Prevalence of Arrhythmias Late After the Fontan Operation Javier J. Lasa, MDa,*, Andrew C. Glatz, MD, MSCEa, Ankana Daga, MDb, and Maully Shah, MBBSa The extracardiac conduit (ECC) modification of the Fontan procedure has been theorized to reduce the risk of sinus node dysfunction and atrial arrhythmia compared with the intraatrial lateral tunnel (ILT) Fontan. This study aimed to compare the prevalence of early and late arrhythmias in patients who underwent ECC and ILT Fontan from a similar era with long-term follow-up at a single institution. A retrospective cohort study was conducted of all patients who underwent ECC or ILT Fontan from 1995 to 2005 at The Children’s Hospital of Philadelphia. Bradyarrhythmias (including sinus node dysfunction), tachyarrhythmias, and pacemaker burden prevalence was determined throughout early (30 days) postoperative periods. Of 434 patients undergoing the Fontan procedure during the study period, a total of 87 and 106 patients who underwent ECC and ILT Fontan, respectively, met the inclusion criteria. There were no significant differences in risk of sinus node dysfunction or tachyarrhythmia in both early and late postoperative periods. Although the overall risk of late postoperative pacemaker therapy was lower for the ECC cohort (4.9% vs 15.7%, p [ 0.03), when adjusting for follow-up time, no significant difference was observed (odds ratio 3.1, 95% confidence interval 0.6 to 15.2, p [ 0.16). In conclusion, the overall prevalence of late postoperative arrhythmias observed after contemporary Fontan modifications is low. Intra-atrial reentrant tachycardia, a potentially fatal complication of the atriopulmonary Fontan operation was infrequently encountered in both ECC and ILT Fontan cohorts. Pacemaker use was higher in the ILT group, although this difference may be explained by differences in follow-up time. Despite the low prevalence of arrhythmias after contemporary Fontan modifications, ongoing surveillance is warranted as the onset of arrhythmias may emerge after longer follow-up time. Ó 2014 Elsevier Inc. All rights reserved. (Am J Cardiol 2014;113:1184e1188)
Postoperative arrhythmias after the Fontan operation have been described since the procedure was introduced in 1971.1,2 Currently, the 2 most commonly employed surgical forms of the total cavopulmonary connection are the intra-atrial lateral tunnel (ILT) and the extracardiac conduit (ECC). For more than a decade, the ECC connection has been the preferred Fontan modification in several institutions,3e5 yet comparative data on the incidence of arrhythmias after ILT and ECC have been limited and controversial.6e10 The ECC Fontan procedure has been theorized to reduce the risk of sinus node dysfunction (SND) and atrial arrhythmia compared with ILT Fontan because of the avoidance of extensive atrial suture lines and exclusion of the atrial chamber from elevated systemic venous pressure. Yet previous injury of the crista terminalis, large atrial wall incisions at the time of intracardiac procedures, and multiple-stage operations may predispose patients to atrial arrhythmias after the ECC Fontan procedure as well. Recent attempts to define rhythm status in this population have included patients with the traditional atriopulmonary form of the Fontan procedure. Yet results a
Division of Cardiology, The Children’s Hospital of Philadelphia, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania and b Department of Pediatric and Adolescent Medicine, Einstein Medical Center, Philadelphia, Pennsylvania. Manuscript received September 19, 2013; revised manuscript received and accepted December 18, 2013. See page 1188 for disclosure information. *Corresponding author: Tel: (215) 590-7430; fax: (215) 590-5825. E-mail address: [email protected] (J.J. Lasa). 0002-9149/14/$ - see front matter Ó 2014 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.amjcard.2013.12.025
from studies such as the Pediatric Heart Network Fontan Cross-Sectional Study demonstrate a disproportionate arrhythmia burden for this older subset of patients who underwent the Fontan procedure, thereby making results difficult to interpret in the current era.6,8 Although additional investigations have excluded patients who underwent traditional atriopulmonary Fontan, these studies are also limited in their lack of sufficient follow-up time and insufficient statistical power for identification of arrhythmia predictors.1,9e12 From 1995 to 2005, The Children’s Hospital of Philadelphia cardiothoracic surgical experience evolved to include an overall balance of ECC and ILT modifications, performed in parallel, without using the traditional atriopulmonary Fontan procedures. We sought to better define the prevalence of arrhythmias in this population while comparing differences in arrhythmias and pacemaker burden between the 2 most commonly employed modifications of the Fontan procedure in the current era. Methods The medical and surgical records of all patients undergoing Fontan palliation from January 1, 1995 to December 31, 2005 at The Children’s Hospital of Philadelphia were reviewed retrospectively. The Institutional Review Board approved this study. Inclusion criteria for this study included (1) presence of the ILT or ECC Fontan procedure, (2) follow-up at The Children’s Hospital of Philadelphia, and (3) electrocardiographic testing within 2 years before www.ajconline.org
Arrhythmias and Conduction Disturbances/Arrhythmias After Fontan Operation
the termination of data collection. Additionally, patients were required to have at least one 15-lead electrocardiogram before Fontan procedure, 1 in the early postoperative period (30 days). Supporting electrocardiographic data in the form of Holter monitoring was additive; Holter monitoring was not an inclusion requirement. Exclusion criteria included (1) presence of arrhythmia before ECC or ILT Fontan, (2) previous atriopulmonary Fontan procedure, (3) concomitant arrhythmia surgery at the time of ECC or ILT Fontan procedure, and (4) any patient undergoing transplantation during the follow-up period. Age at Fontan procedure and time from Fontan to the most recent outpatient clinical appointment were evaluated. Additional clinical variables obtained from chart review included ventricular morphology (e.g., right ventricle dominant vs noneright ventricle dominant) and presence of fenestration at the time of Fontan procedure. All available electrocardiographic records and 24- or 48-hour ambulatory Holter monitor recordings were analyzed retrospectively. Any impairment of rhythm origin or conduction was assessed as an arrhythmia. The following groups of rhythm disturbances were defined as bradyarrhythmias: (1) SND, which includes sinus bradycardia, ectopic atrial rhythm or bradycardia, predominant junctional rhythm, or sinus pauses exceeding 2 seconds, and (2) complete heart block. The following groups of rhythm disturbances were defined as tachyarrhythmias: (1) supraventricular tachycardia, which included atrial fibrillation, atrial flutter, ectopic atrial tachycardia, junctional ectopic tachycardia, or atrioventricular (AV) reciprocating tachycardia, and (2) ventricular arrhythmias including ventricular tachycardia and ventricular fibrillation. Rhythm disturbances documented during the early postoperative period (30 days) after Fontan operation were considered late arrhythmias. Data are expressed as mean SD for normally distributed continuous variables, median (range) for skewed continuous variables, and count (percentage of total) for categorical variables. Testing of differences in demographic and clinical data based on Fontan type (ECC vs ILT) was accomplished with either unpaired student t test or Wilcoxon rank sum test for continuous variables and with either Pearson’s chi-square test or Fisher’s exact test for categorical variables, as appropriate. Measures of association between potential predictor variables and the primary outcome variables were determined first by univariate logistic regression. Covariates with p
Postoperative arrhythmias after the Fontan operation have been described since the procedure was introduced in 1971.1,2 Currently, the 2 most commonly employed surgical forms of the total cavopulmonary connection are the intra-atrial lateral tunnel (ILT) and the extracardiac conduit (ECC). For more than a decade, the ECC connection has been the preferred Fontan modification in several institutions,3e5 yet comparative data on the incidence of arrhythmias after ILT and ECC have been limited and controversial.6e10 The ECC Fontan procedure has been theorized to reduce the risk of sinus node dysfunction (SND) and atrial arrhythmia compared with ILT Fontan because of the avoidance of extensive atrial suture lines and exclusion of the atrial chamber from elevated systemic venous pressure. Yet previous injury of the crista terminalis, large atrial wall incisions at the time of intracardiac procedures, and multiple-stage operations may predispose patients to atrial arrhythmias after the ECC Fontan procedure as well. Recent attempts to define rhythm status in this population have included patients with the traditional atriopulmonary form of the Fontan procedure. Yet results a
Division of Cardiology, The Children’s Hospital of Philadelphia, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania and b Department of Pediatric and Adolescent Medicine, Einstein Medical Center, Philadelphia, Pennsylvania. Manuscript received September 19, 2013; revised manuscript received and accepted December 18, 2013. See page 1188 for disclosure information. *Corresponding author: Tel: (215) 590-7430; fax: (215) 590-5825. E-mail address: [email protected] (J.J. Lasa). 0002-9149/14/$ - see front matter Ó 2014 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.amjcard.2013.12.025
from studies such as the Pediatric Heart Network Fontan Cross-Sectional Study demonstrate a disproportionate arrhythmia burden for this older subset of patients who underwent the Fontan procedure, thereby making results difficult to interpret in the current era.6,8 Although additional investigations have excluded patients who underwent traditional atriopulmonary Fontan, these studies are also limited in their lack of sufficient follow-up time and insufficient statistical power for identification of arrhythmia predictors.1,9e12 From 1995 to 2005, The Children’s Hospital of Philadelphia cardiothoracic surgical experience evolved to include an overall balance of ECC and ILT modifications, performed in parallel, without using the traditional atriopulmonary Fontan procedures. We sought to better define the prevalence of arrhythmias in this population while comparing differences in arrhythmias and pacemaker burden between the 2 most commonly employed modifications of the Fontan procedure in the current era. Methods The medical and surgical records of all patients undergoing Fontan palliation from January 1, 1995 to December 31, 2005 at The Children’s Hospital of Philadelphia were reviewed retrospectively. The Institutional Review Board approved this study. Inclusion criteria for this study included (1) presence of the ILT or ECC Fontan procedure, (2) follow-up at The Children’s Hospital of Philadelphia, and (3) electrocardiographic testing within 2 years before www.ajconline.org
Arrhythmias and Conduction Disturbances/Arrhythmias After Fontan Operation
the termination of data collection. Additionally, patients were required to have at least one 15-lead electrocardiogram before Fontan procedure, 1 in the early postoperative period (30 days). Supporting electrocardiographic data in the form of Holter monitoring was additive; Holter monitoring was not an inclusion requirement. Exclusion criteria included (1) presence of arrhythmia before ECC or ILT Fontan, (2) previous atriopulmonary Fontan procedure, (3) concomitant arrhythmia surgery at the time of ECC or ILT Fontan procedure, and (4) any patient undergoing transplantation during the follow-up period. Age at Fontan procedure and time from Fontan to the most recent outpatient clinical appointment were evaluated. Additional clinical variables obtained from chart review included ventricular morphology (e.g., right ventricle dominant vs noneright ventricle dominant) and presence of fenestration at the time of Fontan procedure. All available electrocardiographic records and 24- or 48-hour ambulatory Holter monitor recordings were analyzed retrospectively. Any impairment of rhythm origin or conduction was assessed as an arrhythmia. The following groups of rhythm disturbances were defined as bradyarrhythmias: (1) SND, which includes sinus bradycardia, ectopic atrial rhythm or bradycardia, predominant junctional rhythm, or sinus pauses exceeding 2 seconds, and (2) complete heart block. The following groups of rhythm disturbances were defined as tachyarrhythmias: (1) supraventricular tachycardia, which included atrial fibrillation, atrial flutter, ectopic atrial tachycardia, junctional ectopic tachycardia, or atrioventricular (AV) reciprocating tachycardia, and (2) ventricular arrhythmias including ventricular tachycardia and ventricular fibrillation. Rhythm disturbances documented during the early postoperative period (30 days) after Fontan operation were considered late arrhythmias. Data are expressed as mean SD for normally distributed continuous variables, median (range) for skewed continuous variables, and count (percentage of total) for categorical variables. Testing of differences in demographic and clinical data based on Fontan type (ECC vs ILT) was accomplished with either unpaired student t test or Wilcoxon rank sum test for continuous variables and with either Pearson’s chi-square test or Fisher’s exact test for categorical variables, as appropriate. Measures of association between potential predictor variables and the primary outcome variables were determined first by univariate logistic regression. Covariates with p
