled 99m Technetium of Sodium Diphosphate Decahydrate in Assessing Mechanical Dyssynchrony of Myocardium and Intracardiac Hemodynamics in Ventricular Arrhythmias in Children

The study was performed to identify the possibility of radionuclide tomo-ventriculorgraphy (RTVG) in the evaluation of mechanical dyssynchrony of myocardium intracardiac hemodynamics in ventricular arrhythmias in children. We examined 76 children with ventricular arrhythmias (average age 13.2 ± 3.7 years), including 16 patients before and after radiofrequency ablation procedures. All patients underwent RTVG. In patients with ventricular arrhythmias we identified zones of asynchronous contraction of the myocardium (ACM) and reduction hemodynamics with increasing intraventricular dyssynchrony. After radiofrequency ablation (RFA) there was a significant decrease in the number of ACM, improvement of contractile function and decrease of intraventricular dyssynchrony of the right ventricle.

Idiopathic ventricular arrhythmia in children and adolescents: early effectiveness of radiofrequency current ablation.

The aim of the study was to evaluate early effectiveness of radiofrequency (RF) current ablation for idiopathic ventricular arrhythmia (iVA) in children and to identify factors affecting treatment results. Among over 600 children, 30 ablation procedures were performed for iVA. Patient age ranged from 2.0 to 17.9 years (mean 14.7 ± 3.1). We analysed arrhythmia recurrences at 24 h and the effect of patient age, arrhythmia location, type of anaesthesia, and the presence of spontaneous arrhythmia during the procedure on the treatment results. Sixteen (53%) children had right ventricular (RV) arrhythmia, including RV outflow tract arrhythmia in 9 of them (56%). In 14 (47%) children, arrhythmia was located in the left ventricle (LV), including LV outflow tract in 2 children, and the posterior fascicle in 4 children. The procedure was effective in 13 (81%) children in the RV arrhythmia group and in 11 (78%) children in the LV arrhythmia group, including all children with fascicular tachycardia. The only variable that affected the treatment results was the presence of spontaneous arrhythmia during the procedure (p = 0.012). No procedural complications were noted. RF current ablation of iVA is a safe procedure with high early effectiveness. The only variable that affected the treatment results was the presence of spontaneous arrhythmia during the procedure.

QRS prolongation is strongly associated with life-threatening ventricular arrhythmias in children with dilated cardiomyopathy

The incidence of sudden death in children with dilated cardiomyopathy has been estimated at < 1% annually. This number, however, may underestimate the incidence of life-threatening arrhythmias. The objective of this study was to assess the incidence of and identify risk factors for life-threatening arrhythmias in children with dilated cardiomyopathy. We conducted a retrospective record review of 183 children with dilated cardiomyopathy treated at a single center between 2000 and 2011. Life-threatening arrhythmia was defined as any ventricular arrhythmia that resulted in syncope or hypotension and required medical intervention. Risk factors for life-threatening arrhythmias were identified with univariate analyses. A prediction model was constructed with multivariate logistic regression and receiver operating characteristic curves. Nineteen patients experienced life-threatening arrhythmias, representing an annualized rate of 4.9%. Outpatient life-threatening arrhythmias occurred at a rate of 2.2% per year. Predictors of outpatient life-threatening arrhythmias were longer QRS duration (p = 0.003) and increased left ventricular posterior wall (LVPWd) thickness (p = 0.03). Only QRS duration remained significant in multivariate logistic regression (odds ratio, 1.8 for every unit increase in z-score; 95% CI, 1.01-1.9; p = 0.04). For all life-threatening arrhythmias, prolonged QRS duration was the only significant risk factor in multivariate logistic regression (odds ratio, 1.5; 95% CI, 1.1-2.2; p = 0.02). In children with dilated cardiomyopathy, as QRS duration increases, so too does the risk of life-threatening arrhythmias. Life-threatening arrhythmias occurred at an annual rate of 5%, which was much higher than the previously reported rate of sudden cardiac death in this population.

Catheter ablation of idiopathic ventricular arrhythmia in children

Catheter ablation of idiopathic ventricular arrhythmia in children

INFLUENCE OF THE POLYMORPHISM OF THE RENIN-ANGIOTENSIN SYSTEM GENES ON THE CARDIAC ARRHYTHMIAS IN CHILDREN WITH HYPERTROPHIC CARDIOMYOPATHY

Hypertrophic cardiomyopathy (HCMP) is a genetically determined myocardial disease, characterized by massive hypertrophy of the myocardium of the left and/or (rarely) the right ventricle, often associated with obstruction of the left ventricular outflow tract and diastolic dysfunction. The course of disease can be complicated by development of various cardiac arrhythmias. It was reported that severity of HCMP course depends at certain degree on polymorphism of candidate genes, including genes of the renin angiotensin system (RAS). Influence of RAS genes polymorphism on the frequency and character of cardiac arrhythmias in childhood is almost not studied. Aim : to determine the influence of RAS genes polymorphism on the prevalence and structure of cardiac arrhythmias in children with HCMP. Patients and methods : analysis of influence of RAS genes polymorphism on the prevalence and structure of cardiac arrhythmias was performed in 32 children with HCMP. All the patients were carried out ECG, cardiac ultrasound and ECG Holter monitoring. Polymorphism of the RAS genes (renin gene (REN) G83A, angiotensinogen gene (AGT) M235T, angiotensin-converting enzyme gene (ACE) I/D, angiotensin II receptor type 1 gene (AGTR1) A1166C). Results : in patients with HCMP was established a higher frequency of TT-genotype and T-alleles of angiotensinogen gene than in comparison group. In homozygous patients with T-allele of angiotensinogen gene ventricular arrhythmia was found reliably more often than in patients with MT- and MM-genotypes, which suggested that M235T polymorphism of angiotensinogen gene influenced on intensity of ventricular arrhythmias in children with HCMP. Conclusions : in children with HCMP and cardiac arrhythmias analysis of M235T polymorphism of angiotensinogen gene can be used as an additional criterion for revealing of patients with high risk of arrhythmic complications and for development of preventative measures.

Ventricular arrhythmias in children with attention deficit disorder – a symptom of autonomic imbalance?

Potential side effects of stimulants for attention deficit disorder are in the focus of scientific discussions, intensified by the higher number of prescriptions. Children with known arrhythmias or other severe cardiac problems should not receive stimulants because of their sympathomimetic effects. This is a retrospective analysis of 24-hour Holter electrocardiograms from 100 consecutive children with attention deficit disorder from January, 2006 to April, 2012. In all, nine children had significant ventricular arrhythmia (mean age 11.4 ± 3.1 years, 77% male, 77% received methylphenidate). All these children had ventricular parasystole - four of them with an accelerated idioventricular rhythm. A significant circadian rhythm of premature ventricular contractions in seven children and the effect of standing and exercise clearly indicate the influence of the autonomic nervous system. In these children, hourly analysis of circadian rhythm within a 24-hour period showed a highly significant correlation between premature ventricular contractions and the vagal tone indicated by the heart rate variability parameter RMSSD (r = -0.83; p < 0.001). Ventricular arrhythmia was unaffected in seven children who received methylphenidate before diagnosis and decreased during metoprolol treatment in two children. By Holter electrocardiogram analysis, we observed a remarkably high incidence of ventricular parasystole and accelerated idioventricular rhythm in nine of 100 children with attention deficit disorder, which depends on autonomic imbalance and not on stimulant treatment.

Heart rate variability in children with aortic valve stenosis - a pilot study.

IntroductionThe aim of our prospective study was to evaluate heart rate variability (HRV) in children with aortic valve stenosis (AS) and its relationship with left ventricular mass and peak transaortic valve pressure gradient (PG).Material and methodsSixty children with AS divided into 3 groups according to their PG and 60 healthy controls were studied. Holter ECG monitoring with time domain HRV analysis was performed. Left ventricular mass was calculated by echocardiography.ResultsMean values of all HRV parameters were statistically significantly lower (p < 0.001) in children with AS than in controls (respectively: SDNN 127.8 ±28.2 ms; 162.6 ±38.0 ms, SDNN day 99.7 ±26.6 ms; 134.1 ±36.1 ms, SDNN night 99.9 ±32.8 ms; 123.4 ±45.7 ms, SDANN 112.2 ±27.7 ms; 142.4 ±34.6, SDNNi 62.2 ±16.2 ms; 75.9 ±21.6, RMSSD 39.6 ±12.1 ms; 50.3 ±16.7 ms, rMSSD day 33.6 ±10.9 ms; 43.1 ±14.7 ms, rMSSD night 49.8 ±18.1 ms; 64.4 ±24.9 ms, pNN50 16.4 ±9.5%; 23.5 ±11.7%, pNN50 day 12.0 ±8.5%; 18.4 ±10.7%, pNN50 night; 26.5 ±14.8%; 36.4 ±17.4%. No significant differences between the mean values of HRV parameters in children with different PG and with and without myocardial hypertrophy were found. In children with AS and ventricular arrhythmia SDNN day was significantly lower (p < 0.05) compared to patients without arrhythmia (94.9 ±22.1 ms vs. 109.3 ±22.5 ms).ConclusionsIn children with AS the balance of the autonomic nervous systemic disturbed which manifests in an increase in sympathetic and decrease in parasympathetic activity. Transaortic valve pressure gradient and myocardial hypertrophy do not influence the HRV. The SDNN reduction during the day period may indicate the risk of ventricular arrhythmia in children with AS.

Nonfluoroscopic and Radiation-Limited Ablation of Ventricular Arrhythmias in Children and Young Adults: A Case Series

The purpose of this study was to report the feasibility and procedural technique of minimal or no fluoroscopy in the ablation of ventricular arrhythmias in the pediatric population. A retrospective review was performed of all patients <21 years old who underwent ablation of ventricular arrhythmias using three-dimensional (3D) mapping with no or minimal fluoroscopy at a single institution. Five patients underwent electrophysiology studies for ventricular tachycardia or frequent premature ventricular complexes. Three patients had right-sided arrhythmias, and two patients had left-sided arrhythmias. Electro-anatomic mapping with the 3D EnSite NavX system and radiofrequency ablation was used in all patients. No fluoroscopy was used in the patients with right-sided arrhythmias. The two patients with left-sided arrhythmias had 1.0 and 1.9 min of fluoroscopy, respectively. The mean procedure time was 168 min (range 95 to 270). There has been no recurrence at mean follow-up of >1 year. Three-dimensional mapping systems have allowed pediatric electrophysiologic procedures to be performed with minimal to no fluoroscopy in patients with challenging arrhythmias, including ventricular arrhythmias. The decrease in radiation exposure decreases the risk of long-term adverse sequelae resulting from radiation exposure, which is especially important in children.

Ventricular arrhythmia in children: Diagnosis and management

With increasing awareness of genetic abnormalities and the aging of patients with structural cardiac disease, particularly those who have had cardiac surgery, primary ventricular tachycardia is being recognized more frequently in children and adolescents and is becoming a larger management issue. The distinction of primary versus secondary is based on whether ventricular tachycardia is the inciting arrhythmia or the end result of a prolonged ischemic event, such as prolonged bradycardia with resultant ventricular tachycardia. This article discusses only primary ventricular tachycardia. The incidence clearly increases with age after cardiac surgery, particularly in specific cardiac abnormalities, such as tetralogy of Fallot post repair, transposition of the great arteries, post atrial switch operation, and hypertrophic obstructive cardiomyopathy. In addition, as genetic abnormalities are becoming better appreciated, conditions such as long QT syndrome, arrhythmogenic right ventricular cardiomyopathy, and Brugada syndrome, with their risk for ventricular tachycardia and fibrillation, are being seen increasingly in the pediatric population. Long-term treatment of ventricular tachycardia includes drug therapy, implantable device therapy, invasive ablation therapy, and combinations of these modalities. To choose the appropriate therapy, the clinician must consider the arrhythmia's effect on the patient's hemodynamic status and the potential for sudden cardiac death.

Laparoscopic Surgery: Does It Increase the Probability of Atrial and Ventricular Arrhythmias in Children?

Despite the minor physiologic changes those occur during laparoscopic procedures, pneumoperitoneum with CO2 insufflation may induce alterations in electrocardiographic (ECG) variables, which may predict severe atrial and ventricular arrhythmias. This study aims to assess QT dispersion (QTD) and P wave dispersion (PWD) changes in children who have undergone laparoscopic appendectomy. Sixteen patients (12 males and 4 females) who had preoperative diagnosis of appendicitis were included in the study. As laparoscopic exploration revealed appendicitis in all patients, laparoscopic appendectomy was performed. Preinsufflation (ECG1), postinsufflation (ECG2), predesufflation (ECG3), and postdesufflation (ECG4) ECGs were achieved at a speed of 25 mm/s for QTD and PWD analyses. Although mean corrected QTD and PWD at ECG2 and ECG3 were significantly greater than ECG1 and ECG4, those changes induced by insufflation of CO2 were reversible. The clinical significance of pneumoperitoneum, which causes an increase in corrected QTD and PWD in children, remains to be determined with further studies.

Arrhythmogenic right ventricular dysplasia: An underestimated cause of perioperative death?

ARRHYTHMOGENIC RIGHT ventricular dysplasia (ARVD) is a cardiomyopathy,1 which is familial in some patients,2 with hypokinetic areas involving the wall of the right ventricle. The most common pattern of inheritance is autosomal dominant, but penetrance ranges from 20% to 50%.3 Its prevalence is estimated at 1:10,000.4 The risk of ARVD is sudden death caused by arrhythmia, but evolution toward chronic heart failure has been described.5 ARVD is similar to Uhl's anomaly (parchment-thin right ventricular wall) and can be an important cause of ventricular arrhythmias in children and young adults with an apparently normal heart and occasionally in older patients.

Ventricular Fibrillation During Anesthetic Induction in a Child With Undiagnosed Mitral Valve Prolapse

Ventricular Fibrillation During Anesthetic Induction in a Child With Undiagnosed Mitral Valve Prolapse

New antiarrhythmic drug in pediatric use: sotalol.

Sotalol is a noncardioselective beta-blocking agent with additional class III antiarrhythmic properties (action potential duration prolongation). These combined electrophysiologic effects make it a valuable drug for treating various arrhythmias. Its effectiveness for suppressing supraventricular reentrant tachycardias in children is well documented. Atrial flutter in children can be effectively managed in a high percentage of those treated. Ventricular arrhythmias in children can be adequately controlled by the administration of oral sotalol. Side effects are those typically seen during the course of treatment with a beta-blocker and lead to discontinuation of the drug in 3-6% of children. Proarrhythmia is another concern after sotalol administration. Increased ventricular ectopy, impairment of atrioventricular conduction, and suppression of sinus node activity with exacerbation of bradycardia (especially in children with sinus node dysfunction) may be found in a considerable number of treated patients, usually within a few days of sotalol initiation. Sotalol is an effective antiarrhythmic drug, but its potential side effects warrant inpatient treatment initially and close electrocardiographic monitoring.

Ventricular arrhythmias in children with an apparently normal heart

Ventricular ectopy occurs frequently in normal children. In the presence of a normal heart, these arrhythmias, including asymptomatic, nonsustained ventricular tachycardia, carry a benign prognosis and are not associated with sudden, unexpected death. However, complex ventricular arrhythmias frequently indicate the presence of underlying cardiac disease; patients with such arrhythmias must undergo an appropriately thorough evaluation before decisions regarding prognosis and the need for therapy can be made.

Identification of ventricular arrhythmias in children with heart disease using high resolution electrocardiography

Identification of ventricular arrhythmias in children with heart disease using high resolution electrocardiography

Developmental Cellular Electrophysiologic Effects of d-Sotalol on Canine Cardiac Purkinje Fibers

d-Sotalol may be a clinically useful class III antiarrhythmic agent for controlling ventricular arrhythmias in children. Because age-related differences in repolarization currents may contribute to developmental differences in response to antiarrhythmic agents that primarily affect repolarization, the electrophysiologic effects of d-sotalol were compared in Purkinje fibers from neonatal and adult dogs. Significant age-related changes characterized the antiarrhythmic profile of d-sotalol. d-Sotalol (10(-4) M) significantly prolonged the action potential duration of adult Purkinje fibers (310 +/- 8 to 380 +/- 7 ms, p less than 0.01) and neonatal fibers (247 +/- 5 to 342 +/- 9 ms, p less than 0.01). However, the lengthening of action potential duration was significantly greater in the immature age group. d-Sotalol had no significant effect on maximum diastolic potential, action potential amplitude, or phase zero upstroke velocity in normally polarized fibers. In contrast, different electrophysiologic effects were observed in K(+)-depolarized Purkinje fibers. Superfusion of adult K(+)-depolarized fibers with d-sotalol suppressed excitability in five (38%) of 13 fibers and significantly decreased action potential amplitude (88 +/- 2 to 83 +/- 1 mV, p less than 0.05) and phase zero upstroke velocity (180 +/- 14 to 105 +/- 3 V/s, p less than 0.01) in the other eight fibers. The membrane depressant effects observed in the younger age group were significantly less [no suppression of excitability and a smaller decrease in phase zero upstroke velocity (121 +/- 22 to 101 +/- 23 V/s, p less than 0.05). The magnitude of action potential duration prolongation by d-sotalol in K(+)-depolarized fibers was less than in normally polarized fibers.(ABSTRACT TRUNCATED AT 250 WORDS)

Treatment of ventricular arrhythmias in children without structural heart disease with class IC agents as guided by invasive electrophysiology

Although the efficacy of class IC antiarrhythmic agents in the treatment of supraventricular and ventricular arrhythmias in adults has been clearly demonstrated, serious proarrhythmic effects have been reported. 1 These agents have also proven useful in the pediatric population, but there is growing concern that similar proarrhythmic potential exists. 2,3 Recognizing that these drugs, although very useful, may also be deadly, we have adopted a protocol at the Medical University of South Carolina that uses invasive ventricular stimulation after drug administration to help assess the risk/benefit ratio of these agents in the treatment of ventricular arrhythmias. Since mid-1987, all 23 children with ventricular arrhythmias treated with IC agents have had invasive stimulation performed after drug administration to evaluate efficacy or proarrhythmia, or both. Ten of these children with structurally normal hearts, treated solely with IC agents, were tested in the electrophysiology laboratory both before and after drug administration; data from these 10 patients were used in this investigation (Table I). I Class IC Therapy for Pediatric Ventricular Arrhythmias as Evaluated by Electrophysiologic Studies Pt. Age(yr) &Sex Clinical Arrhythmia VT Induced Before IC Therapy IC Therapy VT Induced After IC Therapy EPS 1 2F VT + Encainide 0 2 2F VT + Flecainide 0 3 5F VT + Flecainide 0 4 5M VT + Flecainide 0 5 8F VT + Flecainide 0 6 8F VT + Flecainide + 7 13M VT(NS) +(NS) Flecainide 0 8 15M VT(NS) +(NS) Flecainide 0 9 16M AF(NS) VT(NS) +(NS) Flecainide 0 10 18M VT(NS) +(NS) Encainide 0 AF = atrial flutter; EPS = electrophysiologic study; IC = class IC agent; NS = nonsustained; VT = ventricular tachycardia; + = present; 0 = absent.