Right Atrial Thrombosis: Association With Constrictive Pericarditis Mikio Katagiri, MD, Yasuhiko Tanabe, MD, Masashi Takahashi, MD, and Shigetaka Kasuya, MD The Cardiovascular Center, Tachikawa General Hospital, Niigata, Japan

We report a 73-year-old man with right atrial thrombosis associated with both constrictive pericarditis and persist- ent sinus rhythms of the heart who successfully under- went thrombectomy and pericardiectomy.

(Ann Thorac Surg 1990;49:145-6)

ight atrial mural thrombosis is quite rare and is R seldom diagnosed antemortem [ 11. Lethal complica- tions of pulmonary embolism, severe right heart failure, or both, frequently develop in this lesion [2]. We report a patient with right atrial thrombosis associated with tuber- culous constrictive pericarditis for whom thrombectomy together with pericardiectomy was performed.

A 73-year-old man with hypertension was admitted to our hospital on March 1, 1988, because of progressive exer- tional dyspnea for more than 6 months. His blood pres- sure was 140/100 mm Hg, and his pulse rate was 100 beats per minute. Cervical venous distention, which did not disappear in a sitting position, severe hepatomegaly, and bilateral pretibial edemas were noted. Neither cardiac murmurs nor respiratory rales were audible. Chest roent- genogram showed dullness of bilateral costophrenic an- gles with mild interlobal pleural effusion. Echocardiogram demonstrated a 49% left ventricular ejection fraction and dilatation of the right atrium. Contrast computed tomog- raphy confirmed a low-density area, 2 cm in diameter, in the right atrium (Fig 1) and noncalcified severely thick- ened pericardium. Cinemagnetic resonance imaging also showed a low-signal area as detected by computed to- mography and immobile thickened pericardium. Pulmo- nary scintigram showed no perfusion defects. Cardiac catheterization revealed similarly elevated mean right atrial, right and left ventricular end-diastolic, and pulmo- nary artery wedge pressures, which were 18, 19, 20, and 17 mm Hg, respectively. A ”dip and plateau” pattern was noted in both ventricles. The cardiac index was 1.7 L1 min/m2. The findings on coronary arteriogram were nor- mal. Thus, the diagnosis of a right atrial mass associated with constrictive pericarditis was made.

On April 7, 1988, standard pericardiectomy was per- formed through median sternotomy and ultrasonography showed the right atrial mass. Under cardiopulmonary

Accepted for publication June 14, 1989.

Address reprint requests to Dr Katagiri, Division of Cardiovascular Sur- gery, The Cardiovascular Center, Tachikawa General Hospital, 3-2-11 Kandamachi, Nagaoka, Niigata 940, Japan.

Fig 1. Contrast computed tomography shows a low-density area in the right atrium (arrows) and noncalcified severely thickened pericar- dium.

bypass, the mass, 2 x 1.5 x 0.8 cm in size, was visualized through a right atriotomy attaching to the atrial pectinate muscle anterolaterally (Fig 2) and was easily detached. Pathological examination proved tuberculous pericarditis, and the mass was a fibrinous thrombus. The patient was given antitubercular agents and is free of symptoms 10 months after operation.

Comment Right-sided cardiac thrombosis occurs very rarely except when some intracardiac foreign bodies coexist. Right atrial thrombus has been found in patients with dilated cardiomyopathy, restrictive cardiomyopathy due to amy- loidosis, idiopathic enlargement of the right atrium, infec- tive endocarditis, and endocardial fibroelastosis. Our pa- tient is an unusual case in that right atrial thrombus was visualized in the state of sinus rhythms of the heart with constrictive pericarditis, although 1 similar previously reported case with atrial fibrillation [3] is described in the English-language literature.

Two main causes of intracardiac thrombi include hemo- stasis and endocardial injury of the heart. In constrictive pericarditis, impairment of filling of the ventricles during diastole causes intracardiac hemostasis, which is consid- erably worsened by the complication of atrial fibrillation, in turn causing thrombus formation. In addition, myo- carditis in association with pericarditis leads to an en- docardial inflammatory process [4], also facilitating

0 1990 by The Society of Thoracic Surgeons 0003-4975/90/$3.50

146 CASE REPORT KATAGIRI ET AL RIGHT ATRIAL THROMBOSIS

Ann Thorac Surg 1990:49:1456

ported patients with primary atrial thrombosis showed that 12 (60%) had pulmonary embolism, and 6 of them died. Three others had thrombotic incarceration in the tricuspid annulus and severe cardiac failure, and all died. The total mortality rate of these 20 cases was as high as 45%. Thus, in patients with right atrial thrombi, both the incidence of pulmonary embolism and the mortality rate are considered very high. Instability of the right atrial thrombus, as confirmed in our patient, increases the risk of its spontaneous detachment from the atrial wall and makes anticoagulant therapy unsatisfactory. Early surgi- cal thrombectomy together with standard pericardiec- tomy is considered the procedure of choice.

Fig 2 . A thrombus (arrows) exposed through right atriotomy attach- ing to the pectinate muscular endocardium of the anterolateral wall apart from the appendage of the right atrium.

References 1. Adams PC, Cohen M, Chesebro JH, Fuster V. Thrombosis and

embolism from cardiac chambers and infected valves. I Am Coll Cardiol 1986;8:76B87B.

2. Chakko s, Richard F 111. Right-sided cardiac thrombi and pulmonary embolism. Am J Cardiol 1987;59:195-6.

3. Nishimura T, Misawa T, Park Y, et al. Visualization of right atria, thrombus associated with constrictive pericarditis by indium-111 oxine platelet imaging. J Nucl Med 1987;28:1344-7.

4. Levine HD. Myocardial fibrosis in constrictive pericarditis. Electrocardiographic and pathologic observations. Circulation 1973;48:126%81.

thrombosis. our patient, despite having been in sinus rhythm, demonstrated severe hemostasis, which is con- sidered to have contributed greatly to thrombus formation together with atrial endocardia1 inflammation.

Chakko and Richard [21 reported that 24 of 30 (80%) autopsied patients with right-sided cardiac thrombi had pulmonary embolism. Our study of 20 previously re-