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

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.

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.

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.

Analysis of clinical and candidate genetic risk factors for postoperative atrial tachycardia after congenital heart surgery in infants

BACKGROUND

Atrial tachycardia (AT) after infant congenital heart disease (CHD) surgery is associated with increased mortality. Polymorphisms in PITX2 (rs2200733) and IL6 (rs1800795) are associated with postoperative atrial fibrillation in adults but have not been studied in CHD. The objective was to test the hypothesis that clinical factors and variants in PITX2 and IL6 are associated with postoperative AT in infants with CHD.

METHODS

Infants (<1 year of age) undergoing CHD surgery between September 2007 and May 2016 were included. Subjects had daily assessment of telemetry and were genotyped for the 2 variants. Univariate and multivariate analyses were performed to test for factors independently associated with AT.

RESULTS

Of 1,067 enrolled infants, 164 had postoperative AT (15.4%); 95 required treatment (8.9%). AT was associated with risk for extracorporeal membrane oxygenation, operative mortality, and longer duration of ventilation, as well as intensive care unit and hospital stays. PITX2 and IL6 genotypes were not associated with AT or AT requiring treatment. In multivariate analysis, use of 2 or more inotropes, age ≤ 28 days; Risk Adjusted classification for Congenital Heart Surgery, Version 1, score ≥ 3; and bypass time were all independently associated with AT. Factors independently associated with treated AT include use of 2 or more inotropes; age ≤ 28 days; and Risk Adjusted classification for Congenital Heart Surgery, Version 1, score ≥ 3.

CONCLUSION

AT occurs in 15% of infants after CHD surgery and is associated with increased morbidity and mortality. Risk factors include use of 2 or more inotropes, neonatal age, and higher surgical complexity score. We observed no association between common genetic variants in PITX2 and IL6 and AT in infants after CHD surgery.

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.

Development and impact of arrhythmias after the Norwood procedure: A report from the Pediatric Heart Network

OBJECTIVES

The study objective was to determine the predictors of new-onset arrhythmia among infants with single-ventricle anomalies during the post-Norwood hospitalization and the association of those arrhythmias with postoperative outcomes (ventilator time and length of stay) and interstage mortality.

METHODS

After excluding patients with preoperative arrhythmias, we used data from the Pediatric Heart Network Single Ventricle Reconstruction Trial to identify risk factors for tachyarrhythmias (atrial fibrillation, atrial flutter, supraventricular tachycardia, junctional ectopic tachycardia, and ventricular tachycardia) and atrioventricular block (second or third degree) among 544 eligible patients. We then determined the association of arrhythmia with outcomes during the post-Norwood hospitalization and interstage period, adjusting for identified risk factors and previously published factors.

RESULTS

Tachyarrhythmias were noted in 20% of subjects, and atrioventricular block was noted in 4% of subjects. Potentially significant risk factors for tachyarrhythmia included the presence of modified Blalock-Taussig shunt (P = .08) and age at Norwood (P = .07, with risk decreasing each day at age 8-20 days); the only significant risk factor for atrioventricular block was undergoing a concomitant procedure at the time of the Norwood (P = .001), with the greatest risk being in those undergoing a tricuspid valve procedure. Both tachyarrhythmias and atrioventricular block were associated with longer ventilation time and length of stay (P < .001 for all analyses). Tachyarrhythmias were not associated with interstage mortality; atrioventricular block was associated with mortality among those without a pacemaker in the unadjusted analysis (hazard ratio, 2.3; P = .02), but not after adding covariates.

CONCLUSIONS

Tachyarrhythmias are common after the Norwood procedure, but atrioventricular block may portend a greater risk for interstage mortality.

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.

Arrhythmias Following Comprehensive Stage II Surgical Palliation in Single Ventricle Patients

Post-operative arrhythmias are common in pediatric patients following cardiac surgery. Following hybrid palliation in single ventricle patients, a comprehensive stage II palliation is performed. The incidence of arrhythmias in patients following comprehensive stage II palliation is unknown. The purpose of this study is to determine the incidence of arrhythmias following comprehensive stage II palliation. A single-center retrospective chart review was performed on all single ventricle patients undergoing a comprehensive stage II palliation from January 2010 to May 2014. Pre-operative, operative, and post-operative data were collected. A clinically significant arrhythmia was defined as an arrhythmia which led to cardiopulmonary resuscitation or required treatment with either pacing or antiarrhythmic medication. Statistical analysis was performed with Wilcoxon rank-sum test and Fisher's exact test with p < 0.05 significant. Forty-eight single ventricle patients were reviewed (32 hypoplastic left heart syndrome, 16 other single ventricle variants). Age at surgery was 185 ± 56 days. Cardiopulmonary bypass time was 259 ± 45 min. Average vasoactive-inotropic score was 5.97 ± 7.58. Six patients (12.5 %) had clinically significant arrhythmias: four sinus bradycardia, one 2:1 atrioventricular block, and one slow junctional rhythm. No tachyarrhythmias were documented for this patient population. Presence of arrhythmia was associated with elevated lactate (p = 0.04) and cardiac arrest (p = 0.002). Following comprehensive stage II palliation, single ventricle patients are at low risk for development of tachyarrhythmias. The most frequent arrhythmia seen in these patients was sinus bradycardia associated with respiratory compromise.

Tachyarrhythmias after the Norwood procedure: relationship and effect of vasoactive agents

Tachyarrhythmias are common after the Norwood stage I palliation. The effects of vasoactive medications on the development of post-operative tachyarrhythmias have not been studied. The primary objective was to identify associations between postoperative tachyarrhythmias and vasoactive medication usage after Norwood stage 1 palliation. Secondary objectives included evaluation for morbidities of tachyarrhythmias and for associations with anatomical or surgical variables. Retrospective chart review was performed on all patients who underwent the Norwood stage 1 palliation at Children's Hospital Colorado between January 2008 and June 2012. Primary outcomes were development of postoperative tachyarrhythmias and the effects of vasoactive medications. Dopamine, epinephrine, milrinone, and vasopressin duration, cumulative dose, highest dose, and dose at onset of tachyarrhythmia were identified. The effects of surgical variables and anatomy were also studied. Sixty-six patients underwent the Norwood procedure, and 33 (50 %) of these patients had postoperative tachyarrhythmias. Patients with tachyarrhythmias had longer ICU stays (p = 0.02) and hospital stays (p < 0.01), but no change in mortality (p = 1.0). Multivariate Cox regression analysis showed that the right ventricle to pulmonary artery shunt (p < 0.01), longer duration of epinephrine treatment (p = 0.02), and higher milrinone dose (p = 0.002) were associated with tachyarrhythmias. Postoperative tachyarrhythmias are common after the Norwood procedure and are associated with longer ICU and hospital stays. High doses of milrinone, longer duration of epinephrine treatment, and the right ventricle to pulmonary artery shunt were associated with for the development of tachyarrhythmias. Further studies are required to determine the effects of anatomy on post-operative tachyarrhythmias.

Tachyarrhythmia Following Norwood Operation

Background:

The purpose of this study was to characterize tachyarrhythmias in children following the Norwood procedure.

Methods:

This is a single-center retrospective study including all children who underwent stage I Norwood procedure (n = 98; January 2003-September 2011). The primary outcome measure is the development of tachyarrhythmia during hospitalization after the Norwood procedure. Secondary aims include quantification of mortality in patients with tachyarrhythmias and evaluation of potential risk factors for the development of tachyarrhythmia.

Results:

Tachyarrhythmia occurred in 33 (34%) of 98 patients. The median time to onset of tachyarrhythmia was ten days (0-47 days). Tachyarrhythmia conferred no increase in overall mortality ( P = .45), including operative mortality ( P = .37) or interstage mortality ( P = 1.00). There was no significant difference in the incidence of arrhythmia based on demographic, anatomic, or surgical variables, including shunt type ( P = .23) except that patients with tachyarrhythmias were slightly larger (median weight 3.2 kg) at the time of stage I than those without tachyarrhythmia (median weight 2.93 kg; P = .02]. The odds of arrhythmia in males were 8.7 times higher than that in females (95% confidence interval 2.9-31.3; P < .0001).

Conclusions:

Postoperative tachyarrhythmia is common, occurring in 34% of patients after the Norwood operation. Onset of tachyarrhythmia occurred later after the Norwood operation than reported previously, and male gender is a risk factor. Further studies to elucidate the etiology and the timing of tachyarrhythmias after the Norwood procedure are necessary.

A common angiotensin-converting enzyme polymorphism and preoperative angiotensin-converting enzyme inhibition modify risk of tachyarrhythmias after congenital heart surgery

BACKGROUND

The angiotensin-converting enzyme insertion/deletion (ACE I/D) polymorphism is described in association with numerous phenotypes, including arrhythmias, and may provide predictive value among pediatric patients undergoing congenital heart surgery.

OBJECTIVE

The purpose of this study was to examine the role of a common polymorphism on postoperative tachyarrhythmias in a large cohort of pediatric patients undergoing congenital heart surgery with cardiopulmonary bypass (CPB).

METHODS

Subjects undergoing congenital heart surgery with CPB at our institution were consecutively enrolled from September 2007 to December 2012. In addition to DNA, perioperative clinical data were obtained from subjects.

RESULTS

Postoperative tachyarrhythmias were documented in 45% of 886 enrollees and were associated with prolonged mechanical ventilation (P <.001) and intensive care unit length of stay (P <.001). ACE I/D was in Hardy-Weinberg equilibrium (19% I/I, 49% I/D, 32% D/D). I/D or D/D genotypes were independently associated with a 60% increase in odds of new tachyarrhythmia (odds ratio [OR] 1.6, 95% confidence interval [CI] 1.1-2.3, P = .02). Preoperative ACE inhibitor administration was independently associated with a 47% reduction in odds of postoperative tachyarrhythmia in the entire cohort (OR 0.53, 95% CI 0.32-0.88, P = .01), driven by a 5-fold reduction in tachyarrhythmias among I/I genotype patients (OR 0.19, 95% CI 0.04-0.88, P = .02).

CONCLUSION

The risk of tachyarrhythmias after congenital heart surgery is independently affected by the ACE I/D polymorphism. Preoperative ACE inhibition is associated with a lower risk of postoperative tachyarrhythmias, an antiarrhythmic effect that appears genotype dependent. An understanding of genotype variation may play an important role in the perioperative management of congenital heart surgery.

Pediatric postoperative cardiac care

Postoperative care of cardiac patients requires a comprehensive and multidisciplinary approach to critically ill patients with cardiac disease whose care requires a clear understanding of cardiovascular physiology. When a patient fails to progress along the projected course or decompensates acutely, prompt evaluation with bedside assessment, laboratory evaluation, and echocardiography is essential. When things do not add up, cardiac catheterization must be seriously considered. With continued advancements in the field of neonatal and pediatric postoperative cardiac care, continued improvements in overall outcomes for this specialized population are anticipated.

Mechanical circulatory support in children: bridge to transplant versus recovery

The number of children and adolescents suffering from heart failure is increasing dramatically. Some of these patients will progress to need advanced therapies in the form of mechanical circulatory support (MCS). Over the past few years, increased attention has been focused on clinical use of existing devices as well the development of pediatric-specific ventricular assist devices (VADs). As in adult populations, these devices offer unique opportunities to successfully support children as a bridge-to-transplant, but increasing data suggest that bridge-to-recovery and bridge-to-destination are also viable options in select pediatric populations. Herein, we will review existing approaches as well describe future potential MCS options.

Arrhythmia management in patients with a common arterial trunk and d-transposition of the great arteries

Arrhythmias in patients with congenital heart disease present a challenge to the care of these patients and can result in significant morbidity and mortality. Transposition of the great arteries and common arterial trunk are no exceptions. It is important to identify risk factors for arrhythmia development in the peri-operative period. The peri-operative arrhythmia burden may relate to the underlying congenital heart disease, haemodynamic perturbations, operative events, and potential residual lesions. In addition, these patients are at risk for developing arrhythmias later in life, and non-invasive and potentially invasive arrhythmia surveillance should be a routine part of the care of these patients. This article highlights important strategies to manage arrhythmia development and prevention in this patient population.