Pericardial effusions in patients with end-stage renal disease.

Echocardiography has greatly increased the accurate recognition of pericardial effusion. Echocardiograms were performed prospectively on the total group of 35 stable asymptomatic patients on chronic haemodialysis to determine the incidence of pericardial effusion. Effusions were shown in 11 per cent (4/35); only 6 per cent (2/35) were estimated as greater than 100 ml. For comparison, records were reviewed retrospectively from 41 haemodialysis patients referred during a 27-month period for echocardiographic assessment of suspected pericardial effusion. These 41 patients came from a total group of 108 patients treated with chronic dialysis over this interval. Of 41 examined, 21 (51%) or 21 of 108 (19%) of the population at risk had an effusion. Of 21 with echocardiographic effusions, 15 (71%), or 15 of 41 (37%) of those with clinically suspected effusion, had more than 100 ml fluid. Gross (greater than 100 ml) pericardial effusions are infrequent in stable, asymptomatic patients with end-stage renal disease. When clinical findings suggest pericardial disease, the echocardiographic demonstration of over 100 ml pericardial fluid is indicative of new effusion, rather than coincidental pre-existing effusion.     

How do the clinical findings in patients with pericardial effusions influence the success of aspiration?

OBJECTIVE--To identify features associated with success or failure of aspiration of pericardial effusion. METHOD--A retrospective analysis of 36 drainage procedures in 30 patients with pericardial effusion was performed using patient records and echocardiograms. RESULTS--Unsuccessful aspiration was associated with pericardial loculation but not with the seniority of the operator or the size and position of the effusion. Pericardiocentesis relieved symptoms of breathlessness in 21 of 26 patients who had a pericardial effusion suspected of causing dyspnoea. These 21 patients had few clinical or echocardiographic signs of classic tamponade. CONCLUSION--The paucity of abnormal physical or echocardiographic signs of tamponade in breathless patients with pericardial effusion does not exclude symptomatic benefit being derived from pericardiocentesis. Pericardial aspiration is safe in appropriate hands, although aspiration of loculated effusions may not be as successful as aspiration of non-loculated effusions.     

Pericardial involvement in human immunodeficiency virus infection

STUDY OBJECTIVES: Previous studies have showed that the pericardium is frequently involved in HIV infection. However, the characteristics and etiology of the pericardial abnormalities that have been found remained poorly defined. We analyzed the features of pericardial involvement in these patients and investigated the clinical variables associated with moderate and severe effusions. DESIGN: Prospective, clinical, and echocardiographic study. SETTING: The service of infectious diseases of a university hospital. PATIENTS: 181 consecutive patients at all stages of HIV infection. RESULTS: Only one patient (0.55%) had acute pericarditis. Seventy-five patients (41%) had an asymptomatic pericardial effusion; in 23 patients (13% of all patients), the effusion was either moderate or severe. Ten cases (5.5% of all patients) of moderate or severe effusions resulted in right atrium diastolic compression, and three of these cases (1.6% of all patients) required pericardiocentesis for the management of tamponade. Six patients (3%) presented with echogenic pericardial masses of undetermined etiology. A moderate or severe effusion was present in a greater number of patients with symptomatic HIV infection than was present in asymptomatic HIV-infected patients, respectively: 17 vs 2% (p = 0.015). The following are variables independently associated with moderate or severe pericardial effusions: heart failure (odds ratio, 20.3; p = 0.0001); Kaposi's sarcoma (odds ratio, 8.6; p = 0.01), tuberculosis (TB; odds ratio, 47.2; p = 0.0006); and other pulmonary infections (odds ratio,15.0; p = 0.02). CONCLUSIONS: Most of these moderate or severe effusions are clinically unsuspected, but they can lead to life-threatening tamponade. This fact seems to justify echocardiographic surveillance in HIV-infected patients, especially in those with heart failure, Kaposi's sarcoma, TB, or other pulmonary infections.     

So-called uremic heart diseases

The overall cardiovascular mortality in patients with chronic renal failure is about 30 per cent of which 10 per cent is attributed to myocardial infarction. This prevalence led some workers to propose a hypothesis of "accelerated atherosclerosis" due to the hyperlipidaemia observed in 30 to 70 per cent of patients. However, the concept of accelerated atherosclerosis, which was based essentially on clinical studies, has been questioned. Pericardial effusion is a common complication of chronic renal failure and has been reported in over 62 per cent of patients in echocardiographic studies. There are many causes and symptoms are often mild; systematic echocardiographic examination of patients with renal failure undergoing haemodialysis has shown 32 per cent of pericardial effusions to be asymptomatic. There are two potential complications: cardiac tamponade and, lesser frequently, constrictive pericarditis. Cardiac failure is a common cause of death in patients undergoing long-term dialysis. The myocardial histological appearances are those of fibrosis, the etiology of which is not fully understood although the dialysis membranes and hypotensive episodes occurring during haemodialysis have been thought to play a role. Left ventricular hypertrophy and fibrosis may give rise to ventricular arrhythmias which could explain some of the cases of sudden death observed in patients with renal failure and often wrongly attributed to ischemic heart disease. Another form of myocardial disease which is observed later is characterised by an alteration of systolic function with left ventricular dilatation and hypokinesia and increased end diastolic pressures without an increase in left ventricular wall thickness. Valvular heart disease may also result from renal failure.(ABSTRACT TRUNCATED AT 250 WORDS)     

Echocardiographic features of progressive systemic sclerosis (PSS). Correlation with hemodynamic and postmortem studies.

Echocardiographic abnormalities were noted in 37 (69 per cent) of 54 patients with progressive systemic sclerosis (PSS). Thirty-one of the 54 patients also underwent right heart catheterization. Eight of the 11 patients who died underwent postmortem examination. Pericardial effusion was noted in 22 subjects (41 per cent), although it was suspected on clinical grounds in only seven. Echocardiography appeared to be an excellent tool for evaluating and quantitating pericardial effusions. The presence of a small pericardial effusion (<50 ml) did not affect prognosis, but the presence of a large effusion (>200 ml) was associated with a poor prognosis. The finding on echocardiogram of right ventricular dilatation, left atrial dilatation, asymmetrical septal hypertrophy, paradoxic motion of the interventricular septum or signs of pulmonary hypertension were seen predominantly or exclusively in patients who had pulmonary artery hypertension at cardiac catheterization. Pericardial effusions and abnormal mitral valve diastolic slope on echocardiogram did not correlate with pulmonary hypertension.The present study confirms clinically the frequent involvement of myocardium and pericardium that has been reported in autopsy series. At the same time, however, it suggests that the usefulness of the echocardiogram in clinical practice may really be limited to evaluating pericardial effusion and cardiomegaly, and to substantiating pulmonary artery hypertension in a safe, noninvasive manner.     

Large pericardial effusions of inflammatory origin in childhood

OBJECTIVES: Our aim was to review the clinical records from children with large pericardial effusions of inflammatory origin presenting to a tertiary referral centre over the last 21 years, with emphasis on their clinical presentation, management and outcome. BACKGROUND: The common identifiable causes of pericardial effusion in children include prior cardiac surgery, bacterial pericarditis, malignancy, and connective tissue disorders. In a significant number of children, however, despite extensive investigation, it is not possible to identify a clear aetiology. A viral cause is often considered, though rarely confirmed. The clinical course of such large idiopathic pericardial effusions in children has not been extensively reported. METHODS AND RESULTS: We reviewed retrospectively the records of all patients seen between 1981 and 2001 with large pericardial effusions of inflammatory origin requiring drainage, excluding the effusions related to cardiac surgery or malignancy. We found 31 patients fulfilling our criterions for study. They could be divided into three groups, with 15 patients having no specific identifiable aetiology despite extensive investigation, 12 patients having evidence of bacterial pericarditis, and four with a probable immunologic disorder. Fever was present in only eight patients (53%) in the idiopathic group. All patients in the other groups had fever. Except for fever and the resultant tachycardia, it was not possible to distinguish on clinical grounds, nor on the presence or otherwise of cardiac tamponade, between those with idiopathic aetiology and those with bacterial infection. Of the patients with presumed bacterial pericarditis, five (42%) had both positive blood and pericardial fluid cultures, three (25%) had positive blood cultures, while a further three patients (25%) had only positive pericardial fluid cultures. All patients required drainage of the pericardial effusion, either under echocardiographic guidance or surgically. None of the patients died. The hospital stay was significantly shorter for those with idiopathic as opposed to bacterial pericarditis. Of those with an idiopathic aetiology, six required readmission due to recurrence of the pericardial effusion, with four patients requiring further surgical drainage. No patients required readmission with a bacterial or immunologic aetiology. No patient developed constrictive pericarditis after a median follow-up of 22 months. CONCLUSION: Patients with large idiopathic pericardial effusion had relatively few constitutional symptoms as compared with their gross echocardiographic findings. Those with bacterial pericarditis had more urgent need for treatment. Patients with pericardial effusion of inflammatory origin, when treated appropriately, had an excellent outcome with no mortality or development of constrictive pericarditis.     

Clinical and echocardiographic spectrum of pericardial effusions in routine M-mode echocardiographic examinations of hospitalized patients

In 123 (13.2%) out of 926 hospitalized patients pericardial effusions were diagnosed during routine M-mode echocardiographic examination. 53 (43.0%) presented a small (group 1), 31 (25.3%) a moderate (group 2) and 38 (31.7%) a great amount of fluid (group 3). Pericardial effusion could be diagnosed only by echocardiographic examination in 18 patients (34.0%) of the first group, in 8 (26.0%) of the second and in 7 (18.0%) of the third group. Routine M-mode echocardiographic examination in hospitalized patients allows the detection of small pericardial effusions often missed by conventional methods. This method also makes possible rapid diagnosis of pericardial effusion in cardiac patients in a critical condition or with haemodynamic disturbances sometimes difficult to identify.     

Pericardial effusion after cardiac surgery: incidence, site, size, and haemodynamic consequences.

OBJECTIVE--To evaluate the incidence, characteristics, and haemodynamic consequences of pericardial effusion after cardiac surgery. DESIGN--Clinical, echocardiographic, and Doppler evaluations before and 8 days after cardiac surgery; with echocardiographic and Doppler follow up of patients with moderate or large pericardial effusion after operation. SETTING--Patients undergoing cardiac surgery at a tertiary centre. PATIENTS--803 consecutive patients who had coronary artery bypass grafting (430), valve replacement (330), and other types of surgery (43). 23 were excluded because of early reoperation. MAIN OUTCOME MEASURES--Size and site of pericardial effusion evaluated by cross sectional echocardiography and signs of cardiac tamponade detected by ultrasound (right atrial and ventricular diastolic collapse, left ventricular diastolic collapse, distension of the inferior vena cava), and Doppler echocardiography (inspiratory decrease of aortic and mitral flow velocities). RESULTS--Pericardial effusion was detected in 498 (64%) of 780 patients and was more often associated with coronary artery bypass grafting than with valve replacement or other types of surgery; it was small in 68.4%, moderate in 29.8%, and large in 1.6%. Loculated effusions (57.8%) were more frequent than diffuse ones (42.2%). The size and site of effusion were related to the type of surgery. None of the small pericardial effusions increased in size; the amount of fluid decreased within a month in most patients with moderate effusion and in a few (7 patients) developed into a large effusion and cardiac tamponade. 15 individuals (1.9%) had cardiac tamponade; this event was significantly more common after valve replacement (12 patients) than after coronary artery bypass grafting (2 patients) or other types of surgery (1 patient after pulmonary embolectomy). In patients with cardiac tamponade aortic and mitral flow velocities invariably decreased during inspiration; the echocardiographic signs were less reliable. CONCLUSIONS--Pericardial effusion after cardiac surgery is common and its size and site are related to the type of surgery. Cardiac tamponade is rare and is more common in patients receiving oral anticoagulants. Echo-Doppler imaging is useful for the evaluation of pericardial fluid accumulations after cardiac surgery. It can identify effusions that herald cardiac tamponade.     

Quantification of pericardial effusions by three-dimensional echocardiography

Objectives. The purpose of this study was to examine the accuracy of three-dimensional echocardiography for the quantification of asymmetric pericardial effusion volume and to compare this new technique with two-dimensional echocardiography.Background. Quantification of pericardial effusion by two-dimensional echocardiography relies on a symmetric distribution of the fluid. Three-dimensional echocardiography can quantitate volume without these limitations, but its accuracy for pericardial effusin volume has not been assessed.Methods. In six open chest dogs, 41 different asymmetrically distributed pericardial effusions of known volume were created by serial infusions of fluid through a pericardial catheter. The hearts were imaged using an automated echocardiographic method that integrates three-dimensional spatial and imaging data. The surfaces of the pericardial sac and heart were then reconstructed, and the volumes of pericardial effusions were calculated. Two-dimensional echocardiography was performed simultaneously, and volumes were calculated using the prolate ellipsoid method. Asymmetric distribution of the fluid was obtained by applying localized hydrostatic pressure to the pericardium.Results. The volumes of pericardial effusion quantified using three-dimensional echocardiography correlated well with actual volumes (y = 1.0x − 1.4, SEE = 7.7 ml, r = 0.98). Two-dimensional echocardiography had an acceptable correlation (y = 1.0x + 2.3, SEE = 23 ml, r = 0.84), but a marked degree of variation from the true value was observed for any individual measurement.Conclusions. Three-dimensional echocardiography accurately quantifies pericardial effusion volume in vivo, even when the fluid is distributed asymmetrically, whereas two-dimensional echocardiography is less reliable. This new technique may be of clinical value in quantitating pericardial effusion, especially in the serial evaluation of asymmetric or loculated effusions.     

Echocardiographic mimicry of pericardial effusion

Echocardiography is a sensitive technique for the detection of pericardial effusion, but the abnormal echocardiographic patterns seen with effusions are not, however, entirely specific for that diagnosis. This study describes four patients in whom anatomic structures, a coronary artery to coronary sinus fistula (one case) and tumors metastatic to pericardium (three cases), produced posterior and, in two cases, anterior spaces compatible with pericardial fluid. Echocardiographic patterns mimicking pericardial effusion have previously been reported in patients with anatomic abnormalities such as mitral anular calcification, pleural effusions, left atrial enlargement, anterior mediastinal or pericardial tumors, foramen of Morgagni hernia and pseudoaneurysm of the left ventricle. It appears that structures of fluid or tissue density, interposed between the heart and the airfilled lung, can produce echocardiographic patterns simulating pericardial effusion.     

Correlation of echocardiographic and clinical findings in patients with pericardial effusion.

Clinical data and echocardiographic findings were correlated in 20 patients with pericardial effusion. Moderate to large effusions were associated with increased motion of the entire heart within the pericardial sac. A correlation was found between the estimated volume of fluid and the diastolic excursion and velocity of the right ventricular and left ventricular walls (P less than 0.01). For any given volume of fluid as estimated from the echocardiogram neoplastic effusions resulted in greater increments in wall motion (P less than 0.02). Patterns of "pseudo" mitral valve prolapse occurred and were correlated with the extent and timing of cardiac swinging and heart rate. A diminished E-F slope of the mitral valve echo and notch on the right ventricular epicardial echo during early systole were found in all four patients with pericardial tamponade. These preliminary observations suggest that echocardiographic examination of patients with pericardial effusion may provide clues to the presence or absence of tamponade in addition to providing an estimate of the quantity of fluid in the pericardial sac.     

Tumormarker im Perikarderguss bei malignen und nichtmalignen Perikarderg��ssen

Background

The differential diagnosis of pericardial effusion is often challenging because different etiologies can be discussed. Of particular therapeutic and prognostic importance is the definitive differentiation of malignant pericardial effusion from benign effusions. The definitive diagnosis of malignant pericardial effusion is established by a positive cytological examination of the pericardial fluid. However, pericardial fluid cytology, although specific has variable sensitivity. Tumor markers are often investigated after pericardiocentesis but their utility as an aid for the diagnosis of malignant pericardial effusion is not well established. The aim of this study was to measure the concentrations of the tumor markers CEA, CA?19-9, CA?72-4, SCC and NSE in malignant and non-malignant pericardial effusions and to assess their diagnostic utility in differentiating malignant from benign pericardial effusion.

Methods

We investigated the pericardial fluid of 29?patients with proven malignant pericardial effusion and 25?patients with non-malignant pericardial effusion. The etiology of the pericardial effusion was defined by pericardial cytology, epicardial histology and PCR for cardiotropic viruses from pericardial and epicardial tissue acquired by pericardioscopy. The group with non-malignant pericardial effusion comprised 15?patients with autoreactive effusion and 10?patients with viral pericardial effusion. We analyzed the following tumor markers in the pericardial fluid: carcinoembryonic antigen (CEA), carbohydrate antigen (CA)?19-9, carbohydrate antigen (CA)?72-4, squamous cell carcinoma (SCC) antigen and neuron-specific enolase (NSE).

Results

Of the tumor markers tested the mean concentrations of the CEA, CA?72-4 and CA?19-9 were significantly higher in malignant pericardial effusions than in non-malignant effusions (CEA 450.66 ±1620.58???g/l vs. 0.72 ±1.49???g/l, p<0.001; CA?19-9 1331.31 ±3420.87?kU/l vs. 58.85 ±17.53?kU/l, p=0.04; CA?72-4 707.90 ±2397.55?kU/l vs. 0.48 ±2.40?kU/l, p<0.001). ROC curve analysis showed that pericardial fluid CA?72-4 yielded an area under the curve (AUC) of 0.85 (95% confidence interval 0.74?C0.95), followed by CEA with 0.80 (95% confidence interval 0.68?C0.92). Pericardial fluid CA?72-4 levels >1.0?kU/l had 72% sensitivity (95% confidence interval 53%?C87%) and 96% specificity (95% confidence interval 80%?C99.9%) and CA?72-4 levels >2.5?kU/l had 69% sensitivity (95% confidence interval 49%?C85%) and 96% specificity (95% confidence interval 80%?C99.9%) in differentiating malignant pericardial effusions from effusions due to benign conditions.

Conclusion

Malignant pericardial effusions are associated with significantly higher pericardial concentrations of the tumor markers CEA, CA?72-4 and CA?19-9. Of the tested tumor markers, measurement of CA?72-4 levels in pericardial fluid offered the best diagnostic accuracy. Based on our data evaluation of every patient with unexplained pericardial effusion and negative pericardial fluid cytology should include the measurement of pericardial fluid CA?72-4 levels. Under these circumstances the elevation of pericardial fluid CA?72-4 levels should include malignancy as a probable diagnosis.     

Echocardiographic quantitation of pericardial effusion

This study was undertaken to test the validity of M-mode echocardiographic quantitation of pericardial effusion. M-mode estimate of the volume of pericardial effusion in 27 patients was compared with the actual volume of pericardial effusion removed during surgical pericardial drainage. The 16 two-dimensional echocardiographic studies in patients with small, moderate, and large pericardial effusions were reviewed to examine the distribution of pericardial fluid around the heart. Although there was good correlation between the echocardiographic estimate and the actual volume removed during surgery (r = 0.78), significant overestimation and underestimation were noted. Our findings suggest that the errors in the estimate could be attributed in part to difficulties in precise measurement of the epicardial and pericardial landmarks and in part to nonuniform distribution of pericardial fluid around the heart.     

Usefulness of nuclear magnetic resonance imaging for evaluation of pericardial effusions, and comparison with two-dimensional echocardiography

Nuclear magnetic resonance (NMR) imaging clearly delineates cardiovascular structures without interference from overlying bone and lung tissue. The techniques of NMR imaging and echocardiography were compared in 26 patients with pericardial effusions, 10 of whom had associated pleural effusions. In those patients with fluid detected by both techniques, estimated size of the effusion tended to be somewhat larger by NMR. NMR imaging detected several small pericardial effusions that were not visualized by echocardiography. Both techniques demonstrated loculation well, although NMR imaging was better for detecting fluid located superiorly at the aortic pericardial reflection site, medially at the border of the right atrium and posteriorly at the left ventricular apex. In the 14 patients with documented exudative effusions (10 pericardial, 4 pleural) NMR signals of varying intensity were present in the effusion. One patient had a documented transudative effusion and no NMR signal was observed in the fluid. NMR imaging clearly distinguished pericardial from pleural effusions. NMR imaging is indicated when a suspected pericardial effusions is not detected by echocardiography or when specific localization or fluid characterization is desired.     

Two-dimensional echocardiography in cardiac tamponade occurring after cardiac surgery

Cardiac tamponade is an important complication after cardiac surgery, yet little has been published on the echocardiographic diagnosis of this situation. The two-dimensional echocardiograms of 11 patients who required surgical relief of cardiac tamponade complicating cardiac surgery were therefore reviewed. Four had nonloculated pericardial effusions surrounding both ventricles. The other seven patients had a loculated posterior pericardial effusion; in three of these the effusion altered left ventricular posterior wall contour so that it was concave toward the effusion in the long-axis view; in two, a strikingly abnormal motion of the left ventricular posterior wall was noted, such that the width of the posterior pericardial space diminished in systole and widened abruptly in early diastole. The quantity of pericardial contents (fluid, blood or clot) evacuated surgically was smaller than usually encountered in patients with tamponade due to various "medical" conditions. Thus, unlike tamponade with other pericardial effusions, tamponade after cardiac surgery is due to a pericardial effusion that is smaller in volume, often loculated posteriorly and associated with certain unique two-dimensional echocardiographic features.     

Pericardial effusion: diagnostic value of the subcostal acoustic window (inferior vena cava-right atrial projection)

To validate the usefulness of the subcostal acoustic window (inferior vena cava-right atrial projection) for the echocardiographic diagnosis of pericardial effusion we studied 40 patients with pericardial effusion detected through the parasternal approach. A group of 100 patients without evidence of effusion constitutes the control group. In all patients in the control group, a contact between the right atrial wall and the diaphragm was noted during the cardiac cycle (specificity: 100%). This had also been detected in 15 of 18 patients with mild effusion and in only 1 of 11 patients with moderate effusion, and in none of 11 patients with severe effusion (overall sensitivity: 60%). Therefore, moderate and severe pericardial effusions can be detected in most cases (95.4%) below the right atrial wall through the subcostal inferior vena cava-right atrial projection. The echocardiographic criteria for its diagnosis is the lack of contact through the cardiac cycle between right atrial wall and the diaphragm.     

Clinical clues to the causes of large pericardial effusions

PURPOSE: To examine whether the size of the effusion, the presence of tamponade, and inflammatory signs are useful in determining the causes of moderate or severe pericardial effusions.SUBJECTS AND METHODS: All echocardiograms performed at a general hospital between January 1990 and April 1996 were screened for pericardial effusion. Patients with moderate (echo-free space of 10 to 20 mm during diastole) or severe (echo-free space >20 mm) effusions were studied. RESULTS: We identified 322 patients (166 [52%] men, mean [+/- SD] age 56 +/- 17 years [range 15 to 88 years]), 132 (41%) with moderate and 190 (59%) with severe pericardial effusion. The most frequent etiologic diagnoses were acute idiopathic pericarditis (n = 66 [20%]), iatrogenic effusions (n = 50 [16%]), cancer (n = 43 [13%]), and chronic idiopathic pericardial effusion (n = 29 [9%]). In 192 (60%) of the patients, the cause of the effusion was a known medical condition. In the 130 other patients, inflammatory signs were associated with acute idiopathic pericarditis (likelihood ratio = 5. 4, P < 0.001), severe effusions without inflammatory signs or tamponade were associated with chronic idiopathic pericardial effusion (likelihood ratio = 20, P < 0.001), and tamponade without inflammatory signs was associated with malignant effusions (likelihood ratio = 2.9, P < 0.01).CONCLUSIONS: In many patients, pericardial effusions are due to a known underlying disease or condition. In patients without underlying diseases, inflammatory signs, the size of effusion, and the presence or absence of cardiac tamponade can be helpful in establishing cause.     

Problems and pitfalls in the echocardiographic assessment of pericardial effusion

The echocardiographic diagnosis of pericardial effusions is usually based on visualization of a sonolucent circumcardiac space of varying width. However, potential fallacies in interpretation can arise if sonolucent spaces adjacent to the heart (pleural effusions, ascites, pericardial cysts) are mistaken for pericardial effusions. Loculated pericardial effusions, especially if unusual in location or configuration, can cause diagnostic difficulty on occasion. The differential diagnosis of various "solid" echoes within a pericardial effusion is of clinical relevance, yet not widely discussed. Inflammatory tissue, neoplastic involvement, pus, caseous material, and extravasated blood all have characteristic echocardiographic morphologies. All of the various reported echocardiographic signs of tamponade do not have the same significance, so that caution is necessary not to over- or under-read tamponade. Chamber collapse can be absent in real tamponade in specific situations. On the other hand, "regional" tamponade can occur if loculated pericardial effusions are sufficiently large and high tension; echocardiographic appearances are "atypical" but diagnostically valuable if correctly interpreted. These and certain other unusual variants of tamponade deserve to be better known among echocardiographers not only because of their intrinsic interest, but also to avoid potential pitfalls in the echocardiographic assessment of patients with suspected disease.     

Pericardial effusion diagnosed by echocardiography. Clinical and electrocardiographic findings in 171 patients

Clinical and electrocardiographic findings in 171 patients with pericardial effusion diagnosed by echocardiographic studies were reviewed. In 70 patients the effusion was unsuspected. There were 87 small, 50 moderate, and 31 large effusions. Cardiac tamponade was present in three patients. Congestive heart failure was the most common cause of pericardial effusion and occurred in 37 patients. Other frequently noted conditions included cardiac disease without congestive heart failure, neoplasms, acute nonspecific pericarditis, renal failure, and acute myocardial infarction. A pericardial friction rub was present in 23 patients, two-thirds of whom had moderate or large effusions. Atrial arrhythmias were common. Low voltage occurred in 31 of 136 patients and was more common with large effusions. The ability to distinguish between a small effusion and the quantity of pericardial fluid present normally is a problem requiring further clarification.