Intracardiac two-dimensional echocardiography in patients with pericardial effusion and cardiac tamponade.

The utility of intracardiac two-dimensional echocardiography in the identification of pericardial effusion was assessed in five patients with pericardial effusion and cardiac tamponade. A 20 MHz, mechanically rotating ultrasound catheter was used for intracardiac imaging. In all five patients, intracardiac echocardiography yielded high resolution of images of the right atrial cavity, the right atrial wall, and the pericardial effusion. In two patients, right atrial collapse could be identified during real-time imaging. Although the entire right atrial cavity and the pericardial effusion could not be displayed in a single imaging field because of the limited depth of field associated with the 20 MHz catheter, manipulation of the catheter allowed visualization of the pericardial effusion and the parietal pericardium in each patient. The effusion was seen to surround the superior vena cava, as well, in all patients. After pericardiocentesis, the reduction in the size of the effusion and increase in the right atrial cavity size could be recognized by intracardiac echocardiography. The introduction and manipulation of the ultrasound catheter was easily performed without any complications. This experience presents one clinical application for intracardiac echocardiography and indicates its potential value in the invasive cardiac laboratory.