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The introduction of digital echocardiography has significantly enhanced our ability to select the best set of frames for analysis. However, despite the beneficial attributes of transthoracic dobutamine stress echocardiography, poor quality 2-dimensional images continue to be a significant limiting factor in patients with chest deformities, severe chronic obstructive lung disease, marked obesity, and previous chest surgery. Transesophageal echocardiography provides a new window to monitor left ventricular contractility without the interference of bone and air-filled structures of the thoracic cage. The transesophageal dobutamine stress test is a logical but poorly explored modality to image/stress the heart in certain patients with known or suspected myocardial ischemia. Overall sensitivity (< or = 85%) and specificity (< or = 95-100%) of transesophageal dobutamine stress echocardiography appear to be similar to that of previous transthoracic studies, although no direct comparison has been accomplished between transthoracic and transesophageal stress images. False negative transesophageal dobutamine stress echocardiography results have been described in patients with single-vessel disease in whom ischemic regions may not have been visualized throughout the entire study. False positive study results may be present in patients with hypertension and myocardial hypertrophy that may have signs and symptoms of myocardial ischemia in absence of obstructive disease of the epicardial coronary arteries, presumably related to either microvascular disease or impaired vasodilatory reserve. The proportion of patients with coronary artery disease who need a transesophageal examination for reliable assessment of echocardiographic response to stress varies depending on the operators' skills, the interpreters' experience, and the use of videotape or digitizing systems for image analysis. Although clinically useful in its present transthoracic and transesophageal form, a major limitation of dobutamine stress echocardiographic study is the subjective visual interpretation of endocardial motion and wall thickening, which is only semiquantitative. Color kinesis and tissue Doppler imaging (TDI) are 2 novel echocardiographic techniques that color code endocardial motion and myocardial velocity online and have the potential to objectively quantify regional left ventricular function. Quantitative standardization of transthoracic and transesophageal data interpretation, such as establishing endocardial motion by color kinesis or velocity thresholds by TDI for an abnormal segmental response to stress, has the potential to decrease interobserver variability and increase interinstitutional agreement. [ABSTRACT FROM AUTHOR]

The clinical arena in which we must consider the role of echocardiography is characterized by 2 fundamental findings: (1) most patients with chest pain and suspected acute myocardial infarction (MI) do not present diagnostic electrocardiograms; and (2) an early and correct diagnosis is necessary to match the patient with the most adequate treatment. Echocardiography may be very useful in the coronary care unit, allowing a correct diagnosis of ischemic heart disease when electrocardiography is unclear, even before the rise of cardiac enzymes is detected. It may also play a role in decision-making for thrombolytic therapy. In addition, echocardiography provides useful information for early risk stratification. In fact, although high-risk patients are well identified by simple clinical or instrumental variables (i.e., Killip classification, enzymatic data, blood-gas analysis, electrocardiogram, etc.), most patients (>60%) are identified as low risk, and several subjects classified into the low-risk groups have a poor prognosis and are not detected using a single variable. In our experience, 2-dimensional echocardiography was able to further stratify between patients of low-risk classes. Therefore, echocardiography plays an important role in the early stratification of acute MI patients, especially in those without signs or symptoms of heart failure.

The available data suggest that digitalis improves symptoms of a failing heart in the presence of sinus rhythm as well as supraventricular arrhythmias. Intravenous digitalis administration in patients with chronic heart failure and baseline hemodynamic deterioration increases cardiac index and reduces heart rate. These beneficial effects are maintained with long-term oral therapy and are comparable with those obtained using dobutamine in patients with chronic severe heart failure. The addition of digoxin to therapy with vasodilators and diuretics confers clinical benefit in patients with moderate to severe heart failure symptoms because of systolic ventricular dysfunction. Digoxin effects on diastolic function appear to be different in patients with preserved systolic function in comparison to patients with overt heart failure and systodiastolic dysfunction. In patients with right ventricular dysfunction digoxin does not appear to influence hemodynamic measurements unless concomitant left ventricular dysfunction is present.

9 patients with persistent truncus arteriosus, 11 patients with pseudotruncus and 2 patients with hemitruncus, ranging in age from 6 months to 29 years, have been studied by M-mode and two-dimensional echocardiography (2-D echo). In all patients the diagnosis was confirmed by cardiac catheterization and angiocardiography; in 10 of them surgical or autopsy documentation was available. Peripheral contrast echocardiography was performed in 13 patients. A variable degree of truncal or aortic override was observed in 7 of 9 patients with truncus arteriosus and in all patients with pseudotruncus by M-mode or two-dimensional echocardiography. By 2-D echo the truncal origin of the right and left pulmonary arteries was visualized in 7 of 9 of the patients with truncus arteriosus. Visualization of one aberrant pulmonary artery from the aortic wall was assessed retrospectively in 2 patients with hemitruncus. A pulmonary atretic valve region was recorded in 10 of 11 of the patients with pseudotruncus. Peripheral contrast echocardiography enabled to distinguish patients with complete obstruction to pulmonary flow from patients with unobstructed right ventricular outflow tract. By showing no direct connection between the pulmonary arteries and the ascending aorta or direct continuity between one or both pulmonary arteries and truncal or aortic root, differentiation of pseudotruncus arteriosus from truncus or hemitruncus may be achieved by 2-D echo.