Current management of late failure after classic Fontan modifications: Fontan conversion

BACKGROUND: Re-establishment of Fontan circulation by eliminating the drawbacks of classic Fontan modifications has been proposed recently to improve the functional class and quality of life of patients with failed Fontan circulation. METHODS: Five patients underwent extracardiac and lateral tunnel Fontan conversion due to failure of the Fontan circulation, after classic Fontan modifications. All of the patients were female and mean age was 10.2 +/- 2.2 years (range: 8-14 years). Previous Fontan modifications were atrio-pulmonary anastomosis in 3 and Kawashima operation in 2 patients. Time to re-operation for Fontan conversion was 6 +/- 1.5 years (range: 4-8 years). Indications for re-operation were right heart failure, right atrial dilatation, and intractable atrial arrhythmias in patients with previous atrio-pulmonary anastomosis, progressive hypoxia and exercise intolerance in patients with previous Kawashima operation due to pulmonary arteriovenous fistulas. Previous atrio-pulmonary anastomoses were converted to intra-atrial or lateral tunnel Fontan operation with modified right atrial Maze procedure. Extracardiac Fontan completion was carried out after previous Kawashima operations by redirection of hepatic veins to the lungs. RESULTS: There was no mortality and no major morbidity. All patients were discharged from the hospital in good condition and in sinus rhythm. No prolonged or recurrent effusions were observed. On follow-up, all patients were in sinus rhythm and had NYHA class I functional capacity. In two Kawashima patients, SpO(2) gradually increased from 60 % to 90 % six months after the operation. DISCUSSION: We suggest that Fontan conversion should be considered in patients with previous atrio-pulmonary anastomosis, when right atrial dilatation or intractable atrial arrhythmias with deteriorating functional status develops. Redirection of hepatic venous flow to lungs induces regression of pulmonary arteriovenous fistulas and improves arterial saturation in patients with previous Kawashima operation.     

Catheter Ablation of Atrial Arrhythmias in Patients Post-Fontan

Atrial arrhythmias are highly prevalent in the aging Fontan population and contribute importantly to morbidity and mortality. Although the most common arrhythmia is scar-based intra-atrial re-entrant tachycardia, various other arrhythmias may occur, including focal atrial tachycardia, atrioventricular node-dependent tachycardias, and atrial fibrillation. The type and prevalence of atrial arrhythmia is determined, in part, by the underlying congenital defect and variant of Fontan surgery. Although the cumulative incidence of atrial tachyarrhythmias has decreased substantially from the atriopulmonary anastomosis to the more recent total cavopulmonary-connection Fontan, the burden of atrial arrhythmias remains substantial. Management is often multifaceted and can include anticoagulation, anti-arrhythmic drug therapy, pacing, and cardioversion. Catheter ablation plays a key role in control of arrhythmia. Risks and benefits must be carefully weighed. Among the important considerations are the clinical burden of arrhythmia, ventricular function, hemodynamic stability in tachycardia, suspected arrhythmia mechanisms, risks associated with anaesthesia, venous access, approaches to reaching the pulmonary venous atrium, and accompanying comorbidities. Careful review of surgical notes, electrocardiographic tracings, and advanced imaging is paramount, with particular attention to anatomic abnormalities such as venous obstructions and displaced conduction systems. Despite numerous challenges, ablation of atrial arrhythmias is effective in improving clinical status. Nevertheless, onset of new arrhythmias is common during long-term follow-up. Advanced technologies, such as high-density mapping catheters and remote magnetic guided ablation, carry the potential to further improve outcomes. Fontan patients with atrial arrhythmias should be referred to centres with dedicated expertise in congenital heart disease including catheter ablation, anaesthesia support, and advanced imaging.     

Ablation of atrial tachycardia after surgery for congenital and acquired heart disease using an electroanatomic mapping system: Which circuits to expect in which substrate?

OBJECTIVES: The purpose of this study was to compare atrial tachycardia circuits after a range of cardiac operations. BACKGROUND: Knowledge of circuits occurring in a given postsurgical substrate should help to ablate these challenging tachycardias and develop potential preventive strategies. METHODS: We analyzed tachycardia circuits in 83 consecutive patients (60 males; median age 47 years, range 9-73) after atrial incisions undergoing ablation of atrial tachycardias. A combined strategy of electroanatomic (CARTO) and entrainment mapping was used. Fifty-two patients (63%) underwent operation for congenital and 31 (37%) for acquired heart disease. Patients were divided into subgroups based on the intervention performed in the atria: right lateral atriotomy (39 patients), left atrial (11) and superior transseptal (10) approach to the mitral valve, biatrial heart transplantation (8), Mustard (8) and Fontan (4) procedure, and other interventions (3). RESULTS: Most of the 119 tachycardias mapped were isthmus-dependent atrial flutter (66) and incisional tachycardia (30). Isthmus-dependent atrial flutter was the most frequent arrhythmia in all subgroups except for Fontan patients, in whom incisional tachycardia was most frequent. The distribution of tachycardia circuits did not differ significantly among groups. CONCLUSIONS: The observed circuits did not differ among the postsurgical substrates. Isthmus-dependent atrial flutter should be the first circuit considered in patients after atrial incisions.     

Surgical management of refractory supraventricular tachycardia in infants and children

Sixty-seven children underwent attempted surgical correction of refractory supraventricular arrhythmias using a combination of intraoperative electrophysiologic mapping followed by surgical division or cryoablation of an aberrant conduction pathway or atrial ectopic focus. The patients ranged in age from 4 months to 18 years (mean 11.4 years). Fifty-five patients (82%) had an abnormal conduction pathway crossing the atrioventricular junction (Kent bundle). Thirty-six (65%) of these 55 patients had classic Wolff-Parkinson-White syndrome with a delta wave of pre-excitation on the surface electrocardiogram. Nineteen (35%), however, demonstrated only retrograde conduction across the Kent bundle and had a normal surface electrocardiogram when tachycardia was not present. Kent bundles were isolated to the following locations: right anterior or lateral in 19 (34.5%), left posterior or lateral in 22 (40%), posteroseptal in 10 (18%), anteroseptal in 2 (4%) and both right and left in 2 (4%). Follow-up evaluation of as long as 8 years (mean 34.9 months) has shown seven immediate failures and one late recurrence of arrhythmia (14.5%). Recent refinements in technique and the use of cryoablation for septal aberrant pathways have improved these results. There have been two failures (8%) in the last 25 attempts. Twelve patients underwent surgery for an atrial ectopic focus by the following techniques: cryoablation in seven patients, excision in one patient and both excision and cryoablation in four patients. At a mean follow-up of 16.6 months, there was one late recurrence in the group with an atrial ectopic focus.(ABSTRACT TRUNCATED AT 250 WORDS)     

Location of acutely successful radiofrequency catheter ablation of intraatrial reentrant tachycardia in patients with congenital heart disease

Intraatrial reentrant tachycardia (IART) is common after surgery for congenital heart disease (CHD). Radiofrequency (RF) catheter ablation of IART targets anatomic areas critical to the maintenance of the arrhythmia circuit, areas that have not been well defined in this patient population. The purpose of this study was to determine the anatomic areas critical to IART circuits, defined by activation mapping and confirmed by an acutely successful RF ablation at the site. A total of 110 RF ablation procedures in 88 patients (median age 23.4 years, range 0.1 to 62.7) with CHD were reviewed. Patients were grouped according to surgical intervention: Mustard/Senning (n = 15), other biventricular repaired CHD (n = 24), Fontan (n = 43), and palliated CHD (n = 6). In first-time ablation procedures, > or = 1 IART circuits were acutely terminated in 80% of Mustard/Senning, 71% of repaired CHD, and 72% of Fontan (p = NS). The palliated CHD group underwent 1 of 6 successful procedures (17%), and this patient was excluded. The locations of acutely successful RF applications in Mustard/Senning patients (n = 14 sites) were at the tricuspid valve isthmus (57%) and at the lateral right atrial wall (43%). In patients with repaired CHD (n = 18 sites), successful RF sites were at the isthmus (67%) and the lateral (22%) and anterior (11%) right atria. In the Fontan group (n = 40 sites), successful RF sites included the lateral right atrial wall (53%), the anterior right atrium (25%), the isthmus area (15%), and the atrial septum (7%). Location of success was statistically different for the Fontan group (p = .002). In conclusion, the tricuspid valve isthmus is a critical area for ablation of IART during the Mustard/ Senning procedure and in patients with repaired CHD. IART circuits in Fontan patients are anatomically distinct, with the lateral right atrial wall being the more common area for successful RF applications. This information may guide RF and/or surgical ablation procedures in patients with CHD and IART.     

Early and late arrhythmias after the Fontan operation: predisposing factors and clinical consequences.

OBJECTIVE--To study the incidence, predisposing factors, and clinical significance of arrhythmias early and late after the Fontan operation for congenital heart disease. PATIENTS AND METHODS--All 104 consecutive patients undergoing Fontan repair from 1975 to 1988 were studied retrospectively. Hospital records were reviewed for perioperative arrhythmia. Clinical information and annual electrocardiograms were available for all 78 hospital survivors during a follow up of up to 13 years (mean 3.7 years). Ambulatory electrocardiographic monitoring was performed in 67 patients (81%). RESULTS--Eleven patients (10.6%) developed a perioperative tachycardia (eight, atrial flutter; three, His bundle tachycardia). Multivariate analysis showed that raised preoperative mean pulmonary artery pressure and low aortic saturation were significant risk factors for the development of atrial flutter (r2 = 0.32, p = 0.0001) but not for His bundle tachycardia. Despite intensive medical treatment 10 of these 11 patients died. At the last visit 72 (92%) of the 78 patients were in sinus rhythm on their standard 12 lead electrocardiogram. Junctional rhythm was present in three patients, two patients had atrial flutter, and one had a paced rhythm. Ambulatory monitoring did not show important bradycardia or ventricular arrhythmias. Actuarial survival free of supraventricular arrhythmia was 82% at eight years after operation. Multivariate analysis identified older age, increased right atrial size, and raised mean preoperative pulmonary artery pressure as risk factors for arrhythmia during intermediate follow-up (r2 = 0.46, p less than 0.001). Late tachycardias, in contrast to those occurring in the perioperative period, were not associated with an increased mortality. CONCLUSIONS--Except for his bundle tachycardia in the perioperative period, early and late arrhythmias after a Fontan operation seem to be a consequence of adverse preoperative and postoperative haemodynamic function. The perioperative outcome is therefore poor even when the patient can be restored to sinus rhythm. Medical and surgical modifications to improve the haemodynamic disturbances associated with arrhythmias are therefore indicated.     

Early and late arrhythmias after the Fontan operation: predisposing factors and clinical consequences.

OBJECTIVE--To study the incidence, predisposing factors, and clinical significance of arrhythmias early and late after the Fontan operation for congenital heart disease. PATIENTS AND METHODS--All 104 consecutive patients undergoing Fontan repair from 1975 to 1988 were studied retrospectively. Hospital records were reviewed for perioperative arrhythmia. Clinical information and annual electrocardiograms were available for all 78 hospital survivors during a follow up of up to 13 years (mean 3.7 years). Ambulatory electrocardiographic monitoring was performed in 67 patients (81%). RESULTS--Eleven patients (10.6%) developed a perioperative tachycardia (eight, atrial flutter; three, His bundle tachycardia). Multivariate analysis showed that raised preoperative mean pulmonary artery pressure and low aortic saturation were significant risk factors for the development of atrial flutter (r2 = 0.32, p = 0.0001) but not for His bundle tachycardia. Despite intensive medical treatment 10 of these 11 patients died. At the last visit 72 (92%) of the 78 patients were in sinus rhythm on their standard 12 lead electrocardiogram. Junctional rhythm was present in three patients, two patients had atrial flutter, and one had a paced rhythm. Ambulatory monitoring did not show important bradycardia or ventricular arrhythmias. Actuarial survival free of supraventricular arrhythmia was 82% at eight years after operation. Multivariate analysis identified older age, increased right atrial size, and raised mean preoperative pulmonary artery pressure as risk factors for arrhythmia during intermediate follow-up (r2 = 0.46, p less than 0.001). Late tachycardias, in contrast to those occurring in the perioperative period, were not associated with an increased mortality. CONCLUSIONS--Except for his bundle tachycardia in the perioperative period, early and late arrhythmias after a Fontan operation seem to be a consequence of adverse preoperative and postoperative haemodynamic function. The perioperative outcome is therefore poor even when the patient can be restored to sinus rhythm. Medical and surgical modifications to improve the haemodynamic disturbances associated with arrhythmias are therefore indicated.     

Surgical treatment of right atrial focal tachycardia in adults

Although successful operative treatment of atrial focal tachycardia has been reported in children, there are only isolated reports of surgical treatment of this arrhythmia in adults. In this case series of eight patients (aged 10 to 53 years) with drug-resistant right atrial focal tachycardia, results of electrophysiologic studies, surgical techniques and long-term follow-up are described. Atrial focal tachycardia was reproduced during electrophysiologic study, and endocardial mapping localized the earliest onset of atrial activation in the right atrium in all patients. Epicardial mapping confirmed the location of atrial tachycardia foci in seven of eight patients whose tachycardia was inducible intraoperatively. Of four patients treated with epicardial cryoablation alone, two had recurrent tachycardia and required a second procedure. None have had arrhythmia recurrence. In all four patients after right atrial excision (two of whom had intraoperative recurrence of atrial focal tachycardia after epicardial cryoablation alone), there has been no recurrence during a clinical follow-up period of 11 to 67 months (mean 30). It is concluded that in adult patients 1) electrophysiologic study with endocardial and epicardial mapping permits successful surgical treatment of atrial focal tachycardia; 2) epicardial cryoablation alone may be associated with recurrence of atrial focal tachycardia either intraoperatively or postoperatively; and 3) subtotal right atrial resection appears to be a well tolerated procedure with no long-term recurrence of atrial focal tachycardia.     

Supraventricular arrhythmia before and after surgical closure of atrial septal defects: spectrum, prognosis and management.

Supraventricular arrhythmias are often observed in patients before and after atrial septal defect repair. Although several papers report different incidences of sustained supraventricular arrhythmias, postoperative 'incisional' macroreentrant tachycardias have not been systematically investigated. METHODS: We reviewed 136 consecutive patients (79 female, 57 male, mean age 36.8+/-17.8 years) who underwent atrial septal defect repair at our institutions between January 1990 and January 1999. Coexisting valve disease requiring surgical intervention was noted in 13 patients (9.5%). The mean follow-up period was 78.8+/-30.1 months. RESULTS: Sustained supraventricular arrhythmias occurred in 12 patients (8.8%) before surgery (atrial fibrillation in 11 patients). Using multivariate analysis the occurrence of arrhythmia significantly correlated with the presence of coexisting heart disease (P< 0.001) and age at surgery (P=0.011) After surgery sustained supraventricular arrhythmias were recorded in 16 patients (11.7%). Eleven of them had atrial fibrillation, permanent in 8 cases, 4 'incisional' macroreentrant atrial tachycardia and 1 atrioventricular re-entry tachycardia. There was a significant correlation between pre and postoperative arrhythmia (P< 0.001). Two of the 4 patients with macroreentrant atrial tachycardia underwent successful radiofrequency catheter ablation, whereas the arrhythmia was controlled medically in the remaining 2 patients. CONCLUSIONS: Atrial fibrillation remains the most frequent form of arrhythmia before and after surgical closure of atrial septal defects in adulthood, and relates to age at the time of repair and coexisting heart disease. Incisional macroreentrant atrial tachycardia is an identifiable, albeit less common, form of tachycardia, which can be treated by transcatheter ablation.     

Management of intra-atrial reentrant tachycardia

PURPOSE OF REVIEW: Intraatrial reentrant tachycardia (IART), a difficult arrhythmia to manage, is likely to become more prevalent as the population of patients with congenital heart disease grows. While pharmacologic therapy alone often remains inadequate, important advances in nonpharmacologic therapy have occurred recently, enhancing the currently available therapeutic options. This review focuses on advances in electroanatomic mapping and catheter ablation, developments in arrhythmia surgery, and device therapy for IART. RECENT FINDINGS: While catheter ablation for IART has high early recurrence rates, the lack of late recurrence in long-term follow-up is encouraging. Acute success may be improved with greater appreciation for reentrant circuits with current electroanatomic mapping systems, and with larger lesions that can be achieved with the use of irrigated-tip catheters. Arrhythmia surgery at the time of Fontan revision has good short-term and medium-term results, and is being studied as a prophylactic measure at initial Fontan surgery. Device therapy for IART now includes algorithms to prevent atrial arrhythmias, as well as antitachycardia pacing, which can be used safely and has very high efficacy for certain subgroups. SUMMARY: Due to recent advances in mapping and ablation technology, coupled with developments in arrhythmia surgery and device therapy, the armamentarium of nonpharmacologic management of IART has become more potent. There are still, however, unique challenges posed by patients with congenital heart disease, and long-term follow-up in large numbers of patients with IART are required for this expanding population of patients.     

Predictors and rates of recurrence of atrial arrhythmias following catheter ablation in adults with congenital heart disease

Background: Catheter ablation is commonly performed to treat atrial arrhythmias in adult congenital heart disease (ACHD). Despite the frequency of ablations in the ACHD population, predictors of recurrence remain poorly defined.
Objective: We sought to determine predictors of arrhythmia recurrence in ACHD patients following catheter ablation for atrial arrhythmias.
Methods: We performed a retrospective study of all catheter ablations for atrial arrhythmias performed in ACHD patients between January 12, 2005 and February 11, 2015 at our institution. Prespecified exposures of interest and time from ablation to recurrence were determined via chart review.
Results: Among 124 patients (mean age: 45 years) who underwent catheter ablation, 96 (77%) were treated for macro‐reentrant atrial tachycardia, 10 (7%) for focal atrial tachycardia, 9 (7%) for atrial fibrillation, 7 (6%) for atrioventricular nodal reentrant tachycardia, and 2 (2%) for atrioventricular reentrant tachycardia. 15 (12%) required transseptal/transbaffle puncture. Fifty‐one percent of patients recurred with a median time to recurrence of 1639 days. By univariate and multivariable analysis, body mass index (BMI) and Fontan status were the only variables associated with recurrence. Dose‐dependent effect was observed with overweight (HR = 2.37, P = .012), obese (HR = 2.67, P = .009), and morbidly obese (HR = 4.23, P = .003) patients demonstrating an increasing risk for arrhythmia recurrence postablation. There was no significant different in recurrence rates by gender, age, non‐Fontan diagnosis, or need for transseptal puncture.
Conclusions: In our cohort of ACHD patients, BMI was a significant risk factor for arrhythmia recurrence postablation, independent of Fontan status. These findings may help guide treatment decisions for persistent arrhythmias in the ACHD population.     

Cardiac surgery for arrhythmias

Cardiac arrhythmia surgery was initiated in 1968 with the first successful division of an accessory AV connection for the Wolff-Parkinson-White syndrome. Subsequent surgical procedures included the left atrial isolation procedure and right atrial isolation procedure for automatic atrial tachycardias, discrete cryosurgery of the AV node for AV nodal reentrant tachycardia, the atrial transection procedure, the corridor procedure, and the maze procedure for atrial fibrillation, the right ventricular disconnection procedure for arrhythmogenic right ventricular tachycardia, and the encircling endocardial ventriculotomy, subendocardial resection procedure, endocardial cryoablation, the Jatene procedure, and the Dor procedure for ischemic ventricular tachycardia. Because of monumental strides in the treatment of most refractory arrhythmias by endocardial catheter techniques during the past decade, the only remaining viable surgical procedures for cardiac arrhythmias are the maze procedure for atrial fibrillation and the Dor procedure for ischemic ventricular tachycardia. Nevertheless, the 25 to 30 years of intense activity in the field of cardiac arrhythmia surgery provided the essential foundation for the development of these catheter techniques and represent one of the most exciting and productive eras in the history of medicine. In one short professional career, we have witnessed the birth of arrhythmia surgery, its adolescence as an "esoteric" specialty, its prime as an enlightening yet exhausting period, and finally its waning years as a source of knowledge and wisdom upon which better methods of treatment have been founded. One could hardly ask for a more rewarding experience. (J Cardiovasc Electrophysiol, Vol. 15, pp. 250-262, February 2004)     

The Spectrum of Long‐term Electrophysiologic Abnormalities in Patients with Univentricular Hearts

Patients with univentricular hearts experience a wide range of electrophysiolgic abnormalities which tend to develop years after cardiovascular surgical interventions. Intra‐atrial reentrant tachycardia (atrial flutter) in the Fontan population is the most common arrhythmia and, as such, has the largest body of literature addressing its cause and treatment. However, sinus node dysfunction, other atrial arrhythmias, ventricular arrhythmias, and cardiac dysynchrony also occur in this patient population. The purpose of this article is to review the prevalence, mechanisms, and treatment of these electrophysiologic abnormalities within the single ventricle and Fontan patient.     

Arrhythmia Recurrence in Adult Patients with Single Ventricle Physiology Following Surgical Fontan Conversion

Objectives. To evaluate the incidence of atrial tachy-arrhythmia (AT) recurrence following conversion from right atrial-pulmonary artery (RA-PA) Fontan to total cavopulmonary connection (TCPC) in adults. Background. AT is a recognized sequel of Fontan palliation, especially in RA-PA Fontans, and is associated with significant morbidity. While catheter ablation achieves fairly reliable short-term success with low morbidity, conversion to TCPC with arrhythmia surgery is a highly effective treatment option for the classical Fontan patients with incessant AT. Methods. Single center retrospective review. Results. Twenty-seven adults underwent Fontan conversion from RA-PA to TCPC, mostly for AT indications (n = 24). Nine (33%) underwent conversion to a lateral tunnel (LT) and 18 (67%) to an extracardiac (EC) Fontan. Two patients died <30 days post-operatively. Both had liver failure and had been turned down for cardiac/liver transplantation. In-hospital complications occurred in 15/27 patients (55%), including recurrence of AT requiring cardioversion in six patients (22%) and persistent pleural effusions in 4 (15%). Mean follow-up was 4.2 years (range 3 months–14 years). Functional capacity improved from mean New York Heart Association (NYHA) class 1.8 pre-conversion to 1.2 post-conversion (P= 0.008). Twenty-one patients had concomitant arrhythmia surgery (MAZE in 12 patients with IART and Cox-MAZE in nine patients with A-Fib +/− IART). Of these, 3/21 (14%) had AT recurrence >3 months following conversion. Conclusions. Conversion from RA-PA Fontan to TCPC, with arrhythmia surgery, decreases AT recurrence and improves functional capacity. The risk of peri-operative mortality is highest in patients with cirrhosis. AT recurred in 14% of patients.     

Cardiac rhythm and symptomatic arrhythmia in right atrial isomerism

Background The conduction system in right atrial isomerism may be complicated by the presence of paired sinus nodes and twin atrioventricular nodes. With a large cohort of infants and children with right atrial isomerism, we sought to investigate the nature of atrial rhythm, its prevalence, factors predisposing patients to symptomatic cardiac arrhythmia, and the relation of arrhythmia to long-term morbidity and mortality. Methods Standard 12-lead baseline electrocardiograms were performed in 110 infants and children with right atrial isomerism at a median age of 1 day, and their clinical records were reviewed. The type, timing, and precipitating factors of symptomatic cardiac arrhythmia that occurred in 15 patients, among a cohort of 85 patients who had or were awaiting surgical interventions, were noted. Results All patients except 1 had a sinus rhythm with intact atrioventricular conduction. Of these, 87% (95/109) had single P-wave morphology, whereas 13% (14/109) had multiple P-wave morphologies. For patients with a single P-wave morphology, the frontal P-wave axis was between 0 degrees and 90 degrees in 62% (59/95), 90 degrees and 180 degrees in 23% (22/95), and superior in 15% (14/95). There was no relation between either P-wave axis or morphology and cardiac anatomy. Symptomatic cardiac arrhythmia occurred in 15 of 85 patients (18%); 11 of the 15 patients had supraventricular tachycardia, and 1 patient each had atrial tachycardia, atrial flutter, ventricular tachycardia, and congenital complete heart block. The arrhythmias occurred before surgery in 4 patients, early after surgery in 5 patients, and late after surgery in 6 patients. Although 3 of the 7 patients who died suddenly had a history of symptomatic arrhythmia, arrhythmia was the documented cause of mortality in only 1 of the 32 fatalities (3.1%). Freedom from arrhythmia at 1, 5, 10, 15, and 20 years was 93% ± 3%, 86% ± 4%, 80% ± 6%, 73% ± 9%, and 48% ± 15% (mean ± SE), respectively. No risk factors for symptomatic arrhythmia were identified by means of logistic regression. Conclusions The atrial pacemaker varies in location within and between patients with right atrial isomerism. Although symptomatic cardiac arrhythmias are not uncommon, they do not seem to relate to the overall high mortality rate and occurrence of sudden death in this patient group. Nonetheless, detailed assessment and aggressive management of cardiac arrhythmias once they occur are warranted because of the precarious single ventricular hemodynamics. (Am Heart J 2002;144:159-64.)     

Pulmonary vein firing triggering atrial fibrillation after open heart surgery

We report the case of a 44-year-old woman with obstructive hypertrophic cardiomyopathy without history of prior arrhythmias who underwent surgical myectomy. She developed symptomatic postoperative atrial fibrillation (AF) that was refractory to antiarrhythmic therapy and could not be adequately rate controlled. AF always was preceded by short and fast runs of atrial tachycardia. In the electrophysiology laboratory, this arrhythmia appeared to originate from the right superior pulmonary vein and conducted with variable degrees of exit block. Pulmonary vein isolation guided by circular mapping was performed, and no further episodes of either atrial tachycardia or AF were noted. This case highlights the potential role of the pulmonary veins in the pathophysiology of postoperative AF.     

Long-term follow-up after surgical correction of Wolff-Parkinson-White syndrome

The long-term efficacy of surgical correction of Wolff-Parkinson-White syndrome was evaluated in 45 consecutive patients. Before surgery, 42 patients had reciprocating tachycardia and 12 had atrial fibrillation. The principal operative procedure was endocardial incision in 42 patients, endocardial cryoablation in 2 patients and epicardial cryoablation without dissection of the atrioventricular (AV) fat pad in 1 patient. Two patients had perioperative complications. One patient had bleeding that necessitated reoperation, and one had a right cerebral stroke with subsequent clearing of neurologic deficit. At postoperative electrophysiologic study, only the patient who underwent epicardial cryoablation had conduction over an accessory connection. Two others had intermittent delta waves in the early postoperative period but no accessory connection conduction at electrophysiologic study. During a mean follow-up of 3.1 years, the patient with ineffective cryoablation had recurrent orthodromic tachycardia, and one other patient had late recurrence of delta waves without arrhythmias. Four other patients had frequent palpitation, which was caused by premature ventricular complexes in three and sinus tachycardia in one. Seventeen patients had occasional "skipped beats" without recurrence of tachyarrhythmias. Twelve of 13 patients whose arrhythmias limited employment before surgery returned to work after surgery. By actuarial analysis at 1, 2 and 3 years, all patients were alive and 98% were free from tachyarrhythmias. Surgical correction of Wolff-Parkinson-White syndrome provides excellent long-term results with low morbidity. Patients who are disabled by arrhythmias return to work after successful surgery. Delta waves may persist or recur without return of arrhythmias. Minor postoperative episodes of palpitation are common and do not correlate with tachyarrhythmias.     

Ventricular arrhythmias after LV remodelling: surgical ventricular restoration or ICD?

Ventricular arrhythmias cause ~50% of deaths in remodeled ventricles after myocardial infarction, and the Multicenter Automatic Defibrillator Implantation Trial (MADIT II) showed that the Implantable Cardioverter Defibrillator (ICD) saved lives in high risk coronary patients with advanced left ventricular dysfunction. We studied 382 patients with remodeled hearts by preoperative Ventricular stimulation (PVS) to evaluate surgical ventricular restoration (SVR) that excludes scar and lower ventricular volume alters the early and late arrhythmia process without ICD utilization. METHODS: Clinical and hemodynamic results before and after SVR in post-infarction patients, are compared to contrast spontaneous and/or inducible ventricular tachycardia to patients without arrhythmias. Study arrhythmia groups included: Spontaneous in 87 patients with clinical documented ventricular arrhythmias and inducible or not inducible ventricular tachycardia: Inducible in 105 patients without clinical ventricular arrhythmias but PVS inducible ventricular tachycardia; and No arrhythmias in 190 patients without spontaneous or PVS inducible ventricular tachycardia. RESULTS: Preoperative LV end systolic volume index helped define preoperative arrythmia potential: Spontaneous > 120/m(2), inducible > 100 ml/m(2), and none < 100ml/m(2). Overall operative mortality rate was 7.6% (29/382). Sudden cardiac death rate was 2.5% causing 18.7% of all deaths. Surgical management reduced inducible ventricular tachycardia, from 41% preoperatively (144/352) to 8% (26/307) at early study, and 8% (14/177) one year later. Cardiac mortality was low at 5-years and not different between groups, despite use of only one late ICD device. CONCLUSIONS: Favorable electrical success rate and low mortality always included volume reduction to interrupt functional re-entry circuits, but also added endocardiectomy, cryoablation, CABG and mitral repair when needed. Overall SVR findings show volume and shape alteration limits ventricular arrhythmias that impair prognosis, and suggests ICD devices are not needed.     

Iatrogenic atrioventricular bypass tract following a Fontan operation for tricuspid atresia

A 16 year old female with tricuspid atresia had undergone a Fontan operation at four years of age. Two years later she first presented with a narrow complex tachycardia which could only be partially controlled on flecainide in high doses. On electrophysiological study, the tachycardia was found to be due to atrioventricular re-entry within the surgical right atrial to right ventricular outflow tract anastomosis. Radiofrequency ablation at this site abolished the arrhythmia and she is now symptom-free on no medication.     

Surgical treatment of arrhythmias in children

Primary surgical treatment of many tachyarrhythmias in children is now possible. In those with life-threatening arrhythmias not responsive to any form of medical treatment, the choice for surgery is clear. These arrhythmias include atrial fibrillation with the Wolff-Parkinson-White syndrome, PJRT, or atrial ectopic tachycardia with severe congestive cardiomyopathy, incessant ventricular tachycardia in infancy, and recurrent sustained ventricular tachycardia in postoperative congenital heart disease. In the majority of patients, however, surgical treatment remains an option to be weighed carefully against chronic medical treatment. Surgery is now possible with very low mortality for infants and children with Kent bundles, atrial ectopic tachycardia, and the permanent form of junctional reciprocating tachycardia. The mortality, morbidity, and likelihood of eventual resolution of the arrhythmia with each type of management plan should be considered. With possible direct surgical ablation of atrial flutter and newer forms of catheter treatment of arrhythmias, the future looks promising.