Left atrial ball thrombus: Review of clinical and echocardiographic manifestations with suggestions for management David Wrisley, MD, Alessandro Giambartolomei, William Brownlee, RDMS. Syracuse, N. Y.
MD, Ira Lee, RDMS, and
Systemic embolization arising from left atria1 thrombus is an abundantly described and familiar clinical syndrome. Occasionally such thrombi detach from the atrial wall, after they have become so large relative to the size of the mitral valve orifice they cannot immediately escape into the general circu1ation.l The result is free-floating intraatrial thrombi. Such loose bodies may cause syncope12, 3 pulmonary congestion,4-7 or sudden deaths, g via a ball-valve effect. In addition, repeated collisions with atria1 walls and the mitral valve apparatus occur and may cause fragmentation and subsequent embolization of small or relatively larger pieces to the periphery. Cerebrovascular accident43 5, g or potential loss of a limb1°-12 may occur. Myocardial ischemia, probably the result of coronary artery embolus, has been suggested in one case.5 Overall left atria1 ball thrombus appears to be an unusual occurrence. Whether its infrequency is real or results in part from failure of detection is unclear. The term “ball thrombus” was first applied to this entity by Wood in 1814, who described autopsy findings in a l&year-old girl with rheumatic mitral stenosis and syncope (Wood W. Edinburg Med J 1814;10:50, cited in reference 8). Since then numerous additional reports have appeared, including English language reviews in 1924,13 1939,14 and 1955.‘” However, no comprehensive discussion of this topic has been presented in recent years. In view of modern methods of cardiac evaluation such as echocardiography and heart catheterization, as well as therapeutic options including anticoagulation, From the State University Hospital Health Center, Received
for publication
Reprint requests: NY 13088. 411128754
1784
David
of New York Health Science and Upstate Mobile Services, July Wrisley,
16, 1990; accepted
Sept.
Center, Inc.
St. Joseph’s
I, 1990.
MD, 5100 W. Taft Rd., Suite 25, Liverpool,
thrombolysis, and open-heart surgery, a reconsideration of this clinical entity seems timely. The purpose of this article is twofold: First, a suctint summary of the preechocardiography literature describing left atria1 ball thrombus will be presented. Limited analytic attention will be given to reports from the “premodern” era, except where they have application to raising clinical suspicion concerning the presence of a free-floating left atria1 thrombus. Second, reports that have appeared since the emergence of echocardiography will be discussed in detail. Such cases will necessarily belong to the era of cardiac catheterization and open-heart surgery and more recently thrombolytic therapy. Although little has been published on the systematic approach to therapy in these patients, it is our view that reasonable recommendations for treatment can be made based on recent experience. These will be presented in the concluding portion of this article. DEFINITION
We will address only true free-floating thrombi of the left atrium. Obviously excluded are circulating masses in the right atrium and massive or “occlusive” thrombi of the left atrium, which have distinct attachments to the atria1 wall or septum. Pedunculated thrombi will also be excluded. The two latter entities may of course give rise to free-floating thrombi at a later time. Mention will be made of the diagnostic distinction between free-floating and pedunculated masses. In earlier literature the artifactual production of free intracavitary thrombus by postmortem handling was cited as a potential source of diagnostic error when autopsy was the principal means of definitive evaluation’e Presently the routine use of echocardiography should permit antemortern diagnosis in most patients, and therapy should thus be directed such that autopsy will no longer be an important means of detection.
Volume
121
Number
6.
Part
Left atria1 ball thrombus
1
Fig.
PREMODERN
1. Large ball thrombus
within
opened
ERA
In a comprehensive review published in 1924, Abramson13 recounted in detail the 22 patients with left atria1 ball thrombus reported since Wood’s article and added a detailed description of his own patient. Several characteristics of patients with left atria1 ball thrombus are apparent. As suggested previously, peripheral embolism, heart failure, syncope, and sudden death were common presenting features. In all of the patients he described, diagnosis was made at autopsy. All patients but one had enlarged left atria1 cavities. Mitral stenosis, often of such severity that admission of only “the tip of one’s little finger just to engage the orifice” was described in most. Another striking characteristic was the large size attained by many of these masses. Individual sizes ranged from golfball to billiard ball. An example of a large, loose thrombus is shown in Fig. 1. This is an in situ photograph of the thrombus from Dr. Abramson’s own patient, which illustrates the degree to which such a body may fill the atria1 cavity. Other reports appeared occasionally over the next several decades.16-20 The frequent association of left atria1 dilation and mitral stenosis with ball thrombus was reconfirmed, and Elsonl’j commented for the first time on the frequent presence of atria1 fibrillation. He also stressed that rapid, often evanescent changes in the peripheral circulation occurred in these patients. These included cyanosis or pallor, coldness, and loss of pulsations. Schwartz and Biloon17 emphasized that the onset of disturbances in the peripheral circulation was a grave prognostic sign
left atrium
from Abramson’s
1785
1924 review.
followed shortly by death in most instances. Smithies1 had suggested earlier that once sufficient symptoms and signs were present to make the diagnosis appear likely, the principal question was how long it would be until death occurred. Another review was published in 1955.l” These investigators counted approximately 60 cases of left atria1 ball thrombus to that date reported in the world literature. Among four patients they described, only one had a true free-floating left atria1 thrombus. This patient was noteworthy because he had no pathologic condition of the mitral valve. He did have biventricular hypertrophy and a dilated left atrium demonstrated at autopsy. Premortem physical examination of this patient yielded findings such as the unpredictability of the presence and intensity of peripheral pulses that occurred during evaluation. His diastolic murmur was also reported to vary in intensity from cycle to cycle. These peripheral and central fluctuations were attributed to periodic, transient, partial, or total obstruction of the mitral valve as the free thrombus intermittently engaged itself within the orifice. These findings and their origins have also been described in more recent work. MODERN DIAGNOSIS Presenting symptoms
and signs. It is not surprising that the symptoms described in more recent cases of left atria1 ball thrombus are similar to those reported in the earlier literature. In 11 cases published in English since 1976 (Table I), paroxysmal dyspnea was prominent in four, syncope and peripheral arte-
June
1766
Wrisley
et al.
American
Table I. Primary and secondary thrombus in 11 cases reported
Reference
Chen et a1.2 Gottdiener et a1.3 Balbarini et aL4 Wrisley et a1.5 Szkopiec et al.‘j Warda et a1.7 Lie and Entmans
symptoms of left atria1 ball since 1976
Primary symptom
Recurrent syncope Syncope Paroxysmal dyspnea Paroxysmal dyspnea and coughing Paroxysmal dyspnea Exertional dyspnea, orthopnea Sudden death
Furukawa et a1.g
Femoral artery embolism
Sunagawa et al.‘O
Multiple repeated peripheral arterial embolism, cerebral arterial embolism Cerebral arterial embolism Popliteal arterial embolism
Wrisley et al.“* Zur-Binenboim et all2
Additional symptoms and findings
Previous transient aphasia Transient right arm paralysis Syncope, transient aphasia
Recurrent antemortem syncope Mesenteric atria1 embolism, cerebral arterial embolism Dyspnea on exertion
Superficial femoral artery embolism
rial embolism each occurred in three, and one patient died suddenly and unexpectedly. In the latter a formerly floating thrombus was found firmly impacted within the mitral valve orifice at autopsy. Table I lists the primary and secondary symptomatic features of each individual patient. The principal findings on cardiac physical examination were those of mitral stenosis in 10 of the 11 patients. In one patientll results of the cardiac examination were normal, and the absence of mitral valve or left atria1 abnormality was confirmed by two-dimensional echocardiography. Among the 10 patients with mitral stenosis, physical findings were detailed in seven. Accentuated first heart sounds and diastolic rumbles were heard in all seven.2, 5-8, lo, *l Of these, three patients were believed to have diastolic rumbles of variable intensity.2y 7t g Associated physical findings were consistent with those of mitral regurgitation, pulmonary congestion, and pulmonary hypertension. Specific extracardiac physical findings were not described in any of the reports. Echocardiographic findings. In 6 of the 11 patients results of M-mode echocardiography were de-
Heart
1991 Journal
scribed.2> 4, 6, 7t g. lo As would be expected, left atria1 dilation and mitral stenosis were usually seen. The M-mode feature common to all the patients was the intermittent appearance of bandlike echoes behind the anterior mitral valve leaflet during diastole. These echoes were not seen during all diastoles, and their presence and duration were neither consistent nor predictable. Their disappearance at the onset of ventricular systole was rapid (Fig. 2). These observations differ from the typical M-mode presentation of a pedunculated mass such as a myxoma. As seen in Fig. 3, the tethering of such a mass to the atria1 wall or septum imposes a regularity on its movement, and similar echodensities appear behind the anterior mitral valve leaflet during each diastole. Two studies29 7 demonstrated the coincidence of movement of M-mode echoes into the mitral valve orifice and the phonocardiographic disappearance of the diastolic murmur (Fig. 2). As is readily seen, the portion of diastole during which thrombus echoes are present within the valve orifice is variable in duration. Likewise the duration of the murmur is roughly inversely proportional to the length of the period of valve obstruction, thus explaining its variability from beat to beat. Two-dimensional echocardiography is particularly useful for identifying left atria1 ball thrombus and for demonstrating its behavior through consecutive cardiac cycles.2-7, g-12These intraatrial masses move erratically through the cavity, careening against opposing walls or the mitral valve apparatus and then floating off on another trajectory. There is periodic diastolic impaction of the mass against the mitral valve orifice (Figs. 4 and 5), with abrupt rebound back into the left atria1 cavity toward the pulmonic vein orifices with the onset of ventricular systole. Fig. 6 illustrates a very large but still sessile left atria1 thrombus in a patient who had previously undergone closed mitral commissurotomy. She was reevaluated because of the abrupt onset of paroxysmal dyspnea and near-syncope. In Figs. 4 and 7 the mass has become loose within the atrium. It is located in the middle of the cavity in Fig. 7 and is shown completely occluding the mitral valve orifice in Fig. 4. In Fig. 5 a free thrombus of smaller size is shown occluding the orifice of a much more stenotic mitral valve. In most cases2, 4-7, lo* l2 the free-floating thrombi have been either described echocardiographically or demonstrated surgically to be spherical or ovoid in configuration. Surgical specimens when described are uniformly relatively rounded and smooth surfaced. These morphologic features likely result from the sculpting effect of numerous randomly oriented collisions with the walls of the left atrium and with the mitral valve apparatus. Centripetal forces result-
Volume
121
Number
6,
Part
1
Left atria1 ball thrombus
1787
Fig. 2. Simultaneous phonocardiogram and M-mode echocardiogram illustrating disappearance of diastolic murmur as free thrombus intermittently engages in mitral valve orifice. aml, anterior mitral leaflet; DM, diastolic murmur; RV, right ventricle; VS, ventricular septum. (From Chen CC et al. Br Heart cJ 1983;50:190-2. Reproduced with permission.)
Fig. 3. M-mode echocardiographic appearance of mitral valve with diastolic impaction of pedunculated left atria1 myxoma (m). Note regularity of appearance of mass echoes behind anterior leaflet. This is in contrast to irregular diastolic presence of mass echoes in valve orifice seen with free-floating mass such as ball thrombus, as seen in Fig. 2. (From Morganroth J, et al. Noninvasive cardiac imaging. Chicago: Year Book Medical Publishers, Inc, 1983:336. Reproduced with permission.)
ing from the observed constant spinning of these masses may also contibute to their shape. Clinical outcome and management. The complications of left atria1 ball thrombus are serious and have been discussed previously. Such clinical events are inevitable given the inherently unstable nature of such masses, and some sort of corrective therapeutic maneuver would seem to be imperative. Because of the relative infrequency of this lesion, no clinical trials exist that might direct the choice of treatment. We must therefore rely predominantly on individual patient outcomes as related through case reports and not unimportantly on common sense. The standard treatment for fixed left atria1 thrombi
once identified is anticoagulation with heparin and/ or warfarin. The goal of anticoagulation is to arrest the further development of existing thrombi and particularly to halt the formation of fresh presumably more emboligenic matieral on the surface of an existing thrombus. However, anticoagulation does not solve the immediate problem of the presence of an unstable body ricocheting around the left atrium, liable to fragment into embolizable pieces or produce life-threatening mitral valve obstruction at any moment. Anticoagulation would not appear to have a role in the acute management of left atria1 ball thrombus, although its importance in prevention of recurrence is obvious. In at least two reported cases325
1788
June
Wrisley et al.
Fig. 4. Apical four-chamber ifice, an event that occurred of coughing. (From Wrisley
American
view showing transient impaction of ball thrombus within every five to six beats during examination and was associated D et al. AM HEART J 198&l 16:lXYl.J
Heart
1991 Journal
mitral valve orwith paroxysms
Fig. 5. Parasternal long-axis view showing relatively small free thrombus (arrows) occluding very stenotic mitral valve. This thrombus eventually embolized to patient’s left superficial femoral artery several days after this echocardiogram was obtained. LA, left atrium; LV, left ventricle; MV, mitral valve; RV, right ventricle.
large thrombi become free floating after the initiation of anticoagulation therapy. Whether direct causation was involved in these instances is unclear, but this should perhaps be considered when determining the management of very large atria1 thrombi, free floating or not. More recently thrombolytic therapy has been attempted in a variety of clinical settings, most successfully during the acute phase of myocardial in-
farction. To our knowledge no one has attempted to treat left atria1 ball thrombus in this manner, but reports of thrombolytic therapy in other forms of intracardiac thrombosis have appeared. Blazer et a1.21 attempted to treat a large fixed left atria1 thrombus with streptokinase. After 3 days of continuous infusion the patient had bilateral femoral artery emboli requiring embolectomy. Echocardiographically the mass had been greatly reduced in size and had
Volume 121 Number 6. Part 1
Left atria1 ball thrombus
Fig. 6. Apical four-chamber view of massive left atria1 thrombus ley I) et al. AM HEART J 1988;116:1351.)
Fig.
7.
Wrisley
Apical four-chamber view showing left atria1 ball thrombus D et al. AM HEART J 1988;116:1351-2.)
become highly mobile, although it remained attached to the atria1 septum by a pedicle. This remnant was considered to be significantly emboligenic and was finally removed surgically. Grunewald et a1.22 attempted to lyse a large right ventricular pacing wire thrombus with tissue plasminogen activator and provoked cardiovascular collapse in their patient. They believed that destabilization of this mass caused either pulmonary embolism or obstruction through a ball-valve effect at the pulmonic valve orifice. Mahoney et a1.23were more successful in their use of streptokinase to dissolve a thrombus that occluded
shown before detachment.
floating
(From
freely in atria1 cavity.
1789
Wris-
(From
the anastomosis between the right atrium and the pulmonary artery in a young patient who had previously undergone a modified Fontan procedure. In another study Kremer et a1.24used urokinase to treat post-myocardial infarction left ventricular thrombus. Fourteen of 16 patients in their series were either completely or partially relieved of their left ventricular thrombus, and only one had a significant (although cerebrovascular) complication. However, neither of the latter favorable reports is directly applicable to patients with left atria1 ball thrombus.
1790
Wrisley et al.
DEFINITIVE
MANAGEMENT
Two-dimensional transthoracic echocardiography alone or associated with transesophageal imaging is the most reliable method for identifying the presence of left atria1 ball thrombus and in most instances permits accurate definition of pathologic conditions of the mitral valve. One group5 suggested that twodimensional echocardiographic findings are impressive enough that further diagnostic procedures are not required. In 10 of the 11 previously cited recent cases of left atria1 ball thrombus, open-heart surgery was done to extract the atria1 mass and in most of these to either replace mitral valves or perform commissurotomy. The other patient died suddenly. However, echocardiography cannot exclude the presence of significant coronary artery disease, and in patients at risk for coronary artery disease coronary angiography should be done as part of the preoperative evaluation. Given the unpredictability of other modalities for treating free-floating left atrial thrombi and the obvious inevitability of eventual catastrophic complications, prompt surgical removal is the therapy of choice. Mitral valve commissurotomy, repair, or replacement can be done concomitantly with bypass surgery if the latter is deemed necessary.
American
We thank Karen Semak and Dawn Hoyt tance in the preparation of the manuscript.
expert
assis-
REFERENCES
1. Smithies 2.
3.
4.
5.
6.
7.
8.
9.
10.
SUMMARY
Left atria1 ball thrombus is an infrequent clinical syndrome, which can have a catastrophic outcome but can be readily treated when recognized. It is usually a complication of long-standing rheumatic mitral stenosis. Symptomatic presentation is variable: fragmentation of the thrombus followed by peripheral embolization will produce ischemia or infarction of myocardium, brain, viscera, or extremities; random, intermittent, partial, or total occlusion of the mitral valve orifice may cause syncope, pulmonary congestion, and occasionally sudden death in other patients. Embolic and obstructive phenomena may also occur together. Cardiac physical findings usually suggest mitral stenosis; variability in the intensity of the diastolic rumble is common. Two-dimensional echocardiography is the gold standard for identifying ball thrombus. Cardiac catheterization provides assessment of coronary artery status when needed. The outcome of untreated ball thrombus is unlikely to be favorable. The results of anticoagulation and thrombolysis are unpredictable and potentially as harmful as no treatment at all. Current evidence although scant suggests that prompt surgical removal of the free thrombus, often in conjunction with mitral valve repair or replacement, is the appropriate therapeutic course in most patients.
for their
June 1991 Heart Journal
11.
12.
13. 14. 15. 16. 17. 18. 19. 20. 21.
22.
23.
24.
F. Cardiac thrombosis: the clinical and pathological features in three cases. JAMA 1909:17:1347-53. Chen CC, Hsiung MC, Chaing BN. Variable diastolic rumbling murmur caused by floating left atria1 thrombus. Br Heart J 1983;50:190-2. Gottdiener JJ, Temeck BK, Patterson RH, Fletcher RD. Transient (hole-in-one) occlusion of the mitral valve orifice by a free-floating left atria1 ball thrombus: identification by twodimensional echocardiography. Am J Cardiol 1984;53:1730. Balbarini A, Pugliese P, Mariani M. Echocardiographic and surgical findings of a ball-like thrombus floating freely in the left atrium. J Cardiovasc Surg 1987;28:135-8. Wrisley D, Giambartolomei A, Levy I, Brownlee W, Lee I, Erickson J. Left atria1 ball thrombus: apparent detachment following initiation of anticoagulation therapy. AM HEART J 1988;116:1351-2. Szkopiec RL, Torstveit JR, Prakash NS, Desser KB, Benchimol A. Non-invasive diagnosis of a free-floating left atria1 thrombus with emphasis on two-dimensional echocardiographic features. Angiology 1983;34:102-10. Warda M, Garcia J, Pechacek LW, Massumkhani A, Hall RF. Auscultatory and echocardiographic features of mobile left atria1 thrombus. J Am Co11 Cardiol 1985;5:379-82. Lie JT, Entman ML. “Hole-in-one” sudden death: mitral stenosis and left atria1 ball thrombus. AM HEART J 1976; 91:798-804. Furukawa K, Katsume H, Matsukubo H, Inoue D. Echocardiographic findings of floating thrombus in left atrium. Br Heart J 1980;44:599-601. Sunagawa K, Yasuhiko 0, Tanaka S, Kibuchi Y, Nakamura M, Hirata T. Left atria1 ball thrombus diagnosed by two-dimensional echocardiography. AM HEART J 1980; 100:89-94. Wrisley D, Lee I, Parker F, Brownlee W, Ismail M. Recurrent systemic embolization from left atria1 ball thrombus: the case for earlv surgical intervention. NY State J Med 1990:9:74-5. Zur-Binenboim C, Ammor R, Grenadier E, Veisler A, Freund M, Palant A. Detection of round floating left atria1 thrombus simulating left atria1 myxoma by two-dimensional echocardiography. AM HEART J 1985;110:492-3. Abramson JL. Ball thrombus of the heart. Ann Clin Med 1924;3:327-64. Aronstein CG. Neuman L. Ball thrombus of the heart. Arch Path01 1939;27:907-12. Read SL. Porter RR. Russ1 S. Kriz JR. Occlusive auricular thrombi. ‘Circulation 1955;12:250-8. Elson J. Free ball thrombus of the left auricle. AM HEART J 1934;10:120-3. Schwartz SP, Biloon S. The clinical signs of occluding thrombus of the left auricle. AM HEART J 1931;7:84-94. Covey GW, Crook R, Rogers FL. Ball thrombus in left auricle. Am J Med Sci 1928;175:60-6. Garvin CF. Ball thrombus in the heart. AM HEART J 1941;21: 371-4. Evans W, Benson R. Mass thrombus of the left auricle. Br Heart J 1948;10:39-47. Blazer D, Degroat T, Kotler MN, et al. Peripheral embolization during thrombolytic therapy for left atria1 thrombus. Am J Cardiol 1986;58:554-5. Grunewald RA, Smith PLC, Nihoyannopoupos P, et al. Right ventricular pacing wire thrombus presenting as pyrexia of unknown origin. Clin Cardiol 1989;12:106-8. Mahoney L, Nikaidoh H, Fixler DE. Thrombolytic treatment with streptokinase for late intra-atria1 thrombosis after modified Fontan procedure. Am J Cardiol 1988;62:343-4. Kremer P, Fiebig R, Tilsner V, Bleifeld W, Mathey DG. Lysis of left ventricular thrombi with urokinase. Circulation 1985; 72:112-8.
MD, Ira Lee, RDMS, and
Systemic embolization arising from left atria1 thrombus is an abundantly described and familiar clinical syndrome. Occasionally such thrombi detach from the atrial wall, after they have become so large relative to the size of the mitral valve orifice they cannot immediately escape into the general circu1ation.l The result is free-floating intraatrial thrombi. Such loose bodies may cause syncope12, 3 pulmonary congestion,4-7 or sudden deaths, g via a ball-valve effect. In addition, repeated collisions with atria1 walls and the mitral valve apparatus occur and may cause fragmentation and subsequent embolization of small or relatively larger pieces to the periphery. Cerebrovascular accident43 5, g or potential loss of a limb1°-12 may occur. Myocardial ischemia, probably the result of coronary artery embolus, has been suggested in one case.5 Overall left atria1 ball thrombus appears to be an unusual occurrence. Whether its infrequency is real or results in part from failure of detection is unclear. The term “ball thrombus” was first applied to this entity by Wood in 1814, who described autopsy findings in a l&year-old girl with rheumatic mitral stenosis and syncope (Wood W. Edinburg Med J 1814;10:50, cited in reference 8). Since then numerous additional reports have appeared, including English language reviews in 1924,13 1939,14 and 1955.‘” However, no comprehensive discussion of this topic has been presented in recent years. In view of modern methods of cardiac evaluation such as echocardiography and heart catheterization, as well as therapeutic options including anticoagulation, From the State University Hospital Health Center, Received
for publication
Reprint requests: NY 13088. 411128754
1784
David
of New York Health Science and Upstate Mobile Services, July Wrisley,
16, 1990; accepted
Sept.
Center, Inc.
St. Joseph’s
I, 1990.
MD, 5100 W. Taft Rd., Suite 25, Liverpool,
thrombolysis, and open-heart surgery, a reconsideration of this clinical entity seems timely. The purpose of this article is twofold: First, a suctint summary of the preechocardiography literature describing left atria1 ball thrombus will be presented. Limited analytic attention will be given to reports from the “premodern” era, except where they have application to raising clinical suspicion concerning the presence of a free-floating left atria1 thrombus. Second, reports that have appeared since the emergence of echocardiography will be discussed in detail. Such cases will necessarily belong to the era of cardiac catheterization and open-heart surgery and more recently thrombolytic therapy. Although little has been published on the systematic approach to therapy in these patients, it is our view that reasonable recommendations for treatment can be made based on recent experience. These will be presented in the concluding portion of this article. DEFINITION
We will address only true free-floating thrombi of the left atrium. Obviously excluded are circulating masses in the right atrium and massive or “occlusive” thrombi of the left atrium, which have distinct attachments to the atria1 wall or septum. Pedunculated thrombi will also be excluded. The two latter entities may of course give rise to free-floating thrombi at a later time. Mention will be made of the diagnostic distinction between free-floating and pedunculated masses. In earlier literature the artifactual production of free intracavitary thrombus by postmortem handling was cited as a potential source of diagnostic error when autopsy was the principal means of definitive evaluation’e Presently the routine use of echocardiography should permit antemortern diagnosis in most patients, and therapy should thus be directed such that autopsy will no longer be an important means of detection.
Volume
121
Number
6.
Part
Left atria1 ball thrombus
1
Fig.
PREMODERN
1. Large ball thrombus
within
opened
ERA
In a comprehensive review published in 1924, Abramson13 recounted in detail the 22 patients with left atria1 ball thrombus reported since Wood’s article and added a detailed description of his own patient. Several characteristics of patients with left atria1 ball thrombus are apparent. As suggested previously, peripheral embolism, heart failure, syncope, and sudden death were common presenting features. In all of the patients he described, diagnosis was made at autopsy. All patients but one had enlarged left atria1 cavities. Mitral stenosis, often of such severity that admission of only “the tip of one’s little finger just to engage the orifice” was described in most. Another striking characteristic was the large size attained by many of these masses. Individual sizes ranged from golfball to billiard ball. An example of a large, loose thrombus is shown in Fig. 1. This is an in situ photograph of the thrombus from Dr. Abramson’s own patient, which illustrates the degree to which such a body may fill the atria1 cavity. Other reports appeared occasionally over the next several decades.16-20 The frequent association of left atria1 dilation and mitral stenosis with ball thrombus was reconfirmed, and Elsonl’j commented for the first time on the frequent presence of atria1 fibrillation. He also stressed that rapid, often evanescent changes in the peripheral circulation occurred in these patients. These included cyanosis or pallor, coldness, and loss of pulsations. Schwartz and Biloon17 emphasized that the onset of disturbances in the peripheral circulation was a grave prognostic sign
left atrium
from Abramson’s
1785
1924 review.
followed shortly by death in most instances. Smithies1 had suggested earlier that once sufficient symptoms and signs were present to make the diagnosis appear likely, the principal question was how long it would be until death occurred. Another review was published in 1955.l” These investigators counted approximately 60 cases of left atria1 ball thrombus to that date reported in the world literature. Among four patients they described, only one had a true free-floating left atria1 thrombus. This patient was noteworthy because he had no pathologic condition of the mitral valve. He did have biventricular hypertrophy and a dilated left atrium demonstrated at autopsy. Premortem physical examination of this patient yielded findings such as the unpredictability of the presence and intensity of peripheral pulses that occurred during evaluation. His diastolic murmur was also reported to vary in intensity from cycle to cycle. These peripheral and central fluctuations were attributed to periodic, transient, partial, or total obstruction of the mitral valve as the free thrombus intermittently engaged itself within the orifice. These findings and their origins have also been described in more recent work. MODERN DIAGNOSIS Presenting symptoms
and signs. It is not surprising that the symptoms described in more recent cases of left atria1 ball thrombus are similar to those reported in the earlier literature. In 11 cases published in English since 1976 (Table I), paroxysmal dyspnea was prominent in four, syncope and peripheral arte-
June
1766
Wrisley
et al.
American
Table I. Primary and secondary thrombus in 11 cases reported
Reference
Chen et a1.2 Gottdiener et a1.3 Balbarini et aL4 Wrisley et a1.5 Szkopiec et al.‘j Warda et a1.7 Lie and Entmans
symptoms of left atria1 ball since 1976
Primary symptom
Recurrent syncope Syncope Paroxysmal dyspnea Paroxysmal dyspnea and coughing Paroxysmal dyspnea Exertional dyspnea, orthopnea Sudden death
Furukawa et a1.g
Femoral artery embolism
Sunagawa et al.‘O
Multiple repeated peripheral arterial embolism, cerebral arterial embolism Cerebral arterial embolism Popliteal arterial embolism
Wrisley et al.“* Zur-Binenboim et all2
Additional symptoms and findings
Previous transient aphasia Transient right arm paralysis Syncope, transient aphasia
Recurrent antemortem syncope Mesenteric atria1 embolism, cerebral arterial embolism Dyspnea on exertion
Superficial femoral artery embolism
rial embolism each occurred in three, and one patient died suddenly and unexpectedly. In the latter a formerly floating thrombus was found firmly impacted within the mitral valve orifice at autopsy. Table I lists the primary and secondary symptomatic features of each individual patient. The principal findings on cardiac physical examination were those of mitral stenosis in 10 of the 11 patients. In one patientll results of the cardiac examination were normal, and the absence of mitral valve or left atria1 abnormality was confirmed by two-dimensional echocardiography. Among the 10 patients with mitral stenosis, physical findings were detailed in seven. Accentuated first heart sounds and diastolic rumbles were heard in all seven.2, 5-8, lo, *l Of these, three patients were believed to have diastolic rumbles of variable intensity.2y 7t g Associated physical findings were consistent with those of mitral regurgitation, pulmonary congestion, and pulmonary hypertension. Specific extracardiac physical findings were not described in any of the reports. Echocardiographic findings. In 6 of the 11 patients results of M-mode echocardiography were de-
Heart
1991 Journal
scribed.2> 4, 6, 7t g. lo As would be expected, left atria1 dilation and mitral stenosis were usually seen. The M-mode feature common to all the patients was the intermittent appearance of bandlike echoes behind the anterior mitral valve leaflet during diastole. These echoes were not seen during all diastoles, and their presence and duration were neither consistent nor predictable. Their disappearance at the onset of ventricular systole was rapid (Fig. 2). These observations differ from the typical M-mode presentation of a pedunculated mass such as a myxoma. As seen in Fig. 3, the tethering of such a mass to the atria1 wall or septum imposes a regularity on its movement, and similar echodensities appear behind the anterior mitral valve leaflet during each diastole. Two studies29 7 demonstrated the coincidence of movement of M-mode echoes into the mitral valve orifice and the phonocardiographic disappearance of the diastolic murmur (Fig. 2). As is readily seen, the portion of diastole during which thrombus echoes are present within the valve orifice is variable in duration. Likewise the duration of the murmur is roughly inversely proportional to the length of the period of valve obstruction, thus explaining its variability from beat to beat. Two-dimensional echocardiography is particularly useful for identifying left atria1 ball thrombus and for demonstrating its behavior through consecutive cardiac cycles.2-7, g-12These intraatrial masses move erratically through the cavity, careening against opposing walls or the mitral valve apparatus and then floating off on another trajectory. There is periodic diastolic impaction of the mass against the mitral valve orifice (Figs. 4 and 5), with abrupt rebound back into the left atria1 cavity toward the pulmonic vein orifices with the onset of ventricular systole. Fig. 6 illustrates a very large but still sessile left atria1 thrombus in a patient who had previously undergone closed mitral commissurotomy. She was reevaluated because of the abrupt onset of paroxysmal dyspnea and near-syncope. In Figs. 4 and 7 the mass has become loose within the atrium. It is located in the middle of the cavity in Fig. 7 and is shown completely occluding the mitral valve orifice in Fig. 4. In Fig. 5 a free thrombus of smaller size is shown occluding the orifice of a much more stenotic mitral valve. In most cases2, 4-7, lo* l2 the free-floating thrombi have been either described echocardiographically or demonstrated surgically to be spherical or ovoid in configuration. Surgical specimens when described are uniformly relatively rounded and smooth surfaced. These morphologic features likely result from the sculpting effect of numerous randomly oriented collisions with the walls of the left atrium and with the mitral valve apparatus. Centripetal forces result-
Volume
121
Number
6,
Part
1
Left atria1 ball thrombus
1787
Fig. 2. Simultaneous phonocardiogram and M-mode echocardiogram illustrating disappearance of diastolic murmur as free thrombus intermittently engages in mitral valve orifice. aml, anterior mitral leaflet; DM, diastolic murmur; RV, right ventricle; VS, ventricular septum. (From Chen CC et al. Br Heart cJ 1983;50:190-2. Reproduced with permission.)
Fig. 3. M-mode echocardiographic appearance of mitral valve with diastolic impaction of pedunculated left atria1 myxoma (m). Note regularity of appearance of mass echoes behind anterior leaflet. This is in contrast to irregular diastolic presence of mass echoes in valve orifice seen with free-floating mass such as ball thrombus, as seen in Fig. 2. (From Morganroth J, et al. Noninvasive cardiac imaging. Chicago: Year Book Medical Publishers, Inc, 1983:336. Reproduced with permission.)
ing from the observed constant spinning of these masses may also contibute to their shape. Clinical outcome and management. The complications of left atria1 ball thrombus are serious and have been discussed previously. Such clinical events are inevitable given the inherently unstable nature of such masses, and some sort of corrective therapeutic maneuver would seem to be imperative. Because of the relative infrequency of this lesion, no clinical trials exist that might direct the choice of treatment. We must therefore rely predominantly on individual patient outcomes as related through case reports and not unimportantly on common sense. The standard treatment for fixed left atria1 thrombi
once identified is anticoagulation with heparin and/ or warfarin. The goal of anticoagulation is to arrest the further development of existing thrombi and particularly to halt the formation of fresh presumably more emboligenic matieral on the surface of an existing thrombus. However, anticoagulation does not solve the immediate problem of the presence of an unstable body ricocheting around the left atrium, liable to fragment into embolizable pieces or produce life-threatening mitral valve obstruction at any moment. Anticoagulation would not appear to have a role in the acute management of left atria1 ball thrombus, although its importance in prevention of recurrence is obvious. In at least two reported cases325
1788
June
Wrisley et al.
Fig. 4. Apical four-chamber ifice, an event that occurred of coughing. (From Wrisley
American
view showing transient impaction of ball thrombus within every five to six beats during examination and was associated D et al. AM HEART J 198&l 16:lXYl.J
Heart
1991 Journal
mitral valve orwith paroxysms
Fig. 5. Parasternal long-axis view showing relatively small free thrombus (arrows) occluding very stenotic mitral valve. This thrombus eventually embolized to patient’s left superficial femoral artery several days after this echocardiogram was obtained. LA, left atrium; LV, left ventricle; MV, mitral valve; RV, right ventricle.
large thrombi become free floating after the initiation of anticoagulation therapy. Whether direct causation was involved in these instances is unclear, but this should perhaps be considered when determining the management of very large atria1 thrombi, free floating or not. More recently thrombolytic therapy has been attempted in a variety of clinical settings, most successfully during the acute phase of myocardial in-
farction. To our knowledge no one has attempted to treat left atria1 ball thrombus in this manner, but reports of thrombolytic therapy in other forms of intracardiac thrombosis have appeared. Blazer et a1.21 attempted to treat a large fixed left atria1 thrombus with streptokinase. After 3 days of continuous infusion the patient had bilateral femoral artery emboli requiring embolectomy. Echocardiographically the mass had been greatly reduced in size and had
Volume 121 Number 6. Part 1
Left atria1 ball thrombus
Fig. 6. Apical four-chamber view of massive left atria1 thrombus ley I) et al. AM HEART J 1988;116:1351.)
Fig.
7.
Wrisley
Apical four-chamber view showing left atria1 ball thrombus D et al. AM HEART J 1988;116:1351-2.)
become highly mobile, although it remained attached to the atria1 septum by a pedicle. This remnant was considered to be significantly emboligenic and was finally removed surgically. Grunewald et a1.22 attempted to lyse a large right ventricular pacing wire thrombus with tissue plasminogen activator and provoked cardiovascular collapse in their patient. They believed that destabilization of this mass caused either pulmonary embolism or obstruction through a ball-valve effect at the pulmonic valve orifice. Mahoney et a1.23were more successful in their use of streptokinase to dissolve a thrombus that occluded
shown before detachment.
floating
(From
freely in atria1 cavity.
1789
Wris-
(From
the anastomosis between the right atrium and the pulmonary artery in a young patient who had previously undergone a modified Fontan procedure. In another study Kremer et a1.24used urokinase to treat post-myocardial infarction left ventricular thrombus. Fourteen of 16 patients in their series were either completely or partially relieved of their left ventricular thrombus, and only one had a significant (although cerebrovascular) complication. However, neither of the latter favorable reports is directly applicable to patients with left atria1 ball thrombus.
1790
Wrisley et al.
DEFINITIVE
MANAGEMENT
Two-dimensional transthoracic echocardiography alone or associated with transesophageal imaging is the most reliable method for identifying the presence of left atria1 ball thrombus and in most instances permits accurate definition of pathologic conditions of the mitral valve. One group5 suggested that twodimensional echocardiographic findings are impressive enough that further diagnostic procedures are not required. In 10 of the 11 previously cited recent cases of left atria1 ball thrombus, open-heart surgery was done to extract the atria1 mass and in most of these to either replace mitral valves or perform commissurotomy. The other patient died suddenly. However, echocardiography cannot exclude the presence of significant coronary artery disease, and in patients at risk for coronary artery disease coronary angiography should be done as part of the preoperative evaluation. Given the unpredictability of other modalities for treating free-floating left atrial thrombi and the obvious inevitability of eventual catastrophic complications, prompt surgical removal is the therapy of choice. Mitral valve commissurotomy, repair, or replacement can be done concomitantly with bypass surgery if the latter is deemed necessary.
American
We thank Karen Semak and Dawn Hoyt tance in the preparation of the manuscript.
expert
assis-
REFERENCES
1. Smithies 2.
3.
4.
5.
6.
7.
8.
9.
10.
SUMMARY
Left atria1 ball thrombus is an infrequent clinical syndrome, which can have a catastrophic outcome but can be readily treated when recognized. It is usually a complication of long-standing rheumatic mitral stenosis. Symptomatic presentation is variable: fragmentation of the thrombus followed by peripheral embolization will produce ischemia or infarction of myocardium, brain, viscera, or extremities; random, intermittent, partial, or total occlusion of the mitral valve orifice may cause syncope, pulmonary congestion, and occasionally sudden death in other patients. Embolic and obstructive phenomena may also occur together. Cardiac physical findings usually suggest mitral stenosis; variability in the intensity of the diastolic rumble is common. Two-dimensional echocardiography is the gold standard for identifying ball thrombus. Cardiac catheterization provides assessment of coronary artery status when needed. The outcome of untreated ball thrombus is unlikely to be favorable. The results of anticoagulation and thrombolysis are unpredictable and potentially as harmful as no treatment at all. Current evidence although scant suggests that prompt surgical removal of the free thrombus, often in conjunction with mitral valve repair or replacement, is the appropriate therapeutic course in most patients.
for their
June 1991 Heart Journal
11.
12.
13. 14. 15. 16. 17. 18. 19. 20. 21.
22.
23.
24.
F. Cardiac thrombosis: the clinical and pathological features in three cases. JAMA 1909:17:1347-53. Chen CC, Hsiung MC, Chaing BN. Variable diastolic rumbling murmur caused by floating left atria1 thrombus. Br Heart J 1983;50:190-2. Gottdiener JJ, Temeck BK, Patterson RH, Fletcher RD. Transient (hole-in-one) occlusion of the mitral valve orifice by a free-floating left atria1 ball thrombus: identification by twodimensional echocardiography. Am J Cardiol 1984;53:1730. Balbarini A, Pugliese P, Mariani M. Echocardiographic and surgical findings of a ball-like thrombus floating freely in the left atrium. J Cardiovasc Surg 1987;28:135-8. Wrisley D, Giambartolomei A, Levy I, Brownlee W, Lee I, Erickson J. Left atria1 ball thrombus: apparent detachment following initiation of anticoagulation therapy. AM HEART J 1988;116:1351-2. Szkopiec RL, Torstveit JR, Prakash NS, Desser KB, Benchimol A. Non-invasive diagnosis of a free-floating left atria1 thrombus with emphasis on two-dimensional echocardiographic features. Angiology 1983;34:102-10. Warda M, Garcia J, Pechacek LW, Massumkhani A, Hall RF. Auscultatory and echocardiographic features of mobile left atria1 thrombus. J Am Co11 Cardiol 1985;5:379-82. Lie JT, Entman ML. “Hole-in-one” sudden death: mitral stenosis and left atria1 ball thrombus. AM HEART J 1976; 91:798-804. Furukawa K, Katsume H, Matsukubo H, Inoue D. Echocardiographic findings of floating thrombus in left atrium. Br Heart J 1980;44:599-601. Sunagawa K, Yasuhiko 0, Tanaka S, Kibuchi Y, Nakamura M, Hirata T. Left atria1 ball thrombus diagnosed by two-dimensional echocardiography. AM HEART J 1980; 100:89-94. Wrisley D, Lee I, Parker F, Brownlee W, Ismail M. Recurrent systemic embolization from left atria1 ball thrombus: the case for earlv surgical intervention. NY State J Med 1990:9:74-5. Zur-Binenboim C, Ammor R, Grenadier E, Veisler A, Freund M, Palant A. Detection of round floating left atria1 thrombus simulating left atria1 myxoma by two-dimensional echocardiography. AM HEART J 1985;110:492-3. Abramson JL. Ball thrombus of the heart. Ann Clin Med 1924;3:327-64. Aronstein CG. Neuman L. Ball thrombus of the heart. Arch Path01 1939;27:907-12. Read SL. Porter RR. Russ1 S. Kriz JR. Occlusive auricular thrombi. ‘Circulation 1955;12:250-8. Elson J. Free ball thrombus of the left auricle. AM HEART J 1934;10:120-3. Schwartz SP, Biloon S. The clinical signs of occluding thrombus of the left auricle. AM HEART J 1931;7:84-94. Covey GW, Crook R, Rogers FL. Ball thrombus in left auricle. Am J Med Sci 1928;175:60-6. Garvin CF. Ball thrombus in the heart. AM HEART J 1941;21: 371-4. Evans W, Benson R. Mass thrombus of the left auricle. Br Heart J 1948;10:39-47. Blazer D, Degroat T, Kotler MN, et al. Peripheral embolization during thrombolytic therapy for left atria1 thrombus. Am J Cardiol 1986;58:554-5. Grunewald RA, Smith PLC, Nihoyannopoupos P, et al. Right ventricular pacing wire thrombus presenting as pyrexia of unknown origin. Clin Cardiol 1989;12:106-8. Mahoney L, Nikaidoh H, Fixler DE. Thrombolytic treatment with streptokinase for late intra-atria1 thrombosis after modified Fontan procedure. Am J Cardiol 1988;62:343-4. Kremer P, Fiebig R, Tilsner V, Bleifeld W, Mathey DG. Lysis of left ventricular thrombi with urokinase. Circulation 1985; 72:112-8.
