Julia S. Rasor

Determination of Cardiac Output by Two-Dimensional Contrast Echocardiography

Contrast echocardiography refers to the process of opacifying cardiac chambers and major vessels with dense “clouds” of reflected echoes by means of the intravascular injection of a variety of fluids [1]. Although the exact source of the contrast effect is not known, available evidence overwhelmingly points to the role of microscopic air bubbles in the genesis of the contrast effect [2]. Although indocyanine green, saline, and dextrose in water have been the solutions most routinely used to produce contrast echocardiograms, even intravascular injection of the patient’s own blood can elicit similar phenomena. Recently a variety of gas containing substances have been utilized in the experimental laboratory to standardize the contrast recordings obtained [3].