Myocardial Contrast Echocardiography

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					                                                                           Cardiac Imaging        ECHOCARDIORAPHY

                                                                Myocardial Contrast Echocardiography

       a report by
       E r i c H C Yu , M D , M E d , F R C P ( C ) , F A C C

       Associate Director of Echocardiography, University Health Network, University of Toronto

Contemporary approved echo contrast agents share a              the evaluation of left ventricular and valvular           Eric H C Yu, MD, MEd, FRCP(C),
                                                                                                                          FACC, is Associate Director of
common approved indication of left ventricular                  function.The opacification of the blood pool also aids
                                                                                                                          Echocardiography at the University
opacification and enhancement of endocardial border             in the structural assessment of cardiovascular anatomy.   Health Network and Assistant
delineation for the assessment of left ventricular              Clear identification of the endocardial borders helps     Professor of Medicine at the
                                                                                                                          University of Toronto. He also holds
function in patients with technically suboptimal                to facilitate the diagnosis of left ventricular
                                                                                                                          the position of Director of the
echocardiograms (ECGs). The use of echo contrast                hypertrophy and the apical variant of hypertrophy         Training Program in Adult
agents with advanced imaging technologies has resulted          associated with hypertrophic cardiomyopathy.              Cardiology at the same university.
in the conversion of many non-diagnostic ECGs to
those of diagnostic quality. The use of echo contrast           Complications of myocardial infarction (MI) have
agents for left ventricular opacification has been shown        been demonstrated using echo contrast, including
to be particularly useful in situations in which standard       myocardial rupture, pseudoaneurysm, and aneurysm
echocardiographic imaging is technically the most               formation. The identification of intracardiac masses,
challenging, including obesity, chronic pulmonary               including tumors and thrombi, left ventricular non-
disease, critically ill patients on respirators, and image      compaction, and a variety of abnormalities of right
acquisition during stress echocardiography.                     ventricular morphology (including right ventricular
                                                                dysplasia, right ventricular tumor and thrombi), has
The accurate assessment of left ventricular ejection            been facilitated with the use of echo contrast agents.
fraction is important because it provides important             Echo contrast agents can also help to improve
prognostic information in the evaluation and                    visualization of the right ventricle and great vessels.
management of patients with cardiovascular disease.
Accurate evaluation of regional and global ventricular          Echo contrast agents have added a new dimension to
function by echocardiography is dependent upon                  the role of ultrasound imaging in cardiology, and help
adequate endocardial border definition. While native            physicians to provide better and safer patient care. ■
tissue harmonic imaging enables better endocardial
definition than standard fundamental imaging and
reduces the number of patients with inadequate                      Contrast Echocardiography—
studies, contrast-enhanced left ventricular opacification           The Opportunities
confers additional benefits.                                        • Enhance Doppler studies:
                                                                      – Tricuspid regurgitation, aortic stenosis,
The use of echo contrast agents has helped to improve                   pulmonary vein flow.
the accuracy of ventricular function and volume                     • Enhance endocardial definition:
measurement by echocardiography in the assessment of                  – Difficult patients;
left ventricular function compared with standard and                  – Stress echo: major role.
fundamental imaging, and is comparable in accuracy                  • Delineate anatomy:
with current gold standard techniques such as magnetic                – Thrombus;
resonance imaging and radionuclide angiography. The                   – Fistulae, etc.
use of echo contrast agents improves the ability to                 • Myocardial perfusion:
identify and grade resting wall motion abnormalities,                 – Near future.
and provides superior endocardial visualization with                • Drug delivery:
stress echocardiography.The use of echo contrast agents               – Far future.
has resulted in an improvement in interobserver                     • Pressure measurement:
agreement, as well as physician confidence in qualitative             – Far future.
and quantitative measurements.                                      • Now reimbursed.
                                                                    • New agents becoming available.
Echo contrast agents are also useful in the                         • Equipment progressing fast.
enhancement of Doppler signals routinely used for                                                                                                        95


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