Contrast echocardiography is a technique that improves endocardial demarcation and provides real-time data on blood circulation (blood flow, velocity). Left ventricle imaging study using contrast agents that cross the pulmonary circulation allows an improved visualization of endocardial tissue. This creates a more accurate ultrasound evaluation of left ventricular dimensions and its kinetics. Contrast echocardiography can improve Doppler mode evaluation and can provide information on myocardial perfusion precisely through this mechanism.

Microbubble contrast agents are second-generation ultrasound contrast agents and are especially useful in endocardial demarcation. Second generation ultrasound contrast agents available now, include “Definity”, “Optison” – available in almost all countries with an average medical system except for Europe and “SonoVue” – available in most European countries. Contrast agents are represented by microbubbles between 1-10μm in diameter, containing a gas surrounded by a phospholipid membrane (SonoVue) or protein (Optison).

Because the microbubble ultrasound characteristics used are different from the characteristics of the surrounding tissue or blood elements and cardiac structures, their diffusion produce very strong acoustic signals, which are directly proportional to blood volume. Quantitative assessment of myocardial microcirculation is now possible due to the advancing techniques in contrast echocardiography, provided that the left ventricular cavity has an increased echogenicity compared with the surrounding myocardium (which has a lower blood volume).