Contrast echocardiography has been used to opacify the left ventricular cavity, delineate endocardial borders, and assess myocardial perfusion. Since capillary integrity is essential for myocardial viability, the presence of contrast in dysfunctional myocardial segments may be used as indirect evidence of preserved viability in patients with left ventricular dysfunction.1It has been shown that 50–60% of patients with severe left ventricular dysfunction and coronary artery disease have evidence of myocardial viability, and the demonstration of viable myocardium in these patients has profound therapeutic and prognostic implications.2 The recent development of second generation contrast agents that can be administered intravenously has enhanced the applicability of contrast echocardiography. Contrast agents transit the pulmonary capillary circulation after intravenous administration. They could theoretically have adverse effects on pulmonary vascular resistance and oxygen saturation.3 It has also been suggested that a high pulmonary vascular impedance could hinder the pulmonary transit of contrast agents, thereby compromising efficacy. Sonovue (Bracco, Spa, Milan, Italy) is an aqueous suspension of phospholipid encapsulated sulfur hexafluoride microbubbles, developed as an intravenous contrast agent for echocardiography.4Although the safety of transpulmonary contrast agents has been previously established in human studies, it has not been specifically examined in patients with severe left ventricular dysfunction where the technique is likely to be increasingly used to determine myocardial viability.

Thus, the purpose of this study was to determine the cardiopulmonary and haemodynamic effects of bolus doses of Sonovue in patients with …