Junctional ectopic tachycardia after surgery for congenital heart disease in children

Epidemiology of Postoperative Junctional Ectopic Tachycardia in Infants Undergoing Cardiac Surgery

BACKGROUND

Junctional ectopic tachycardia (JET) complicates congenital heart surgery in 2% to 8.3% of cases. JET is associated with postoperative morbidity in single-center studies. We used the Pediatric Cardiac Critical Care Consortium data registry to provide a multicenter epidemiologic description of treated JET.

METHODS

This is a retrospective study (February 2019-August 2022) of patients with treated JET. Inclusion criteria were (1) <12 months old at the index operation, and (2) treated for JET <72 hours after surgery. Diagnosis was defined by receiving treatment (pacing, cooling, and medications). A multilevel logistic regression analysis with hospital random effect identified JET risk factors. Impact of JET on outcomes was estimated by margins/attributable risk analysis using previous risk-adjustment models.

RESULTS

Among 24,073 patients from 63 centers, 1436 (6.0%) were treated for JET with significant center variability (0% to 17.9%). Median time to onset was 3.4 hours, with 34% present on admission. Median duration was 2 days (interquartile range, 1-4 days). Tetralogy of Fallot, atrioventricular canal, and ventricular septal defect repair represented >50% of JET. Patient characteristics independently associated with JET included neonatal age, Asian race, cardiopulmonary bypass time, open sternum, and early postoperative inotropic agents. JET was associated with increased risk-adjusted durations of mechanical ventilation (incidence rate ratio, 1.6; 95% CI, 1.5-1.7) and intensive care unit length of stay (incidence rate ratio, 1.3; 95% CI, 1.2-1.3), but not mortality.

CONCLUSIONS

JET is treated in 6% of patients with substantial center variability. JET contributes to increased use of postoperative resources. High center variability warrants further study to identify potential modifiable factors that could serve as targets for improvement efforts to ameliorate deleterious outcomes.

Postoperative Cardiac Arrhythmias in Pediatric and Neonatal Patients with Congenital Heart Disease-A Narrative Review

Cardiac arrhythmias are a frequent complication in the evolution of patients with congenital heart disease. Corrective surgery for these malformations is an additional predisposition to the appearance of arrhythmias. Several factors related to the patient, as well as to the therapeutic management, are involved in the etiopathogenesis of cardiac arrhythmias occurring post-operatively. The risk of arrhythmias in the immediate postoperative period is correlated with the patient's young age and low weight at surgery. The change in heart geometry, hemodynamic stress, and post-surgical scars represent the main etiopathogenic factors that can contribute to the occurrence of cardiac arrhythmias in the population of patients with operated-on congenital heart malformations. Clinical manifestations differ depending on the duration of the arrhythmia, underlying structural defects, hemodynamic conditions, and comorbidities. The accurate diagnosis and the establishment of specific management options strongly influence the morbidity and mortality associated with arrhythmias. As such, identifying the risk factors for the occurrence of cardiac arrhythmias in the case of each patient is essential to establish a specific follow-up and management plan to improve the life expectancy and quality of life of children.

Clinical risk prediction score for post-operative accelerated junctional rhythm and junctional ectopic tachycardia in children with congenital heart disease

BACKGROUND

Accelerated junctional rhythm (AJR) and Junctional ectopic tachycardia (JET) are common post-operative arrhythmias associated with morbidity/mortality. Studies suggest that pre- or intra-operative treatment may improve outcomes, but patient selection remains a challenge.

OBJECTIVES

Our objective was to describe contemporary outcomes of post-operative AJR/JET and develop a risk-prediction score to identify patients at highest risk.

METHODS

Retrospective cohort study of children 0-18 years undergoing cardiac surgery (2011-2018). AJR was defined as usual complex tachycardia with ≥1:1 ventricular-atrial association and junctional rate >25^th percentile of sinus rate for age but < 170 bpm while JET was defined as a rate >170 bpm. A risk prediction score was developed using random forest analysis and logistic regression.

RESULTS

From 6364 surgeries, AJR occurred in 215 (3.4%) and JET in 59 (0.9%). Age, heterotaxy syndrome, aortic cross-clamp time, ventricular septal defect closure and atrio-ventricular canal repair were independent predictors of AJR/JET on multivariate analysis and included in the risk prediction score. The model accurately predicted the risk of AJR/JET with a C-index of 0.72 [95% CI 0.70, 0.75]. Post-operative AJR and JET was associated with prolonged ICU and hospital length of stay, but not with early mortality.

CONCLUSION

We describe a novel risk prediction score to estimate the risk of post-operative AJR/JET permitting early identification of at-risk patients who may benefit from prophylactic treatment.

Randomized controlled trial to evaluate the effect of prophylactic amiodarone versus dexmedetomidine on reducing the incidence of postoperative junctional ectopic tachycardia after pediatric open heart surgery

Background

Junctional ectopic tachycardia (JET) is the most common arrhythmia after pediatric open-heart surgeries (OHS), causing high morbidity and mortality. As diagnosis is often missed in patients with minimal hemodynamic instability, its incidence depends on active surveillance. A prospective randomized trial evaluated the efficacy and safety of prophylactic amiodarone and dexmedetomidine to prevent and control postoperative JET.

Methods

Consecutive patients aged under 12 years were randomized into amiodarone, dexmedetomidine (initiated during anesthetic induction) and control groups. Outcome measures included incidence of JET, inotropic score, ventilation, and intensive care unit (ICU) duration and hospital stay, as well as adverse drug effects.

Results

Two hundred and twenty-five consecutive patients with a median age of 9 months (range 2 days-144 months) and a median weight of 6.3 kg (range 1.8 kg-38 kg) were randomized with 70 patients each to amiodarone and dexmedetomidine groups, and the rest were controls. Ventricular septal defect and Fallot's tetralogy were the common defects. The overall incidence of JET was 16.4%. Syndromic patients, hypokalemia, hypomagnesemia, longer bypass, and cross-clamp duration were the risk factors for JET. Patients with JET had significantly prolonged ventilation (P = 0.043), longer ICU (P = 0.004), and hospital stay (P = 0.034) than those without JET. JET was less frequent in amiodarone (8.5%) and dexmedetomidine (14.2%) groups compared to controls (24.7%) (P = 0.022). Patients receiving amiodarone and dexmedetomidine had significantly lower inotropic requirements, lower ventilation duration (P = 0.008), ICU (P = 0.006), and hospital stay (P = 0.05). Adverse effects such as bradycardia and hypotension after amiodarone and ventricular dysfunction after dexmedetomidine were not significantly different from controls.

Conclusion

Prophylactic amiodarone or dexmedetomidine started before OHS is effective and safe for the prevention of postoperative JET.

Early and Late Postoperative Tachyarrhythmias in Children and Young Adults Undergoing Congenital Heart Disease Surgery

The population of patients with congenital heart disease is constantly growing with an increasing number of individuals reaching adulthood. A significant proportion of these children and young adults will suffer from tachyarrhythmias due to the abnormal anatomy, the hemodynamic burden, or as a sequela of surgical treatment. Depending on the underlying mechanism, arrhythmias may arise in the early postoperative period (hours to days after surgery) or in the late postoperative period (usually years after surgery). A good understanding of the electrophysiological characteristics and pathophysiological mechanisms is therefore crucial to guide the therapeutic approach. Here, we synthesize the current state of knowledge on epidemiological features, risk factors, pathophysiological insights, electrophysiological features, and therapy regarding tachyarrhythmias in children and young adults undergoing reparative surgery for congenital heart disease. The evolution and latest data on treatment options, including pharmacological therapy, ablation procedures, device therapy decision, and thromboprophylaxis, are summarized. Finally, throughout this comprehensive review, knowledge gaps and areas for future research are also identified.

Routine Perioperative Esmolol After Infant Tetralogy of Fallot Repair: Single-Center Retrospective Study of Hemodynamics

OBJECTIVES

Currently, surgical repair of tetralogy of Fallot (TOF) is associated with an 1.1% 30-day mortality rate. Those with junctional ectopic tachycardia (JET) and restrictive right ventricular physiology have poorer outcomes. Routine postoperative adrenergic or inodilator therapy has been reported, while beta-blockade following cardiopulmonary bypass has not. This study evaluated routine perioperative treatment with esmolol in infants undergoing TOF repair.

DESIGN

Retrospective chart review of the perioperative course following TOF repair.

SETTING

Single-center case series describing perioperative management of TOF in a cardiac ICU.

PATIENTS

This study reviewed all patients less than 18 months old who underwent TOF repair, excluding cases of TOF with absent pulmonary valve or atrioventricular septal defect, at our institution from June 2018 to April 2021.

INTERVENTIONS

This review investigates the hemodynamic effects of esmolol following cardiopulmonary bypass for TOF repair.

MEASUREMENTS AND MAIN RESULTS

Preoperative clinical characteristics and perioperative course were extracted from the medical record. Descriptive statistics were used. Twenty-six patients receiving perioperative esmolol after TOF repair were identified and included. Postoperative hemodynamic parameters were within a narrow range with minimal vasoactive support in most patients. Three of 26 patients experienced JET, and one of 26 of whom had a brief cardiac arrest. Median and interquartile range (IQR) for hospital and postoperative length of stay was 7 days (IQR, 6-9 d) and 6 days (IQR, 5-8 d), respectively. There were no 30-day or 1-year mortalities.

CONCLUSIONS

In this infant cohort, our experience is that the routine use of postoperative esmolol is associated with good cardiac output with minimal requirement for vasoactive support in most patients. We believe optimal postoperative management of infant TOF repair requires a meticulous multidisciplinary approach, which in our experience is enhanced with routine postoperative esmolol treatment.

β1-receptor polymorphisms and junctional ectopic tachycardia in children after cardiac surgery

Junctional ectopic tachycardia (JET) is a potentially life-threatening postoperative arrhythmia in children with specific congenital heart defects and can contribute significantly to postoperative morbidity for at-risk populations. In adults, β1-adrenergic receptor (ADRB1) and β2-adrenergic receptor (ADRB2) genotypes have been associated with increased risk for arrhythmias. However, their association with arrhythmia risk in children is unknown. We aimed to test associations between ADRB1 and ADRB2 genotypes and postoperative JET in patients with congenital heart defects. Children who underwent cardiac surgery were genotyped for the ADRB1 p.Ser49Gly (rs1801252; c.145A>G), p.Arg389Gly (rs1801253; c.1165C>G), ADRB2 p.Arg16Gly (rs1042713; c.46A>G), and p.Glu27Gln (rs1042714; c.79G>C) polymorphisms. The occurrence of postoperative JET was assessed via cardiologist-interpreted electrocardiograms. Genotype associations with JET were analyzed via logistic regression, adjusted for clinical variables associated with JET, with separate analysis in patients not on a β-blocker. Of the 343 children included (median age 8 months, 53% boys, 69% European ancestry), 45 (13%) developed JET. The Arg389Arg genotype was not significantly associated with JET in the overall population (odds ratio [OR] = 1.96, 95% confidence interval [CI] = 0.96-4.03, p = 0.064), but was nominally associated in patients not taking a β-blocker (n = 324, OR = 2.25, 95% CI = 1.05-4.80. p = 0.034). None of the other variants were associated with JET. These data suggest that the ADRB1 Arg389Arg genotype may predict risk for JET following cardiac surgery in pediatric patients in the absence of β-blockade. Whether treatment with a β-blocker ameliorates this association requires further research.

Efficacy and safety of dexmedetomidine in maintaining hemodynamic stability in pediatric cardiac surgery: a systematic review and meta-analysis

OBJECTIVES

Dexmedetomidine (DEX) is a highly selective alpha-2 adrenergic receptor agonist, which is the main sedative in the intensive care unit. This study aims to investigate the effectiveness and adverse events of DEX in maintaining hemodynamic stability in pediatric cardiac surgery.

SOURCES

Databases such as PubMed, Cochrane, Web of Science, WANFANG STATA and China National Knowledge Infrastructure were searched for articles about the application of DEX in maintaining hemodynamic stability during and after pediatric cardiac surgery up to 18th Feb. 2021. Only randomized controlled trials were included and random-effects model meta-analysis was applied to calculate the standardized mean deviation (SMD), odds ratio (OR) and 95% confidence interval (CI).

SUMMARY OF THE FINDINGS

Fifteen articles were included for this meta-analysis, and 9 articles for qualitative analysis. The results showed that preoperative prophylaxis and postoperative recovery of DEX in pediatric patients undergoing cardiac surgery were effective in maintaining systolic blood pressure (SBP), mean arterial pressure (MAP), diastolic blood pressure (DBP) and reducing heart rate (HR) (SBP: SMD = -0.35,95% CI: -0.72, 0.01; MAP: SMD = -0.83, 95% CI: -1.87,0.21; DBP: SMD = -0.79,95% CI: -1.66,0.08; HR: SMD = -1.71,95% CI: -2.29, -1.13). In addition, the frequency of Junctional Ectopic Tachycardia in the DEX treatment group was lower than that in the placebo group.

CONCLUSIONS

The application of DEX for preoperative prophylaxis and postoperative recovery in pediatric cardiac surgery patients are effective in maintaining hemodynamic stability, and the clinical dose of DEX is not significantly related to the occurrence of pediatric adverse events which may be related to individual differences.

Ivabradine Versus Amiodarone in the Management of Postoperative Junctional Ectopic Tachycardia: A Randomized, Open-Label, Noninferiority Study

OBJECTIVES

This study sought to compare the efficacy of ivabradine and amiodarone in the management of postoperative junctional ectopic tachycardia (JET) after cardiac surgery in children.

BACKGROUND

JET is a serious arrhythmia occurring in children after cardiac surgery and requires aggressive management. Amiodarone has been conventionally used in its treatment. Recent studies have reported the utility of ivabradine in this regard.

METHODS

In this open-label randomized controlled trial, 94 children (age ≤18 years) who developed postoperative JET were allocated to receive either amiodarone or ivabradine. The primary endpoint was restoration of normal sinus rhythm.

RESULTS

Sinus rhythm was achieved in 43 out of the 46 patients (93.5%) in the amiodarone group and 46 out of the 48 patients (95.8%) in the ivabradine group (mean difference of treatment effect: 2.3%; 95% confidence interval: -6.7% to 11.5%). The median (interquartile range) time taken to achieve sinus rhythm conversion was similar in both the groups: 21.5 (17-30.2) hours versus 22 (13.4-38.5) hours (p = 0.36)]. The time taken to rate control of JET was significantly less in the amiodarone group: median 7.0 (5.5-9.5) hours versus 8.0 (5.8-10.8) hours (p = 0.02)]. No drug-related adverse events were observed in the ivabradine group.

CONCLUSIONS

Oral ivabradine is not inferior to intravenous amiodarone in converting postoperative JET to sinus rhythm. There was no difference in time taken to sinus rhythm conversion between the groups, although the rate control was earlier in patients who received amiodarone. Monotherapy with ivabradine may be considered as an alternative to amiodarone in the management of postoperative JET. (Comparison of Two Drugs, Ivabradine and Amiodarone, in the Management of Junctional Ectopic Tachycardia, an Abnormality in Cardiac Rhythm in Patients Under 18 years Who Undergo Cardiac Surgery: CTRI/2018/08/015182).

Impact of Perioperative Tachydysrhythmias on Mortality and Length of Stay in Complete Repair of Tetralogy of Fallot: A Multicenter Retrospective Cohort Study from the Pediatric Health Information System

INTRODUCTION

Tachydysrhythmias (TDS) frequently occur after complete repair of tetralogy of Fallot (TOF). However, not much is known about the effect of TDS on morbidity and mortality after TOF repair. We sought to assess the associations between TDS and mortality and morbidity after repair of TOF using a multicentre database.

MATERIALS AND METHODS

We identified all children aged 0-5 years in the Pediatric Health Information System who underwent TOF repair between 2004 and 2015. Codes for TDS were used to identify cases. Outcome variables were inpatient mortality and total length of stay (LOS). Univariate and multiple logistic and linear regression analyses were used to identify the effects of multiple risk factors, including TDS, on mortality and LOS.

RESULTS

A total of 7,749 patients met inclusion criteria, of which 1,493 (19%) had codes for TDS. There was no association between TDS and inpatient mortality. However, TDS were associated with 1.1 days longer LOS and accounted for 2% of the variation observed in LOS.

CONCLUSION

After complete repair of TOF, TDS were not associated with mortality and appeared to have only a modest effect on LOS.

Ivabradine as an Adjunct for Refractory Junctional Ectopic Tachycardia Following Pediatric Cardiac Surgery: A Preliminary Study

Objectives:

Junctional ectopic tachycardia (JET) is a relatively common narrow complex rhythm typically characterized by atrioventricular dissociation or retrograde atrial conduction in a 1:1 pattern. Junctional ectopic tachycardia can be a life-threatening disorder, causing severe hemodynamic compromise and increased morbidity and mortality. The treatment of refractory JET can be very difficult, even with multimodal therapeutic interventions. The purpose of this study was to assess the role of ivabradine in cases of JET refractory to amiodarone and esmolol.

Methods:

A total of 480 congenital heart surgeries were carried out at our center in 2017. Twenty (4.16%) patients had postoperative JET. Among these, five infants, aged 7 to 12 months (median: 8 months), had refractory JET. These patients (three tetralogy of Fallot, one ventricular septal defect, one complete atrioventricular septal defect) were treated with oral ivabradine in the dose range of 0.1 to 0.2 mg/kg/12 h as an adjunct to amiodarone.

Results:

All five patients achieved rate reduction and eventual conversion to sinus rhythm. Mean duration to achieve heart rate of <140 bpm after initiation of ivabradine therapy was 16.8 hours (±7.2 hours), while mean duration to achieve sinus rhythm was 31.6 hours (±13.6 hours). No patient had any recurrence of JET. No patient exhibited any hemodynamic derangement nor side effects attributable to oral ivabradine.

Conclusion:

Oral ivabradine has the potential to be used as an adjunct to amiodarone in the treatment of JET in infants after surgery for congenital heart disease.

Efficacy of different analgesic or sedative drug therapies in pediatric patients with congenital heart disease undergoing surgery: a network meta-analysis

BACKGROUND

Surgery is an effective therapy for congenital heart disease (CHD) and the management after surgery poses challenges for the clinical workers. We performed this network meta-analysis to enhance the corresponding evidence with respect to the relative efficacy of different drug treatments applied after the CHD surgery.

METHODS

Embase and PubMed were systematically retrieved to identify all published controlled trials investigating the effectiveness of drugs for patients up to 25 August, 2018. Mean differences (MD), odds ratios and their 95% credible intervals (CrIs) were used to evaluate multi-aspect comparisons. Surface under cumulative ranking curve (SUCRA) was used to analyze the relative ranking of different treatments in each endpoint.

RESULTS

Compared to saline, all the drugs achieved better preference under the efficacy endpoints except fentanyl in JET. As for ventilator time, all drugs were more effective than saline while only the difference of dexmedetomidine was statistically obvious (MD = 6.92, 95% CrIs 1.77-12.54). Under the endpoint of ICU time, dexmedetomidine was superior to saline as well (MD = 1.26, 95% CrIs 0.11-2.45). When all the endpoints were taken into consideration and with the help of ranking probabilities and SUCRA values, fentanyl combined with dexmedetomidine was one of the recommended drugs due to its shorter time on ventilator and stay in hospital as well as lower mortality.

CONCLUSIONS

Overall, based on the comprehensive consideration of all the endpoints, fentanyl combined with dexmedetomidine was considered to be the best-recommended clinical interventions among all the methods.

Tetralogy of Fallot: Everything you wanted to know but were afraid to ask

Tetralogy of Fallot (TOF) has four anatomic features: right ventricular hypertrophy (RVH), ventriculoseptal defect (VSD), overriding aorta and right ventricular outflow tract obstruction (RVOT) with an occurrence of 3.9 /10,000 births. The pathophysiologic effects in TOF are largely determined by the degree of RVOT and not the VSD. Intra-operative anesthetic management is also dependent on the degree of RVOT obstruction and influenced by the extent of surgical RVOT repair.

Risk Factors and Outcome of Post Fallot Repair Junctional Ectopic Tachycardia (JET)

BACKGROUND

Junctional ectopic tachycardia (JET) is a common arrhythmia causing hemodynamic impairment following corrective cardiac surgery such as tetralogy of Fallot (TOF) repair.

METHODS

We report our experience with postoperative JET following surgical repair of TOF. The retrospective study was done from 2003 to 2012 with a total of 105 patients who underwent TOF repair. These patients' clinical and electrocardiographic data (pre-, intra-, and postoperative) were monitored to identify risk factors for the occurrence of JET and to evaluate the outcome of the affected patients.

RESULTS

Incidence-Fourteen patients developed JET, with only four patients going directly from sinus rhythm to JET. In all others, either a transient atrioventricular (AV) block or a junctional rhythm preceded JET, mostly intraoperatively, showing a significant relation ( P = .010). Age-Patients with JET were of younger age ( P = .025) and had longer cardiopulmonary bypass ( P = .044) and aortic cross-clamping times ( P = .038). Increased cost and care-The occurrence of JET was associated with a longer stay in the intensive care unit (ICU) and a prolonged need for inotropic support and mechanical ventilation. Time to rate control correlated with length of ICU and hospital stay.

MORTALITY

All JET patients converted into sinus rhythm, one of them died shortly after cessation of JET and two patients subsequently developed a first-degree AV block.

CONCLUSION

The occurrence of JET remains an important complication during the initial postoperative period by increasing mechanical ventilation time, the need for inotropic support, and prolonging the length of ICU and hospital stay. Risk factors are younger age, longer aortic cross-clamping/bypass times, and intraoperative arrhythmias.

Efficacy of prophylactic dexmedetomidine in preventing postoperative junctional ectopic tachycardia in pediatric cardiac surgery patients: A systematic review and meta-analysis

BACKGROUND

Junctional ectopic tachycardia is a serious tachyarrhythmic complication following pediatric cardiac surgery. It is difficult to manage and is associated with significant morbidity and mortality. Conventional nonpharmacological and pharmacological measures have shown limited effects. Dexmedetomidine is an α2 agonist which has recently been shown in multiple studies to be effective.

AIMS

The aim of this systematic review with meta-analysis was to evaluate the efficacy of prophylactic dexmedetomidine administration in the prevention of junctional ectopic tachycardia in pediatric patients following cardiac surgeries.

METHODS

We searched MEDLINE, EMBASE, Cochrane, Web of Science, and relevant references published in English before December 20, 2017 and performed meta-analysis on the selected studies, with one group receiving prophylactic perioperative dexmedetomidine administration and another group receiving placebo. The primary outcome was the incidence of junctional ectopic tachycardia, secondary outcomes included bradycardia, hypotension, intensive care unit stay, total hospital stay, inotropic scores, and total mechanical ventilation time. Odds ratio or mean difference with 95% confidence intervals were calculated using a random effect model.

RESULTS

Seven studies (5 prospective randomized studies and 2 retrospective case-controlled studies) with a total of 1616 patients were analyzed. The incidence of junctional ectopic tachycardia in the dexmedetomidine group was significantly reduced compared to placebo. Similarly, intensive care unit stay, inotropic scores, and total mechanical ventilation time were also significantly decreased in the dexmedetomidine group. No significant increases in adverse events were found. Mortality was low in both groups.

CONCLUSION

Prophylactic dexmedetomidine is effective in reducing the incidence of postoperative junctional ectopic tachycardia without significant increases in adverse events in pediatric patients undergoing surgery for congenital heart diseases.

Junctional ectopic tachycardia following tetralogy of fallot repair in children under 2 years

Background

Junctional ectopic tachycardia is a serious arrhythmia that frequently occurs after tetralogy of Fallot repair. Arrhythmia prophylaxis is not feasible for all pediatric cardiac surgery patients and identification of high risk patients is required. The objectives of this study were to characterize patients with JET, identify its predictors and subsequent complications and the effect of various treatment strategies on the outcomes in selected TOF patients undergoing total repair before 2 years of age.

Methods

From 2003 to 2017, 609 patients had Tetralogy of Fallot repair, 322 were included in our study. We excluded patients above 2 years and patients with preoperative arrhythmia. 29.8% of the patients (n = 96) had postoperative JET.

Results

JET patients were younger and had higher preoperative heart rate. Independent predictors of JET were younger age, higher preoperative heart rate, cyanotic spells, non-use of B-blockers and low Mg and Ca (p = 0.011, 0.018, 0.024, 0.001, 0.004 and 0.001; respectively). JET didn’t affect the duration of mechanical ventilation nor hospital stay (p = 0.12 and 0.2 respectively) but prolonged the ICU stay (p = 0.011). JET resolved in 39.5% (n = 38) of patients responding to conventional measures. Amiodarone was used in 31.25% (n = 30) of patients and its use was associated with longer ICU stay (p = 0.017). Ventricular pacing was required in 4 patients (5.2%). Median duration of JET was 30.5 h and 5 patients had recurrent JET episode. Timing of JET onset didn’t affect ICU (p = 0.43) or hospital stay (p = 0.14) however, long duration of JET increased ICU and hospital stay (p = 0.02 and 0.009; respectively).

Conclusion

JET increases ICU stay after TOF repair. Preoperative B-blockers significantly reduced JET. Patients with preoperative risk factors could benefit from preoperative arrhythmia prophylaxis and aggressive management of postoperative electrolyte disturbance is essential.

The Impact of Time to Rate Control of Junctional Ectopic Tachycardia After Congenital Heart Surgery

Background:

Junctional ectopic tachycardia (JET) after congenital heart disease (CHD) surgery is often self-limiting but is associated with increased risk of morbidity and mortality. Contributing factors and impact of time to achieve rate control of JET are poorly described.

Methods:

From January 2010 to June 2015, a retrospective, single-center cohort study was performed of children who developed JET after CHD surgery . We classified the cohort into two groups: patients who achieved rate control of JET in ≤24 hours and in >24 hours. We examined factors associated with time to rate control and compared clinical outcomes (mortality, duration of mechanical ventilation, length of intensive care unit [ICU], and hospital stay) between the two groups.

Results:

Our cohort included 27 children, with a median age of 3 (interquartile range: 0.7-38] months. The most common CHD lesions were ventricular septal defect (n = 10, 37%), tetralogy of Fallot (n = 7, 25.9%), and transposition of the great arteries (n = 4, 14.8%). In all, 15 (55.6%) and 12 (44.4%) patients achieved rate control of JET in ≤24 hours and >24 hours, respectively. There was a difference in median mechanical ventilation time (97 [21-145) vs 311 [100-676] hours; P = .013) and ICU stay (5.0 [2.0-8.0] vs 15.5 [5.5-32.8] days, P = .023) between the patients who achieved faster rate control than those who didn’t. There was no difference in length of hospital stay and mortality between the groups.

Conclusion:

Our study demonstrated that time to achieve rate control of JET was associated with increased duration of mechanical ventilation and ICU stay.

Arrhythmias in Cardiac Critical Care

OBJECTIVES

Here, we characterize the frequency, mechanisms, clinical impact, and potential treatment options for several arrhythmias commonly encountered in pediatric cardiac critical care.

DATA SOURCE

MEDLINE and PubMed.

CONCLUSIONS

Arrhythmias among children in the cardiac critical care setting are common and clinically important, associated independently with prolonged mechanical ventilation, critical care unit stay, and an increase in mortality. The precise characterization of an arrhythmia may provide clues as to an underlying mechanism as well as serve to guide treatment. Arrhythmia therapy, pharmacologic or otherwise, is directed toward addressing the underlying mechanism, and as such may be applicable to the treatment of more than one specific rhythm disturbance. Decisions concerning therapy must call into consideration an arrhythmia's underlying etiology, mechanism, and associated hemodynamic embarrassment, along with the potential for adverse effects of treatment.

Late-Onset Postoperative Junctional Ectopic Tachycardia in Nonsurgical Procedures

Postoperative junctional ectopic tachycardia (JET) is a narrow complex tachycardia and most frequently occurs during and after surgical repair of certain types of congenital heart defects. Postoperative junctional ectopic tachycardia may produce unfavorable hemodynamics that prolongs stays in the cardiac intensive care unit and hospital, prolongs time on a ventilator, and occasionally requires the use of extracorporeal membrane oxygenation (ECMO) as rescue therapy. The present report describes a rare case of late-onset postoperative junctional ectopic tachycardia, which occurred 13 days after the deployment of a perimembranous ventricular septal defect (PmVSD) occluder in a 17-year-old female teenager. To the best of our knowledge, late-onset postoperative junctional ectopic tachycardia has not previously been reported as a complication in nonsurgical procedures. In this case, the junctional ectopic tachycardia remained resistant to medicines and the haemodynamic imbalance caused a serious life-threatening situation in the patient. The occluder was removed by an emergent thoracotomy; then, the patient was successfully cured by being supported with extracorporeal membrane oxygenation. The findings suggest that during follow-up management, the physician should pay attention postoperatively to junctional ectopic tachycardia even after discharge from the hospital.

Ischemia-reperfusion destabilizes rhythmicity in immature atrioventricular pacemakers: A predisposing factor for postoperative arrhythmias in neonate rabbits

BACKGROUND

Postoperative arrhythmias such as junctional ectopic tachycardia and atrioventricular block are serious postoperative complications for children with congenital heart disease. We hypothesize that ischemia-reperfusion (I/R) related changes exacerbate these postoperative arrhythmias in the neonate heart and administration of postoperative inotropes is contributory.

OBJECTIVE

The purpose of this study was to study the effects of I/R and postischemic dopamine application on automaticity and rhythmicity in immature and mature pacemaker cells and whole heart preparations.

METHODS

Single pacemaker cells and whole heart models of postoperative arrhythmias were generated in a rabbit model encompassing 3 primary risk factors: age, I/R exposure, and dopamine application. Single cells were studied using current clamp and line scan confocal microscopy, whereas whole hearts were studied using optical mapping.

RESULTS

Four responses were observed in neonatal atrioventricular nodal cells (AVNCs): slowing of AVNC automaticity (from 62±10 to 36 ± 12 action potentials per minute, P<.05); induction of arrhythmicity or increased beat-to-beat variability (0.08 ± 0.04 to 3.83 ± 1.79, P<.05); altered automaticity (subthreshold electrical fluctuations); and disruption of calcium transients. In contrast, these responses were not observed in mature AVNCs or neonatal sinoatrial cells. In whole heart experiments, neonatal hearts experienced persistent postischemia arrhythmias of varying severity, whereas mature hearts exhibited no arrhythmias or relatively transient ones.

CONCLUSION

Neonatal pacemaker cells and whole hearts demonstrate a susceptibility to I/R insults resulting in alterations in automaticity, which may predispose neonates to postoperative arrhythmias such as junctional ectopic tachycardia and atrioventricular block.

Safety and Efficacy of Prophylactic Amiodarone in Preventing Early Junctional Ectopic Tachycardia (JET) in Children After Cardiac Surgery and Determination of Its Risk Factor

Postoperative arrhythmia is a common complication after open heart surgery in children. JET is the most common and dangerous arrhythmia. We aimed to assess safety and efficacy of prophylactic amiodarone in preventing JET in children underwent cardiac surgery and to assess risk factors for JET among our patients. In total, 117 children who underwent cardiac surgery for CHD at Tanta University Hospital from October 2011 to April 2015 were divided in two groups; amiodarone group (65 patients) was given prophylactic amiodarone intraoperatively and placebo group (52 patients). Amiodarone is started as loading dose of 5 mg/kg IV in the operating room after induction of anesthesia and continued for 3 days as continuous infusion 10-15 μg/kg/min. Primary outcome and secondary outcomes of amiodarone administration were reported. We studied pre-, intra- and postoperative factors to determine risk factors for occurrence of JET among these children. Prophylactic amiodarone was found to significantly decrease incidence of postoperative JET from 28.9 % in placebo group to 9.2 % in amiodarone group, and symptomatic JET from 11.5 % in placebo group to 3.1 % in amiodarone group, and shorten postoperative intensive care unit and hospital stay without significant side effects. Risk factors for occurrence of JET were younger age, lower body weight, longer cardiopulmonary bypass, aortic cross-clamp time, hypokalemia, hypomagnesemia, acidosis and high dose of inotropes. JET was more associated with surgical repair of right ventricular outlet obstruction as in case of tetralogy of Fallot and pulmonary stenosis. Most of JET 15/21 (71.4 %) occurred in the first day postoperatively, and 6/21 occurred in the second day (28.6 %). Prophylactic amiodarone is safe and effective in preventing early JET in children after open heart surgery.

A Low-Cost Simulation Model for R-Wave Synchronized Atrial Pacing in Pediatric Patients with Postoperative Junctional Ectopic Tachycardia

Background

Postoperative junctional ectopic tachycardia (JET) occurs frequently after pediatric cardiac surgery. R-wave synchronized atrial (AVT) pacing is used to re-establish atrioventricular synchrony. AVT pacing is complex, with technical pitfalls. We sought to establish and to test a low-cost simulation model suitable for training and analysis in AVT pacing.

Methods

A simulation model was developed based on a JET simulator, a simulation doll, a cardiac monitor, and a pacemaker. A computer program simulated electrocardiograms. Ten experienced pediatric cardiologists tested the model. Their performance was analyzed using a testing protocol with 10 working steps.

Results

Four testers found the simulation model realistic; 6 found it very realistic. Nine claimed that the trial had improved their skills. All testers considered the model useful in teaching AVT pacing. The simulation test identified 5 working steps in which major mistakes in performance test may impede safe and effective AVT pacing and thus permitted specific training. The components of the model (exclusive monitor and pacemaker) cost less than $50. Assembly and training-session expenses were trivial.

Conclusions

A realistic, low-cost simulation model of AVT pacing is described. The model is suitable for teaching and analyzing AVT pacing technique.

Factors affecting perioperative mortality in tetralogy of Fallot

BACKGROUND

We evaluated the preoperative, operative and postoperative risk factors affecting early mortality in patients who underwent total correction of tetralogy of Fallot (TOF).

METHODS

One hundred and twenty-two TOF patients who underwent reparative surgery between January 2010 and November 2013 were enrolled in the study.

RESULTS

Mean patient age and weight was 2.3 ± 2.5 years and 11.3 ± 6.4 kg, respectively. Cardiac catheterization was performed in 101 patients (83%),and coronary anomalies were found in 11 patients. Mean McGoon index, pulmonary annulus z-score, main pulmonary artery z-score, left pulmonary artery z-score and right pulmonary artery z-score were 2.0 ± 0.4, -1.85 ± 1.54, -2.84 ± 2.06, 1.17 ± 1.73, and 0.74 ± 1.57, respectively. Total reparative surgery with a transannular patch was performed in 97 patients (79.6%); the rest underwent valve-sparing surgery. Median duration of postoperative mechanical ventilation, intensive care and hospital stay were 19 h, 3 days and 9 days, respectively. Extracorporeal membrane oxygenation (ECMO) was required in 10 patients in the postoperative early period. Arrhythmias occurring in the early postoperative period were junctional ectopic tachycardia (n = 13), complete atrioventricular block(n = 10; permanent epicardial pacemaker implanted in four) and ventricular tachycardia (n = 4). Nine patients died in the early postoperative period (7.3%). Parameters found to be associated with increased mortality were low preoperative oxygen saturation; high right ventricular/aortic pressure ratio immediately after surgery; presence of coronary anomaly; requirement of postoperative ECMO; and pacemaker (P = 0.02, P = 0.04, P = 0.01, P = 0.0001, P = 0.03, respectively).

CONCLUSIONS

Poor preoperative oxygenation, presence of coronary anomaly, complete AV block in the early postoperative period, high RV pressure and requirement of ECMO appear to be the most significant factors that affect early mortality in the surgical treatment of TOF. Appropriate preoperative assessment, correct surgical strategies and attentive intensive care monitoring are required in order to reduce mortality.

Magnesium Lowers the Incidence of Postoperative Junctional Ectopic Tachycardia in Congenital Heart Surgical Patients: Is There a Relationship to Surgical Procedure Complexity?

Magnesium sulfate was given to pediatric cardiac surgical patients during cardiopulmonary bypass period in an attempt to reduce the occurrence of postoperative junctional ectopic tachycardia (PO JET). We reviewed our data to evaluate the effect of magnesium on the occurrence of JET and assess a possible relationship between PO JET and procedure complexity. A total of 1088 congenital heart surgeries (CHS), performed from 2005 to 2010, were reviewed. A total of 750 cases did not receive magnesium, and 338 cases received magnesium (25 mg/kg). All procedures were classified according to Aristotle score from 1 to 4. Overall, there was a statistically significant decrease in PO JET occurrence between the two groups regardless of the Aristotle score, 15.3 % (115/750) in non-magnesium group versus 7.1 % (24/338) in magnesium group, P < 0.001. In the absence of magnesium, the risk of JET increased with increasing Aristotle score, P = 0.01. Following magnesium administration and controlling for body weight, surgical and aortic cross-clamp times in the analyses, reduction in adjusted risk of JET was significantly greater with increasing Aristotle level of complexity (JET in non-magnesium vs. magnesium group, Aristotle level 1: 9.8 vs. 14.3 %, level 4: 11.5 vs. 3.2 %; odds ratio 0.54, 95 % CI 0.31-0.94, P = 0.028). Our data confirmed that intra-operative usage of magnesium reduced the occurrence of PO JET in a larger number and more diverse group of CHS patients than has previously been reported. Further, our data suggest that magnesium's effect on PO JET occurrence seemed more effective in CHS with higher levels of Aristotle complexity.

Intra-operative arrhythmia predicts post-operative arrhythmia and the need for temporary pacing wires

OBJECTIVE

Protocols for the placement of temporary pacing wires vary among institutions. Our current protocol is to selectively place temporary pacing wires in those patients who develop haemodynamically significant intra-operative arrhythmia. We wished to identify how effective our current protocol is at identifying who will develop post-operative arrhythmia and need temporary pacing wires.

METHODS

The charts of 880 patients over 8 years who underwent cardiopulmonary bypass were reviewed to find patients who developed intra-operative arrhythmia, had temporary pacing wires placed, and whether or not they developed post-operative arrhythmia and required utilisation of the pacing wires.

RESULTS

A total of 87 (9.9%) out of 880 patients who required cardiopulmonary bypass over 8 years had intra-operative arrhythmia and had temporary pacing wires placed. Of these, 59 (67.8%) had post-operative arrhythmia and utilised the pacing wires, whereas 28 (32.2%) did not have post-operative arrhythmia or utilise the pacing wires. In all, seven patients who did not have intra-operative arrhythmia or temporary pacing wires placed developed post-operative arrhythmia.

CONCLUSION

Intra-operative arrhythmia is predictive of post-operative arrhythmia (70.2%) and our protocol is a sensitive means of identifying those who will develop post-operative arrhythmia (89.3%).

Efficacy of dexmedetomidine for the control of junctional ectopic tachycardia after repair of tetralogy of Fallot

Background:

Junctional ectopic tachycardia occurs frequently after congenital cardiac surgery and can be a cause of increased morbidity and mortality. Dexmedetomidine (DEX) is an α2 adrenoreceptor agonist, has properties of controlling tachyarrhythmia by regulating the sympatho-adrenal system.

Objective:

To evaluate the efficacy of DEX for control of junctional ectopic tachycardia after repair of Tetralogy of Fallot (TOF).

Materials and Methods:

Two hundred and twenty pediatric cardiac patients with TOFs were enrolled in a prospective randomized control study. Patients underwent correction surgery. They were divided into two groups, i.e., Group 1 (DEX) and Group 2 (control). Heart rate, rhythm, mean arterial pressure (MAP) were recorded after the anesthetic induction (T1), after termination of bypass (T2), after 04 hours (T3), and 08 hours after transferring the patient to intensive care unit (ICU; T4).

Results:

Heart rate was comparable between two groups before starting the drug but statistically significant after bypass until 08 hours after transferring the patient to ICU. Junctional ectopic tachycardia occurred more in Group-2 (20%) as compared to Group-1 (9.09%; P = 0.022). Junctional ectopic tachycardia occurs early in Group-2 (0.14 ± 0.527 hours) as compared to Group 1 (0.31 ± 1.29 hours; P = 0.042). The duration of junctional ectopic tachycardia was more prolonged in Group-2 (1.63 ± 3.64 hours) as compared to Group-1 (0.382 ± 1.60 hours; P = 0.012). The time to withdraw from mechanical ventilation and ICU stay of Group 1 patient was less than of Group 2 patients (P = <0.001).

Conclusion:

DEX had a therapeutic role in the prevention of junctional ectopic tachycardia in patients undergoing repair for TOF.

Predictors of Intensive Care Unit Morbidity and Midterm Follow-up after Primary Repair of Tetralogy of Fallot

Background

Our objectives were to review our institutional early and midterm experience with primary tetralogy of Fallot (TOF) repair, and identify predictors of intensive care unit (ICU) morbidity.

Methods

We analyzed perioperative and midterm follow-up data for all cases of primary TOF repair from 2001 to 2012. The primary endpoint was early mortality and morbidity, and the secondary endpoint was survival and functional status at follow-up.

Results

Ninety-seven patients underwent primary repair. The median age was 4.9 months (range, 1 to 9 months), and the median weight was 5.3 kg (range, 3.1 to 9.8 kg). There was no early surgical mortality. The incidence of junctional ectopic tachycardia and persistent complete heart block was 2% and 1%, respectively. The median length of ICU stay was 6 days (range, 2 to 21 days), and the median duration of mechanical ventilation was 19 hours (range, 0 to 136 hours). By multiple regression analysis, age and weight were independent predictors of the length of ICU stay, while the surgical era was an independent predictor of the duration of mechanical ventilation. At the 8-year follow-up, freedom from death and re-intervention was 97% and 90%, respectively.

Conclusion

Primary TOF repair is a safe procedure with low mortality and morbidity in a medium-sized program with outcomes comparable to national standards. Age and weight at the time of surgery remain significant predictors of morbidity.

Risk factors for morbidity in infants undergoing tetralogy of fallot repair

Background:

Primary repair of tetralogy of Fallot (TOF) has low surgical mortality, but some patients still experience significant postoperative morbidity.

Aim:

To review our institutional experience with primary TOF repair, and identify predictors of intensive care unit (ICU) morbidity.

Settings and Design:

Medium-sized pediatric cardiology program. Retrospective study.

Subjects and Methods:

We retrospectively reviewed all the patients with TOF and pulmonic stenosis who underwent primary repair in infancy at our institution from January 2001 to December 2012. Preoperative, operative, and postoperative demographic and morphologic data were analyzed. ICU morbidity was defined as prolonged ICU stay (≥7 days), and/or prolonged duration of mechanical ventilation (≥48 h).

Statistical Analysis Used:

Multiple logistic regression analysis.

Results:

Ninety-seven patients underwent primary surgical repair during the study period. The median age was 4.9 months (1-9 months) and the median weight was 5.3 kg (3.1-9.8 kg). There was no early surgical mortality. Incidence of junctional ectopic tachycardia (JET) and persistent complete heart block was 2 and 1%, respectively. The median length of ICU stay was 6 days (2-21 days) and median duration of mechanical ventilation was 19 h (0-136 h). By multiple regression analysis, age and weight were independent predictors of length of ICU stay, while surgical era was an independent predictor of duration of mechanical ventilation.

Conclusion:

Primary TOF repair is a safe procedure with low mortality and morbidity in a medium-sized program with outcomes comparable to national standards. Age and weight at the time of surgery remain significant predictors of morbidity.

Anticipation and management of junctional ectopic tachycardia in postoperative cardiac surgery: Single center experience with high incidence

BACKGROUND

Junctional ectopic tachycardia (JET) often occurs in the early postoperative period following surgery for congenital heart diseases and may lead to hemodynamic compromise. Its exact etiology is unknown, however, longer cardiopulmonary bypass (CPB) time, aortic cross clamp (ACC) time, catecholamines, and hypomagnesemia are known risk factors. JET is associated with increased postoperative morbidity and mortality.

MATERIALS AND METHODS

A prospective cohort study of 194 consecutive children who underwent open heart surgery on CPB over 1 year period, patients was divided into three groups; JET, non-JET arrhythmia, and no arrhythmia groups. Information on patient's demographics (sex, age, and body weight), type of surgical interventions, duration of CPB and ACC, the use of inotropic support, duration of intensive care unit (ICU) stay, and response to different therapeutic methods were collected.

RESULTS

JET was documented in 53 patients (27%) most commonly following tetralogy of Fallot (TOF) repair and was associated with longer CPB and ACC times (118 and 77 min, respectively) as compared to non-JET arrhythmia (93.9 and 55.3 min, respectively) and no arrhythmia groups (94.9 and 54.8 min, respectively). Patients with JET required more inotropic support and longer ICU stay as compared to other groups. Amiodarone was safe and effective in treatment of JET. Atrial electrocardiogram (ECG) and Lewis lead ECG were helpful tools in JET diagnosis. The mortality was 11.5% in JET patients.

CONCLUSIONS

Incidence of JET was 27% possibly due to the large number of Fallot repair and Senning operation. Longer CPB and ACC times are risk factors for JET.

Low incidence of arrhythmias in the right ventricular infundibulum sparing approach to tetralogy of Fallot repair

To improve outcomes, including arrhythmia incidence, for patients with tetralogy of Fallot (TOF), the authors' institution adopted an approach that minimizes or avoids transmural incision of the right ventricular outflow tract. When pulmonary blood flow is insufficient during the neonatal period, placement of an aortopulmonary artery shunt is preferred, followed by complete repair later in infancy. This study reviewed the perioperative and mid-term arrhythmia outcomes at the authors' institution using this approach. Patients who underwent TOF repair from 1995 to 2008 were included in the study. Patient demographics and surgical history were collected. The primary end points of the study included documented perioperative arrhythmias and arrhythmias at the 10-year follow-up assessment. Of the 298 patients who underwent TOF repair, 50 (17 %) had undergone prior placement of a systemic-to-pulmonary artery shunt. The median age at repair was 9.7 months (interquartile range, 6.3-16.2 months). Clinically significant perioperative arrhythmias were found in 12 patients (4 %) including 6 junctional tachycardias, 4 atrial tachycardias, and 1 temporary complete heart block. No patients were receiving antiarrhythmic medications more than 24 months after surgery. Of the 298 patients, 86 (29 %) had a follow-up period of 10 years or longer (median, 12.2 years). No patients experienced new arrhythmias, received antiarrhythmic therapy, experienced post-discharge ventricular tachycardia, had atrioventricular block, or required a pacemaker or defibrillator. The right ventricular infundibulum sparing approach is associated with an extremely low incidence of perioperative and midterm arrhythmias. The perioperative and mid-term outcomes compare favorably with existing data from programs favoring neonatal repair. Long-term follow-up evaluation is essential to determine whether this strategy can effectively alter late pathophysiology and minimize late-term arrhythmias and associated mortality.

Primary tetralogy of Fallot repair: Predictors of intensive care unit morbidity

Background

Primary repair of tetralogy of Fallot has low surgical mortality, but some patients still experience significant postoperative morbidity. Our objectives were to review our institutional experience with primary tetralogy of Fallot repair, and identify predictors of intensive care unit morbidity.

Methods

We reviewed all patients with tetralogy of Fallot who underwent primary repair in infancy from 2001 to 2012. Preoperative, operative, and postoperative demographic and morphologic data were analyzed. Intensive care unit morbidity was defined as prolonged intensive care unit stay (≥7 days) and/or prolonged duration of mechanical ventilation (≥48 h).

Results

97 patients who underwent primary surgical repair during the study period were included in the study. The median age was 4.9 months (range 1–9 months) and the median weight was 5.3 kg (range 3.1–9.8 kg). There was no early surgical mortality. The incidence of junctional ectopic tachycardia and persistent complete heart block was 2% and 1%, respectively. The median intensive care unit stay was 6 days (range 2–21 days) and the median duration of mechanical ventilation was 19 h (range 0–136 h). Age and weight were independent predictors of intensive care unit stay, while surgical era predicted the duration of mechanical ventilation.

Conclusion

Primary tetralogy of Fallot repair is a safe procedure with low mortality and morbidity in a medium-sized program with outcomes comparable to national standards. Age and weight at the time of surgery were significant predictors of morbidity.

R-wave synchronised atrial pacing in post-operative junctional ectopic tachycardia using a transoesophageal pacemaker

We report the first case of R-wave synchronised atrial pacing using a transoesophageal pacemaker. A 3-month-old baby developed a junctional ectopic tachycardia after surgical closure of a ventricular septal defect. R-wave synchronised atrial pacing with an external pacemaker was not possible owing to dislocation of the atrial epimyocardial pacing wires. Therefore, a temporary oesophageal pacemaker was connected in series to the external pacemaker to allow transoesophageal atrial pacing triggered by the preceding ventricular actions.

Vasoactive-inotropic score after pediatric heart transplant: a marker of adverse outcome

VIS, a quantitative index of pressor support, has been shown to be a predictor of morbidity and mortality in infants younger than six months who underwent CPB. Data on its prognostic utility following pediatric OHT are lacking. This study compared clinical outcomes in children with differential VIS after pediatric OHT. A retrospective cohort study of 51 consecutive heart transplants from 2004 to 2011 was performed at a pediatric tertiary care facility. Peak VIS was computed within initial 24 and 48 h after OHT and was weighted for peak dose and administration of any or all of six pressors. Patients with peak VIS ≥ 15 constituted high VIS group. Children who persistently required a higher magnitude of pressor support for the first 48 h after OHT, as reflected by high peak VIS, had significantly longer ICU stay (30.2 vs. 15.9 days, p = 0.01), pressor (11.4 vs. 6.8 days, p = 0.02) and ventilatory durations (12.4 vs. 5.9 days, p = 0.05), and higher rates of short-term morbidities. Patients with longer CPB (213 vs. 153 min, p = 0.005) time have higher peak VIS. High peak VIS at 48 h is an effective, yet simple clinical marker for adverse outcomes in pediatric OHT recipients.

Incidence and risk factors of complete atrioventricular block after operative ventricular septal defect repair

BACKGROUND

Complete atrioventricular block (AVB) is a recognized complication of ventricular septal defect (VSD) repair. The objective of this study was to examine incidence and risk factors.

METHODS

This is a single-center, retrospective study. All pediatric patients (age <18 years) who underwent VSD repair between November 2001 and August 2009 with concordant atrioventricular and ventriculoarterial connections were included. Patients were classified as having no AVB or transient AVB, and outcomes of early pacemaker placement (before hospital discharge) or late pacemaker placement (after hospital discharge) were recorded.

RESULTS

Eight hundred twenty-eight patients (48.6% female) underwent VSD repair during the study period. Mean age at repair was 14 ± 29.4 months. A total of 64 patients (7.7%) developed surgical AVB. Among those patients who developed AVB, 48 (75%) had transient AVB. Sixteen patients (1.9%) required a pacemaker, 14 early (88%) and 2 late (12%). Patients <4 kg (4.2% vs. 1%, P ≤ .01) and those with inlet VSDs (11.6% vs. 1.4%, P ≤ .01) were more likely to develop surgical AVB. Surgical AVB was not influenced by the presence of chromosomal abnormalities or other congenital heart disease.

CONCLUSION

The overall incidence of surgical AVB is consistent with previous reports. Weight <4 kg and presence of an inlet VSD were significant risk factors.

Junctional ectopic tachycardia after congenital heart surgery in the current surgical era

To determine the incidence of postoperative junctional ectopic tachycardia (JET) in a modern cohort of pediatric patients, evaluate possible risk factors for JET, and examine the effects of JET on postoperative morbidity and mortality. JET is common after congenital heart surgery. JET-related mortality has been a rare event at our center, which is different from previous reports. We reviewed records for pediatric patients who had postoperative arrhythmias between January 2006 and June 2010 at a large tertiary-care children's hospital. We performed a matched case-control study to identify risk factors for JET and a matched-cohort study to compare outcomes between patients and controls. Whenever possible, each JET case was randomly matched to two controls on the basis of lesion, repair, and surgical period. We identified 54 patients with JET (incidence = 1.4 %). After multivariate logistic regression analysis, low operative weight, cardiopulmonary bypass (CPB) duration >100 min, and immediate postoperative serum lactic acid level >20 mg/dl were associated with increased odds of developing JET. Patients with JET had longer mechanical ventilation time, cardiac intensive care unit (CICU) stay, and hospital stay. There was only one death in JET group (1.8 %) with no significant difference compared with the control group. JET remains a relatively common postoperative arrhythmia, but it is less frequent than previously reported. JET occurs more commonly in smaller patients with longer CPB runs and significant postoperative lactic acidosis levels. Mortality associated with JET is lower than historically reported, but morbidity remains high.