Aneurysm of the left atrium

Aneurysm of the Left Atrium

THOMAS

J. HO&EN,

MD

DONALD

0.

MD,

MULDER,

MICHAEL

T. GYEPES,

ARTHUR

J. MOSS,

FACC

MD

MD,

FACC

Los Angeles, California

Congenital left atria1 aneurysm is a rare anomaly that has been reported only five times prevlously. The usual presenting features Include an abnormal chest roentgenogram, an apical systolic murmur and supraventrlcular tachycardla. Even with clneanglocardlography the dlagnosls Is uncertain, and the lesion is commonly confused wlth cardiac tumor. Aneurysmectomy Is the preferred treatment and has been successful In all patients undergoing operation. The presence of thrombl In the aneurysm necessitates circulatory assistance during excision.

Aneurysms of the left atrium may be congenital or acquired in origin. They are considered congenital when no predisposing cardiac condition is present. Acquired aneurysms may be secondary to rheumatic mitral insufficiency or stenosis, tuberculosis, syphilitic myocarditis or other conditions leading to abnormal atria1 pressures or weakened myocardium.1-5 Congenital aneurysms involve either the atria1 wall (left atria1 aneurysm) or the appendage of the atrium (left atria1 appendage aneurysm). Five cases of the forme+lo and 11 of the latter have been recorded.l’-lg Aneurysms of the left atria1 appendage are often associated with a pericardial defect and, although more common, are probably of less significance. Since the case to be presented is that of an aneurysm of the left atria1 wall, discussion will be limited to this type of lesion. Case Report

The patient, a 13 year old girl, presented initially at age 1 year with congestive heart failure. Cardiomegaly was noted on the chest roentgenogram, and the electrocardiogram showed left atria1 and left ventricular hypertrophy. Cardiac catheterization and angiocardiography revealed a large left atri-

From the Departments of Pediatrics, Surgery and Radiology, University of California, Los AngeleS School of Medicine, Los Angeles, Calif. 90024. Manuscript accepted May 16, 1973. AdUress for reprints: Arthur J. Moss, MD, Department of Pediatrics, University of California, Los Angeles School of Medicine, Los Angeles, Calif. 90024.

um with no associated valvular or septal defects. Diminished cardiac pulsations were observed. The diagnosis could not be established with certainty, but it was presumed that the child had endocardial fibroelastosis. The heart failure responded to decongestive measures, and the patient’s condition remained stable for several months. However, because of persistent cardiomegaly and exercise intolerance, cardiac catheterization was repeated at age 2 years. A large left atrium was again demonstrated, but this time overt mitral insufficiency was present. Although the patient’s clinical condition remained satisfactory, a reassessment of her cardiac status at age 9 was believed indicated. The previous findings were confirmed with no new observations. It was elected to discontinue administration of digoxin at that time. One year later the patient complained of episodes of palpitation followed by syncope. She was hospitalized, and supraventricular tachycardia was documented. The arrhythmia responded promptly to treatment with digoxin, and she was discharged on maintenance dosage. There were numerous recurrent episodes of arrhythmia (atria1 fibrillation and supraventricular tachycardia) and in four instances, these were severe enough to require hospitalization. These were treated by adjusting the dose of digoxin and adding oral propranolol. At age 13 years, calcification in the area of the mitral valve was observed on roentgenogram (Fig. 1) which, in retrospect, could be seen in the films obtained 4 years previously. She was admitted to the hospital for further evaluation.

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Physical examination on admission revealed a thin adolescent girl with a blood pressure of 90/65 mm Hg. Apical pulse rate was 70/min. The chest was clear to percussion and ausculation. Cardiac examination revealed a regular rhythm with no thrill or abnormal impulse. The first heart sound was soft and the second sound was widely split with the pulmonic component louder than the aortic. A grade 3/6 harsh holosystolic murmur was audible at the apex and radiated into the left axilla. A grade 2/6 early diastolic murmur of low intensity also was heard at the apex. No clicks or extracardiac sounds were audible. There was severe dextroscoliosis of the thoracic spine. Since the possibility of a cardiac tumor could not be excluded, a fourth cardiac catheterization with cineangiocardiography was performed. The findings confirmed the presence of mild mitral insufficiency and demonstrated what was believed to be an aneurysm or tumor of the left ventricle (Fig. 2). The cardiac catheterization findings are summarized in Table I. Operation was recommended. A median sternotomy was performed, and upon opening the pericardium, an 8 by 12 cm saccular aneurysm of the left atrium was found (Fig. 3). Under cardiopulmonary bypass, the thin-walled aneurysm was opened. No thrombi were present. The atria1 appendage was normal and the mitral valve leaflets were slightly thickened. The aneurysm was resected and a 0.5 by 4 cm spicule of calcium arising from the endocardium of the posterior wall of the atrium was debrided. The patient had an uneventful postoperative course. No medications were prescribed on discharge.

FIGURE 1. Posteroanterior chest roentgenogram. Moderate scoiiosis is noted. Most of the cardiac shadow is made up by the enlarged left atrium and the large left atrial aneurysm (outer dotted line). The singfe arrow points to the small inner calcification. The inside curviHnear dotted iine (triple arrows) indicates the site of the bottom of the left ventricle which was later confirmed by angiocardiography and surgery. L. = left: VENT = ventricle.

Ai!uM

Al 4EURYSM

.__ ___ __A .__

’

FIGURE 2. Left ventricular angiocardiogram and drawing. The root of the aorta and the left ventricle, visualized by retrograde introduction of the catheter and injection of contrast material, are well delineated. This frame is from the lateral series and clearly shows a very large structure filled with contrast medium that lies directly behind the left ventricle, indenting the ventricular septum. This turned out to be the left atrium and a large left atriai aneurysm. L. = left: LV = left ventricle; m. = muscle.

FIGURE 3 (ieff). Photograph of the heart and left atrial aneurysm showing their relation in situ at the time of surgical exploration. L. = left. FIGURE 4 (above). Photomicrograph of a section of the wall of the left atriai aneurysm dembnstrating the sparse, hypertrophied myocardil fibers and the thick epicardium. (Hematoxylin-eosin X 110. reduced by 50 percent.)

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TABLE Cardiac

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I Catheterization

Data Age

1 Year

Age 2 Years

Age

Age

10 Years

13

Years

Pressures (mm Hg) Left ventricle Ascending aorta Pulmonary wedge Pulmonary artery Right ventricle Right atrium Cardiac index (liters/min per m2)

NR

9216

96/11-14

91/13

86154 NR 36/16 46/O 9-1213

NR 16/14 33113 37/l a/4-12/9

84160

85/52 (66) NR

NR

1.8

(17) 36/20 (22) 28/l-5 a 5; (4) v4 3.46

25/15 2817 d 6; (3.5) v4 4.5

Figures in parentheses indicate mean pressures. 8 = d wave; NR = not recorded; v = v wave.

Pathologic examination of the specimen revealed a 5 by 7 cm saccular structure about 1 mm thick. The atria1 wall fibers were attenuated with thick fibrous epicardium and hypertrophy of the sparse myocardial fibers (Fig. 4). In the 6 months since operation, the patient has remained asymptomatic with no episodes of arrhythmia. Serial roentgenograms have shown decreasing cardiomegaly and electrocardiograms show no evidence of recurrence of the arrhythmia.

Discussion There are several previous reportsl-5v20 of left atrial aneurysm in patients with acquired valvular or myocardial disease. The presence of myocardial disease or chronically increased left atria1 pressure, as seen in severe mitral stenosis secondary to rheumatic heart disease,3 can predispose to development of an aneurysm. The appearance of left atria1 aneurysm in early childhood in the absence of any recognized predisposing causes such as congenital heart disease, acquired inflammatory changes or other pathologic processes in the myocardium indicates a congenital origin. Clinical findings: The clinical data in the six recorded cases (including that reported here) of congenital left atria1 aneurysm are summarized in Table II. There were five children (aged 2 to 13 years) and one adult (aged 64 years). Roentgenographic evidence of cardiomegaly or a mediastinal mass was present in each case, and arrhythmia was observed at some time during the course of the disease in five. The origin of the arrhythmia is not known. It may be caused by tension on the conduction system from the enlarged atria1 muscle mass, a circus movement phenomenon or a congenital defect in the conduction tissues.7 A systolic murmur was present in five cases, the location being apical in four7,8Jo and not indicated in the one.6 Two of these patients also had diastolic murmurslo suggesting real or relative mitral stenosis; one patient had no cardiac murmur.g Lack of angio-

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cardiographic evidence of significant mitral insufficiency suggests that aneurysms are probably not secondary to malfunction of the mitral valve.7qs The preoperative diagnosis was cardiac or mediastinal tumor in four of five cases.6y7TgOne patient had a preoperative diagnosis of left atria1 appendage aneurysm,21 but at operation a left atria1 aneurysm was found.8 Semans and TaussiglO described a patient who was not operated upon and subsequently died. All five patients treated by resection of the aneurysm recovered from operation and had no further episodes of arrhythmia. Differential diagnosis: Although children with congenital mitral insufficiency may present features similar to those of left atria1 aneurysm, there are some subtle differences. Supraventricular tachycardia with congenital mitral insufficiency is not common. In 33 reported cases of congenital mitral insufficiency,22-24 the electrocardiogram demonstrated supraventricular tachycardia in only 3. Thus the presence of supraventricular tachycardia and the murmur of mitral insufficiency should lead one to suspect the possibility of left atria1 aneurysm. In addition, the degree of enlargement of the cardiac silhouette is usually more striking in the patient with an aneurysm. Intracardiac tumors, particularly left atria1 myxomas, present commonly with cardiomegaly, arrhythmia and a cardiac murmur.25-31 In 46 cases of cardiac tumors in children,25~2gJ0~32+33 81 percent of the patients had an abnormal cardiac silhouette and 40 percent had cardiomegaly. Cardiac calcifications were noted in 16 percent. There were eight instances of arrhythmia (18 percent): One patient had atrioventricular block,2g one had nodal extrasystoles,32 two had ventricular tachyarrhythmias,30 two had supraventricular tachycardia,25*30 and in two the type was not described.33 A systolic murmur, usually apical, was present in 24 of the 46 cases (52 percent). Nineteen patients (41 percent) had both systolic and diastolic murmurs. Systemic embolization, a common presenting sign of cardiac tumor, was documented in 19 (41 percent) patients.

The type of arrhythmia may prove helpful in distinguishing left atria1 aneurysm from cardiac tumor. It seems that supraventricular arrhythmias are more ‘often associated with left atria1 aneurysm, and ventricular arrhythmias are more often associated with ventricular tumors. Angiocardiography is the most accurate means of distinguishing left atria1 aneurysms from isolated congenital mitral insufficiency or cardiac tumor. Even with these studies, the diagnosis in some instances can be established only by operation. Complications and management: Left atria1 aneurysm is a potentially lethal disease even in the asymptomatic patient. The threat of embolization is always present and, although no instance of embolization has been recorded, the presence of thrombi in two patients indicates that this is a potential hazard. Serious arrhythmias do occur in most patients with this condition and are potentially fatal. Spontaneous rupture of the left atrium has not been reported, but it seems reasonable to assume that a huge atria1 aneurysm is vulnerable to either spontaneous or traumatic rupture. Operative excision, even in the asymptomatic patient, is the treatment of choice. Cardiopulmonary bypass is essential for the excision of left atria1 aneurysm since it involves a major portion of the atria1 chamber and mural thrombi may be present. This is in contrast to treatment of appendage aneurysms which can be amputated without use of circulatory support. The risk of operation is low, and the probability of eliminating future embolic episodes and arrhythmas is good. Addendum

Eleven months after operation, the patient experienced two episodes of tachycardia highly suggestive of paroxysmal atria1 tachycardia without electrocardiographic documentation. Repeat heart catheterization and angiography demonstrated mild mitral stenosis and mild mitral insufficiency. The patient was discharged without medication and continues to do well.

References 1. De Sanctls RW, Dean DC, Bland EF: Extreme left atrial enfargement: some characteristic features. Circulation 29: 14-23, 1964 2. Edlngton GM, Wllllams AO: Left atrial aneurysms associated with annular subvalvufar left ventricular aneurysms. J Pathol Sact 96273-283. 1968 3. Gabrlele OF, Hood WP: Aneurysm of left atrium. Radiology 97: 397-398. 1970 4. Ingram A, Macfle JWJ: Two further cases of cardiac aneurysms. Ann Trop Med Parasitol 16: 119- 126, 1922 5. Johnson J, Danlelson GK, MacVaugh H, et al: Plication of the giant left atrium at operation for severe mitral regurgitation. Surgery 61:118-121, 1967 6 Herbert WM. Arlsmendl L, Ruhstaller FD, et al: Aneurysm of feft atrium associated with syncope and cyanosis. J Thorac Cardiovasc Surg 49:535-539, 1965 7. Macteod CA, Ankeney JL, Perrln EV, et al: Left atrial aneurysm. Am Heart J 80:683-688, 1970

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8. Parker JD, Connell WF, Lynn RB: Left atrial aneurysm. Am J Cardiol 20579-582, 1967 9. Pltts RM, Potts WJ: Congenital diverticulum of the left atrium. Arch Surg 04~334-336, 1962 10. Semans JH, Taussl9 HB: Congenital “aneurysmal” dilatation of the left auricle. Bull Johns Hopkins Hosp 63:404-414, 1938 Il. Behrendt DM, Aberdeen E: Congenital aneurysm of the left atriurn. Ann Thorac Surg 1354-59, 1972 12. GodwIn TF, Auger P, Key JA, et al: lntrapericardial aneurysmal dilatation of the left atrial appendage. Circulation 37:397-401. 1968 13. Hall J. Dobbs RH: Cerebral emboli from aneurysm of left atrial appendage. Proc R Sot Med 62:9 11, 1969 14. Palaclo J, Gukto JJ. Nager VN, et al: Megaorejenla ifquierda congenita. Prensa Med Argent 47: 1505 15 11, 1960 15. Parmley LF: Congenital atriomegaly. Circulation 25:5x53-558, 1962 16. Salonlkktes N, Tsakonas P, Garetopoulos N, et al: Dilatation

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18. 19. 20. 21. 22. 23.

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anewysmale congenitale de I’auricule gauche. Acta Cardiol 25: 188-198, 1970 Sanderud A, Garman b, Hatle L, et al: Aneurysmabdilatation of the lefl auricle. Stand J Thorac Cardiovasc Surg 5: 143-148, 1971 Sloman 0, Hunt D, Hare WS: Aneurysmal dilation of the lefi atrial appendage. Med J Aust 2:101-102, 1969 WI#la& WO: bilatation of the left atrial appendage. Br Heart J 251637-843, 1963 Wlfflams AO, Edington GM: Unusual cardiac aneurysms in Nigeria. Pathol Microbial (Basel) 35:105-109, 1970 Parker JO, Connell WF: Aneurysmal dilatation of the left atrial appendage. Am J Cardiol 161438-44 1, 1965 Husson OS, Blackman MS, Rlemenschnelder P, et al: Isolated congenital mitral insufficiency. J Pediatr 64:248-259, 1964 Miller G, Brown R, Swan hjc; Isolated congenital mitral insufficiency with particular reference to left heart volumes. Circulation 39:356-385, 1964 Talner NS, Stern AM, Sloan HE Jr: Congenital mitral insufficiency. Circulation 23:339-349, 1961

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25. Geha AS. Weldman WH. Soule EH, et al: Intramural ventricular cardiac fibroma: successful removal in two cases and review of the literature. Circulation 34:427-440, 1987 26. Harvey WP: Clinical aspects of cardiac tumor. Am J Cardiol 21:328-343, 1968 27. Nadas AS, Elllson RC: Cardiac tumors in infancy. Am J Cardiol 21:363-368.1968 28. Penny JL, Gregory JJ, Ayres SM, et al: Calcified left atrial myxoma simulating mitral insufficiency. Circulation 36:417-421, 1967 29. Sterns LP, Eliot RS, Varco RL, et al: lntracavitary cardiac neoplasms: a review of fifteen cases. Br Heart J 28:75-83, 1966 30. Van der Hanwaerl LG: Cardiac tumors in infancy and childhood. Br Heart J 33:125-132. 1971 3 1. Zltnlk RS, Glullanl ER: Clinical recognition of atrial myxoma. Am Heart J 80:689-700.1970 32. Gdding R, Reed G: Rhabdomyoma of the heart: two unusual clinical presentations. N Engl J Med 278:957-959. 1967 33. Stelnke WE, Perry LW, Gold HR, et al: Left atrial myxoma in a child. Pediatrics 49:580-589. 1972

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