Dr. Zoghbi noted echocardiography is valuable when the admission differential diagnosis includes aortic dissection or pericarditis. After admission, echocardiography may be used to diagnose complications. Most of the presentation, however, focused on echocardiography in the setting of pre-discharge risk stratification. In this context, Dr. Zoghbi mentioned at rest and stress testing, especially with use of dobutamine.

Dr. Zoghbi opened by noting that echocardiography can be important before admission when the electrocardiogram is not definitive and the differential diagnosis includes aortic dissection or pericarditis. After admission to a coronary care unit, echocardiography may be useful in the diagnosis of mechanical or hemodynamic complications such as mitral regurgitation or effusion with tamponade.

Most of the presentation focused on the role of echocardiography in pre-discharge risk stratification of patients who have had an uncomplicated infarction. Dr. Zoghbi noted that physicians who want to do an evaluation at rest and with stress can now obtain both with echocardiographic assessment.

Testing at rest provides information on several prognostic factors: ejection fraction, degree of left ventricular remodeling (with increased end systolic volume or end diastolic volume), and mitral flow velocity (with increased filling pressure by Doppler). Testing at rest also allows physicians to check for multiple vessel disease and signs of residual ischemia.

Stress testing with dobutamine infusion allows the physician to evaluate contractile reserve (at lower doses) and residual viability and ischemia (at near maximal doses).

In an Italian series of over 8000 patients (Nicolosi, 1996), echocardiography at a mean time of 12 days post-infarction was found to be safe and was predictive for unstable angina, recurrent infarction, or death. Evaluation was primarily done with high-dose dobutamine evaluating for wall motion abnormalities indicative of ischemia.

A study by Carlos and colleagues with roughly 200 patients demonstrated that the predictive power of resting/stress echocardiography (the latter with low-dose and high-dose dobutamine infusion) was superior to that of the combination of electrocardiogram, clinical data, and resting ventricular function.

Dr. Zoghbi also mentioned that the value of echocardiography may vary depending on the primary therapy for the infarction itself. He stated that the value of the imaging technique for patients who have had thrombolytic therapy is generally very high. It is generally lower for patients who have had angioplasty except in cases where the physician is looking for additional coronary artery disease.

He concluded by mentioning that the future of contrast echocardiography is promising and includes roles in assessment of left ventricular function and myocardial perfusion.