A 52-year-old woman presented with severe dyspnea of 2 weeks’ duration. Echocardiography showed an enlarged left atrium but normal global left ventricular systolic function. However, a huge, irregularly shaped mass at the dilated coronary sinus that extended into the right atrium was noted. Mitral inflow showed restrictive physiology and the E/E’ ratio was significantly elevated, suggesting elevated left ventricular filling pressures. Echocardiography-guided biopsy was performed, and a diagnosis of primary cardiac lymphoma (diffuse large B-cell type) was made. After the first cycle of chemotherapy, the patient’s symptom was markedly improved. A follow-up echocardiogram showed complete removal of the mass and a change in left ventricular filling pattern from restrictive to relaxation abnormality with decreased E/E’. The present case demonstrates a rare cause of diastolic dysfunction due to coronary sinus obstruction by tumor infiltration. Diastolic dysfunction caused by coronary sinus obstruction was improved after the tumor was resolved by chemotherapy.
A 52-year-old woman was admitted to the emergency department because of progressively aggravated shortness of breath for 2 weeks. She had no particular medical history. She reported general weakness and easy fatigue. A physical examination revealed neck vein engorgement and mild pitting edemas on both pretibial areas. An electrocardiogram showed sinus tachycardia at a rate of 104 beats/min, and a chest x-ray revealed cardiomegaly, blunting of both costophrenic angles, and haziness of both hilar regions. A 2-dimensional echocardiogram showed an enlarged left atrium but a normal sized left ventricle (LV) with preserved global LV systolic function (LV ejection fraction 56%). However, there was a huge, heterogeneous mass that extended from the coronary sinus to the right atrium that resulted in obstruction and dilatation of the coronary sinus ( Figure 1 A , B; Videos 1 and 2 ). Pulsed-wave Doppler echocardiography revealed increased E/A ratio and shortened deceleration time, suggesting restrictive physiology of LV filling (E velocity 96 cm/sec, A velocity 39 cm/sec, deceleration time 125 msec). In addition, the E/E’ ratio was elevated, suggesting elevated LV filling pressures ( Figure 2 A , B). Cardiac magnetic resonance imaging also showed a huge, irregularly shaped and lobular mass along the atrioventricular groove originating from the coronary sinus and invading and protruding into the right atrium cavity. However, there was no evidence of the extracardiac mass on positron emission tomography. An echocardiography-guided biopsy was performed by jugular venous approach, and the pathologic examination of the biopsied tissue clearly demonstrated histology of diffuse large B-cell lymphoma, that is, the tumor cells express B-cell antigens, such as CD20 and CD79a, in immunophenotyping. Subsequently, a chemotherapy regimen consisting of 5 drugs (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone) was started. Shortly after, the patient’s dyspnea was markedly improved. A follow-up echocardiogram performed at the end of the first cycle of chemotherapy showed that the mass causing the coronary sinus obstruction had completely disappeared ( Figure 1 C, D; Videos 3 and 4 ). The mitral inflow pattern was changed from restrictive physiology to relaxation abnormality and the E/E’ ratio was also decreased, suggesting improved diastolic function and reduced LV filling pressure ( Figure 2 C, D).
