Early postoperative arrhythmias after open-heart procedures in children with congenital heart disease

Standardized Temporary Atrial Epicardial Wire Locations Lead to Enhanced Atrial Signal Identification

Background: Arrhythmias, common after pediatric cardiac surgery, are associated with increased morbidity and mortality. Atrial epicardial wires (AEW) improve diagnostic accuracy but have variable pacing and sensing properties based on their location. Even so, there are no longitudinal prospective pediatric studies examining ideal placement of AEW. Methods: This multicenter study compared atrial amplitudes, pacing sensitivities and thresholds via AEW placed at Bachmann's Bundle (BB) and the interatrial groove near the right pulmonary veins (IGRPV) versus the surgeons' standard locations. An AtriAmp system was used to obtain an atrial ECG to calculate atrial and ventricular amplitude from atrial electrograms on the bedside monitor. Sensitivities and thresholds via a temporary pacemaker were documented. ANOVA tests with repeated measures and post-hoc pairwise comparisons were performed to compare variables within the first 24-h postoperative hours. Mixed effects linear regression models were employed to examine daily trends. Results: In the first 24-h following cardiac surgery, AEW at BB and IGRPV showed significantly larger atrial amplitudes than the surgeons' standard locations. In addition, there was a negative trend in atrial ECG amplitude in all AEW from postoperative days 0 to 1; however, subsequent days showed a positive mean change in atrial amplitude with largest increase seen at BB. Atrial sensing as measured by the temporary pacemaker had statistically greater atrial signal amplitude from the BB-IGRPV set in both polarities (ie, with the BB as the - or + electrode pair) as compared to the surgeons' standard locations. No difference in atrial thresholds (mA) were noted in the immediate postoperative period or over time, with a relatively low atrial threshold at all sites. Conclusion: Standardization of AEW at Bachmann's Bundle can yield largest atrial amplitudes by atrial ECG and highest atrial sensing parameters without compromising atrial thresholds.

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.

Improvements in Accuracy and Confidence in Rhythm Identification After Cardiac Surgery Using the AtriAmp Signals

Objectives: Following cardiac surgery, 50% to 60% of patients with congenital heart disease will experience an arrhythmia. These arrhythmias are associated with increased morbidity and mortality. Therefore, rapid and accurate identification is paramount to the improvement of patient outcome. We hypothesize that the AtriAmp, a device which allows atrial electrogram (AEG) display on the bedside monitors, will increase provider accuracy and confidence in arrhythmia diagnosis. Design: A prospective observational study. Electrograms were collected from post-operative patients from the bedside monitors surface ECG and an AEG using the AtriAmp. A 12-question online survey was given to critical care and cardiology providers at 9 different programs across the country as well as being posted to the AAP SOCC fall newsletter. Six questions displayed signals from only the surface leads, while the other 6 showed the same arrhythmias with an AEG obtained from the AtriAmp. Answers were then evaluated for confidence and accuracy. A paired t-test along with mixed method modeling was used to assess the data. Setting: Cardiac pediatric ICU. Subjects: Providers in pediatric cardiology and pediatric critical care were evaluated on their ability to diagnose arrhythmias on surface ECG and AEG obtained from bedside monitor. Interventions: The accuracy and confidence of diagnosis of both surface and AEG signals were evaluated through an on-line survey. Results: Eighty-eight providers completed the survey. The study showed that interpreting with the AtriAmp signal, compared to the surface ECG only, significantly increased the accuracy (P = .002) and confidence in provider rhythm diagnosis (P < .001). Junctional ectopic tachycardia, sinus tachycardia, and complete heart block had the most significant increase in accuracy of diagnose when using the AtriAmp signal (P < .001, P = .002, P = .010, respectively). Conclusion: Use of the AtriAmp increased provider accuracy and confidence in post-operative rhythm diagnosis when compared to diagnosis using the surface electrograms only.

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.

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.

A Comparative Effectiveness Systematic Review and Meta-analysis of Drugs for the Prophylaxis of Junctional Ectopic Tachycardia

BACKGROUND

Junctional Ectopic Tachycardia (JET) is an arrhythmia originating from the AV junction, which may occur following congenital heart surgery, especially when the intervention is near the atrioventricular junction.

OBJECTIVE

The aim of this systematic review and meta-analysis is to compare the effectiveness of amiodarone, dexmedetomidine, and magnesium in preventing JET following congenital heart surgery.

METHODS

This meta-analysis was conducted according to the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) statement, where 11 electronic databases were searched from the date of inception to August 2020. The incidence of JET was calculated with the relative risk of 95% Confidence Interval (CI). Quality assessment of the included studies was assessed using the Consolidated Standards of Reporting Trials (CONSORT) 2010 statement.

RESULTS

Eleven studies met the predetermined inclusion criteria and were included in this meta-analysis. Amiodarone, dexmedetomidine, and magnesium significantly reduced the incidence of postoperative JET [Amiodarone: risk ratio 0.34; I2= 0%; Z=3.66 (P=0.0002); 95% CI 0.19-0.60. Dexmedetomidine: risk ratio 0.34; I2= 0%; Z=4.77 (P<0.00001); 95% CI 0.21-0.52. Magnesium: risk ratio 0.50; I2= 24%; Z=5.08 (P<0.00001); 95% CI 0.39-0.66].

CONCLUSION

All three drugs have shown promising results in reducing the incidence of JET. Our systematic review found that dexmedetomidine is better in reducing the length of ICU stays as well as mortality. In addition, dexmedetomidine also has the least pronounced side effects among the three. However, it should be noted that this conclusion was derived from studies with small sample sizes. Therefore, dexmedetomidine may be considered as the drug of choice for preventing JET.

Diagnosis and management of junctional ectopic tachycardia in children

Junctional ectopic tachycardia (JET) is more common in its postoperative form. A thorough understanding of its etiology, pathophysiology, and management strategies is essential. Classically, postoperative JET is considered to arise from surgical trauma. Genetic susceptibility and an intrinsic morphologic/functional defect in the conduction system inherent in congenital heart diseases likely play a significant role. The devastating effects on postoperative hemodynamics warrant prompt attention. A multipronged management approach with general measures, pharmacotherapy, and pacing has decreased morbidity and mortality. Amiodarone and procainamide remain the preferred drugs, while ivabradine appears promising. Carefully planned randomized trials can go a long way in developing a systematic management protocol for postoperative JET.

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.

Association Between Postoperative Dexmedetomidine Use and Arrhythmias in Infants After Cardiac Surgery

BACKGROUND

Dexmedetomidine has been suggested as an arrhythmia prophylactic agent after surgery for congenital heart disease due to its heart rate lowering effect, though studies are conflicting. We sought to study the effect of dexmedetomidine in infants that are at highest risk for arrhythmias.

METHODS

Retrospective cohort study of infants less than six months of age undergoing cardiopulmonary bypass for congenital heart disease. The arrhythmia incidence in the first 48 hours after surgery in infants receiving dexmedetomidine for sedation was compared to those that did not receive dexmedetomidine.

RESULTS

A total of 309 patients were included, 206 patients who did not receive dexmedetomidine and 103 patients who did. The incidence of tachyarrhythmias was similar between the non-DEX group and the DEX group (19% vs 15%, P = .34). When adjusted for baseline differences, the non-DEX group did not have an increased risk of postoperative tachyarrhythmias (odds ratio [OR]: 1.4, 95% confidence interval [CI]: 0.5-3.8). The non-DEX group had an increased need for treatment for arrhythmias (18% vs 8%, P = .012). The three lesions with baseline higher risk for arrhythmias (tetralogy of Fallot, transposition of the great arteries, and complete atrioventricular canal) had an increased incidence of tachyarrhythmias in the non-DEX group (34% vs 6%, P = .027). This risk was not significant in multivariate analysis (OR: 2.5, 95% CI: 0.4-15.5).

CONCLUSIONS

High-risk infants had decreased incidence of tachyarrhythmias when receiving dexmedetomidine, though this was not significant after accounting for baseline differences between groups.

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.

Incidence and effect of early postoperative ventricular arrhythmias after congenital heart surgery

BACKGROUND

Postoperative arrhythmias after pediatric congenital heart disease (CHD) surgery are a known cause of morbidity and are associated with mortality. A comprehensive evaluation of early postoperative ventricular arrhythmias (VAs) after CHD surgery has not been reported.

OBJECTIVES

We sought to determine the incidence of in-hospital VAs after CHD surgery and assess the clinical relevance of this arrhythmia during the postoperative hospital course.

METHODS

Patients undergoing CHD surgery at our center from September 2007 through December 2016 were prospectively enrolled. Univariate and multivariate analysis was used to assess the association between postoperative VAs and in-hospital mortality, adjusting for postoperative extracorporeal membrane oxygenation and stage 1 single ventricle palliation operations.

RESULTS

A total of 2503 postoperative courses in 1835 patients were included. In all, 464 (18.5%) had VAs, of whom 135 (29.1%) received treatment. Monomorphic ventricular tachycardia was the most frequently treated ventricular arrhythmia (TVA; n=91 [62.3%]). TVAs were associated with increased postoperative extracorporeal membrane oxygenation (13.3% vs 5.5%; P < .001) and in-hospital mortality (14.9% vs 4.0%; P < .001). In multivariate analysis, TVA was an independent risk factor for in-hospital mortality (adjusted odds ratio 2.44; 95% confidence interval 1.21-4.92).

CONCLUSION

Early postoperative VAs after CHD surgery are more common than previously reported. Postoperative VAs are associated with increased in-hospital mortality, and the subgroup of TVAs is an independent risk factor for in-hospital mortality.

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.

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.

Cardiac Arrhythmia After Open Thoracoabdominal Aortic Aneurysm Repair

BACKGROUND

Cardiac arrhythmias commonly arise after cardiac surgery and are associated with poor prognosis. In thoracoabdominal aortic aneurysm (TAAA) repair, these complications are poorly understood. We assessed characteristics, incidence, outcomes, and potential predictors of postoperative arrhythmia (PA) after open TAAA repair.

METHODS

From 2010 to 2014, 403 consecutive open TAAA replacement operations were performed in patients without preoperative cardiac rhythm abnormalities at a single tertiary center. We compared preoperative characteristics, operative factors, and postoperative outcomes in patients with and without PA, and we used multivariable logistic regression to identify predictors of PA.

RESULTS

PA occurred after 107 (26.5%) procedures. Atrial fibrillation (23%) was the most common type of PA. Length of hospital stay and operative mortality were greater in patients with PA than in patients without it (p < 0.01 for both). Kaplan-Meier cumulative survival for patients with PA was lower than for patients without PA: 69.2% ± 4.6% versus 88.3% ± 2.0% at 1 year and 59.0% ± 5.3% versus 85.0% ± 2.3% at 3 years (p < 0.001 for both). The odds of PA increased with advancing age (1.07 per year; p < 0.001). In addition, the odds of developing PA were higher in patients who received visceral perfusion (odds ratio, 2.58; p = 0.001) and were lower in patients who underwent extent IV repair (odds ratio, 0.44; p = 0.01).

CONCLUSIONS

Postoperative cardiac arrhythmia was common after open TAAA repair. Older patients and patients who underwent visceral perfusion were more likely to develop PA. Cardiac arrhythmia after TAAA repair was associated with prolonged hospital stay, higher early mortality, and lower midterm survival.

Early postoperative arrhythmias after pediatric cardiac surgery

BACKGROUND

This prospective study proposed to determine the incidence, risk factors, and management protocols for early postoperative arrhythmias after pediatric cardiac surgery, with focus on outcomes, using a uniform protocol, and also to see if children operated on at a later age have different issues from those operated on earlier.

METHODS

Of 224 consecutive pediatric patients undergoing cardiac surgery from September 2013 to July 2014, 24 were excluded because their procedures were performed without cardiopulmonary bypass.

RESULTS

The median age was 24 months (mean 50.1 ± 62.4 months, range 0.5-216 months). Fifteen (7.5%) patients developed arrhythmia, the most common was junctional ectopic tachycardia (n = 7, 46.6%) followed by supraventricular tachycardia (n = 5, 33.3%). All junctional ectopic tachycardias occurred within 24 h of intensive care unit admission. Of the 7 patients with junctional ectopic tachycardia, 5 responded to conventional measures and 2 required amiodarone infusion. There was a significant longer cardiopulmonary bypass time in patients with arrhythmias compared to those without arrhythmias.

CONCLUSION

We observed a very low incidence of arrhythmias, particularly junctional ectopic tachycardia, after open heart surgery in children. Other than a longer cardiopulmonary bypass time, no specific predictors were identified. It appears that the cause of arrhythmias following pediatric cardiac surgery is multifactorial and needs further study with a greater number of patients.

Association between perioperative dexmedetomidine and arrhythmias after surgery for congenital heart disease

BACKGROUND

Dexmedetomidine is commonly used after congenital heart surgery and may be associated with a decreased incidence of postoperative tachyarrhythmias. Using a large cohort of patients undergoing congenital heart surgery, we examined for an association between dexmedetomidine use in the immediate postoperative period and subsequent arrhythmia development.

METHODS AND RESULTS

A total of 1593 surgical procedures for congenital heart disease were performed. Dexmedetomidine was administered in the immediate postoperative period after 468 (29%) surgical procedures. When compared with 1125 controls, the group receiving dexmedetomidine demonstrated significantly fewer tachyarrhythmias (29% versus 38%; P<0.001), tachyarrhythmias receiving intervention (14% versus 23%; P<0.001), bradyarrhythmias (18% versus 22%; P=0.03), and bradyarrhythmias receiving intervention (12% versus 16%; P=0.04). After propensity score matching with 468 controls, the arrhythmia incidence between groups became similar: tachyarrhythmias (29% versus 31%; P=0.66), tachyarrhythmias receiving intervention (14% versus 17%; P=0.16), bradyarrhythmias (18% versus 15%; P=0.44), and bradyarrhythmias receiving intervention (12% versus 9%; P=0.17). After excluding controls exposed to dexmedetomidine at a later time in the hospitalization, dexmedetomidine was associated with increased odds of bradyarrhythmias receiving intervention (odds ratio, 2.18; 95% confidence interval, 1.02-4.65). Furthermore, there was a dose-dependent increase in the odds of bradyarrhythmias (odds ratio, 1.04; 95% confidence interval, 1.01-1.07) and bradyarrhythmias receiving intervention (odds ratio, 1.05; 95% confidence interval, 1.01-1.08).

CONCLUSIONS

Although dexmedetomidine exposure in the immediate postoperative period is not associated with a clinically meaningful difference in the incidence of tachyarrhythmias after congenital heart surgery, it may be associated with increased odds of bradyarrhythmias.

Prevalence of and risk factors for early postoperative arrhythmia in children after cardiac surgery

BACKGROUND

The aims of this study were to (i) evaluate postoperative arrhythmias following congenital heart surgery, on 12-lead electrocardiography and Holter monitoring; and (ii) analyze the association between the type of repair and postoperative arrhythmia.

METHODS

A total of 229 children and 10 neonates with a mean age of 4.71 ± 0.41 years (range, 15 days-17 years) who underwent congenital cardiac surgery were included the study. Twelve-lead electrocardiography and Holter monitoring were used to evaluate arrhythmias after the operation.

RESULTS

Within the evaluation period, 104 patients (43.5%) developed arrhythmias after surgery. No arrhythmias were observed in neonates. Female sex (51.9%) was slightly associated with the occurrence of arrhythmias after operation. The most common arrhythmia was supraventricular extra-systoles (65.4%). Risk factors for supraventricular extra-systoles were repair of secundum atrial septal defect (32.3%), ventricular septal defect (25%) and tetralogy of Fallot (14.7%). Also, ventricular extra-systoles were associated with repair of ventricular septal defect.

CONCLUSIONS

Postoperative arrhythmia is usually a frequent and transient phenomenon after congenital cardiac surgery, and is provoked by both mechanical irritation of the conduction system and humoral factors. Postoperative arrhythmia should be anticipated in patients with congenital cardiac surgery. Finally, the association between this type of surgical repair and arrhythmia may be helpful for estimating the type of arrhythmia that develops after congenital cardiac surgery in children.

Perioperative atrial tachycardia is associated with increased mortality in infants undergoing cardiac surgery

OBJECTIVE

Few data are available on the frequency or importance of perioperative atrial tachycardia in infants. We hypothesized that atrial tachycardia in infants undergoing cardiac surgery is not rare and is associated with increased morbidity and mortality.

METHODS

From 2007 through 2010, 777 infants (median age, 1.8 months; interquartile range, 0.33-5.73) underwent cardiac surgery. Their medical records were reviewed for atrial tachycardia during the perioperative period.

RESULTS

Of the 777 patients, 64 (8.2%) developed atrial tachycardia. The independent risk factors for developing atrial tachycardia included surgical age 6 months or younger (odds ratio, 4.4; 95% confidence interval, 1.1-19.15), use of 3 or more inotropes (odds ratio, 2.9; 95% confidence interval, 1.4-6.2), and heterotaxy syndrome (odds ratio, 2.9; 95% confidence interval, 1.1-7.4). All-cause mortality in the atrial tachycardia group was increased (21.9% vs 7.2%, P<.001) during a median follow-up period of 14.6 months (interquartile range, 6.8-24.6), and atrial tachycardia was independently associated with decreased survival (hazard ratio, 1.9; 95% confidence interval, 1.1-3.8). Infants with perioperative atrial tachycardia had a longer hospital length of stay (32 vs 17 days, P<.001) and duration of inotrope use (10.5 vs 3.0 days, P<.001). A total of 57 patients received antiarrhythmic therapy, with propranolol the most common (n=31). Among the survivors, 48 patients received outpatient antiarrhythmic therapy, which was successfully discontinued in 23 patients at a median duration of 14 months (interquartile range, 5.7-18.6) without recurrence.

CONCLUSIONS

Atrial tachycardia is common in infants undergoing cardiac surgery and is independently associated with decreased survival. Among survivors, antiarrhythmic agents successfully controlled atrial tachycardia in most patients with a low recurrence risk after discontinuation.

Perioperative use of dexmedetomidine is associated with decreased incidence of ventricular and supraventricular tachyarrhythmias after congenital cardiac operations

BACKGROUND

Postoperative tachyarrhythmias remain a common complication after congenital cardiac operations. Dexmedetomidine (DEX), an α-2 adrenoreceptor agonist, can have a therapeutic role in supraventricular tachyarrhythmias for cardioversion to sinus rhythm or heart rate control. Whether routine perioperative use of DEX decreases the incidence of supraventricular and ventricular tachyarrhythmias was studied.

METHODS

In this prospective cohort study, 32 pediatric patients undergoing cardiothoracic operations received DEX and were compared with 20 control patients who did not receive DEX.

RESULTS

Dexmedetomidine was started after anesthesia induction and continued intraoperatively and postoperatively for 38±4 hours (mean dose, 0.76±0.04 μg/kg/h). Ten control patients and 2 DEX patients sustained 16 episodes of tachyarrhythmias (p=0.001), including a 25% vs 0% (p=0.01) incidence of ventricular tachycardia and 25% vs 6% (p=0.05) of supraventricular arrhythmias in the control and DEX group, respectively. Transient complete heart block occurred in 2 control patients and in 1 DEX patient. Control patients had a higher heart rate (141±5 vs 127±3 beats/min, p=0.03), more sinus tachycardia episodes (40% vs 6%; p=0.008), required more antihypertensive drugs with nitroprusside (20±7 vs 4±1 μg/kg; p=0.004) and nicardipine (13±5 vs 2±1 μg/kg; p=0.02), and required more fentanyl (39±8 vs 19±3 μg/kg; p=0.005).

CONCLUSIONS

Perioperative use of dexmedetomidine is associated with a significantly decreased incidence of ventricular and supraventricular tachyarrhythmias, without significant adverse effects.

Prevalence of early postoperative arrhythmias in children with delayed open-heart surgery for severe congenital heart disease

BACKGROUND; Our aim was to determine the incidence, risk factors and outcome of early postoperative arrhythmias in children with delayed treatment of severe congenital heart disease.

METHODS

A prospective study was conducted in 141 consecutive children with delayed referral from emerging countries, who underwent open-heart surgery.

RESULTS

Sinus node dysfunction was noted in 5 cases. Preoperative moderate extrasystoly was common and its incidence significantly increased in the postoperative phase. Overall, 9 patients required specific antiarrhythmic therapy: 6 for sustained atrioventricular reciprocating tachycardia, and 3 respectively for atrial flutter, atrial fibrillation and junctional ectopic tachycardia. Non-sustained atrioventricular and ventricular tachycardia required no therapy in respectively 6 and 1 case. Postoperative complete atrioventricular block was observed in 6 patients and remained permanent in 3. No major complications resulted from those arrhythmias. Preoperative low oxygen saturation, preoperative arrhythmias, as well as long cardiopulmonary bypass time and aortic cross-clamp time, were risk factors for early postoperative arrhythmias.

CONCLUSIONS

Children with delayed surgery for congenital heart disease are at risk of developing early postoperative arrhythmias depending on the complexity of their disease and of its treatment. However, their prevalence (14%) is not higher than in the general population of cardiac children.

Prevalence of and risk factors for perioperative arrhythmias in neonates and children after cardiopulmonary bypass: continuous holter monitoring before and for three days after surgery

Background

A comprehensive evaluation of postoperative arrhythmias following surgery for congenital heart disease by continuous Holter monitoring has not been carried out. We aimed, firstly, to establish the time course of pre- and early postoperative arrhythmias by beat-to-beat analysis following cardiopulmonary bypass and, secondly, to examine which surgical procedures present risk factors for specific arrhythmias.

Methods

494 consecutive patients, including 96 neonates, were studied with serial 24-hour Holter electrocardiograms before as well as uninterruptedly during the first 72 hours after surgery and prior to discharge.

Results

Within 24 hours of surgery 59% of the neonates and 79% of the older children developed arrhythmias. Junctional ectopic tachycardia occurred in 9% of neonates and 5% of non-neonates and ventricular tachycardia in 3% and 15%, respectively.

For neonates, male sex and longer cross-clamping time independently increased the risk for arrhythmias (odds ratios 2.83 and 1.96/minute, respectively). Ventricular septal defect repair was a strong risk factor for junctional ectopic tachycardia in neonates and in older children (odds ratios 18.8 and 3.69, respectively). For infants and children, older age (odds ratio 1.01/month) and closure of atrial septal defects (odds ratio 2.68) predisposed to arrhythmias of any type.

Conclusions

We present the largest cohort of neonates, infants and children that has been prospectively studied for the occurrence of arrhythmias after cardiac surgery. Postoperative arrhythmias are a frequent and transient phenomenon after cardiopulmonary bypass, provoked both by mechanical irritation of the conduction system and by humoral factors.

Diagnosis of postoperative arrhythmias following paediatric cardiac surgery

Arrhythmias are commonly encountered in the paediatric intensive care unit setting, most frequently in the setting of postoperative congenital heart disease. Postoperative arrhythmias are an important cause of morbidity in children in the postoperative period following cardiac surgery for congenital cardiac lesions. It is important for all paediatric critical care physicians involved in the care of these children to understand the potential mechanisms involved and how to make an accurate diagnosis. The existing literature has focused on small groups and specific arrhythmias. There is a paucity of literature to guide the clinician in approaching arrhythmias in the paediatric intensive care unit setting. Our objective was to review the recognition and diagnosis of paediatric arrhythmias in the postoperative period following congenital cardiac surgery. Timely and accurate identification of the rhythm disturbance is mandatory and allows for the institution of effective, rhythm specific management strategies.

Timing of removal of pacing wires following paediatric cardiac surgery

BACKGROUND

Temporary percutaneous epicardial pacing wires are routinely placed in children following cardiac surgery. There is uncertainty in clinical practice about the optimum timing for their removal, and practice varies widely both within and between different institutions.

AIM

The aim of our study was to describe the use of temporary pacing in children undergoing cardiac surgery.

METHODS

We performed a prospective audit of 140 children following cardiac surgery in two institutions. Information on diagnosis, surgical procedure, occurrence of arrhythmias, use of pacing wires, timing of removal of the wire, and complications related to removal was recorded on a daily basis from clinical records.

RESULTS

We studied 140 patients undergoing a total of 141 operations. Of these, 39 (28%) required pacing postoperatively. In 38, pacing was required within the first 24 hours. One patient, who was in nodal rhythm for the first 24 hours, required pacing on the second postoperative day, while 29 patients required pacing beyond the first 24 hours. No patient in sinus rhythm on the first postoperative day required new pacing after this time. The median time to removal of the pacing wires was 4.5 days, with an inter-quartile range from 2 to 9 days. Complications included malfunction of atrial wires in 2 patients.

CONCLUSIONS

Our study shows that no patient who was in sinus rhythm for the first 24 hours post-operatively required pacing before their discharge from hospital. This suggests that, in those patients in a stable state of sinus rhythm, and who have not required pacing within the first 24 hours, it may be safe to remove pacing wires after 24 hours. This could be timed to coincide with the removal of chest drains, thus avoiding the need for multiple distressing procedures.

Early postoperative arrhythmias after pediatric cardiac surgery

OBJECTIVE

Early postoperative arrhythmias are a known complication of cardiac surgery; however, little data exists specific to pediatrics. The purpose of this study was to determine the incidence and risk factors associated with the development of arrhythmias immediately after surgery in a pediatric population.

METHODS

Data were collected in a prospective observational format from pediatric patients undergoing cardiac surgery between September 2000 and May 2003. This format included age, anatomy, surgical repair, and serum magnesium and calcium levels, as well as cardiopulmonary bypass and aortic crossclamp times. Patients were continuously monitored, and hemodynamically significant arrhythmias were recorded.

RESULTS

Arrhythmias occurred in 28 of the 189 patients enrolled (15%) including 16 with junctional ectopic tachycardia, 7 with complete atrioventricular block, 4 with ventricular tachycardia, and 1 with re-entrant supraventricular tachycardia. Significant differences were found between the arrhythmia and nonarrhythmia groups with regard to age (22 vs 45 months), cardiopulmonary bypass time (189 vs 109 minutes), and aortic crossclamp time (105 vs 44 minutes); P < .05. Magnesium and calcium levels were not significantly different between the groups. Two repairs carried an increased risk: complete atrioventricular septal defect repair, 8 of 11 patients (72%), and the arterial switch 5 of 8 patients (62.5%); P < .05. Atrioventricular septal defects had an even higher incidence when controlled for age, bypass time, and crossclamp time (odds ratio = 7.65).

CONCLUSIONS

Hemodynamically significant postoperative arrhythmias are a frequent complication of pediatric cardiac surgery. Younger age and longer bypass and crossclamp times are risk factors for arrhythmia. In addition, the repair of atrioventricular septal defects carries an independent risk of arrhythmias.