Myocardial contrast echocardiography: a reproducible technique of myocardial opacification for identifying regional perfusion deficits.

Abstract

SUMMARY The effects and reliability of a simple method of contrast two-dimensional echocardiographic delineation of myocardium after intracoronary injections were evaluated in closed-chest dogs. Multiple injections of an agitated saline-Renografin (meglumine diatrizoate) mixture (3:2 ratio, 2-ml bolus) into the left main coronary artery as well as at different sites of the left anterior descending and circumflex coronary arteries were studied in several short-axis and long-axis cross sections of the left ventricle. These contrast injections opacified specific regions of left ventricular myocardium depending on the site of injection. Contrast injection into the left main coronary artery provided a clear, echo-free outline (negative contrast) of underperfused myocardium distal to the coronary occlusion. Reproducibility studies of the extent of involved zones measured in echocardiographic cross sections indicated high intra-and interobserver correlation coefficients (r = 0.97 and 0.97). The effects of the intracoronary injection of contrast material appeared minor and brief. ECG ST-T changes lasted 49.4 ± 36.7 seconds, aortic systolic pressure was reduced by 7.6 ± 4.4% for 18.9 ± 4.8 seconds, and the peak rate of left ventricular pressure rise decreased by 14.3 ± 2.6%, but returned to control levels within 19.4 ± 6.1 seconds. The zone of left ventricular asynergy after coronary occlusions was also delineated by cross-sectional echocardiography and corresponded to the contrast-outlined underperfused zone (negative contrast). This new intracoronary echocardiographic technique has only minor hemodynamic consequences and provides reliable quantitation of underperfused and dysfunctioning zones after experimental coronary occlusions. Further investigation and validation of this method may provide useful characterization of the extent and severity of myocardial ischemia and infarction.THE PRIMARY application of contrast echocardiography has been in qualitative studies of the heart and determination of intracardiac defects or shunts'6 and assessment of tricuspid regurgitation.7-"0 The concept of injecting contrast material into the cardiac chambers and analyzing contrast washout in echocardiographic images has been examined in the hope of providing a noninvasive measurement of blood flow. "I Only scant attention has been given to the potential of contrast echocardiography for study of the extent op appropriate microbubbles or fluids that can safely cross the lung and permit study of left ventricular and septal myocardium while being injected intravenously or into the right chamber."'-"'We developed a simple myocardial contrast echocardiographic method that could be readily applied in closed-chest dogs with coronary occlusions. When it appeared that intracoronary injection of an agitated mixture of saline and Renografin (meglumine diatrizoate) provided consistent myocardial opacification and satisfactory outline of acutely ischemic and dysfunctioning myocardium in two-dimensional crosssectional images, we undertook to eva...

Reproducibility of Intravenous Intermittent Triggered Myocardial Contrast Echocardiography in Healthy Subjects

“…The agreement of myocardial opacification between the first and second studies was 87/114 (76%). However, significantly higher peak intensity was obtained in apical septal (8200 ± 6300 au 2 ) and mid septal (8500 ± 6000 au 2 ) segments in the 4 chamber view and in the mid inferior (12400 ± 9300 au 2 ) and apical inferior (10700 ± 6300 au 2 ) segments in the 2 chamber view compared with other segments. The mean differences of the peak intensities according to the Bland and Altman analysis was -1600 ± 5000 au 2 in the intraobserver reproducibility study, and -1100 ± 5300 au 2 in the interinjection reproducibility study.…”

“…The mean differences of the peak intensities according to the Bland and Altman analysis was -1600 ± 5000 au 2 in the intraobserver reproducibility study, and -1100 ± 5300 au 2 in the interinjection reproducibility study. Thus, the measurement error was determined to range from 8400 au 2 to 9500 au 2 in both studies. We conclude that the peak intensity obtained from intravenous intermittent triggered myocardial contrast echocardiography using Levovist varies significantly among segments in the left ventricular myocardium.…”

Short History of The Development of Echocardiograpy With Special Reference to That in Japan (2)

“…Contrast echocardiography has been applied for imaging of blood flow, diagnosing congenital malformation, identifying endocardial surface, enhancing the Doppler signal, etc. However people specialized in contrast echocardiography have been interested in the visualization of myocardial perfusion [116][117][118][119][120]. This new trend might have been due to the influence of the progress of coronary interventional therapies.…”

Myocardial perfusion by contrast echocardiography. Establishment of normal pattern of intracoronary injection and safety in humans

“…Contrast echocardiography using sonicated agents (microbubbles) injected into the coronary arteries during coronary angiography is a new technique that can be used to demonstrate perfusion in the coronary artery territory [1][2][3][4][5][6] and therefore, to detect perfusion abnormalities due to coronary artery obstructions [7][8][9][10][11][12] .…”

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Original ArticleContrast echocardiography using sonicated agents (microbubbles) injected into the coronary arteries during coronary angiography is a new technique that can be used to demonstrate perfusion in the coronary artery territory [1][2][3][4][5][6] and therefore, to detect perfusion abnormalities due to coronary artery obstructions [7][8][9][10][11][12] .Although there are several studies on the use of this technique to evaluate myocardium at risk 2, 13-14 , myocardial viability [15][16][17][18] , presence of collaterals [19][20][21] , the results of angioplasty 22,23 , and of myocardial revascularization surgeries 24 , few studies have been performed to define the normal pattern of the appearance and distribution of contrast in humans without significant obstruction of the epicardial arteries. As far as we know from the literature reviewed at the time of the present study, studies performed to establish the normal perfusion pattern and the safety of this technique involved only a small number of patients.

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