Peripheral venous contrast echocardiography.
Contrast echocardiography is the technique of injecting various echo-producing agents into the bloodstream and, with standard echocardiographic techniques, observing the blood flow patterns as revealed by the resulting cloud of echoes. These techniques have only recently been utilized to evaluate various cardiac defects. Two physical properties of these agents characterize their usefulness: (1) clouds of echoes can be observed downstream as well as at the injection site, and (2) the echo-producing quality of these agents is completely lost with a single transit through either the pulmonary or the systemic capillary bed. Thus, detection of resultant echoes in both the venous and the arterial blood pool is indicative of abnormal shunting. In 60 patients with a spectrum of cardiac defects and a wide range in age of presentation, studies were made of (1) the feasibility of performing contrast echocardiography with superficial peripheral venous injections, and (2) the clinical usefulness of this relatively noninvasive technique in detecting and localizing intracardiac right ot left shunting. Most superficial peripheral veins could be utilized, and the resultant contrast echograms were reproducible and similar in quality to those obtained more central (caval) injections. Right to left shunts could be localized in the atrial, ventricular or intrapulmonary level. Characteristic flow patterns were also recognized for tricuspid atresia and common ventricle.