An echocardiogram is an ultrasound technique used to gather information about the heart.
Standard echocardiograms create images of the heart in two dimensions, thereby named 2D
(two-dimensional) echocardiography. A new technique has been developed allowing images to
be taken of the heart in three dimensions (real time 3D echocardiography).
The 3D echocardiogram uses high frequency sound waves to see and record the movement and
function of the heart muscle. The echocardiogram is taken by placing an instrument called a
transducer against the chest wall over the heart.
In this study patients will undergo a dobutamine stress echocardiogram. Dobutamine is drug
that causes the heart to beat stronger and faster, similar to how it acts when exercising.
Dobutamine allows researchers to tell if the heart is suffering from a lack of oxygen during
exercise or other forms of stress, or if it is permanently damaged.
The purpose of this study is to determine whether stress 3D echocardiography is feasible and
accurate in the detection of heart disease (coronary artery disease). Results of the 3D
echocardiogram will be compared to results from standard 2D echocardiograms.
Stress echocardiography has become a valuable technique for the non-invasive detection of
coronary artery disease. Its accuracy has been shown to be superior to that of the exercise
electrocardiogram and comparable to that of myocardial perfusion imaging. The adequacy of
stress echocardiography with conventional two-dimensional imaging, however, is highly
dependent on operator expertise. Further, interpretation of test results is subjective and
qualitative, and is based on analysis of wall motion after arbitrary segmentation of the
left ventricle. Real time 3-dimensional (RT3D) echocardiography is a new technique that
permits the unrestricted assessment of left ventricular wall motion and function in a single
cardiac beat without ECG or respiratory gating. We hypothesize that RT3D echocardiography
will have similar or greater accuracy for the detection of wall motion abnormalities
compared to the conventional two-dimensional examination. We therefore propose to acquire
RT3D echocardiographic images in patients with known or suspected coronary artery disease
who undergo stress echocardiography. We will correlate these results with findings from
coronary angiography and compare the ability of RT3D echocardiography to detect coronary
artery disease with that of the conventional two-dimensional exam.
Patients older than 18 years of age with known or suspected coronary artery disease who
agree to undergo stress echocardiography and have undergone or will undergo coronary
angiography within 3 months of the stress echocardiogram.
No pre-menopausal patients who are lactating, are pregnant or potentially pregnant as
judged by history, physical examination, ultrasound or urine pregnancy test.
No unstable angina.
No recent myocardial infarction (less than 1 month).
No ventricular ectopy during baseline conditions (i.e., couplets, frequent PVC's [greater
than 6/min], early coupling ["R-on-T" phenomenon], ventricular bigeminy) that might
potentially predispose the patient for the development of dangerous dysrhythmias during
No congestive heart failure.
No significant hypertension (systolic blood pressure greater than 170 mmHg) or hypotension
(systolic blood pressure less than 100 mmHg).
No sinus tachycardia greater than 100 beats/min.
No other acute medical illness.
No atrial fibrillation, or inadequate two-dimensional echocardiographic windows.