Ann Thorac Surg 1998;65:1766-1768
© 1998 The Society of Thoracic Surgeons
Case Reports
Right Atrial Isolation for Atrial Fibrillation Associated With Atrial Septal Defect
Atsushi Harada, MDa,
Takao Ida, MDa,
Masatoshi Ikeshita, MDa
a Division of Cardiac Surgery, Sakakibara Heart Institution, and Second Department of Surgery, Division of Thoracic and Cardiovascular Surgery, Nippon Medical School, Tokyo, Japan
Accepted for publication December 13, 1997.
Address reprint requests to Dr Harada, Department of Cardiovascular Surgery, Ebina General Hospital, 1519 Kawaraguchi Ebina-city, Kanagawa, Japan 243-0433
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Abstract
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Two patients with atrial fibrillation associated with an atrial septal defect underwent simultaneous surgical correction of the atrial septal defect and right atrial isolation. The right atrium was surgically isolated while the continuity with the sinoatrial node was preserved in the remainder of the heart. After the operation, the patients maintained normal sinus rhythm for 99 and 65 months. Thus, right atrial isolation offers an alternative to the current surgical treatment for atrial fibrillation associated with an atrial septal defect.
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Introduction
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The right atrial isolation procedure [1] was developed under the direction of Cox at Washington University. This procedure alleviates the detrimental effects of all supraventricular arrhythmias arising in the right atrium. Atrial fibrillation (AF) associated with an atrial septal defect (ASD) in adult patients may arise from the body of the dilated right atrium induced by chronic volume overload. Therefore, isolation of the right atrium could confine arrhythmogenicity of AF to the body of the right atrium and restore normal sinus rhythm in the remainder of the heart.
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Case reports
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Patient 1
A 52-year-old woman was diagnosed with chronic AF and ASD secundum. Intracardiac repair of ASD and right atrial isolation to restore normal sinus rhythm were proposed. Under general anesthesia with fentanyl citrate, median sternotomy followed by a pericardiotomy was performed, revealing a dilated right atrium with markedly fibrous degeneration of its epicardium. Before institution of cardiopulmonary bypass, AF was converted to sinus rhythm with direct-current countershock, and right atrial activation mapping was performed. Two breakthroughs of sinus rhythm were observed, and the dominant one corresponded to the anatomic sinoatrial node. The fractionated potentials indicating arrhythmogenicity of AF were recorded from the right atrial epicardium just lateral to the sulcus terminalis (Fig 1). After the institution of total cardiopulmonary bypass, the aorta was cross-clamped and the heart was arrested with crystalloid cardioplegia.
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Fig 1. Right atrial activation map during converted sinus rhythm in patient 1. The dominant impulse origin corresponded to the anatomic sinoatrial node. Fractionated potentials, indicated by white arrows in the right panel, were recorded from the dotted area lateral to the sulcus terminalis. (ECG = electrocardiogram; IVC = inferior vena cava; LA = left atrium; MV = mitral valve; PV = pulmonary vein; RA = right atrium; RA Ref = right atrial reference electrogram; RAA = right atrial appendage; RV Ref = right ventricular reference electrogram; SVC = superior vena cava; TV = tricuspid valve.)
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The initial right atriotomy was placed between the sulcus terminalis and the site of the fractionated potentials. The right atriotomy was extended cephalad and caudad, and the body of the right atrium was excluded by an encircling surgical incision. Then, cryolesions (-60°C for 3 minutes) were placed at the end of the incision to sever all atrial fibers at the level of the tricuspid valve annulus (Fig 2).
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Fig 2. Right atrial isolation. See text for details. (ASD = atrial septal defect; CS = coronary sinus; IVC = inferior vena cava; RA = right atrium; SN = sinus node; SVC = superior vena cava; TV = tricuspid valve.)
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The ASD secundum was then closed with a polytetrafluoroethylene patch, and the atrial incision was subsequently closed with a continuous suture. After the aortic clamp was released, the patient maintained sinus rhythm and was weaned from cardiopulmonary bypass without the use of artificial pacing. The patient has maintained normal sinus rhythm without any antiarrhythmic agents for 99 months after the operation.
Patient 2
A 39-year-old man was diagnosed with ASD secundum and transient AF. A preoperative electrophysiologic study revealed that the AF was sustained and induced by rapid atrial pacing. Intraoperative right atrial activation mapping was performed during sinus rhythm because the patient maintained sinus rhythm at the time of the operation. The site of earliest activation corresponded to the site of the anatomic sinoatrial node, and fractionated potentials were recorded from the body of the right atrium. With the same procedure as in patient 1, the right atrium was isolated and the sinoatrial node and sulcus terminalis were preserved in the remainder of the heart. The patient has maintained normal sinus rhythm without any antiarrhythmic agents for 65 months after the operation.
Postoperative electrophysiologic study
Electrophysiologic examinations were performed 3 weeks after the operation in both patients. The isolated right atrium maintained a slow, irregular, intrinsic rhythm. Regular sinus rhythm with normal sinus node recovery time and normal atrioventricular conduction were demonstrated in the remainder of the heart. Right atrial tachycardia simulated by rapid pacing in the isolated right atrium was confined to the isolated right atrium. Sustained AF was not induced by rapid atrial pacing or an extrastimulus method.
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Comment
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The maze procedure is a surgical method to treat AF [2] and was applied to treat AF associated with ASD by Cox, Bonchek, and their associates [2, 3]. In contrast to the complex maze procedure, right atrial isolation is simple and its effectiveness has been reported by Minzioni and associates [4]. We present our clinical experience of right atrial isolation and the long-term results in this communication.
Because a multichannel mapping system was not available at the time of the operation, atrial mapping with a hand-held electrode was performed only during sinus rhythm. Then, fractionated potentials were recorded from the body of the degenerated right atrium. Although the precise mechanism of the fractionated potentials was not known, there is a well-documented relationship between fractionated potentials and arrhythmia. Therefore, we excluded the degenerated right atrium in which the fractionated potentials were recorded.
To maintain a physiologic sinus rhythm, the area of the earliest activation site, including the sinoatrial node identified by intraoperative mapping, was preserved in the remainder of the heart. Preservation of the sinus node artery is also required to maintain sinus rhythm [1]. The surgical incision for right atrial isolation was designed to preserve the sinus node artery identified by preoperative coronary angiography.
The arrhythmogenicity in the isolated right atrium may not always discharge, and its mass may not be enough to maintain AF. Therefore, a slow intrinsic rhythm, instead of fibrillation, may be observed in the isolated right atrium at the time of the postoperative electrophysiologic study.
A previous experimental hemodynamic study of right atrial isolation [5] demonstrated that the procedure does not adversely affect cardiac hemodynamics, despite the loss of synchronous right atrial contractions during sinus rhythm. The 2 patients have maintained normal sinus rhythm and stable hemodynamics corresponding to New York Heart Association class I.
Therefore, right atrial isolation is feasible in the human heart, as in the canine heart, and this technique should be the procedure of choice for the management of AF arising in the right atrium.
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References
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- Harada A., D’Agostino H.J., Jr, Schuessler R.B., Boineau J.P., Cox J.L. Right atrial isolation: a new surgical treatment for supraventricular tachycardia. I. Surgical technique and electrophysiologic effects. J Thorac Cardiovasc Surg 1988;95:643-650.[Abstract]
- Cox J.L., Boineau J.P., Schuessler R.B., Kater K.M., Lappas D.G. Five-year experience with the maze procedure for atrial fibrillation. Ann Thorac Surg 1993;56:814-824.[Abstract/Free Full Text]
- Bonchek L.I., Burlingame M.W., Worley S.J., Vazales B.E., Lundy E.F. Cox/maze procedure for atrial septal defect with atrial fibrillation: management strategies. Ann Thorac Surg 1993;55:607-610.[Abstract/Free Full Text]
- Minzioni A., Graffigna A., Pagani F., Vigano M. Right atrial isolation with atrial septal closure in patients with atrial septal defect and chronic atrial fibrillation. Cardiovasc Surg 1993;1:666-669.[Medline]
- Harada A., D’Agostino H.J., Jr, Boineau J.P., Cox J.L. Right atrial isolation: a new surgical treatment for supraventricular tachycardia. II. Hemodynamic effects. J Thorac Cardiovasc Surg 1988;95:651-657.[Abstract]
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Abstract
Introduction
