empyema is an uncommon complication of pneumonectomy and may occur within 1 day or several weeks after pneumonectomy . although postpneumonectomy empyema ( ppe ) is usually diagnosed during the same hospital visit , some cases are not detected until months or even several years later . late - onset ppe ( > 3 month ) may be very difficult to diagnose and manage . because of the high mortality rate for ppe with combined complications such as bronchopleural fistula , early diagnosis and optimal management is important . we describe the case of a 66-year old man presenting with symptoms and signs of right - sided heart failure due to extrinsic compression of the right atrium caused by late - onset ppe . a 66-year old man presented with a two week history of shortness of breath , facial edema and edema in both lower extremities . forty years prior to this presentation , the patient suffered from primary pulmonary tuberculosis of his right lung . he underwent right pneumonectomy and was treated with antituberculosis therapy for 1 year , with no subsequent problems . the current clinical examination revealed evidence of right - sided heart failure , including peripheral edema and shortness of breath at rest . at admission , the patient 's physical examination revealed a blood pressure of 140/90 mm hg , a pulse rate of 119/minute , a respiration rate of 24/minute and a body temperature of 36. the breathing sounds diminished in the right hemithorax and crackles and wheezing sounds were heard on the left lung field . an evaluation with laboratory tests revealed a hemoglobin concentration of 11.8 g / dl , a white blood cell ( wbc ) count of 8220 cells/l ( neutrophils : 72% , lymphocytes : 14% ) , a platelet count of 267000/l , an increased erythrocyte sedimentation rate of 29 mm / hr , c - reactive protein 7.2 mg / dl and the lactate dehydrogenase a chest radiograph showed total haziness in the right lung field , and this was probably the result of the past pneumonectomy . despite conventional management , including oxygen and a bronchodilator , his condition became worse with worsening despnea at rest , weight gain over 5 kg and increased pretibial pitting edema . the transthoracic echocardiogram revealed a large pericardial effusion in the free wall of the right atrium ( fig . pulsed doppler echocardiography demonstrated an abnormally increased respiratory variation in transvalvular blood flow velocities ( fig . extrinsic right atrial compression was suspected , but was not verified via transthoracic echocardiography due to accompanied severe pericardial effusion . the pericardial fluid showed a lymphocyte - predominant exudate with an increased protein content ( 3800 g / dl ) , an elevated level of ldh ( 1612 u / l ) , a depressed glucose level ( 104 mg / dl ) , wbc count of 1180/mm ( neutrophils : 35% , lymphocytes : 65% ) and an increased level of adenosine deaminase ( ada ) of 53.9 u / l . the polymerase chain reaction we performed for mycobacterium tuberculosis complex from the pericardial fluid was negative . cytologic examination demonstrated no malignant cells . during the pericardial drainage , a contrast enhanced chest computed tomography ( ct ) the chest ct showed that a huge empyema was compressing the right atrium ( fig . the pleural cavity was filled with a large amount of empyema debris and this was completely removed ( fig . , follow - up doppler echocardiography showed no respiratory variation of mitral inflow e wave velocity . this finding suggested that afb and gram staining of the body fluid from the open drainage , including for anaerobes , remained sterile . the patient recovered with resolution of all his signs and symptoms of right atrial compression after the completion of treatment . the heart is centrally located in the mediastinum , so it can be encroached on by abnormal structures originating from the anterior , posterior or superior mediastinum . d'cruz et al.1 ) divided the relationship between the mediastinal masses and the heart into three categories : 1 ) proximity : a contiguous or adjacent structure without chamber deformation , 2 ) encroachment : distortion of the normal cardiovascular architecture without a hemodynamic effect and 3 ) compression . if the mediastinal mass is large and rigid or if it is cystic and under high pressure and located in a way that it would compress the heart , it can produce hemodynamic effects and symptoms akin to tamponade , as seen in our patient . the compressed right atrium of our patient led to two catastrophic effects : right - sided heart failure and cardiac tamponade . fowler et al.2 ) described a similar mechanism that was responsible for causing isolated right atrial tamponade in experimental animals . a negative transmural right atrial pressure due to the right ventricular diastolic suction was observed in that study . in addition , a significant pressure gradient between the superior vena cava and the right atrium , suggesting caval compression during right atrial tamponade , was noted in that study . vena caval compression was not observed when the animals were subjected to tamponade of the entire heart . thus , presumably , both the loss of the negative transmural right atrial pressure gradient and the caval compression are responsible for causing hemodynamic effects in isolated right atrial compression . empyema that occurs after pneumonectomy is a major complication that is usually diagnosed during the same period of hospitalization . this may occur within 1 day or several weeks after pneumonectomy , and some empyemas occur several months or even several years after a pneumonectomy . the incidence of late - onset ( > 3 months ) ppe seems to be quite low , and only a few cases of late - onset ppe have been reported over the last 25 years.3 - 8 ) in our patient , a ppe was diagnosed more than 40 year after his pneumonectomy for tuberculosis . the pathogenesis of late - onset ppe is sometimes difficult to establish because of the many possible sources of infection of the postpneumonectomy space . the hematogenous spread is the usual cause of infections that occur at a later time after surgery . no organism was isolated in 20% of the patients who had frank pus in their pneumonectomy space.9 ) likewise , the cause of the empyema in our patient remained uncertain because of the negative results of afb and gram staining as well as the culturing , and this included mediums for anaerobic organisms . however , we believed that the presumptive causal organism was tuberculosis from some evidence , including the past history of tuberculosis , as well as increased ada and lymphocyte - dominant purulent pericardial fluid . in general , diagnosing late - onset ppe is difficult because these patients are commonly asymptomatic or have nonspecific symptoms such as anorexia , increased body temperature , weight loss , chest discomfort and/or pain . our patient did not visit the hospital until his disease manifested as right - sided heart failure . transthoracic echocardiography is of limited value for diagnosing right atrial compression , but is useful to evaluate hemodynamic changes and cardiac function . chest ct is the test of choice for identifying masses adjacent to the right atrium . it may be used not only to determine the interrelation between the mass and cardiac structures , but also to identify the etiologic cause of the disease . ppe is considered the most problematic among postoperative pleural infections , and is associated with very high morbidity and a mortality rate of 13 - 50%.10 ) therefore , the optimal management of complicated empyema is based on an early diagnosis , appropriate antibiotic treatment and prompt drainage of the pleural space . in conclusion , extrinsic compression of the right atrium is a rare cause of heart failure . other adjacent abnormal mediastinal structures that include an aortic aneurysm , carcinoma , a hepatic cyst and diaphragmatic paralysis may also cause right atrial compression . our case is a rare and unique cause of right - sided heart failure due to significant right atrial compression , and the latter was caused by late - onset ppe in the right pleural space . late - onset ppe is very rare and can cause complicated illnesses in postpneumonectomy patients . it is crucial that an early , accurate diagnosis is made and adequate drainage has been done so that further intervention can proceed in a timely manner .
although it is rare , the right atrium can be encroached on by abnormal mediastinal structures , including aortic aneurysms , carcinomas , hepatic cysts and diaphragmatic paralysis . 
 extrinsic compression of the right atrium causes significant hemodynamic compromise and can lead to fatal outcomes . 
 we describe the case of a 66-year old man with a past history of pulmonary tuberculosis that had undergone right pneumonectomy 40 years previously . 
 he then presented with signs and symptoms of right - sided heart failure . 
 these new signs and symptoms were recognized to be secondary to extrinsic compression of the right atrium , which was due to late - onset postpneumonectomy empyema , and the signs and symptoms were successfully relieved by performing open drainage of the empyema .