Correlation between left ventricular risk area and clinical, electrocardiographic, hemodynamic, and angiographic variables during acute myocardial infarction

The Role of Echocardiography in Acute Myocardial Infarction

The indications for echocardiography in the setting of acute myocardial infarction are to identify wall motion abnormalities, to evaluate left and right ventricular function, and to exclude complications such as pericarditis, mitral regurgitation, and ventricular rupture. Doppler echocardiography can provide important hemodynamic information. In the near future, contrast echocardiography can be expected to delineate myocardial perfusion and three-dimensional echocardiography to better define infarct size.

Myocardial viability on echocardiography predicts long-term survival after revascularization in patients with ischemic congestive heart failure

OBJECTIVES

This study was conducted to evaluate the effect of revascularization on survival in patients with congestive heart failure (CHF) due to ischemic left ventricular (LV) systolic dysfunction based on the presence of myocardial viability (MV).

BACKGROUND

There are insufficient data regarding the survival benefit of revascularization in patients with CHF due to ischemic LV systolic dysfunction.

METHODS

Follow-up was obtained in 87 consecutive patients with CHF due to ischemic LV systolic dysfunction (New York Heart Association [NYHA] class II-IV; LV ejection fraction <0.35) who underwent low-dose dobutamine echocardiography (DE). MV within each of 12 myocardial segments representing the LV was defined as having either: 1) normal function or mild dyssynergy at rest; 2) severe resting dyssynergy that improved on DE, or 3) worsening of function on DE except in the case of akinesia.

RESULTS

At a mean follow-up of 40+/-17 months, 37 patients had received revascularization on the basis of clinical grounds, and there were 22 (25%) cardiac-related deaths. Multivariate Cox regression analysis revealed that when patients with at least five segments showing MV underwent revascularization, mortality was reduced by an average of 93% (confidence interval of 22% to 99%), which was associated with improvement in NYHA class as well as LV ejection fraction. Patients with less than five segments showing MV who underwent revascularization (and thus, showing mostly scar), and those with at least 5 segments demonstrating MV who were treated medically, had a much higher mortality.

CONCLUSIONS

Revascularization produces a clear survival benefit in patients with CHF due to ischemic LV systolic dysfunction who have a significant region of the LV demonstrating MV. These data may have wide-ranging implications in the management of patients with coronary artery disease whose main clinical presentation is CHF.

Value of two-dimensional echocardiography for determining the basis of hemodynamic compromise in critically ill patients: a prospective study

We postulated that because the first step in the management of critically ill patients with hypotension, pulmonary edema, or both is to determine whether the cause is cardiac or noncardiac, direct visualization of the heart with two-dimensional echocardiography would be useful for determining the basis of hemodynamic compromise in such patients. Accordingly, 49 consecutive patients (33 men and 16 women; mean age 61 +/- 15 years) underwent two-dimensional echocardiography within 2 hours of placement of a pulmonary artery flotation catheter for determining the reason for hypotension, pulmonary edema, or both. To discriminate between cardiac and noncardiac causes, hemodynamic and two-dimensional echocardiographic data were evaluated independently by two to three blinded interpreters based on predetermined criteria. There was complete agreement between pulmonary artery catheter and two-dimensional echocardiographic data in 36 (86%) of the 42 patients in whom interpretable data were available in terms of cardiac versus noncardiac causes. The two modalities agreed in all patients with hypotension alone and disagreed in 2 of the 20 patients with pulmonary edema alone and 4 of the 14 patients with combined hypotension and pulmonary edema. In cases of discordance, the two tests provided complimentary information, particularly in patients with sepsis in whom the stroke volume may be normal to high but left ventricular systolic function may be depressed. The time taken for pulmonary artery catheter placement was 63 +/- 45 minutes versus 19 +/- 7 minutes for two-dimensional echocardiography.(ABSTRACT TRUNCATED AT 250 WORDS)

Role of Doppler echocardiography in coronary artery disease

Doppler echocardiography can have a major role in the evaluation of patients with coronary artery disease. This review deals with the imaging planes in relation to coronary vascular territories and the role of Doppler echocardiography in evaluating patients with acute and chronic ischemic syndromes.

Assessment of myocardial perfusion with contrast two-dimensional echocardiography

Myocardial contrast echocardiography (MCE) is a new technique capable of assessing regional myocardial perfusion in vivo in real time. At present, this technique involves the intraaortic or intracoronary injection of microbubbles of air. As these microbubbles traverse the myocardium, they produce opacification of the myocardium in concomitantly performed echocardiographic images. In animal models, MCE has been demonstrated to assess accurately the in vivo risk area (region of the myocardium at risk for necrosis after acute coronary occlusion). It has also been shown to provide quantitative information on regional myocardial blood flow (both antegrade and collateral). This technique has been demonstrated to be safe in humans. In clinical studies it has been shown to be a useful adjunct to cardiac catheterization, particularly in the assessment of coronary blood flow reserve and collateral blood flow. MCE is also used in the operating room to assess regional myocardial perfusion before and after bypass graft operations. The microbubbles used for MCE were shown to opacify the left ventricular cavity after their injection into a peripheral vein. If myocardial opacification after venous injection can be achieved, MCE will have the potential for the simultaneous noninvasive in vivo assessment of regional myocardial perfusion and function in humans.