Outcomes After Late Reoperation in Patients With Repaired Tetralogy of Fallot: The Impact of Arrhythmia and Arrhythmia Surgery

Quantitative Evaluation of Right Ventricular Workload Based on the Stroke Work Index in Patients after Right Ventricular Outflow Tract Reconstruction

The evaluation of right ventricular workload is sometimes complicated in patients after right ventricular outflow tract reconstruction (RVOTR) because both stenotic and regurgitation lesions are involved. In this study, we modified the right ventricular stroke work index (RVSWI) and evaluated the relationship between the modified RVSWI (mRVSWI) and patient prognosis after RVOTR.We enrolled 69 patients who underwent RVOTR (the RVOTR group), including those who needed early reoperation (early reoperation subgroup) and those who did not (follow-up subgroup), and 13 age-matched control participants (control group). Based on the catheterization results 1 year after RVOTR, we compared the mRVSWI between these groups. Additionally, we evaluated the influence of the mRVSWI on the reoperation avoidance rate and survival.The mRVSWI in the RVOTR group was significantly greater than that in the control group (17.7 ± 8.6 vs. 11.0 ± 2.7 g·m/m2, p = 0.008). The mRVSWI in the early reoperation subgroup was significantly greater than that in the follow-up subgroup (32.5 ± 11.1 vs. 15.8 ± 6.0 g·m/m2, p < 0.0001). In the follow-up subgroup, patients with an mRVSWI higher than the upper limit of normal (16.4 g·m/m2) had a greater rate of reoperation than did the other patients (p = 0.0013). One patient died suddenly, and her mRVSWI was consistently high throughout her life.We established the mRVSWI as an index that integrates the pressure and volume load on the right ventricle. Our results indicate the utility of the mRVSWI for predicting patient prognosis after RVOTR.

Electrophysiological study prior to planned pulmonary valve replacement in patients with repaired tetralogy of Fallot

AIM

Ventricular arrhythmias (VAs) are the most common cause of death in patients with repaired Tetralogy of Fallot (rTOF). However, risk stratifying remains challenging. We examined outcomes following programmed ventricular stimulation (PVS) with or without subsequent ablation in patients with rTOF planned for pulmonary valve replacement (PVR).

METHODS

We included all consecutive patients with rTOF referred to our institution from 2010 to 2018 aged ≥18 years for PVR. Right ventricular (RV) voltage maps were acquired and PVS was performed from two different sites at baseline, and if non-inducible under isoproterenol. Catheter and/or surgical ablation was performed when patients were inducible or when slow conduction was present in anatomical isthmuses (AIs). Postablation PVS was undertaken to guide implantable cardioverter-defibrillator (ICD) implantation.

RESULTS

Seventy-seven patients (36.2 ± 14.3 years old, 71% male) were included. Eighteen were inducible. In 28 patients (17 inducible, 11 non-inducible but with slow conduction) ablation was performed. Five had catheter ablation, surgical cryoablation in 9, both techniques in 14. ICDs were implanted in five patients. During a follow-up of 74 ± 40 months, no sudden cardiac death occurred. Three patients experienced sustained VAs, all were inducible during the initial EP study. Two of them had an ICD (low ejection fraction for one and important risk factor for arrhythmia for the second). No VAs were reported in the non-inducible group (p < .001).

CONCLUSION

Preoperative EPS can help identifying patients with rTOF at risk for VAs, providing an opportunity for targeted ablation and may improve decision-making regarding ICD implantation.

Risk factors for atrial arrhythmia recurrence after atrial arrhythmia surgery with pulmonary valve replacement

Objectives

Atrial arrhythmias are a significant cause of late morbidity and mortality in patients after tetralogy of Fallot repair. However, reports on their recurrence following atrial arrhythmia surgery are limited. We aimed to identify the risk factors for atrial arrhythmia recurrence after pulmonary valve replacement (PVR) and arrhythmia surgery.

Methods

We reviewed 74 patients with repaired tetralogy of Fallot who underwent PVR for pulmonary insufficiency at our hospital between 2003 and 2021. Twenty-two patients (mean age, 39 years) underwent PVR and atrial arrhythmia surgery. A modified Cox-maze III was performed in 6 patients with chronic atrial fibrillation, and a right-sided maze was performed in 12 with paroxysmal atrial fibrillation, 3 with atrial flutter, and 1 with atrial tachycardia. Atrial arrhythmia recurrence was defined as any documented sustained atrial tachyarrhythmia requiring intervention. The influence of preoperative parameters on recurrence was assessed with the Cox proportional-hazards model.

Results

The median follow-up period was 9.2 years (interquartile range, 4.5-12.4). Cardiac death and redo-PVR due to prosthetic valve dysfunction were not observed. Eleven patients had atrial arrhythmia recurrence after discharge. Atrial arrhythmia recurrence-free rates were 68% at 5 years and 51% at 10 years after PVR and arrhythmia surgery. Multivariable analysis revealed that right atrial volume index (hazard ratio, 1.04; 95% confidence interval, 1.01-1.08, P = .009) was a significant risk factor for atrial arrhythmia recurrence after arrhythmia surgery and PVR.

Conclusions

Preoperative right atrial volume index was associated with atrial arrhythmia recurrence, which may assist in planning the timing of atrial arrhythmia surgery and PVR.

Ventricular Tachycardia Ablation in Adult Congenital Heart Disease

Patients with congenital heart disease (CHD) are at risk for late ventricular tachycardia (VT) and sudden cardiac death. Slow conducting anatomical isthmuses, bordered by unexcitable tissue created by valve annuli, ventricular incisions, and prosthetic material are the dominant substrate for macroreentrant monomorphic VTs in repaired CHD. These well-defined substrates allow for catheter or surgical transection with clear endpoints. This review elaborates on VT substrates in various CHD, and evolving mapping and ablation approaches. Because most research is conducted in patients with repaired tetralogy of Fallot, this malformation will serve as a paradigm.

Impact of Pulmonary Valve Replacement on Ventricular Arrhythmias in Patients With Tetralogy of Fallot and Implantable Cardioverter-Defibrillator

OBJECTIVES

This study aimed to assess the impact of pulmonary valve replacement (PVR) on ventricular arrhythmias burden in a population of tetralogy of Fallot (TOF) patients with continuous cardiac monitoring by implantable cardioverter-defibrillators (ICDs).

BACKGROUND

Sudden cardiac death is a major cause of death in TOF, and right ventricular overload is commonly considered to be a potential trigger for ventricular arrhythmias.

METHODS

Data were analyzed from a nationwide French ongoing study (DAI-T4F) including all TOF patients with an ICD since 2000. Survival data with recurrent events were used to compare the burden of appropriate ICD therapies before and after PVR in patients who underwent PVR over the study period.

RESULTS

A total of 165 patients (mean age 42.2 ± 13.3 years, 70.1% male) were included from 40 centers. Over a median follow-up period of 6.8 (interquartile range: 2.5 to 11.4) years, 26 patients (15.8%) underwent PVR. Among those patients, 18 (69.2%) experienced at least 1 appropriate ICD therapy. When considering all ICD therapies delivered before (n = 62) and after (n = 16) PVR, the burden of appropriate ICD therapies was significantly lower after PVR (HR: 0.21; 95% confidence interval [CI]: 0.08 to 0.56; p = 0.002). Respective appropriate ICD therapies rates per 100 person-years were 44.0 (95% CI: 35.7 to 52.5) before and 13.2 (95% CI: 7.7 to 20.5) after PVR (p < 0.001). In the overall cohort, PVR before ICD implantation was also independently associated with a lower risk of appropriate ICD therapy in primary prevention patients (HR: 0.29 [95% CI: 0.10 to 0.89]; p = 0.031).

CONCLUSIONS

In this cohort of high-risk TOF patients implanted with an ICD, the burden of appropriate ICD therapies was significantly reduced after PVR. While optimal indications and timing for PVR are debated, these findings suggest the importance of considering ventricular arrhythmias in the overall decision-making process. (French National Registry of Patients With Tetralogy of Fallot and Implantable Cardioverter Defibrillator [DAI-T4F]; NCT03837574).

The Role of Ablation in Prevention of Recurrent Implantable Cardioverter Defibrillator Shocks in Patients With Tetralogy of Fallot

Background

Implantable cardioverter defibrillators (ICDs) are effective in preventing arrhythmic sudden cardiac death in patients with tetralogy of Fallot (TOF). Although ICD therapies for malignant ventricular arrhythmias can be life-saving, shocks could have deleterious consequences. Substrate-based ablation therapy has become the standard of care to prevent recurrent ICD shocks in patients with ischemic cardiomyopathy. However, the efficacy and safety of this invasive therapy in the prevention of recurrent ICD shocks in patients with TOF has not been well evaluated.

Methods

Records of a total of 47 consecutive TOF patients (mean age: 43.1 ± 13.2 years, male sex: n = 34 [72.3%]) who underwent ICD implantation for secondary prevention between 2000 and 2018 were reviewed.

Results

Twenty (42.6%) patients underwent invasive therapy (radiofrequency catheter ablation, n = 8; surgical ablation with pulmonary valve replacement, n = 12) before ICD implantation. Twenty-seven patients (57.4%) were managed noninvasively. During follow-up (median 80.5 [interquartile range, 28.5-131.0] months), 2 (10.0%) patients in the invasive group and 10 (37.0%) patients in the noninvasive group received appropriate ICD shocks (P = 0.036). Logistic regression analysis showed that invasive therapy was associated with a decreased risk of ICD shocks by 81.1% (odds ratio, 0.189; 95% confidence interval, 0.036-0.990; P = 0.049). Furthermore, invasive therapy was associated with decreased risk of the composite outcomes of ICD shock, death, cardiac transplantation, and hospital admission (odds ratio, 0.090; 95% confidence interval, 0.025-0.365; P = 0.013) compared with noninvasive therapy.

Conclusions

Invasive substrate modification therapy was associated with a lower likelihood of ICD shocks and improvement of long-term outcomes in TOF patients.

Early outcomes of usage of cryoFORM® probe for cryomaze procedure in congenital heart surgery

OBJECTIVES

This study aimed to evaluate the early outcomes of patients who underwent a concomitant therapeutic maze procedure for congenital heart surgery.

MATERIALS AND METHODS

Between 2019 and 2020, eight patients underwent surgical cryoablation by using the same type of cryoablation probe.

RESULTS

Three patients had atrial flutter, two had Wolf-Parkinson-White syndrome, two intra-atrial reentrant tachycardia, and one had atrial fibrillation. Four patients underwent electrophysiological study. Preoperatively, one patient was on 3, two were on 2, five were on 1 antiarrhythmic drug. Six patients underwent right atrial maze and two underwent bilateral atrial maze. Five out of six right atrial maze patients underwent right atrial reduction. Nine different lesion sets were used. Some of the lesions were combined and applied as one lesion. In Ebstein's anomaly patients, the lesion from coronary sinus to displaced tricuspid annulus was delicately performed. The single ventricle patient with heterotaxy had junctional rhythm at the time of discharge and was the only patient who experienced atrial extrasystoles 2 months after discharge. Seven of the eight patients were on sinus rhythm. No patient needed permanent pacemaker placement.

CONCLUSION

Cryomaze procedure can be applied in congenital heart diseases with acceptable arrhythmia-free rates by selecting the appropriate materials and suitable lesion sets. The application of cryomaze in heterotaxy patients can be challenging due to differences in the conduction system and complex anatomy. Consensus with the electrophysiology team about the choice of the right-left or biatrial maze procedure is mandatory for operational success.

2019 HRS/EHRA/APHRS/LAHRS expert consensus statement on catheter ablation of ventricular arrhythmias

Ventricular arrhythmias are an important cause of morbidity and mortality and come in a variety of forms, from single premature ventricular complexes to sustained ventricular tachycardia and fibrillation. Rapid developments have taken place over the past decade in our understanding of these arrhythmias and in our ability to diagnose and treat them. The field of catheter ablation has progressed with the development of new methods and tools, and with the publication of large clinical trials. Therefore, global cardiac electrophysiology professional societies undertook to outline recommendations and best practices for these procedures in a document that will update and replace the 2009 EHRA/HRS Expert Consensus on Catheter Ablation of Ventricular Arrhythmias. An expert writing group, after reviewing and discussing the literature, including a systematic review and meta-analysis published in conjunction with this document, and drawing on their own experience, drafted and voted on recommendations and summarized current knowledge and practice in the field. Each recommendation is presented in knowledge byte format and is accompanied by supportive text and references. Further sections provide a practical synopsis of the various techniques and of the specific ventricular arrhythmia sites and substrates encountered in the electrophysiology lab. The purpose of this document is to help electrophysiologists around the world to appropriately select patients for catheter ablation, to perform procedures in a safe and efficacious manner, and to provide follow-up and adjunctive care in order to obtain the best possible outcomes for patients with ventricular arrhythmias.

2019 HRS/EHRA/APHRS/LAHRS expert consensus statement on catheter ablation of ventricular arrhythmias

Ventricular arrhythmias are an important cause of morbidity and mortality and come in a variety of forms, from single premature ventricular complexes to sustained ventricular tachycardia and fibrillation. Rapid developments have taken place over the past decade in our understanding of these arrhythmias and in our ability to diagnose and treat them. The field of catheter ablation has progressed with the development of new methods and tools, and with the publication of large clinical trials. Therefore, global cardiac electrophysiology professional societies undertook to outline recommendations and best practices for these procedures in a document that will update and replace the 2009 EHRA/HRS Expert Consensus on Catheter Ablation of Ventricular Arrhythmias. An expert writing group, after reviewing and discussing the literature, including a systematic review and meta-analysis published in conjunction with this document, and drawing on their own experience, drafted and voted on recommendations and summarized current knowledge and practice in the field. Each recommendation is presented in knowledge byte format and is accompanied by supportive text and references. Further sections provide a practical synopsis of the various techniques and of the specific ventricular arrhythmia sites and substrates encountered in the electrophysiology lab. The purpose of this document is to help electrophysiologists around the world to appropriately select patients for catheter ablation, to perform procedures in a safe and efficacious manner, and to provide follow-up and adjunctive care in order to obtain the best possible outcomes for patients with ventricular arrhythmias.

Outcomes of Atrial Arrhythmia Surgery in Patients With Congenital Heart Disease: A Systematic Review

Background The improved life expectancy of patients with congenital heart disease is often accompanied by the development of atrial tachyarrhythmias. Similarly, the number of patients requiring redo operations is expected to continue to rise as these patients are aging. Consequently, the role of arrhythmia surgery in the treatment of atrial arrhythmias is likely to become more important in this population. Although atrial arrhythmia surgery is a well-established part of Fontan conversion procedures, evidence-based recommendations for arrhythmia surgery for macroreentrant atrial tachycardia and atrial fibrillation in other patients with congenital heart disease are still lacking. Methods and Results Twenty-eight studies were included in this systematic review. The median reported arrhythmia recurrence was 13% (interquartile range, 4%-26%) during follow-up ranging from 3 months to 15.2 years. A large variation in surgical techniques was observed. Based on the acquired data, biatrial lesions are more effective in the treatment of atrial fibrillation than exclusive right-sided lesions. Right-sided lesions may be more appropriate in the treatment of macroreentrant atrial tachycardia; evidence for the superiority of additional left-sided lesions is lacking. There are not enough data to support the use of exclusive left-sided lesions. Theoretically, prophylactic atrial arrhythmia surgery may be beneficial in this population, but evidence is currently limited. Conclusions To be able to provide recommendations for arrhythmia surgery in patients with congenital heart disease, future studies should report outcomes according to the type of preoperative arrhythmia, underlying congenital heart disease, lesion set, and energy source. This is essential for determining which surgical techniques should ideally be applied under which circumstances.

Clinical significance of right atrial volume in patients with repaired tetralogy of Fallot

OBJECTIVES

Atrial arrhythmia and right ventricular (RV) diastolic dysfunction are associated with increased morbidity and mortality in patients with repaired tetralogy of Fallot (TOF). This study was performed to determine whether the preoperative right atrial (RA) volume can predict the development of atrial arrhythmia after pulmonary valve replacement (PVR) in patients with TOF.

METHODS

Forty-seven consecutive adult patients with repaired TOF underwent PVR from 2003 to 2018. Seventeen patients showed preoperative atrial arrhythmia and underwent the Maze procedure concomitantly. The preoperative RA volume was evaluated with computed tomography and image analysis software.

RESULTS

The median follow-up period after PVR was 6.8 years. Among 17 patients who underwent the Maze procedure, recurrent atrial arrhythmia developed in 8 patients. Among 30 patients without preoperative atrial arrhythmia, novel atrial arrhythmia developed in 2 patients. The RA volume index was a significant predictor according to the multivariate analysis (P = 0.003). The RA volume index showed a significant positive correlation with the RV end-diastolic pressure (P < 0.001).

CONCLUSIONS

The RA volume predicts the development of atrial arrhythmia after PVR in patients with repaired TOF. RA volume measurement is strongly recommended in the management of this patient population.

Postoperative and short-term atrial tachyarrhythmia burdens after transcatheter vs surgical pulmonary valve replacement among congenital heart disease patients

OBJECTIVE

We examined the atrial tachyarrhythmia (AT) burden among patients with congenital heart disease (CHD) following transcatheter (TC-) or surgical (S-) pulmonary valve replacement (PVR).

DESIGN/SETTING

This was a retrospective observational study of patients who underwent PVR from 2010 to 2016 at UCLA Medical Center.

PATIENTS

Patients of all ages who had prior surgical repair for CHD were included. Patients with a history of congenitally corrected transposition of the great arteries, underwent a hybrid PVR procedure, or had permanent atrial fibrillation (AF) without a concomitant ablation were excluded.

OUTCOME MEASURES

The primary outcome was a time-to-event analysis of sustained AT. Sustained ATs were defined as focal AT, intra-atrial reentrant tachycardia/atrial flutter, or AF lasting at least 30 seconds or terminating with cardioversion or antitachycardia pacing.

RESULTS

Two hundred ninety-seven patients (TC-PVR, n = 168 and S-PVR, n = 129) were included. During a median follow-up of 1.2 years, nine events occurred in TC-PVR group (5%) vs 23 events in S-PVR group (18%). In the propensity adjusted models, the following factors were associated with significant risk of AT after PVR: history of AT, age at valve implantation, severe right atrial enlargement, and S-PVR. In the secondary analysis, TC-PVR was associated with lower adjusted risk of AT events in the postoperative epoch (first 30 days), adjusted IRR 0.31 (0.14-0.97), P = .03, but similar risk in the short-term epoch, adjusted IRR 0.64 (0.14-2.94), P = .57.

CONCLUSION

There was an increased risk of AT in the first 30 days following S-PVR compared to TC-PVR. Additional factors associated with risk of AT events after PVR were a history of AT, age at valve implantation, and severe right atrial enlargement.

2019 HRS/EHRA/APHRS/LAHRS expert consensus statement on catheter ablation of ventricular arrhythmias

Ventricular arrhythmias are an important cause of morbidity and mortality and come in a variety of forms, from single premature ventricular complexes to sustained ventricular tachycardia and fibrillation. Rapid developments have taken place over the past decade in our understanding of these arrhythmias and in our ability to diagnose and treat them. The field of catheter ablation has progressed with the development of new methods and tools, and with the publication of large clinical trials. Therefore, global cardiac electrophysiology professional societies undertook to outline recommendations and best practices for these procedures in a document that will update and replace the 2009 EHRA/HRS Expert Consensus on Catheter Ablation of Ventricular Arrhythmias. An expert writing group, after reviewing and discussing the literature, including a systematic review and meta-analysis published in conjunction with this document, and drawing on their own experience, drafted and voted on recommendations and summarized current knowledge and practice in the field. Each recommendation is presented in knowledge byte format and is accompanied by supportive text and references. Further sections provide a practical synopsis of the various techniques and of the specific ventricular arrhythmia sites and substrates encountered in the electrophysiology lab. The purpose of this document is to help electrophysiologists around the world to appropriately select patients for catheter ablation, to perform procedures in a safe and efficacious manner, and to provide follow-up and adjunctive care in order to obtain the best possible outcomes for patients with ventricular arrhythmias.

Recommendations for the use of electrophysiological study: Update 2018

The field of cardiac electrophysiology has greatly developed during the past decades. Consequently, the use of electrophysiological studies (EPSs) in clinical practice has also significantly augmented, with a progressively increasing number of certified electrophysiology centers and specialists. Since Zipes et al published the Guidelines for Clinical Intracardiac Electrophysiology and Catheter Ablation Procedures in 1995, no official document summarizing current EPS indications has been published. The current paper focuses on summarizing all relevant data of the role of EPS in patients with different types of cardiac pathologies and provides up-to-date recommendations on this topic. For this purpose, the PubMed database was screened for relevant articles in English up to December 2018 and ESC and ACC/AHA Clinical Practice Guidelines, and EHRA/HRS/APHRS position statements related to the current topic were analyzed. Current recommendations for the use of EPS in clinical practice are discussed and presented in 17 distinct cardiac pathologies. A short rationale, evidence, and indications are provided for each cardiac disease/group of diseases. In conclusion, because of its capability to establish a diagnosis in patients with a variety of cardiac pathologies, the EPS remains a useful tool in the evaluation of patients with cardiac arrhythmias and conduction disorders and is capable of establishing indications for cardiac device implantation and guide catheter ablation procedures.

Successful Treatment of Ventricular Arrhythmia in Tetralogy of Fallot Repair Using Catheter Ablation

Tetralogy of Fallot (ToF) is one of the most prevalent congenital heart disease. Its surgical corrections may haemodinamically correct a disease, but the incisions may create scars that will originate ventricular arrhythmias. Even though life threatening arrhythmias are not common, some patients present unstable ventricular tachycardia (VT) of ectopic ventricular beats triggering heart failure and symptoms. We describe the treatment of a 16-years-old woman with late ToF repair and drug refractory Implantable cardioverter defibrillator (ICD) shocks. The patient underwent successful ablation of VT using X-ray and anatomic landmarks without the use of electroanatomical mapping. We were able to reduce drugs after one month of ablation and improve quality of life and symptoms. In this paper we describe the indications and perform a brief review of the key points for successful radiofrequency catheter ablation of VT in ToF patients.

Surgery for supraventricular tachycardia and congenital heart defects: long-term efficacy of the combined approach in adult patients

Aims

Supraventricular arrhythmias are a major cause of morbidity and mortality in adult patients with congenital heart disease (CHD). Intraoperative ablation offers an alternative for patients who failed ablation procedures or are requiring concomitant surgical intervention. We present our long-term results with the surgical treatment of arrhythmias in adults with CHD (ACHD) undergoing elective cardiac surgery and the clinical predictors for arrhythmia recurrence.

Methods and results

Between 2002 and 2013, 80 consecutive patients with CHD, mean age of 39 years, underwent intraoperative ablation with monopolar irrigated radiofrequency during cardiac surgery procedures. Significant clinical predictors of arrhythmia recurrence were determined by univariate analysis. We performed 47 right-sided Maze procedures, and 33 Cox-Maze III procedures. In 75 survivors, the ablation was effective immediately. Over an average follow-up period of 72 months (12-155 months), arrhythmias recurred in nine (20%) patients after right-sided Maze, and in six (19%) patients after Cox-Maze III. Eleven patients were controlled with medical therapy, three underwent catheter ablation of the arrhythmia, and one required a permanent pacemaker. Preoperative arrhythmia length ≥3 years (P ≤ 0.001), tetralogy of Fallot (P ≤ 0.006), and preoperative atrial fibrillation (P ≤ 0.016) were associated with recurrence arrhythmia. Conversely, NYHA class <3 (P ≤ 0.047) was associated with a lower risk of recurrence.

Conclusion

Surgical treatment of unresponsive supraventricular arrhythmia during concomitant cardiac surgery in ACHD is a safe and effective procedure. Freedom from arrhythmias recurrence is 75% after 6 years of follow-up. Long-term recurrence of arrhythmia in these patients seems to be strongly correlated to preoperative arrhythmia duration.

[Pulmonary revalvulation and rhythmologenic risks in patients with repaired tetralogy of Fallot]

Tetralogy of Fallot is a frequent congenital heart disease that has been repaired since the mid-1950s. The follow-up after repair is good despite a persistent risk of sudden death. The risk factors in long-term follow-up are advanced age at repair, hemodynamic status of the right ventricle, QRS duration≥180ms, left ventricular dysfunction, and existence of sustained or not ventricular tachycardia. In the presence of significant pulmonary regurgitation, it is necessary to perform revalvulation either by classic surgery or cardiac catheterization. To correct the risk of ventricular arrhythmia, some have proposed radiofrequency ablation of critical isthmus, or cryo-application during surgery. However, the use of implantable cardioverter defibrillator is another therapeutic option that is more and more employed as secondary or primary prevention in patients at risk of sudden death.

Arrhythmia Surgery for Adults with Congenital Heart Disease

Patients with repaired or unrepaired congenital heart anomalies are at increased risk for arrhythmia development throughout their lives, often paralleling the need for reoperations for hemodynamic residua. The ability to incorporate arrhythmia surgery into reoperations can result in improvement in functional class and decreased need for antiarrhythmic medications. Every reoperation for congenital heart disease can be viewed as an opportunity to assess the electrical and arrhythmia substrates and to intervene to improve the arrhythmias and the hemodynamic condition of the patient. The authors review and summarize the operative techniques for arrhythmia surgery that are based on the arrhythmia mechanisms.

Pulmonary valve replacement in older children and adults using stented bioprostheses

More than 50% of children who undergo repair of tetralogy of Fallot (TOF) using a transannular patch will require pulmonary valve replacement (PVR) in early adulthood. The premise of PVR in this setting is to ameliorate the relentless right ventricular (RV) dilatation that otherwise occurs in the presence of severe pulmonary regurgitation. Severe RV dilatation is associated with RV dysfunction, symptoms of exercise intolerance, tricuspid regurgitation and-occasionally-life-threatening RV failure or dangerous ventricular tachyarrhythmia. Increasingly, patients referred for PVR are asymptomatic young adults with busy lives and dependants. Redo cardiac surgery in this setting is high-stakes surgery. Here, we outline the surgical approach taken in a centre with a history of >1000 such operations.

Prophylactic arrhythmia surgery in association with congenital heart disease

Certain congenital heart anomalies make patients more susceptible to arrhythmia development throughout their lives. This poses the question whether prophylactic arrhythmia surgery should be incorporated into reparative open heart procedures for congenital heart disease. There is currently no consensus on what constitutes a standard prophylactic procedure, owing to the questions that remain regarding lesions to be performed; energy sources to use; proximity of energy source or incisions to coronary arteries, sinoatrial node, atrioventricular node; circumstances for right atrial, left atrial, or biatrial appendectomy; and whether to perform a right, left, or biatrial maze procedure. These considerations are important because prophylactic arrhythmia procedures are performed without knowing if the patient will actually develop an arrhythmia in his or her lifetime. By reviewing and summarizing the literature, congenital heart disease patients who are at risk for developing atrial arrhythmias can be identified and lesion sets can be suggested in an effort to standardize experimental protocols for prophylactic arrhythmia surgery.

Fontan Conversion

Early survival after the Fontan operation has improved significantly leading to a lifetime of Fontan circulation for patients. There is a natural progression of pulmonary artery pressure during the human lifetime that is easily tolerated in two-ventricle physiology but is deleterious for single-ventricle physiology. Obstructions in the venous to pulmonary artery pathway and pulmonary venous return or ventricular outflow, atrioventricular valve dysfunction (regurgitation), pulmonary arteriovenous malformations, venous thrombosis, and the development of atrial arrhythmias can lead to reduced functional status. These complications have been demonstrated in older patients with largely atriopulmonary connections owing to time accrual and unfavorable flow characteristics. Various surgical and catheter interventions aimed at reducing morbidity and mortality have been attempted to treat these identifiable abnormalities. The purpose of this article is to review the extant literature on Fontan Conversion and to assess the lessons learned over 20 years.

Preservation of the Pulmonary Valve During Early Repair of Tetralogy of Fallot: Surgical Techniques

During the last decade interest in preserving pulmonary valve (PV) function has stimulated a few surgeons to apply valve-sparing techniques in repairing tetralogy of Fallot (TOF), with the aim of preserving long-term right ventricular function. Since June 2007, we embarked upon a program for preserving PV function in selected patients during TOF repair. More recently, the introduction of more complex PV plasty techniques allowed us to further extend the applicability of PV preservation techniques. We believe that preservation of PV function during early repair of TOF, by combining different intraoperative surgical maneuvers, can be extended to almost all patients with classic TOF.

[Right ventricular outflow tract tachycardia 30 years after surgical correction of tetralogy of Fallot]

This case report describes a 31-year-old man with a sustained wide complex tachycardia with left bundle brunch block morphology after surgical repair of a tetralogy of Fallot. The tachycardia was inducible after orciprenaline administration after ventricular stimulation with one extra beat. In combination with the three-dimensional electroanatomic mapping system and pace mapping technique the origin of the tachycardia was identified at the lateral free wall of the right ventricular outflow tract tachycardia (RVOT) inferior of the pulmonary valve. Successful radiofrequency ablation was performed and the patient is still free from ventricular tachycardia.

Ventricular arrhythmia risk stratification in patients with tetralogy of Fallot at the time of pulmonary valve replacement

BACKGROUND

Most patients with repaired tetralogy of Fallot require pulmonary valve replacement (PVR), but the evaluation for and management of ventricular arrhythmia remain unclear. This study is aimed at clarifying the optimal approach to this potentially life-threatening issue at the time of PVR.

METHODS AND RESULTS

A retrospective analysis was performed on 205 patients with repaired tetralogy of Fallot undergoing PVR at our institution between 1988 and 2010. Median age was 32.9 (range, 25.6) years. Previous ventricular tachycardia occurred in 16 patients (8%) and 37 (16%) had left ventricular dysfunction, defined as left ventricular ejection fraction <50%. Surgical right ventricular outflow tract cryoablation was performed in 22 patients (10.7%). The primary outcome was a combined event including ventricular tachycardia, out-of-hospital cardiac arrest, appropriate implantable cardioverter defibrillator therapy, and sudden cardiac death. Freedom from the combined event at 5, 10, and 15 years was 95%, 90%, and 79%, respectively. In the first year after PVR, 2 events occurred. Conversely, in the 22 patients who underwent surgical cryoablation, a single event occurred 7 years after PVR. A history of ventricular tachycardia and left ventricular dysfunction was associated with higher risk for the combined event (hazard ratio, 4.7; P=0.004 and hazard ratio, 0.8; P=0.02, respectively).

CONCLUSIONS

Patients with repaired tetralogy of Fallot undergoing PVR with history of ventricular tachycardia or left ventricular dysfunction appear to be associated with a higher risk of arrhythmic events after operation. Events in the first year after PVR are rare, and in select high-risk patients, surgical cryoablation does not seem to increase arrhythmic events and may be protective.

Prophylactic atrial arrhythmia surgical procedures with congenital heart operations: review and recommendations

Specific congenital heart anomalies significantly increase the risk for late atrial arrhythmias, raising the question whether prophylactic arrhythmia operations should be incorporated into reparative open heart procedures. Currently no consensus exists regarding standard prophylactic arrhythmia procedures. Questions remain concerning the arrhythmia-specific lesions to perform, energy sources to use, need for atrial appendectomy, and choosing a right, left, or biatrial Maze procedure. These considerations are important because prophylactic arrhythmia procedures are performed without knowing if the patient will actually experience an arrhythmia. This review identifies congenital defects with a risk for the development of atrial arrhythmias and proposes standardizing lesion sets for prophylactic arrhythmia operations.

Arrhythmias in Complex Congenital Heart Disease

Late after surgical repair of complex congenital heart disease, atrial arrhythmias are a major cause of morbidity, and ventricular arrhythmias and sudden cardiac death are a major cause of mortality. The six cases in this article highlight common challenges in the management of arrhythmias in the adult congenital heart disease population.