CASE REPORTS. Congenital Aneurysm of the Left Atrium

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1 CASE REPORTS Congenital Aneurysm of the Left Atrium Douglas M. Behrendt, M.D., and Eoin Aberdeen, F.R.C.S. ABSTRACT Aneurysm of the left or right atrium is a rare congenital abnormality that may go undetected or be misdiagnosed. Peripheral emboli, supraventricular tachycardia, and fatigue are the symptoms commonly seen. The condition is not benign, and operation, which is curative, is recommended for all patients with a true aneurysm. A 5-year-old boy underwent operation with a preoperative diagnosis of left ventricular tumor or aneurysm. A left atrial aneurysm was found and was repaired successfully. Only 13 patients with this unusual anomaly have been reported. A 5-year-old boy was referred to the Hospital for Sick Children in London for treatment of a cardiac tumor which had been discovered when he was admitted to another hospital with a cerebral embolus. At operation, a large aneurysm of the left atrial appendage was found without other cardiac anomalies. This report describes the clinical manifestations and operative management of this very unusual cardiac anomaly. A 5-year-old boy was admitted for investigation of a cardiac tumor. He was the product of an uncomplicated pregnancy and delivery, and early infancy had proceeded normally. When he was 10 months old a sudden, transient right hemiparesis occurred, followed the next week by seizures. A chest roentgenogram taken at that time showed a mass contiguous with the left heart border. He recovered and remained well until the age of 2 years, when he experienced a seizure, syncope, and transient left hemiparesis. Two weeks later a third episode occurred, resulting in a permanent right hemiparesis and complete loss of speech. Anticoagulants were then begun, and From the Thoracic Unit, The Hospital for Sick Children, Great Ormond St., London. England. We wish to thank Dr. R. A. Dobbs for referring this patient for trealment. Accepted for publication Dec. 16, Address reprint requests to Dr. Aberdeen, The Children s Hospital, 1740 Bainbridge St., Philadelphia, Pa THE ANNALS OF THORACIC SURGERY

2 CASE REPORT: Congenital Aneurysm of Left Atrium he remained well. He was referred to the Hospital for Sick Children three years later. Physical examination was entirely normal except for the right hemiparesis and inability to speak. Laboratory investigations showed only a prolonged prothrombin time consistent with his anticoagulation. The electrocardiogram was normal. Chest roentgenograms (Fig. 1) showed marked cardiomegaly as a result of a mass at the left cardiac border. A presumptive diagnosis of left ventricular tumor or aneurysm was made. However, coronary arteriograms were normal. An operation was performed on December 5, 1966, through a median sternotomy (Fig. 2). The pericardium was intact. A 10 x 3 cm. aneurysm of the left atrial appendage with a 2% x 2% cm. neck was found. The mitral valve was normal, and there was no obstruction to blood flow within the left atrium or left ventricle. The aneurysm wall was not unusually thin and appeared to be composed of normal atrial muscle. Pressures measured were normal in all cardiac chambers. To prevent embolization of thrombus, cardiopulmonary bypass was begun, a left ventricular vent was inserted, and the aorta was clamped before the aneurysm was manipulated. The aneurysm was then opened and excised, and the atrium was closed by imbricating the cut edges over one another to make two layers. No thrombus was found in the specimen. Microscopical sections of the aneurysm wall showed marked hypertrophy and degenerative changes of the myocardial fibers. There was also some increase in subendocardial and elastic tissue with mild lymphocytic infiltration. A FIG. I. B Chest roentgenograms, posteroanterior (A) and lateral CB), taken preoperatively. VOL. 13, NO. 1, JANUARY,

3 BEHRENDT AND ABERDEEN The child has remained asymptomatic in the three years since operation, aside from his neurological deficit. His chest film and electrocardiogram are normal. Comment Aneurysmal dilatation of the atria as a consequence of valvular heart disease is a common occurrence, but congenital aneurysm of the atrium is rare. True primary aneurysm of the left atrium such as occurred in the present patient has been clearly documented only seven times previously [4, 6-9, 11, 151 (Table). Only five true saccular right atrial aneurysms have been documented [l, 5, 10, 12, 131, but diffuse idiopathic enlargement of the right atrium has been reported in 9 patients in whom no operation was performed [31. On both the left and right side, some of these aneurysms have involved the atrial appendage and some have not, and they are all probably variants of the same condition. One extraordinary case of multiple saccular aneurysms involving both atria in an infant has been reported [141. Five other patients with herniation of the left atrial appendage through a congenital pericardial defect have been reported [Z]. Although the appendage becomes enlarged in this situation, the enlargement is probably secondary to the congenital pericardial defect. A congenital origin in the present patient seems reasonably certain because of the child s age, the lack of other cardiac anomalies, and the lack of histological evidence of a specific degenerative disease. For the same reasons, in the previously reported instances the anomaly should be considered congenital in origin, although most aneurysms were encountered in older patients. Histological examination of the atrial wall has, in all reported patients, shown atrial muscle fibers to be present, sometimes hypertrophied and intermingled with fibrous tissue. Intracardiac hemodynamics have been normal except for a reduced cardiac index in 2 instances. The signs encountered-supraventricular arrhythmias, emboli, and fatigue-are easily understood. As suggested by Morrow and Behrendt [5], the arrhythmias probably result from the large area of abnormal atrial wall. In their patient, the atrial arrhythmia terminated at the precise moment when division of the aneurysmal sac was completed. Furthermore, in no reported patient has supraventricular tachycardia recurred after operation. The occurrence of thrombosis within the aneurysm with peripheral embolization must be a consequence of low flow and turbulence within the huge sac. The fatigue experienced by a few patients is doubtless a result of compression of the heart within the pericardium by the aneurysm, leading to limitation of diastolic expansion of the ventricles and a reduced cardiac output. Atrial aneurysm is not a benign condition. The present patient and 3 others have had major cerebral embolisms. Supraventricular tachycardias 56 THE ANNALS OF THORACIC SURGERY

4 CASE REPORT: Congenital Aneurysm of Left Atrium A FZG. 2. Appearance of the aneurysm through the median sternotomy incision (A). Bypass was begun, the aorta clamped, and left ventricular vent inserted. The heart was then retracted to the right. The aneurysm was opened, exposing the interior of the left atrium (B). Then the sac wall was excised, and a double-layer closure was performed (C). B C have incapacitated 5 patients and have occurred transiently in 6 others. A 16-year-old boy with recurrent tachycardias died suddenly at home of unknown cause, and a 5-year-old child died of congestive heart failure with supraventricular tachycardia. Thus, we believe that operation is indicated in all patients with true atrial aneurysm. This has proved uniformly safe and curative. To minimize the risk of systemic or pulmonary embolization, operation should be done VOL. 13, NO. 1, JANUARY,

5 ~ w 0 ;1 M ti 2: PATIENTS WITH ATRIAL ANEURYSM CONFIRMED AT OPERATION OR POSTMORTEM EXAMINATION" Year of Operation or Age at Postmortem Operation Other v) K Author Examination Signs (yr.) Anomalies Bypass Results 8 LEFT ATRIAL + 3: Seamans & Taussig HI SVT, CHF 5 Dextro-... No operation; died s cardia K Pitts & Potts SVT 2 None No Well, NSR I4 n E d E Parmley [ SVT, emboli 9 ASD No Well, NSR Williams Emboli 29 None No Well, NSR ga Palacio & associates [6] 1960 Emboli 32 None No Well, NSR Parker & associates SVT 52 None No Well, NSR Godwin & associates [ SVT 26 None No Well, NSR Behrendt & Aberdeen 1966 Emboli 5 None Yes Well, NSR RIGHT ATRIAL Bailey [ll 1955 SVT 29 None No Well, NSR Saigusa & associates [lo] 1962 SVT 43 None Yes Well Morrow & Behrendt [ SVT 23 None Yes Well, NSR Sheldon & associates [ SVT, CHF 43 None Yes Well, NSR Tenckhoff & associates SVT 16 None... No operation; died MULTIPLE Varghese & associates [ SVT 5mo. None No Well, NSR defect. 'Excluding patients with pericardial defect and herniated left atrial appendage. SVT = supraventricular tachycardia, atrial fibrillation, or flutter: CHF =congestive heart failure: NSR =normal sinus rhythm; ASD = atrial septa1

6 CASE REPORT: Congenital Aneurysm of Left Atrium using cardiopulmonary bypass with minimal manipulation of the aneurysm before the aorta or pulmonary art.+ is clamped. On the other hand, those patients with herniation of the left atrial appendage through a pericardial defect or moderate diffuse right atrial enlargement have minor symptoms and probably warrant no treatment. References 1. Bailey, C. P. Surgery of the Heart. Philadelphia: Lea & Febiger, P Dimond, E. G., Kittle, C. F., and Voth, D. W. Extreme hypertrophy of the left atrial appendage. Am. J. Cardiol. 5:122, Eshaghpour, E., Olley, P. M., and Collins, G. F. N. Idiopathic right atrial enlargement in childhood. Am. Heart J. 78:373, Godwin, T. F., Auger, P., Key, J. A., and Wigle, E. D. Intrapericardial aneurysmal dilatation of the left atrial appendage. Circulation 38:397, Morrow, A. G., and Behrendt, D. M. Congenital aneurysm (diverticulum) of the right atrium. Circulation 38:124, Palacio, J., Guido, J. J., Noger, V. N., Gonnella, C. G., and Villegas-Videla, A. F. Megaorejuela izquierda congenita. Prensa Med. Argent. 47: 1505, Parker, J. O., Connell, W. F., and Lynn, R. B. Left atrial aneurysm. Am. J. Cardiol. 20:579, Parmley, L. F. Congenital atriomegaly. Circulation 25:553, Pitts, R. M., and Potts, W. J. Congenital diverticulum of the left atrium. Arch. Surg. 84:334, Saigusa, M., Morimoto, K., Koike, T., Hori, T., and Sato, T. Idiopathic enlargement of the right atrium. Jap. Heart J. 3:373, Seamans, J. H., and Taussig, H. B. Congenital aneurysmal dilatation of the left auricle. Bull. Johns Hopkins Hosp. 63:404, Sheldon, W. C., Johnson, C. D., and Favaloro, R. G. Idiopathic enlargement of the right atrium. Am. J. Cardiol. 23:278, Tenckhoff, L., Stamm, S. J., and Beckwith, J. B. Sudden death in idiopathic (congenital) right atrial enlargement. Circulation 40:227, Varghese, P. J., Simon, A. L., Rosenquist, G. C., Buger, M., Rowe, R. D., and Bender, H. W. Multiple saccular congenital aneurysms of the atria causing persistent atrial tachyarrhythmia in an infant. Pediatrics 44:429, Williams, W. G. Dilatation of the left atrial appendage. Br. Heart J. 25: 637, VOI,. 13, NO. 1, JANUARY,