Contrast echocardiography is superior to tissue harmonics for assessment of left ventricular function in mechanically ventilated patients

Background Assessment of left ventricular function by echocardiography is f requently challenging in mechanically ventilated patients. We evaluated the potential value of contrast-enhanced imaging and tissue harmonic imaging o ver standard fundamental imaging for endocardial border detection [EBD) in these patients. Methods and Result Fifty patients underwent standard transthoracic 2D echoc ardiography and were imaged in fundamental and tissue harmonic modes and su bsequently with intravenous contrast (Optison). Two echocardiographers revi ewed all studies for ease of visualization of endocardial border segments a nd scoring of wall motion. EBD for each wall segment was graded from to 4 ( 1 = excellent EBD). Wall motion was scored by a standard 16-segment model a nd 1 to 5 scale. Studies were categorized as nondiagnostic if 4 of 6 segmen ts in the apical 4-chamber view were either poorly seen or not seen (EBD sc ore 3 or 4). Quantification of election fraction was independently performe d of nine. Visualization of 68% of all segments improved with contrast echo cardiography versus 17% improvement with tissue harmonics compared with fun damental mode. Significant improvement (poor/not seen to good/excellent) oc curred in 60% of segments with contrast echocardiography versus 18% with ti ssue harmonics. A total of 850 segments were deemed poor/not seen, 78% of w hich improved to good/excellent with contrast echocardiography versus 23% w ith tissue harmonics. Interobserver agreement on EBD was 64% to 70%. Conver sion of nondiagnostic to diagnostic studies occurred in 85% of patients wit h contrast echocardiography versus 15% of patients with tissue harmonics. S caring of wall motion with fundamental mode, tissue harmonics, and contrast echocardiography was possible in 61%, 74%, and 95% of individual segments, respectively (P <.001). Wail motion scoring was altered in 17% of segments with contrast echocardiography and in 8% with tissue harmonics. Interobser ver agreement on wall motion scoring was 84% to 88%. Contrast echocardiogra phy permitted measurement of election fraction 45% (P =.003) more often ove r fundamental mode versus a 27% (P =.09) increase with tissue harmonics. Conclusions Contrast echocardiography is superior to tissue harmonic imagin g for EBD, wall motion scoring, and quantification of election fraction in mechanically ventilated patients.