Early postoperative arrhythmias after pediatric cardiac surgery

Clinical presentation and surgical outcomes in patients with Shone's complex: a systematic review

OBJECTIVE

Shone's complex comprises of a combination of congenital cardiac anomalies causing obstructions in the left ventricle's inflow and outflow tracts. This systematic review aims to evaluate the clinical features and surgical outcomes of Shone's complex.

METHODS

An electronic literature search of PubMed and Scopus was performed to identify relevant studies related to the presentation, management, and outcomes of Shone's complex. Two reviewers independently performed selection. Data on study characteristics, participant demographics, interventions, outcomes, and follow-up durations were extracted and analyzed.

RESULTS

A total of 691 papers were identified, with 18 studies included in the final analysis. The majority of the studies (n = 12) focused on the pediatric age group. The most common clinical presentations were coarctation of the aorta (n = 17) and mitral stenosis (n = 12). Surgical interventions often involved staged approaches, prioritizing outflow before inflow obstructions. Mitral valve repair was preferred over replacement due to better long-term outcomes (n = 8). Biventricular repair was recommended due to improved postoperative outcomes, but often needed reoperations. Reoperations were common, primarily due to recurrent coarctation (n = 10), subaortic stenosis (n = 8), and mitral valve dysfunction (n = 7). Pulmonary hypertension (n = 10) and arrhythmias (n = 11) were significant complications. Most patients were in modified Ross/NYHA functional class 1 on follow-up. Mortality rates ranged from 4 to 28%, with better outcomes associated with early and strategic surgical interventions.

CONCLUSION

Early diagnosis and biventricular repair were associated with better outcomes while transplantation was often an eventuality. Standardized diagnostic criteria, long-term follow-up, and consensus guidelines are needed to improve the management of this congenital heart disease.

A multimodal deep learning tool for detection of junctional ectopic tachycardia in children with congenital heart disease

Background

Junctional ectopic tachycardia (JET) is a prevalent life-threatening arrhythmia in children with congenital heart disease. It has a marked resemblance to normal sinus rhythm, often leading to delay in diagnosis and management.

Objective

The study sought to develop a novel multimodal automated arrhythmia detection tool that outperforms existing JET detection tools.

Methods

This is a cohort study performed on 40 patients with congenital heart disease at Texas Children's Hospital. Electrocardiogram and central venous pressure waveform data produced by bedside monitors are captured by the Sickbay platform. Convolutional neural networks (CNNs) were trained to classify each heartbeat as either normal sinus rhythm or JET based only on raw electrocardiogram signals.

Results

Our best model improved the area under the curve from 0.948 to 0.952 and the true positive rate at 5% false positive rate from 71.8% to 80.6%. Using a 3-model ensemble further improved the area under the curve to 0.953 and the true positive rate at 5% false positive rate to 85.2%. Results on a subset of data show that adding central venous pressure can significantly improve area under the receiver-operating characteristic curve from 0.646 to 0.825.

Conclusion

This study validates the efficacy of deep neural networks to notably improve JET detection accuracy. We have built a performant and reliable model that can be used to create a bedside alarm that diagnoses JET, allowing for precise diagnosis of this life-threatening postoperative arrhythmia and prompt intervention. Future validation of the model in a larger cohort is needed.

Prevalence and risk factors analysis of early postoperative arrhythmia after congenital heart surgery in pediatric patients

Background

Arrhythmia is one of the most common complications after cardiac surgery. The objectives of this study were to determine the prevalence and analyze the risk factors of postoperative arrhythmia in pediatric patients after cardiac surgery for congenital heart defects (CHD) at a single center in Bali, Indonesia over 2 years period.

Methods

A cross-sectional study, among 120 pediatric patients with CHD who underwent cardiac surgery, 92 patients met inclusion criteria in this study. The data were taken from medical records included demographic data, anthropometry, electrocardiography, surgical procedures, perioperative parameters, electrolyte levels, and management of postoperative arrhythmias.

Results

Among 92 patients, 14 (15.2%) developed postoperative arrhythmias. Complete heart block (CHB) the most common arrhythmia, observed in five patients (35.7%), followed by supraventricular tachycardia three patients (21.4%). There were statistically significant differences between arrhythmia and nonarrhythmia groups for cardiopulmonary bypass (CPB) duration (171.23 vs. 108.01 min), aortic cross-clamp duration (115.58 vs. 73.59 min), ischemia duration (106.33 vs. 65.43 min), and potassium level (3.33 vs. 3.88 mmol/L) with p < .05. Based on multivariate linear regression analysis, CPB time and potassium level were found to be independent risk factor.

Conclusions

Early postoperative arrhythmia observed 15.2% in this study, dominated by CHB. CPB duration, aortic cross-clamping, ischemia time, and potassium level were statistically significantly different between arrhythmia and nonarrhythmia groups.

Comparison of the effects of conventional method and primary sutureless techniques on early postoperative rhythm problems in patients with total abnormal pulmonary venous return anomaly

BACKGROUND

Total abnormal pulmonary venous return anomaly is a CHD characterised by abnormal pulmonary venous flow directed to the right atrium. In this study, we aimed to compare the effects of these techniques on early rhythm problems in total abnormal pulmonary venous return anomaly cases operated with conventional or primary sutureless techniques.

METHOD

Seventy consecutive cases (median age 1 month, median weight 4 kg) who underwent total abnormal pulmonary venous return anomaly repair with conventional or primary sutureless technique between May 1 2020 and May 1 2022 were evaluated. The rate, diagnosis, and possible risk factors of postoperative arrhythmias were investigated. The results were evaluated statistically.

RESULTS

When the total abnormal pulmonary venous return anomaly subgroup of 70 cases was evaluated, 40 cases were supracardiac, 18 cases were infracardiac, 7 cases were cardiac, and 5 cases were mixed type. Twenty-eight (40%) cases had a pulmonary venous obstruction. Primary sutureless technique (57%, supracardiac n = 24, mixed = 3, infracardiac = 13) was used in 40 patients. Median cardiopulmonary bypass time (110 versus 95 minutes) and median aortic clamp time (70 versus 60 minutes), median peak lactate (4.7 versus 4.8 mmol/l) in the first 72 hours, and median peak vasoactive inotropic score in the first 72 hours of the primary sutureless and conventional technique used cases value (8 versus 10) were similar. The total incidence of arrhythmias in the conventional group was significantly higher than in the primary sutureless group (46.7% versus 22.5%, p = 0.04). Supraventricular early beat was observed in 3 (7.5%), sinus tachycardia was seen in 6 (15%), junctional ectopic tachycardia was seen in 1 (2.5%), intra-atrial reentry tachycardia was seen in 1 (2.5%), usual supraventricular tachyarrhythmia was seen in 2 cases (5%) in the primary sutureless group. In the conventional group, supraventricular early beat was observed in six of the cases (20%), sinus tachycardia in five (16.7%), junctional ectopic tachycardia in four (13.3%), intra-atrial reentry tachycardia (10%) in three, and supraventricular tachyarrhythmia in seven cases (23.3%). In the first 30 days, there was a similar mortality rate (10% versus 10%), with four patients in the primary sutureless group and three in the conventional group. The median follow-up period of the cases was 8 months (interquartile range (IQR) 6-10 months). In the follow-up, arrhythmias were detected in two cases (one supraventricular tachyarrhythmia and one intra-atrial reentry tachycardia) in the primary sutureless group and three cases (two supraventricular tachyarrhythmia, one intra-atrial reentry tachycardia) in the conventional technique. All cases were converted to normal sinus rhythm with cardioversion and combined antiarrhythmic therapy.

CONCLUSION

Different arrhythmias can be observed in the early period in patients with operated total abnormal pulmonary venous return anomaly. Although a higher rate of rhythm problems was observed in the early period in the conventional method compared to the primary sutureless technique, no significant effect was found on mortality and morbidity between the groups.

Ectopic Atrial Tachycardia in Infants Following Congenital Heart Disease Surgery

Although ectopic atrial tachycardia (EAT) is common following surgery for congenital heart disease (CHD), there are limited data regarding this arrhythmia. This study assessed risk factors and outcomes for patients less than one year of age with post-operative EAT. This was a retrospective analysis of infants undergoing CHD surgery from 2007 to 2020. Patients and surgeries with EAT were compared to controls without EAT. Out of 5372 infant CHD surgeries, EAT developed in 129 (2.5%). Compared to controls, the EAT cohort was younger (median 7 vs 85 days, p < 0.01), weighed less at time of surgery (3.3 vs 4.2 kg, p < 0.01), and was more likely to have DiGeorge syndrome (7.7% vs 3.0%, p < 0.01). Multivariate analysis revealed total anomalous venous connection (TAPVC) repair (odds ratio [OR] 2.8; 95% confidence interval 1.5-5.2), DiGeorge syndrome (OR 2.4; 1.1-5.2), Society of Thoracic Surgeons-European Association for Cardio-Thoracic surgery (STAT) category ≥ 4 (OR 2.1; 1.0-4.4), and longer cardiopulmonary bypass times (OR 1.1; 1.0-1.2) as independent risk factors for EAT. The onset of EAT occurred a median of 9 days (IQR 5-14 days) after CHD surgery. Antiarrhythmic treatment was initiated in 109/129 patients (84%) with propranolol (71%) and amiodarone (24%) the most commonly used medications. Although 15 (11.6%) patients did not survive to hospital discharge, EAT was not directly implicated in any deaths. EAT occurred after 2.5% of infant CHD surgeries. In addition to TAPVC repair, longer and more complex surgeries were associated with an increased the risk for the development of post-operative EAT.

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.

A novel automated junctional ectopic tachycardia detection tool for children with congenital heart disease

Background

Junctional ectopic tachycardia (JET) is a prevalent life-threatening arrhythmia in children with congenital heart disease (CHD), with marked resemblance to normal sinus rhythm (NSR) often leading to delay in diagnosis.

Objective

To develop a novel automated arrhythmia detection tool to identify JET.

Methods

A single-center retrospective cohort study of children with CHD was performed. Electrocardiographic (ECG) data produced by bedside monitors is captured automatically by the Sickbay platform. Based on the detection of R and P wave peaks, 2 interpretable ECG features are calculated: P prominence median and PR interval interquartile range (IQR). These features are used as input to a simple logistic regression classification model built to distinguish JET from NSR.

Results

This study analyzed a total of 64.5 physician-labeled hours consisting of 509,833 cardiac cycles (R-R intervals), from 40 patients with CHD. The extracted P prominence median feature is much smaller in JET compared to NSR, whereas the PR interval IQR feature is larger in JET compared to NSR. The area under the receiver operating characteristic curve for the unseen patient test cohort was 93%. Selecting a threshold of 0.73 results in a true-positive rate of 90% and a false-positive rate of 17%.

Conclusion

This novel arrhythmia detection tool identifies JET, using 2 distinctive features of JET in ECG-the loss of a normal P wave and PR relationship-allowing for early detection and timely intervention.

Early postoperative arrhythmias after pediatric congenital heart disease surgery: a 5-year audit from a lower- to middle-income country

Background

Arrhythmias are known complication after surgery for congenital heart disease (CHD). This study aimed to identify and discuss their immediate prevalence, diagnosis and management at a tertiary care hospital in Pakistan.

Methods

A retrospective study was conducted at a tertiary care hospital in Pakistan between January 2014 and December 2018. All pediatric (<18 years old) patients admitted to the intensive care unit and undergoing continuous electrocardiographic monitoring after surgery for CHD were included in this study. Data pertaining to the incidence, diagnosis, and management of postoperative arrhythmias were collected.

Results

Amongst 812 children who underwent surgery for CHD, 185 (22.8%) developed arrhythmias. Junctional ectopic tachycardia (JET) was the most common arrhythmia, observed in 120 patients (64.9%), followed by complete heart block (CHB) in 33 patients (17.8%). The highest incidence of early postoperative arrhythmia was seen in patients with atrioventricular septal defects (64.3%) and transposition of the great arteries (36.4%). Patients were managed according to the Pediatric Advanced Life Support guidelines. JET resolved successfully within 24 hours in 92% of patients, while 16 (48%) patients with CHB required a permanent pacemaker.

Conclusions

More than one in five pediatric patients suffered from early postoperative arrhythmias in our setting. Further research exploring predictive factors and the development of better management protocols of patients with CHB are essential for reducing the morbidity and mortality associated with postoperative arrhythmia.

Critical arrhythmia in postoperative cardiac children: Recognition and management

Arrhythmias after pediatric cardiac surgery are common and can be life-threatening. They occur intraoperatively or may appear shortly after surgery during postoperative care. They require early management and specific intervention. In this review, we describe important critical arrhythmias that are encountered during postoperative management of children undergoing cardiac surgery. We review the diagnosis, management, and explain the role of epicardial electrocardiogram in diagnosing certain types of postoperative rhythm abnormalities seen during early period after pediatric cardiac surgery.

Effects of Hypothermic Hypoxia/Reoxygenation Fibroblast Culture Medium Containing Sevoflurane on Cardiomyocytes

We established a model of hypothermic hypoxia/reoxygenation injury of fibroblasts, simulated the process of ischemia/reperfusion injury during cardiopulmonary bypass, and studied the effects of cardiac fibroblasts on cardiomyocyte activity, connexin 43 (Cx43), and calmodulin kinase II (CaMKII) expression. Furthermore, the effects of sevoflurane-treated fibroblast culture medium on cardiac activity, Cx43 protein, and CaMKII expression were observed. The results showed that the fibroblast culture medium damaged by hypothermic hypoxia/reoxygenation could reduce the beating frequency of cardiomyocytes, increase the mortality of cardiomyocytes, decrease the relative expression of Cx43, and increase the relative expression of CaMKII. However, sevoflurane containing hypothermic hypoxia/reoxygenation injury fibroblast culture medium can increase the beating frequency of cardiomyocytes, reduce the mortality of cardiomyocytes, increase the relative expression of Cx43 protein, and decrease the relative expression of CaMKII. The results suggest that the antiarrhythmic effects of sevoflurane on the expression of Cx43 and CaMKII are related to fibroblasts.

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.

Early postoperative arrhythmias in patients undergoing congenital heart surgery

Background

This study aims to evaluate early postoperative arrhythmias in children undergoing congenital cardiac surgery.

Methods

A total of 670 pediatric patients (355 males, 315 females; median age: 4 months; range, 1 day to 18 years) who underwent cardiac surgery due to congenital heart defects between December 2018 and November 2019 were included. The rate of postoperative arrhythmias, diagnosis, potential risk factors, and management strategies were evaluated. Multivariate regression analysis was used to identify significant factors of development of postoperative arrhythmias.

Results

Tachyarrhythmia was detected in 54 patients (8.1%), and the most common tachyarrhythmia was junctional ectopic tachycardia. Medical treatment was required in 25/38 (66%) of junctional ectopic tachycardia patients. Amiodarone was initiated in 18, dexmedetomidine in five, and flecainide + amiodarone in two of the patients. Different degrees of atrioventricular block were observed in 30 patients (4.5%). In 12 patients, permanent pacemakers were implanted during hospitalization. Age at the time of surgery under one-year-old, high inotropic scores, prolonged operation time, and high Aristotele"s scores were independent risk factors associated with early postoperative arrhythmia (p<0.05). The most common operations associated with early postoperative arrhythmia were left ventricular outflow tract, (6/20, 30%), complete atrioventricular septal defect (13/53, 24%), and tetralogy of Fallot (20/134, 14%) surgeries.

Conclusion

Cardiac arrhythmias are common in the early period after congenital heart surgery in children. The diagnosis and frequency of arrhythmias may vary according to different surgical procedures.

An alternative technique for intracardiac exposure during transatrial repair of tetralogy of fallot

The commonly used technique to facilitate intracardiac exposure during transatrial repair of tetralogy of fallot involves considerable retraction of the tricuspid valve using retractors. We describe an alternative surgical technique in which it is possible to dispense away with the retractors. The advantages of such a technique are discussed.

Incidence, Risk Factors, and Outcome of Cardiac Arrhythmia Postcardiac Surgery in Children

Objective

To study the incidence of postoperative cardiac arrhythmias in children undergoing cardiac surgery and to evaluate the risk factors and outcome of these patients.

Materials and Methods

This retrospective observational study was conducted in the cardiac pediatric intensive care unit and included children <18 years of age. Children were monitored in the early postoperative period (72 h) for any sustained rhythm abnormality and were classified using standard definition. Details of treatment and their response were assessed. Risk factors for arrhythmias were evaluated using multivariate logistic regression analysis.

Results

Five hundred and thirty-six children were included and the prevalence of arrhythmia was 14.4% (n = 77). The most common arrhythmia was complete heart block (CHB) (n = 28; 5.2%), followed by junctional ectopic tachycardia (JET) (n = 25; 4.7%), junctional escape rhythm (n = 13; 2.4%), supraventricular tachycardia (SVT) (n = 8; 1.5%), and ventricular tachycardia (VT) (n = 3; 0.6%). Cardiac pacing was required in all CHB; 8 (28.6%) required a permanent pacemaker. Six (24%) patients with JET responded to conventional measures; 19 (76.0%) patients required amiodarone and 5 (20%) required cooling to 34°C or cardiac pacing. Temporary cardiac pacing was required in 9 (69.2%) cases of junctional escape rhythm. Seven (87.5%) events of SVT responded to adenosine and 1 (12.5%) required cardioversion. Two (66.7%) of VT responded to cardioversion while 1 (33.3%) was refractory. Five (6.5%) patients with arrhythmia died. In the multivariate logistic regression analysis, age <1 year, risk adjustment for congenital heart surgery category ≥3, and cross-clamp time >67 min were independent risk factors.

Conclusion

Early postoperative period following cardiac surgery is extremely vulnerable to cardiac arrhythmias. Although majority are self-limiting, some can be life-threatening.

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.

Does dexmedetomidine have an antiarrhythmic effect on cardiac patients? A meta-analysis of randomized controlled trials

Background

Cardiac surgery patients often experience several types of tachyarrhythmias after admission to the intensive care unit (ICU), which increases mortality and morbidity. Dexmedetomidine (DEX) is a popular medicine used for sedation in the ICU, and its other pharmacological characteristics are gradually being uncovered.

Purpose

To determine whether DEX has an antiarrhythmic effect after cardiac surgery.

Methods

The three primary databases MEDLINE, Embase (OVID SP) and the Cochrane Central Register of Controlled Trials (CENTRAL) were searched, and all English-language and randomized control-designed clinical publications comparing DEX to control medicines for sedation after elective cardiac surgery were included. Two colleagues independently extracted the data and performed other quality assessments. A subgroup analysis was performed according to the different medicines used and whether cardiopulmonary bypass (CPB) was applied. All tachyarrhythmias that occurred in the atria and ventricles were analyzed.

Results

A total of 1295 patients in 9 studies met the selection criteria among 2587 studies that were screened. After quantitative synthesis, our results revealed that the DEX group was associated with a lower incidence of ventricular arrhythmia (VA, OR 0.24, 95% CI 0.09–0.64, I² = 0%, P = 0.005) than the control group. Subgroup analysis did not reveal a significant difference between the DEX and propofol subgroups (OR 0.13, 95% CI 0.03–0.56, I² = 0%, P = 0.007). Additionally, no difference in the incidence of atrial fibrillation (AF) was observed regardless of the different control medicines (OR 0.82, 95% CI 0.60–1.10, I² = 25%, P = 0.19) or whether CPB was applied.

Conclusions

This meta-analysis revealed that DEX has an antiarrhythmic effect that decreases the incidence of VA compared to other drugs used for sedation following cardiac surgery. DEX may not have an effect on AF, but cautious interpretation should be exercised due to high heterogeneity.

Risk Factors for Development of Ectopic Atrial Tachycardia in Post-operative Congenital Heart Disease

Ectopic atrial tachycardia (EAT) is common in surgically repaired congenital heart disease (CHD) and carries the potential for significant hemodynamic compromise. Our objective was to determine the incidence, and risk factors of EAT after CHD surgery. Prospective study of patients that underwent surgery for CHD from February to October 2016 was performed. Demographic, perioperative and electrophysiologic data were collected. Sustained EAT (> 30 s) was documented by telemetry or electrocardiogram and confirmed by a pediatric electrophysiologist. All patients were followed through index hospitalization. During the study period, 17/204 (8%) of patients developed EAT with median time-to-event of 14 days. 15/17 (88%) received anti-arrhythmic therapy for sustained EAT. By univariate analysis, younger age (5 vs. 284 days, P < .001), lower weight (3.2 vs. 7.5 kg, P < .001), single ventricle physiology (P = .05), longer cardiopulmonary bypass time (176 vs. 94 min, P < .001), need for delayed sternal closure (P < .001), and higher STAT category (P < .001) were associated with EAT. Incidence among single ventricle patients was 7/44 (16%), and of those 7/13 (54%) were < 30 days of age. Multivariable Cox regression analysis confirmed age at surgery < 30 days (hazard ratio = 11.7, P = .002) and use of milrinone (hazard ratio = 4.4, P = .007) as independent predictors of EAT. Post-operative EAT is frequent following surgery for CHD especially in neonates. Further study is warranted, specifically in the single ventricle population, given the high potential risk for arrhythmia-induced hemodynamic compromise in this vulnerable population.

Arrhythmias in Children in Early Postoperative Period After Cardiac Surgery

Background:

Postoperative arrhythmias are a known complication after cardiac surgical repairs for congenital heart disease.

Methods:

Data were reviewed pertaining to incidence, diagnosis, potential risk factors, and management of postoperative arrhythmias in 369 consecutive patients under 18 years of age, undergoing elective open heart surgery. All children were admitted to the intensive care unit and continuous electrocardiographic monitoring was performed. Patient factors such as Aristotle Basic Complexity Score, total surgical duration, hypotension, tachycardia, serum lactate level, and inotropic score were analyzed. Univariate analysis was done to assess associations between these factors and the occurrence of postoperative arrhythmias.

Results:

Twenty-five (6.7%) patients developed arrhythmias. Junctional ectopic tachycardia (JET) was the most common arrhythmia occurring in 15 (60%) patients, followed by supraventricular tachycardia in 3 (12%), ventricular premature contractions in 3 (12%), hemodynamically unstable ventricular tachycardia and fibrillation in 3 (12%), and atrial fibrillation in 1 (4%) patient. Different grades of heart block were noted in 13 patients. Aristotle score (P = .014), total surgical duration (P < .01), hypotension (P = .02), heart rate (beats per minute) (P = .001), serum lactate level (P = .04), and inotropic score (P = .02) in the early postoperative period were associated with arrhythmia occurrence. Surgeries for ventricular septal defect alone or in association with other diseases including tetralogy of Fallot (TOF) and transposition of the great arteries (TGA) were found to be associated with higher risk of arrhythmias.

Conclusion:

This study showed a low incidence of arrhythmias, JET being the commonest, seen more in TOF repair and these could be treated efficiently. Higher Aristotle score, longer surgical time, hypotension, tachycardia, high inotropic score, and high serum lactate levels were associated with the occurrence of arrhythmias postoperatively.

Management of postoperative junctional ectopic tachycardia in pediatric patients: a survey of 30 centers in Germany, Austria, and Switzerland

Postoperative junctional ectopic tachycardia (JET) is a frequent complication after pediatric cardiac surgery. Current recommendations on how and when to treat JET are inconsistent. We evaluated the management strategies of postoperative JET in German-speaking countries. We sent an online survey to 30 centers of pediatric cardiology that perform surgery for congenital heart defects in Germany (24), Austria (4), and Switzerland (2). The survey asked 18 questions about how and in what treatment sequence postoperative JET was managed. All 30 centers completed the survey (100% return rate). There was general agreement that the management of JET is based on administration of antiarrhythmic drugs, body surface cooling, and temporary pacing. Many centers presented treatment algorithms based on published literature, all centers named amiodarone as the first drug of choice. Significant disagreement was found concerning the timing and sequential order of additional therapeutic measures and particularly about the dosing of amiodarone and the role of R-wave synchronized atrial pacing.

CONCLUSION

This survey reveals that from center to center, the treatment of postoperative JET may vary substantially. Future work should focus on those treatment modalities where a high rate of variation is found. Such studies may be of value to achieve commonly adopted treatment recommendations. What is known: • Treatment of postoperative junctional ectopic tachycardia is predominantly based on administration of antiarrhythmic drugs, therapeutic cooling, and temporary pacing. • Amiodarone is the antiarrhythmic drug of choice in this context. What is new: • Dosing and duration of administration of amiodarone differ relevantly from center to center. • The sequential order of drug administration, therapeutic cooling, and pacing is not consistent.

Catheter Ablation of Incisional Atrial Tachycardia

Tachycardias after atrial incisions represent frequent and serious problem. The majority of them are based on a re-entry electrical activation around a combination of anatomic and surgically created obstacles. Considering significant progress of cardiovascular surgery during the last decade along with potential large amount of open-heart procedures in the near future the number of incisional tachycardias has a tendency to increase. The aim of this work was to quantify the magnitude of the problem, characterize the tachycardias after different surgical operations and to analyze possible interventional treatment strategies. Nowadays evolution of mapping and ablation technologies may contribute to radically treatment of this type of arrhythmias while there are still a lot of issues that should be solved to improve the results of interventional treatment of incisional tachycardias.

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.