Usefulness of transesophageal echocardiography in the assessment of aortic dissection.

The acute dissection of the ascending aorta requires prompt and reliable diagnosis to reduce the high risk of mortality; in addition, prognosis is influenced by long-term complications. The aim of this article is to discuss transesophageal echocardiography (TEE) and (1) its diagnostic accuracy in the presurgical evaluation of patients, (2) its role in reducing time of diagnosis and surgery, and (3) its ability to reduce hospital mortality. TEE has also been tested as a screening method in the postsurgical follow-up of these patients. The retrospective investigation concerns a sample of 80 cases of acute dissection of the aorta, submitted for surgical intervention from April 1986 to February 1999. TEE has allowed a precise estimation of aortic diameters and optimal visualization of intimal flap and tear entry with a fine distinction between true and false lumen. A direct comparison of the results of TEE and of transthoracic echocardiography has demonstrated that some elements (visualization of flap and diameters in descending aorta, sites of entry and reentry, direction of jet trough intimal tears, phasic intimal flap movement, diastolic collapse of flap on the valvular plane, false lumen thrombosis, coronary involvement, intramural hematoma, and aortic fissuration) were identified only by TEE, whereas other additional diagnostic elements (cardiac tamponade, aortic valve insufficiency, left ventricular function) show a similar pattern of significance. Routine employment of this method has confirmed a reduction of hospitalization time (about 1.5 hours of waiting time), and hospital mortality has changed from 42.8% to 17.3%. In the follow-up of patients operated on for aortic dissection, fundamental information may be obtained from TEE (assessment of the progression of thrombosis in the false lumen with its complete obliteration and modifications in aortic diameter with a consequent, possible worsening of aortic valve insufficiency). In conclusion, our study demonstrated that TEE may provide fast and efficient detection of acute aortic dissection. In the postsurgical follow-up, TEE has confirmed detection of major complications that can influence long-term prognosis and may be proposed as a method with easy access-one that is repeatable and inexpensive for the screening of aortic dissection surgical patients.

[Diagnostic and therapeutic strategies in post-infarct]. / Strategie diagnostiche e terapeutiche nel post-infarto.

It is of primary importance for the clinical cardiologist to keep in mind the parameters allowing an adequate prognostic stratification in post-infarct patients in view of making the best diagnostic and therapeutic choices. A diagnostic strategy, based on a pathophysiologic approach, should evaluate four aspects: spontaneous and stress-induced ischemia, myocardial viability, and ventricular arrhythmias. Spontaneous ischemia has an undefined prognostic value, especially in the thrombolytic era; therefore it seems reasonable to perform invasive procedures in patients who are not stabilized by an adequate medical therapy or with large jeopardized areas. In asymptomatic patients, a provocative stress test allows a more articulated decisional iter. It is preferably to perform the test by the most physiological exercise EKG, together with the echocardiographic imaging, after the acute phase. It has a high negative predictive value, but a low positive predictive value. The detection of myocardial viability is frequently performed, mainly in patients with large post-ischemic myocardial dysfunction. Among all the proposed methods, the echo-dobutamine test mainly allows to estimate patients in whom revascularization may result in more benefit. The role of ventricular arrhythmias as an independent prognostic factor is debated and has to be always considered in relationship to other parameters, particularly left ventricular function. Regarding the therapeutic strategy, the indications from recent trials, related to antithrombotic drugs, beta-blockers, ACE-inhibitors, nitrates, Ca-blockers and antiarrhythmic drugs, are emphasized.