In this study, TEE provided critical information that was not obtained by TTE in 39 of 78 studies (50 percent). There were two failed TEE attempts. Cardiac surgery was prompted by TEE findings in 14 patients (18 percent) and these findings were all confirmed at operation. There were no major compliDue to the proximity of the heart and esophagus, TEE has proved to be very useful in the diagnosis of various cardiac diseases. The safety has also been documented. However, it was rarely evaluated in the treatment of critically ill patients for whom prompt and accurate diagnoses were important. The most common indication for TEE in our study was the evaluation of aortic dissection. We proved TEE to have greater sensitivity in the diagnosis of aortic dissection than that of TTE, consistent with recent reports. Cardiac surgery was performed in five patients with aortic dissection and hypotension after the TEE study without other examinations. Accurate and rapid diagnoses are critical to these patients when hemodynam-ically unstable. They were too critically ill to be removed from the ICU. In this regard, TEE was superior to other examinations such as computed tomography, magnetic resonance imaging, and aortography, because not only could TEE be performed quickly and safely at bedside without moving the patient or injecting contrast media, but TEE also could provide accurate information about the site and number of intimal tears and branch involvement of dissection important in surgical planning.
Ruling out aortic dissection in patients with acute severe chest pain becomes increasingly important in the era of thrombolytic therapy for acute myocardial infarction. Thrombolytic therapy is beneficial in most cases of acute myocardial infarction, but it is contraindicated in dissection-related myocardial infarction because of catastrophic pericardial hemorrhage. In our study, there was no false-negative diagnosis of aortic dissection by TEE. Therefore, TEE leads to a clinically relevant improvement in the diagnostic potential in patients in whom aortic dissection is suspected or has to be excluded to ensure the safety of thrombolytic therapy. Long-Term Hemodialysis
The second most common indication for the use of TEE in our study was hemodynamic instability. Various cardiac problems responsible for hemodynamic deterioration were readily diagnosed by TEE such as severe mitral regurgitation due to ruptured chordae tendineae and periprosthetic leakage, mechanical valve obstruction with thrombus, patent ductus arteriosus, right-to-left shunt following right ventricular infarction, and postoperative leakage of graft.