Time in Therapeutic Range With Vitamin K Antagonists in Congenital Heart Disease: A Multicentre Study.

BACKGROUND: Vitamin K antagonists (VKAs) are frequently prescribed to patients with congenital heart disease (CHD) for atrial arrhythmias or Fontan palliation, but there is a paucity of data regarding time spent in the therapeutic range (TTR). We sought to determine the TTR in patients with CHD and atrial arrhythmias or Fontan palliation prescribed VKAs and explore associations with thromboembolic and bleeding events. METHODS: A multicentre North American cohort study was conducted on patients with CHD who received VKAs for sustained atrial arrhythmia or Fontan palliation. TTR was calculated using the Rosendaal linear interpolation method. Generalized estimating equations were used to explore factors associated with time outside the therapeutic range. RESULTS: A total of 567 patients, aged 33 ± 17 years, 56% female, received VKAs for 11.5 ± 8.4 years for atrial arrhythmias (63.0%) or Fontan palliation (58.0%). CHD was simple, moderate, and complex in 10.8%, 20.3%, and 69.0%, respectively. Site investigators perceived good control over international normalized ratio (INR) levels in most patients (75.3%), with no or minor compliance or adherence issues (85.6%). The mean TTR was 41.9% (95% confidence interval [CI], 39.0%-44.8%). Forty-seven (8.3%) and 34 (6.0%) patients had thromboembolic and bleeding events, respectively. Thromboembolic events were associated with a higher proportion of time below the therapeutic range (31.3% vs 19.1%, P = 0.003) and bleeding complications with a higher proportion of time above the therapeutic range (32.5% vs 19.5%, P = 0.006). CONCLUSIONS: Patients with CHD who receive VKAs spend < 42% of their time with INR levels in the therapeutic range, with repercussions regarding thromboembolic and bleeding complications.

Patient-Specific Implant for Primary Orbital Reconstruction: A Case Report

ABSTRACT @#The main aim of orbital fracture reconstruction is to restore the functional and aesthetic components of the eye. However, it is known that surgery for complex three-dimensional anatomy of the orbit is always a challenge. With recent advancements in technology, surgical predictability and outcomes have greatly improved. Several methods for orbital reconstruction surgery have been documented such as virtual surgical planning, intraoperative navigation, intraoperative imaging, and the use of patient-specific implant (PSI). PSI made of titanium can be designed by using a computer-aided design process and manufacturing (CAD-CAM) of CT-scan routinely used during diagnostic imaging. With precise analyses in shape and size followed by personalised implant design, the surgical precision can be alleviated further and at the same time, the surgical duration could be reduced with anticipation of better surgical outcomes. However, meticulous planning needs to be done preoperatively, with the timing of the surgery being an important factor. In the present case, pure orbital blowout fracture primarily treated with a personalised-implant solution derived from 3D-printing technology is described. Both pre-surgical and surgical workflow of this computer-assisted surgical method is elaborated. PSI for primary orbital reconstruction can be regarded as a viable alternative surgical solution including its working timeframe and adherence to the surgical protocol or algorithm.

Thromboembolic Risk After Atriopulmonary, Lateral Tunnel, and Extracardiac Conduit Fontan Surgery.

BACKGROUND: Thromboembolic events contribute greatly to morbidity and mortality following Fontan surgery for univentricular hearts. OBJECTIVES: This study sought to evaluate the effect of type of Fontan surgery on thromboembolic risk. METHODS: A North American multicenter retrospective cohort study enrolled 522 patients with Fontan palliation consisting of an atriopulmonary connection (APC) (21.4%), lateral tunnel (LT) (41.8%), or extracardiac conduit (EC) (36.8%). Thromboembolic complications and new-onset atrial arrhythmia were reviewed and classified by a blinded adjudicating committee. Thromboembolic risk across surgical techniques was assessed by multivariable competing-risk survival regression. RESULTS: Over a median follow-up of 11.6 years, 10- and 20-year freedom from Fontan conversion, transplantation, or death was 94.7% and 78.9%, respectively. New-onset atrial arrhythmias occurred in 4.4, 1.2, and 1.0 cases per 100 person-years with APC, LT, and EC, respectively. APC was associated with a 2.82-fold higher risk of developing atrial arrhythmias (p < 0.001), with no difference between LT and EC (p = 0.95). A total of 71 thromboembolic events, 32 systemic and 39 venous, occurred in 12.8% of subjects, for an overall incidence of 1.1%/year. In multivariable analyses, EC was independently associated with a lower risk of systemic (hazard ratio [HR]: 0.20 vs. LT; 95% confidence interval [CI]: 0.04 to 0.97) and combined (HR: 0.34 vs. LT; 95% CI: 0.13 to 0.91) thromboembolic events. A lower incidence of combined thromboembolic events was also observed with antiplatelet agents (HR: 0.54; 95% CI: 0.32 to 0.92) but not anticoagulation (p = 0.53). CONCLUSIONS: The EC Fontan was independently associated with a lower thromboembolic risk after controlling for time-varying effects of atrial arrhythmias and thromboprophylaxis.

Increasing Prevalence of Atrial Fibrillation and Permanent Atrial Arrhythmias in Congenital Heart Disease.

BACKGROUND: Atrial arrhythmias are the most common complication encountered in the growing and aging population with congenital heart disease. OBJECTIVES: This study sought to assess the types and patterns of atrial arrhythmias, associated factors, and age-related trends. METHODS: A multicenter cohort study enrolled 482 patients with congenital heart disease and atrial arrhythmias, age 32.0 ± 18.0 years, 45.2% female, from 12 North American centers. Qualifying arrhythmias were classified by a blinded adjudicating committee. RESULTS: The most common presenting arrhythmia was intra-atrial re-entrant tachycardia (IART) (61.6%), followed by atrial fibrillation (28.8%), and focal atrial tachycardia (9.5%). The proportion of arrhythmias due to IART increased with congenital heart disease complexity from 47.2% to 62.1% to 67.0% in patients with simple, moderate, and complex defects, respectively (p = 0.0013). Atrial fibrillation increased with age to surpass IART as the most common arrhythmia in those ≥50 years of age (51.2% vs. 44.2%; p < 0.0001). Older age (odds ratio [OR]: 1.024 per year; 95% confidence interval [CI]: 1.010 to 1.039; p = 0.001) and hypertension (OR: 2.00; 95% CI: 1.08 to 3.71; p = 0.029) were independently associated with atrial fibrillation. During a mean follow-up of 11.3 ± 9.4 years, the predominant arrhythmia pattern was paroxysmal in 62.3%, persistent in 28.2%, and permanent in 9.5%. Permanent atrial arrhythmias increased with age from 3.1% to 22.6% in patients <20 years to ≥50 years, respectively (p < 0.0001). CONCLUSIONS: IART is the most common presenting atrial arrhythmia in patients with congenital heart disease, with a predominantly paroxysmal pattern. However, atrial fibrillation increases in prevalence and atrial arrhythmias progressively become permanent as the population ages.

Thromboprophylaxis for atrial arrhythmias in congenital heart disease: A multicenter study.

BACKGROUND: There is a paucity of data to guide decisions regarding thromboprophylaxis for atrial arrhythmias in congenital heart disease. METHODS: A retrospective multicenter cohort study enrolled patients with documented sustained atrial arrhythmias and congenital heart disease from 12 North American centers to quantify thromboembolic and bleeding rates associated with antiplatelet and anticoagulation therapy, and explore associated factors. A blinded committee adjudicated all qualifying arrhythmias and outcomes. RESULTS: A total of 482 patients, 45.2% female, age 32.0±18.0years, were followed for 11.3±9.4years since the qualifying arrhythmia. Antiplatelet therapy was administered to 37.8%, anticoagulation to 54.4%, and neither to 7.9%. Congenital heart disease complexity was simple, moderate, and severe in 18.5%, 34.4%, and 47.1%, respectively. Freedom from thromboembolic events was 84.7±2.7% at 15years, with no difference between anticoagulation versus antiplatelet therapy (P=0.97). Congenital heart disease complexity was independently associated with thromboembolic events, with rates of 0.00%, 0.93%, and 1.95%/year in those with simple, moderate, and severe forms (P<0.001). CHADS2 and CHA2DS2-VASc scores were not predictive of thromboembolic risk. Annualized bleeding rates with antiplatelet and anticoagulation therapy were 0.66% and 1.82% (P=0.039). In multivariable analyses, anticoagulation [hazard ratio (HR) 4.76, 95% CI (1.05-21.58), P=0.043] and HAS-BLED score [HR 3.15, 95% CI (1.02, 9.78), P=0.047] were independently associated with major bleeds. CONCLUSION: Current management of atrial arrhythmias in congenital heart disease is associated with a modest rate of thromboembolic events, which is predicted by disease complexity but not CHADS2/CHA2DS2-VASc scores. HAS-BLED score is applicable to the congenital population in predicting major bleeds.

Determination of left atrium volume by fast anatomical mapping and intracardiac echocardiography. The contribution of respiratory gating.

BACKGROUND: The anatomical reconstruction of the left atrium (LA) and pulmonary veins with fast anatomical mapping (FAM) and intracardiac echocardiography (ICE) using the Carto 3 system (Biosense Webster, Inc) provides real-time guidance to catheter manipulation during ablation of atrial fibrillation (AF). The present study compared real-time LA volume reconstruction using FAM and ICE. In addition, the contribution of respiratory gating was assessed. METHODS: LA reconstruction was created using FAM and ICE in 60 consecutive patients (mean age 63 ± 9 years; 38 males) undergoing AF ablation. In the first 30 patients, FAM and ICE were performed without respiratory gating. In the last 30 patients, FAM and ICE were performed with respiratory gating. RESULTS: LA volumes determined by FAM were larger than those obtained with ICE in the absence of respiratory gating (n = 30; 129.5 ± 44 vs 110 ± 39.7 cm(3); p = 0.001). However, respiratory gating reduced LA volume determined with FAM by 17.7 ± 6.6% resulting in similar LA volumes to those obtained using ICE [n = 30; 100 ± 29.7 (61-154) vs 101.53 ± 40.1 (56-212) cm(3), p = 0.7, NS]. CONCLUSIONS: In the absence of respiratory gating, LA volumes determined by FAM are larger than those obtained with ICE. In contrast, with the addition of respiratory gating, both FAM and ICE provide similar real-time LA volumes.

Resection of a Giant Left Atrial Appendage Aneurysm via Limited Thoracotomy.

A left atrial appendage aneurysm is a rare cause of atrial arrhythmia in a young adult. Resection of the aneurysm is uniformly recommended in order to prevent thromboembolism and stroke. In patients without evidence of clot within the aneurysm, operative resection via a limited thoracotomy provides a safe and effective alternative to median sternotomy with cardiopulmonary bypass.

Clinical research priorities in adult congenital heart disease.

BACKGROUND: Adult congenital heart disease (ACHD) clinicians are hampered by the paucity of data to inform clinical decision-making. The objective of this study was to identify priorities for clinical research in ACHD. METHODS: A list of 45 research questions was developed by the Alliance for Adult Research in Congenital Cardiology (AARCC), compiled into a survey, and administered to ACHD providers. Patient input was sought via the Adult Congenital Heart Association at community meetings and online forums. The 25 top questions were sent to ACHD providers worldwide via an online survey. Each question was ranked based on perceived priority and weighted based on time spent in ACHD care. The top 10 topics identified are presented and discussed. RESULTS: The final online survey yielded 139 responses. Top priority questions related to tetralogy of Fallot (timing of pulmonary valve replacement and criteria for primary prevention ICDs), patients with systemic right ventricles (determining the optimal echocardiographic techniques for measuring right ventricular function, and indications for tricuspid valve replacement and primary prevention ICDs), and single ventricle/Fontan patients (role of pulmonary vasodilators, optimal anticoagulation, medical therapy for preservation of ventricular function, treatment for protein losing enteropathy). In addition, establishing criteria to refer ACHD patients for cardiac transplantation was deemed a priority. CONCLUSIONS: The ACHD field is in need of prospective research to address fundamental clinical questions. It is hoped that this methodical consultation process will inform researchers and funding organizations about clinical research topics deemed to be of high priority.

Clinical efficacy of dofetilide for the treatment of atrial tachyarrhythmias in adults with congenital heart disease.

BACKGROUND: Atrial tachyarrhythmias (AT) including atrial fibrillation (AF), atrial flutter (AFL), and atrial tachycardia represent a clinical challenge in the adult with congenital heart disease (CHD). Dofetilide (D) is a rapidly activating delayed rectifier potassium channel (IKr) blocker effective in pharmacological conversion and maintenance of normal sinus rhythm in patients with AF and AFL. There is limited knowledge regarding the role of D in adults with CHD. METHODS: Safety and efficacy of D was evaluated in a consecutive group of thirteen adult patients (age 40 ± 11; six women) with CHD and refractory AT. RESULTS: Ten patients had persistent (four AFL, one AF, and five atrial tachycardia) and three paroxysmal (one AF and two atrial tachycardia) AT. All patients were symptomatic during tachycardia, 12 patients had previously failed 2 ± 1 antiarrhythmic drugs. Mean systemic ventricular ejection fraction was 55 ± 9%; baseline QRS complex duration was 129 ± 45 ms (>120 ms in six patients). Patients were followed on D for 33 ± 39 months (median 16). Among 10 patients with persistent AT, seven patients (70%) pharmacologically converted to sinus rhythm on D and three patients (30%) required direct current cardioversion. Two patients (15.4%) experienced complete arrhythmia suppression, and seven (53.8%) experienced significant clinical improvement with sporadic recurrences; average time to recurrence was 5.5 ± 3.5 months. One patient developed torsade de pointes during loading, and the drug was discontinued. D was discontinued in five (38.5%) other patients due to recurrence of AT (n = 4) and renal failure (n = 1). Corrected QT interval (QTc) increased from 452 ± 61 to 480 ± 49 ms (P = .04) and corrected JT interval (JTc) from 323 ± 39 to 341 ± 33 ms (P = .09). CONCLUSIONS: D should be considered a pharmacologic alternative when adult patients with CHD develop AT. D does not depress conduction, sinus node, or ventricular function but needs close monitoring for potential ventricular pro-arrhythmia.

Heart failure in pregnant women with cardiac disease: data from the ROPAC.

OBJECTIVE: Heart failure (HF) is one of the most important complications in pregnant women with heart disease, causing maternal and fetal mortality and morbidity. METHODS: This is an international observational registry of patients with structural heart disease during pregnancy. Sixty hospitals in 28 countries enrolled 1321 women between 2007 and 2011. Pregnant women with valvular heart disease, congenital heart disease, ischaemic heart disease, or cardiomyopathy could be included. Main outcome measures were onset and predictors of HF and maternal and fetal death. RESULTS: In total, 173 (13.1%) of the 1321 patients developed HF, making HF the most common major cardiovascular complication during pregnancy. Baseline parameters associated with HF were New York Heart Association class ≥ 3, signs of HF, WHO category ≥ 3, cardiomyopathy or pulmonary hypertension. HF occurred at a median time of 31 weeks gestation (IQR 23-40) with the highest incidence at the end of the second trimester (34%) or peripartum (31%). Maternal mortality was higher in patients with HF (4.8% in patients with HF and 0.5% in those without HF p<0.001). Pre-eclampsia was strongly related to HF (OR 7.1, 95% CI 3.9 to 13.2, p<0.001). Fetal death and the incidence of preterm birth were higher in women with HF compared to women without HF (4.6% vs 1.2%, p=0.001; and 30% vs 13%, p=0.001). CONCLUSIONS: HF was the most common complication during pregnancy, and occurred typically at the end of the second trimester, or after birth. It was most common in women with cardiomyopathy or pulmonary hypertension and was strongly associated with pre-eclampsia and an adverse maternal and perinatal outcome.

Improving heart disease knowledge and research participation in adults with congenital heart disease (the Health, Education and Access Research Trial: HEART-ACHD).

OBJECTIVE: The objective of this prospective multi-center study was to evaluate heart disease knowledge within the adult congenital heart disease (ACHD) population, pilot an educational intervention and assess interest in research participation among new patients at ACHD clinics. BACKGROUND: Many adults with congenital heart disease lack knowledge about their heart condition that may contribute to undesirable outcomes. METHODS: Patients ≥18 years of age were recruited upon their first presentation to an ACHD clinic and underwent an educational intervention consisting of creation of a personal health information 'passport' and an introduction to web-based resources. Subjects were asked to complete initial and follow-up surveys documenting their perceived knowledge. RESULTS: Nine hundred twenty-two subjects were recruited from 12 ACHD centers, and 520 (57%) completed follow-up surveys. Patients who completed the follow-up survey were more likely to be women, have more education, and have mild heart disease. At follow-up, the ability of the subjects to name their heart condition improved (78% to 83%, p=0.002). Improvements were seen in mean Likert items regarding perceived knowledge of appropriate exercise (p<0.0001), symptoms of heart rhythm problems or endocarditis (p<0.0001), reasons for cardiac tests (p<0.007), and birth control options and pregnancy safety (p<0.0001). On follow-up, subjects reported a better understanding of medical research (p<0.01), and higher interest in research participation (p<0.003). CONCLUSION: This joint clinician-patient pilot program will help inform future efforts toward patient education and participation in research with a focus on standardization of protocols for life-long longitudinal follow-up and continued multi-center collaboration in the ACHD population.

Prevalence and predictors of gaps in care among adult congenital heart disease patients: HEART-ACHD (The Health, Education, and Access Research Trial).

OBJECTIVES: The goal of this project was to quantify the prevalence of gaps in cardiology care, identify predictors of gaps, and assess barriers to care among adult congenital heart disease (adult CHD) patients. BACKGROUND: Adult CHD patients risk interruptions in care that are associated with undesired outcomes. METHODS: Patients (18 years of age and older) with their first presentation to an adult CHD clinic completed a survey regarding gaps in, and barriers to, care. RESULTS: Among 12 adult CHD centers, 922 subjects (54% female) were recruited. A >3-year gap in cardiology care was identified in 42%, with 8% having gaps longer than a decade. Mean age at the first gap was 19.9 years. The majority of respondents had more than high school education and knew their heart condition. The most common reasons for gaps included feeling well, being unaware that follow-up was required, and complete absence from medical care. Disease complexity was predictive of a gap in care with 59% of mild, 42% of moderate, and 26% of severe disease subjects reporting gaps (p < 0.0001). Clinic location significantly predicted gaps (p < 0.0001), whereas sex, race, and education level did not. Common reasons for returning to care were new symptoms, referral from provider, and desire to prevent problems. CONCLUSIONS: Adult CHD patients have gaps in cardiology care; the first lapse commonly occurred at age ∼19 years, a time when transition to adult services is contemplated. Gaps were more common among subjects with mild and moderate diagnoses and at particular locations. These results provide a framework for developing strategies to decrease gaps and address barriers to care in the adult CHD population.

Left and right ventricular diastolic function in adults with surgically repaired tetralogy of Fallot: a multi-institutional study.

BACKGROUND: Our purpose was to assess the prevalence and clinical implications of left ventricular (LV) and right ventricular (RV) diastolic dysfunction (DD) in patients with repaired tetralogy of Fallot (TOF). METHODS: Adults with repaired TOF at 11 North American congenital heart disease centres were included. Of 556 patients analyzed, 325 had sufficient Doppler data to evaluate for LV DD, defined as mitral lateral e' < 10 cm/s and E/e' ratio > 9. Abnormal RV diastolic function was defined as tricuspid E/A ratio of 0.8 to 2.1 with E/e' ratio > 6 or a tricuspid ratio E/A > 2.1 with a deceleration time < 120 milliseconds, and 105 patients were found to have sufficient Doppler data. RESULTS: Abnormal LV diastolic Doppler indices were prevalent in 13.8% and associated with hypertension, dyslipidemia, 3 or more cardiac operations, and a history of ventricular tachycardia. Abnormal RV indices were prevalent in 52.4% and associated with hypertension, dyslipidemia, diabetes mellitus, and 3 or more cardiac operations. Ventricular tachycardia was more common in those with abnormal RV diastolic function. CONCLUSION: Further prospective studies are needed to evaluate these associations with DD and the impact of treatment risk factors on diastolic function and arrhythmia burden.

Aortic root dilatation in adults with surgically repaired tetralogy of fallot: a multicenter cross-sectional study.

BACKGROUND: Although aortic root pathology has been described in patients with tetralogy of Fallot, the scope of the problem remains poorly defined. We sought to determine the prevalence and predictors of aortic root dilatation in adults with repaired tetralogy of Fallot. METHODS AND RESULTS: A multicenter cross-sectional study was conducted with standardized reassessment of echocardiographic parameters in 474 adults (≥18 years) with surgically repaired tetralogy of Fallot or pulmonary atresia with ventricular septal defect. The aortic root was measured in a parasternal long-axis view, in diastole, at the level of the sinus of Valsalva. Prevalence and predictors of an absolute diameter ≥40 mm and of an observed-to-expected ratio >1.5 were assessed. The aortic root dimension was ≥40 mm in 28.9% (95% confidence interval, 26.9%-30.9%). In multivariate analyses, the only independently associated factor was male sex (odds ratio, 4.48; 95% confidence interval, 1.55-12.89; P=0.006). The prevalence of an observed-to-expected aortic root dimension ratio >1.5 was 6.6% (95% confidence interval, 5.3%-7.9%). It was associated with pulmonary atresia and moderate or severe aortic regurgitation in univariate analyses, but no independent predictor was identified. The side of the aortic arch was not associated with aortic root dimension. The prevalence of moderate or severe aortic regurgitation was 3.5% (95% confidence interval, 2.7%-4.2%). CONCLUSIONS: Although nearly one third of adults with repaired tetralogy of Fallot have an aortic root diameter ≥40 mm, the prevalence of a dilated aortic root, when defined by an indexed ratio of observed-to-expected values, is low. Similarly, moderate or severe aortic regurgitation is uncommon.

Prevalence of left ventricular systolic dysfunction in adults with repaired tetralogy of fallot.

Left ventricular (LV) systolic dysfunction has been observed in patients with repaired tetralogy of Fallot (TOF), although its clinical associations are unknown. Adults with repaired TOF were identified from 11 adult congenital heart disease centers. Clinical history was reviewed. Patients with pulmonary atresia were excluded. Echocardiograms were reanalyzed to estimate LV ejection fraction. LV function was defined as normal (LV ejection fraction ≥ 55%) or mildly (45% to 54%), moderately (35% to 44%), or severely (< 35%) decreased. Right ventricular (RV) and LV dimensions and Doppler parameters were remeasured. Function of all valves was qualitatively scored. Of 511 patients studied, LV systolic dysfunction was present in 107 (20.9%, 95% confidence interval 17.4 to 24.5). Specifically, 74 (14.4%) had mildly decreased and 33 (6.3%) had moderately to severely decreased systolic function. Presence of moderate to severe LV dysfunction was associated with male gender, LV enlargement, duration of shunt before repair, history of arrhythmia, QRS duration, implanted cardioverter-defibrillator, and moderate to severe RV dysfunction. Severity or duration of pulmonary regurgitation was not different. In conclusion, LV systolic dysfunction was found in 21% of adult patients with TOF and was associated with shunt duration, RV dysfunction, and arrhythmia.

Arrhythmia burden in adults with surgically repaired tetralogy of Fallot: a multi-institutional study.

BACKGROUND: The arrhythmia burden in tetralogy of Fallot, types of arrhythmias encountered, and risk profile may change as the population ages. METHODS AND RESULTS: The Alliance for Adult Research in Congenital Cardiology (AARCC) conducted a multicenter cross-sectional study to quantify the arrhythmia burden in tetralogy of Fallot, to characterize age-related trends, and to identify associated factors. A total of 556 patients, 54.0% female, 36.8+/-12.0 years of age were recruited from 11 centers. Overall, 43.3% had a sustained arrhythmia or arrhythmia intervention. Prevalence of atrial tachyarrhythmias was 20.1%. Factors associated with intraatrial reentrant tachycardia in multivariable analyses were right atrial enlargement (odds ratio [OR], 6.2; 95% confidence interval [CI], 2.8 to 13.6), hypertension (OR, 2.3; 95% CI, 1.1 to 4.6), and number of cardiac surgeries (OR, 1.4; 95% CI, 1.2 to 1.6). Older age (OR, 1.09 per year; 95% CI, 1.05 to 1.12), lower left ventricular ejection fraction (OR, 0.93 per unit; 95% CI, 0.89 to 0.96), left atrial dilation (OR, 3.2; 95% CI, 1.5 to 6.8), and number of cardiac surgeries (OR, 1.5; 95% CI, 1.2 to 1.9) were jointly associated with atrial fibrillation. Ventricular arrhythmias were prevalent in 14.6% and jointly associated with number of cardiac surgeries (OR, 1.3; 95% CI, 1.1 to 1.6), QRS duration (OR, 1.02 per 1 ms; 95% CI, 1.01 to 1.03), and left ventricular diastolic dysfunction (OR, 3.3; 95% CI, 1.5 to 7.1). Prevalence of atrial fibrillation and ventricular arrhythmias markedly increased after 45 years of age. CONCLUSIONS: The arrhythmia burden in adults with tetralogy of Fallot is considerable, with various subtypes characterized by different profiles. Atrial fibrillation and ventricular arrhythmias appear to be influenced more by left- than right-sided heart disease.