Echocardiography and Doppler ultrasound in the evaluation of pericardial disease.

Echocardiography and Doppler ultrasound are useful in evaluating a variety of pathological conditions affecting the pericardium. Cardiac tamponade results in right atrial collapse and right ventricular diastolic collapse detectable by echocardiography. These echocardiographic signs have a high degree of sensitivity and specificity. False-negative echocardiographic studies may be seen in patients with pulmonary hypertension, and false-positive studies for cardiac tamponade may occur in severe hypovolemia. Although cardiac tamponade is usually caused by pericardial effusion, less commonly intrapericardial clot may result in hemodynamic compromise. Pericardial clot may be echogenic, and hence the diagnosis potentially can be missed. If the intrapericardial clot is localized, the classic echocardiographic signs of pericardial effusion may be absent, and a localized mass may be seen on the echocardiogram. Increased respiratory variation in transvalvular blood flow velocities detectable by Doppler ultrasound is found in cardiac tamponade. Doppler ultrasound studies may be particularly useful in those patients in whom the characteristic echocardiographic abnormalities are absent. Both M-mode and two-dimensional echocardiography may be useful in diagnosing pericardial thickening. Constrictive pericarditis results in a variety of echocardiographic abnormalities including pericardial thickening; biatrial enlargement with good left ventricular function; a diastolic septal bounce; and a dilated inferior vena cava without significant respiratory variation. Doppler echocardiographic abnormalities are commonly found in constrictive pericarditis. Echocardiography is also useful as a guide to performing pericardiocentesis and in the detection of pericardial adhesions and pericardial metastases.