Right-sided maze procedure for right atrial arrhythmias in congenital heart disease

BACKGROUND: Atrial fibrillation and flutter, commonly associated with congenital heart anomalies that cause right atrial dilatation, may cause significant morbidity and reduction of quality of life, even after surgical repair of the anomalies. METHODS: In an effort to reduce the incidence of atrial tachyarrhythmias after repair of right-sided congenital heart disease, we performed a concomitant right-sided maze procedure. RESULTS: Eighteen patients with paroxysmal atrial fibrillation or flutter (n = 12) or chronic atrial fibrillation or flutter (n = 6) aged 10.9 to 68.4 years (mean 34.9 years) underwent a right-sided maze in association with repair of Ebstein's anomaly (n = 15), congenital tricuspid insufficiency (n = 2), and isolated atrial septal defect (n = 1). There were no early deaths, reoperations, or complete heart block. Discharge rhythm was sinus (n = 16) or junctional (n = 2). Follow-up was complete in all 18 patients and ranged from 3.1 to 17.2 months (mean 8.1 months); all are in New York Heart Association class I. Early postoperative arrhythmias developed in 3 patients (all were converted to sinus rhythm by antiarrhythmic drugs). There were no late deaths or reoperations. CONCLUSIONS: The inclusion of a right-sided maze procedure with cardiac repair in patients having congenital heart anomalies that cause right atrial dilatation and associated atrial tachyarrhythmias is effective in eliminating or reducing the incidence of those arrhythmias.     

Identification of atrial septal defects by cross-sectional contrast echocardiography

Cross-sectional echocardiography, combined with injections of contrast into peripheral arm veins, has been used to study 15 patients with atrial septal defects and 10 patients with an intact interatrial septum. Of 11 patients with ostium secundum or sinus venosus atrial septal defects and left-to-right shunts a defect could be visualised in all, and in eight some degree of transfer of contrast from right atrium to left atrium was seen. In three of four patients with a dominant right-to-left shunt a defect was seen and in all there was free transfer of contrast from right atrium to left atrium. Though there may be variable loss of echoes in the septal image in patients with an intact interatrial septum, in general no fixed defect is seen an there is no transfer of contrast from right atrium to left atrium. This is a potentially valuable technique in the assessment of patients in whom an atrial septal defect is suspected.     

Pure epicarditis after surgical repair of atrial septal defect: a rare form of constrictive pericarditis. Apropos of a case

The authors report a case of constrictive pericarditis occurring two years after surgical repair of an atrial septal defect in a 37 year-old-man. The diagnosis was made by right heart catheterisation and magnetic resonance imaging. The special feature of this clinical case was the exclusive localisation of the fibrosis on the visceral pericardium or epicarditis. The outcome was favourable after resection of the visceral pericardium respecting the parietal pericardium. Magnetic resonance imaging and right heart catheterisation performed 6 months after surgery were normal. Constrictive pericarditis is a classical complication of cardiac surgery but relatively rare after repair of an atrial septal defect. Isolated involvement of the visceral pericardium is rare and allows surgical correction by exclusive epicardectomy respecting the parietal pericardium.     

Transvasal closure of interatrial defects using the Babic double-umbrella occluder system

The purpose of the study was to assess the feasibility and safety of closure of atrial septal defects and patent foramen ovale by means of a new interventional technique. Transvasal closure of ostium secundum atrial septal defect and patent foramen ovale was performed in 18 patients using an occluder system for atrial septal defects. Two patients had undergone unsuccessful direct surgical closure years before. Implantation and follow-up were controlled using radiographic views both with and without contrast injection, transthoracic and multiplane transesophageal echocardiographic imaging, color Doppler sonography, and computed tomography. The defect was closed in 16 patients using 19 procedures. Removal of the devices through the sheath was indicated in 4 patients because of placement failure. Intraprocedural complications were ventricular fibrillation in one patient and fixation of the device in Chiari's network in an additional one. During 7-26 months follow-up occluder damage was seen in two patients and perforation of the left atrium in one patient. Thickening on the occluder surface was observed in two patients. There was no death. The system for closure of atrial septal defect is feasible and safe in patients with defects < or = 27 mm in diameter. Long-term observation of outcome is limited yet.     

Left atrial reduction for chronic atrial fibrillation associated with mitral valve disease

Currently available surgical procedures to control chronic atrial fibrillation associated with mitral valvar disease are not always successful. The size of the left atrium is a major factor in the initiation and maintenance of atrial fibrillation. Here we describe a case of ablation of atrial fibrillation with left atrial reduction and pulmonary vein isolation in a patient with mitral valve disease.     

Radiofrequency and cryoablation of atrial fibrillation in patients undergoing valvular operations

BACKGROUND: Previous studies have shown that the maze operation can restore sinus rhythm and atrial transport function in patients with chronic atrial fibrillation. The purpose of this study was to test the feasibility of the application of radiofrequency and cryoablation as an alternative to the classic maze operation. METHODS: Twelve patients undergoing mitral valve procedures were included in this study. Radiofrequency and cryoablation were applied to create lesions in both atria to simulate the classic maze operation. RESULTS: There were two surgical deaths. At the mean follow-up of 10.25 months for the remaining 10 patients; 6 were in sinus rhythm, 2 in atrial rhythm, 1 in paroxysmal atrial tachycardia, and 1 in atrial fibrillation. Doppler echocardiography at 6-month follow-up showed emergence of biatrial transport function in 3 patients and right atrial contractility in 8. At 12-month follow-up of 5 patients, Doppler echocardiography showed biatrial transport function in 3 and right atrial contractility in 4. CONCLUSIONS: Our modified maze procedure during valvular operation is effective for achieving an acceptable success rate to restore sinus rhythm and atrial transport function in patients with chronic atrial fibrillation.     

Anatomy-guided linear atrial lesions for radiofrequency catheter ablation of atrial fibrillation

The surgical atrial maze procedure has provided proof that atrial fibrillation can be cured by performing atrial incisions based on anatomical and electrophysiological principles. Preliminary reports of attempts at radiofrequency catheter ablation of atrial fibrillation utilizing an anatomy-based "linear incision" method have shown the feasibility of the method. However, postprocedural atrial fibrillation recurrence has been common and in addition new, uniform tachycardias have developed in some patients. Both of these outcomes may be in part due to incomplete or inconsistent lesion deployment. This article details the use of the CARTO system for deploying anatomy guided linear atrial lesions for the purpose of curing atrial fibrillation. The procedure is comprised of three phases, which are discussed in detail: (1) baseline map; (2) lesion deployment and; (3) lesion assessment. Using a single standard ablation electrode, lesions can be deployed safely, and complete lesions can be confirmed. Paradigms for right and left atrial incisions are proposed.     

Should atrial septal defects in adults be closed?

BACKGROUND: By assessing current surgical outcome and symptomatic relief, this study attempts to answer whether atrial septal defects in adults should be closed. METHODS: Thirty-nine adult patients aged 35.2 +/- 13.6 years underwent operation for an atrial septal defect between June 1988 and June 1994. Indications for closure were symptoms (33 patients) or a significant left-to-right atrial shunt (6 patients). Data were obtained from hospital records, and the latest status of the patients was determined by a written questionnaire. RESULTS: There were no deaths. Pulmonary embolism in 1 patient was the only complication observed. The QRS duration on the surface electrocardiogram decreased immediately (p < 0.001), and the cardiothoracic ratio on chest radiographs was significantly lower 3 to 6 months after operation (p < 0.001), both findings reflecting improved hemodynamics. No residual shunts were seen on follow-up (mean follow-up, 3.3 +/- 2.2 years). Twenty-seven (81.8%) of the 33 symptomatic patients improved clinically in terms of exercise performance, atrial arrhythmias, or both. Three (50%) of the 6 previously asymptomatic patients reported improved functional capacity post-operatively. CONCLUSIONS: Today, operation for atrial septal defects in adults can be performed with no mortality and low morbidity and results in symptomatic improvement in the majority of patients. Clinical improvement was seen even in patients who considered themselves asymptomatic preoperatively. We advocate closure of atrial septal defects in adult patients with symptoms or significant atrial shunts.     

Atrial activation during chronic atrial fibrillation in patients with isolated mitral valve disease

BACKGROUND: A computerized 32-channel mapping system has been developed to investigate the characteristics of the atrial activation sequence. The system is capable of displaying sequential atrial maps and provides a rapid and dynamic means of verifying the activation sequence of atrial fibrillation. METHODS: Using this system, we performed intraoperative atrial activation mapping in 10 patients with chronic atrial fibrillation who were undergoing isolated mitral valve operations. RESULTS: Regular and repetitive activation (cycle length ranged from 131 to 228 milliseconds) originated in the left atrium in all 10 patients. Two patterns of repetitive activation in 2 patients and three patterns in 1 patient appeared alternately during the observation period in the left atrium. In contrast to the repetitive activation in the left atrium, the activation sequence of the right atrium was extremely complex and chaotic. In 7 of the 10 patients, the same pattern of right atrial activation was never repeated during the observation period. In 2 patients, revolution of repetitive activation in the right atrium sporadically appeared, but the pattern of activation immediately deteriorated to a complex and chaotic pattern. In 1 patient, repetitive activation emerged from the low lateral portion of the right atrium. Because our mapping technique was limited by the number of available atrial electrodes, discrete reentrant circuits or ectopic foci could not be demonstrated in the present study. However, the activation sequences during chronic atrial fibrillation suggested that (1) the left atrium would act as an electrical driving chamber for atrial fibrillation in the majority of the patients and (2) atrial activation patterns are different in each case. CONCLUSIONS: Computerized intraoperative mapping should guide surgeons in determining the appropriate surgical procedure and facilitate operation for chronic atrial fibrillation associated with mitral valve disease.     

Cardiopulmonary physiology after surgical closure of asymptomatic secundum atrial septal defects in childhood. Exercise performance is unaffected by age at repair

AIMS: Most secundum atrial septal defects, once diagnosed, are corrected at a young age. The evidence to justify early vs delayed or even non-closure is equivocal and little is known regarding long-term effects of later closure. This is particularly pertinent to those patients awaiting transcatheter closure of their defect for whom a device is only just becoming available. We examined the exercise cardiorespiratory physiology of children surgically treated for an isolated secundum defect. METHODS AND RESULTS: One hundred and six healthy control children and 22 children more than 6 months after surgical repair for an isolated secundum atrial septal defect were studied. All were asymptomatic. Measurements of effective pulmonary blood flow, stroke volume, arteriovenous oxygen difference, minute ventilation, heart rate, oxygen consumption and carbon dioxide production were made using a quadrupole mass spectrometer during rest and graded exercise. Data from the normal children allowed calculation of z scores for the atrial septal defect group matched for age, sex, pubertal stage and surface area. Maximal exercise performance was equal between control and atrial septal defect groups, however, the atrial septal defect group had a significantly greater effective pulmonary blood flow and stroke volume but a lower heart rate than controls at a given exercise stage. Stroke volume abnormalities were most closely related to duration of follow-up (29% of the variance explained, P < 0.01) rather than age at surgery. CONCLUSIONS: We were unable to show a medium term benefit from early surgery for an asymptomatic secundum atrial septal defect during exercise. The clinical relevance of the haemodynamic differences that do exist remains unclear.     

Transcatheter closure of residual atrial septal defect following implantation of buttoned device

We report a case in which residual shunting after a buttoned device occlusion of atrial septal defect (ASD) was eliminated by transcatheter retrieval of a portion of the device, followed by implantation of a second device. This method may be helpful for those patients with residual ASDs who decline surgical device retrieval and defect closure.     

Unusual left atrial mass following cardiac surgery in an infant

An unexpected left atrial mass was found during routine postoperative transthoracic echocardiogram in an infant following surgical closure of ventricular septal defect. Thrombus could not be excluded. At reoperation it was found to be an inverted left atrial appendage. This case demonstrates the echocardiographic appearance of an inverted left atrial appendage.     

Electrophysiological properties in patients undergoing atrial compartment operation for chronic atrial fibrillation with mitral valve disease

AIMS: Surgical treatment for atrial fibrillation is now feasible in selective cases. The aim of this study was to assess the electrophysiological properties of patients undergoing atrial compartment operation for chronic atrial fibrillation. METHODS AND RESULTS: Electrophysiological studies were performed in 20 mitral valve patients with atrial fibrillation who had been maintained in sinus rhythm for more than 1 year after atrial compartment operation. Intra-cardiac recording and programmed electrical stimulation were performed in various atrial compartments. The parameters studied included sinus node function, atrial conduction and refractoriness, atrioventricular conduction function and inducible arrhythmias if any. Intra-cardiac recordings showed that the rhythm was of sinus origin in all cases, with the earliest atrial activity located in the high right atrium. The mean sinus cycle length was 750 +/- 110 ms, AH time 106 +/- 29 ms, and HV time 53 +/- 7 ms. The sinus node function was normal in 18 patients (90%), and only two patients had prolonged sinus node recovery and sino-atrial conduction. The right atrial appendage compartment was driven by the sinus node in all patients. However, the conduction time from the high right atrium to the right atrial appendage compartment was markedly prolonged in 12 of 15 patients (80%) undergoing the three-compartment operation in which an incision was placed between the high right atrium and right atrial appendage compartments. On the other hand, the electrical activities in the left atrial compartment were much more varied. In 13 of 20 patients (65%), the left atrial compartment was driven by the sinus node; 11 of the 13 patients had a normal or mildly prolonged conduction time (ranged 75 to 146 ms), whereas two patients had a marked delay in conduction (200 ms and 266 ms, respectively). In the remaining seven patients, the left atrial compartments were dissociated from the rest of the heart; five of them had a quiescent left atrium, one a fluttering left atrial rhythm, and one a slow left atrial rhythm. The effective refractory period was longer in the left atrial compartment (242 +/- 47 ms) as compared to that of the high right atrium (224 +/- 26 ms, P < 0.01) and right atrial appendage compartments (219 +/- 25 ms, P < 0.01). Programmed electrical stimulation could not induce atrial fibrillation in any patient, whereas two patients had inducible atrial flutter and three repetitive atrial responses. CONCLUSIONS: (1) Atrial compartment operation does not impair sinus node function in most cases. (2) Elimination of atrial fibrillation while maintaining the electrical connection between different atrial compartments is feasible.     

Implantable atrial defibrillator for atrial fibrillation

Atrial fibrillation is a common problem. Pharmacological and nonpharmacological approaches have limited therapeutic efficacy in many patients. Low energy transvenous atrial defibrillation using catheters positioned inside the right atrium and cornonary sinus has been shown to be efficacious in converting atrial fibrillation to sinus rhythm. We report the successful use of this technology in an implantable form in a patient with symptomatic atrial fibrillation. The patient could be kept in sinus rhythm using an implanted atrial defibrillator.     

Transcatheter closure of atrial septal defect

Isolated secundum atrial septal defect is one of the most common congenital heart defects. Surgical closure is the treatment of choice but is associated with a chest scar, some morbidity and a relatively long recovery and the use of cardiopulmonary bypass. Transcatheter closure of secundum atrial septal defect is therefore an attractive approach. 3 children, aged 5-10 years, underwent successful transcatheter closure of moderate to large central atrial septal defects with the Cardioseal device. The procedures were performed under x-ray and transesophageal echocardiographic guidance. Our initial experience, and that of others, indicates that transcatheter occlusion of secundum atrial septal defects is safe and effective and can be an appropriate alternative in approximately 60% of patients.     

Repair of secundum atrial septal defect: limiting the incision without sacrificing exposure

A simple and effective technique for repair of secundum atrial septal defect is described. The heart is exposed through a limited midline skin incision and partial sternotomy, and the atrial septal defect is closed through a right atriotomy with ascending aortic and dual venous cannulation. This approach achieves a cosmetically superior result with standard instrumentation and cardiopulmonary bypass techniques, without compromising exposure or using peripheral incisions.     

Occlusion of large atrial septal defects with a centering buttoned device: early clinical experience

A feasibility clinical study was conducted for the transcatheter occlusion of large ostium secundum atrial septal defects with the centering buttoned device. The centering buttoned device is a modification of the regular buttoned device in which a centering counter-occluder is sutured at the central 40% portion of the occluder. During centering it is stretched, forming a parachute-shaped structure and pulling the occluder over the center of the defect. During buttoning, the counter-occluder forms a double figure eight, opposing the right atrial side of the atrial septum. Occlusion was performed in 12 patients aged 6 to 56 years. All had been rejected for transcatheter occlusion by the regular buttoned device, because of either their defect size or the lack of adequate septal rim. The defect size varied between 23 and 31 mm, and the device size varied between 45 and 60 mm. Nine had immediate effective occlusions of their defects and three residual shunts. One patient with unbuttoning had hemolysis at 2 weeks and underwent surgery. Early results of the transcatheter occlusion of large atrial septal defects are promising, and larger clinical trials are justified.     

Left atrial isolation for chronic atrial fibrillation caused by mitral valvular stenosis and regurgitation

Surgical isolation of the left atrium was performed for the treatment of chronic atrial fibrillation secondary to mitral valvular disease in a 65-year-old woman who underwent mitral valvular replacement. Left atrial isolation was simple procedure, prolonging the usual paraseptal atriotomy toward the both mitral valvular commissures anteriorly and posteriorly. The incision was conducted two centimeters apart from the mitral valve annulus, and cryoablation was added at the edges to ensure isolation of the residual left atrium. We suggest performing this simple procedure in patients with chronic atrial fibrillation undergoing mitral valvular replacement, in whom correction of irregular beat and compromised hemodynamics can be obtained.     

Usefulness of PKHs for studying cell proliferation

INTRODUCTION AND OBJECTIVES: The MAZE procedure was developed as a surgical approach to the management of patients with atrial fibrillation refractory to medical treatment. This study seeks to identify the risk and benefits of adding the MAZE procedure in patients with atrial fibrillation undergoing surgery for underlying organic cardiac disorders. MATERIAL AND METHODS: Since november 1993, we have performed 10 interventions with the MAZE procedure, for the treatment of refractory atrial fibrillation. The indication to perform the technique was systemic embolism in 5 patients, contraindication for the anticoagulant treatment in two cases and no response to antiarrhythmic treatment in 5 cases. Two patients had more than one indication. In all the cases another surgical procedure was performed, 5 replacements of mitral valve, a mitral repair, one tricuspid repair and tree repairs of an atrial septal defect. RESULTS: Soon after surgery 9 patients were in sinus rhythm, and one in atrial fibrillation. Four patients needed atrial pacing during the first days. One patient required a pacemaker due to symptomatic sinus bradycardia. During the first 3 months, 4 patients had episodes of paroxysmal atrial fibrillation and flutter. One patient died suddenly one month after surgery. Seven patients have completed two years of follow-up, and are in stable sinus rhythm, in functional class I and free of antiarrhythmic drugs. All of them have echocardiographic evidence of mechanical activity in both atria. Left atrium had been reduced from 5.3 +/- 0.7 cm to 4.5 +/- 0.7 cm (p < 0.05). No patient has presented new embolic events. CONCLUSIONS: The MAZE procedure is a good choice in selected patients with atrial fibrillation refractory to medical treatment, or a precedent of systemic embolism. However, several problems can complicate the patient's course.     

Anastomosis of the left juxtaposed atrial appendages in a patient with tricuspid atresia

A 9-month-old boy with left juxtaposition of the atrial appendages, tricuspid atresia, pulmonary atresia, and ventriculoarterial discordance underwent anastomosis between the atrial appendages after failure of balloon/blade atrial septostomy because of restrictive atrial septal defect. For surgical creation of atrial communication in patients with juxtaposed atrial appendages, anastomosis between the atrial appendages seemed to be safer, more effective, and less invasive than septectomy by Blalock-Hanlon technique or inflow occlusion technique.