PREFACE

Abstract

Echocardiography is a dynamic technology that has extended beyond its traditional role as a portable diagnostic modality from the transthoracic approach. The early potential of this imaging tool was evident but limited by existing imaging capabilities. As technology progressed, hardware and software developments improved the acoustic window. However, the arrival of transesophageal echocardiography (with color-flow Doppler echocardiography) overcame most of the earlier inherent difficulties and greatly enhanced its imaging potential. Transesophageal echocardiography now offered a very powerful diagnostic and monitoring tool for the physician(s) in the cardiac surgical operating room. This was especially evident in diagnosing myocardial ischemia (regional wall motion abnormalities) and assessment of ventricular performance and preload. The appearance of transesophageal echocardiography revolutionized the approach to patients with valvular heart disease (native and prosthetic), both preoperatively and intraoperatively. This was particularly apparent in patients with mitral valve disease in which surgical decisions were altered from the information obtained from transesophageal echocardiography. A new team (cardiologists, anesthesiologists, and cardiac surgeons) was formed focusing on transesophageal echocardiography.This imaging modality of great diagnostic potential affecting patient care could not be limited just to outpatient or intraoperative settings. Extending from the operating room to the emergency department and intensive care environment was the next obvious step. These acute critically ill patients could only benefit from its use. Accurate and expeditious decisions must be made in these environments. Transesophageal echocardiography can assist in the most fundamental of all questions dealing with these patients, for example, preload and ventricular performance. Treatment can be initiated and altered by its use. In the hemodynamically compromised patient, contrasting pathologic states (severe left ventricular dysfunction, pericardial tamponade, and severe hypovolemia) can have similar and misleading clinical findings. Transesophageal echocardiography can immediately delineate these pathologies.Aortic disease is not unknown to the intensivist. Transesophageal echocardiography can easily evaluate the aorta for acute dissection or aneurysm by passing more invasive studies. In the acute traumatic situation, identification of aortic injury is crucial. In the initial examination (ER or ICU), a complete interrogation may identify this life-threatening pathology. Even though atherosclerotic disease is well known it was not totally appreciated until the advent of transesophageal echocardiography. Its extent, including debris of the aorta, is now recognized as an embolic source for central and peripheral end-organ damage.Other embolic sources are now being recognized by transesophageal echocardiography (i.e., atrial and atrial appendage thrombi, vegetations and thrombi associated with prosthetic valves, especially in the mitral valve position). The association and development of intracardiac thrombi in patients with atrial fibrillation, mitral stenosis, and atrial septal aneurysm are depicted better than by transthoracic echocardiography. Patent foramen ovale may be a harbinger for hypoxia and paradoxical embolization and its extent is now being appreciated by transesophageal echocardiography, especially in the critically ill when loading conditions on the atria, both mechanical and physiologic, can amplify the right-to-left shunt. Pulmonary embolism is a disease entity that continues to perplex us in its diagnosis. Transesophageal echocardiography may identify the hemodynamic effects of pulmonary embolism or even the presence of the thrombi.Transesophageal echocardiography can delineate most valvular defects. Besides the anatomic description (normal versus abnormal), the physician must totally understand the normal progression of valvular heart disease, the technical aspects in its interpretation, and the principles of Doppler and color-flow echocardiography.Several studies have shown the efficacy of transesophageal echocardiography in the critically ill. Overall, the management has been altered in 17% to 60% of the cases whereas surgical intervention was instituted in 18% to 29% of them. In a retrospective study, the information obtained from the pulmonary artery catheter was significantly less useful than the information provided by transesophageal echocardiography. Altogether, approximately 40% to 50% of the patients studied with transesophageal echocardiography will have beneficial information that may assist in their management.This issue deals with most of the pathologies that present to the intensivist in which transesophageal echocardiography can be beneficial. A basic anatomic description, as well as the pitfalls in the interpretation of echocardiography, is presented. Echocardiography or transesophageal echocardiography is not inclusive but ever changing. Thus, this field does incorporate intravascular and intracardiac echocardiography and stress echocardiography with discussion of tissue characterization. As the development of contrast agents continues, it will not be limited just to the heart, but to other organs (i.e., the kidney and the liver). Computer software and hardware development will have a major effect on echocardiography (three-dimensional reconstruction) and directly affect the intensivist's understanding of volume and ventricular performance. Is the construction pressure/volume relationship possible with echocardiography? In the editor's opinion, the answer is "Yes."Echocardiography in congenital heart disease was not bypassed by this editor. Unfortunately, because of logistic reasons, this topic is not presented. A major pathology in which transesophageal echocardiography has greatly influenced diagnosis and management is aortic disease. This article will be presented by Professor Raimund Erbel in a later issue of Critical Care Clinics.Transesophageal echocardiography has extended beyond the operating room suite to the intensive care environment where a new team now encompasses the intensivist. Transesophageal echocardiography should be one of the diagnostic instruments used and initiated by the intensivist. They (the critical care physicians) should be part of an institution's echocardiography team in which they are immediately available. However, each physician should be adequately trained so that a high-quality and efficient service can be rendered to the patient, especially in the ever-changing health care atmosphere. There is a continued explosion of information with echocardiography (transesophageal echocardiography), and the physician is challenged with this new field and its application. The outcome of patients can be altered from its use. This issue only touches the surface; however. it provides at least a basis for further knowledge.BibliographyFeigenbaum H: Echocardiography, ed 5. Malvern, Lea & Febiger, 1994Foster E, Schiller NB: The role of transesophageal echocardiography in critical care: USCF experience. J Am Soc Echocardiogr 5:368, 1992Heidenreich P, Stainback R, Redberg R, et al: Transesophageal echocardiography predicts mortality in critically ill patients with unexplained hypotension. J Am Coll Card 26:152, 1995Hwang J, Shyu K, Chen J, et al: Usefulness of transesophageal echocardiography in the treatment of critically ill patients. Chest 104:861, 1993Khoury AF, Afridi I, Quinones MA, et al: Transesophageal echocardiography in critically ill patients: Feasibility, safety, and impact on management. Am Heart J 127:1363, 1994Oh JK, Seward JB, Khandheria BK, et al: Transesophageal echocardiography in critically ill patients. Am J Cardiol 66:1492, 1990Pavlides GS, Hause AM, Stewart JR, et al: Contribution of transesophageal echocardiography to patient diagnosis and treatment: A prospective analysis. Am Heart J 120:910, 1990Pearson AC, Castello R, Labovitz AJ, et al: Safety and utility of transesophageal echocardiography in the critically ill patient. Am Heart J 119:1083, 1990Poelart JI, Trouerbach J, De Buyzere M, et al: Evaluation of transesophageal echocardiography as a diagnostic and therapeutic aid in critical care setting. Chest 107:774, 1995Porembka DT: Transesophageal echocardiography in the critically ill. Critical Care: State of the Art, vol 15. Anaheim, CA, Society of Critical Care Medicine, 1995, p 269Sohn D, Shin G, Oh J, et al: Role of transesophageal echocardiography in hemodynamically unstable patients. Mayo Clin Proc 70:925, 1995Vignon P, Mentec H, Terre S, et al: Diagnostic accuracy and therapeutic impact of transthoracic and transesophageal echocardiography in mechanically ventilated patients in the ICU. Chest 106:1829, 1994Weyman AE: Principles and Practice of Echocardiography, ed 2. Malvern, Lea & Febiger, 1994Wolfe LT, Rossi A, Ritter SB: Transesophageal echocardiography in infants and children: Use and importance in the cardiac intensive care unit. J Am Soc Echocardiogr 6:286, 1993 Echocardiography is a dynamic technology that has extended beyond its traditional role as a portable diagnostic modality from the transthoracic approach. The early potential of this imaging tool was evident but limited by existing imaging capabilities. As technology progressed, hardware and software developments improved the acoustic window. However, the arrival of transesophageal echocardiography (with color-flow Doppler echocardiography) overcame most of the earlier inherent difficulties and greatly enhanced its imaging potential. Transesophageal echocardiography now offered a very powerful diagnostic and monitoring tool for the physician(s) in the cardiac surgical operating room. This was especially evident in diagnosing myocardial ischemia (regional wall motion abnormalities) and assessment of ventricular performance and preload. The appearance of transesophageal echocardiography revolutionized the approach to patients with valvular heart disease (native and prosthetic), both preoperatively and intraoperatively. This was particularly apparent in patients with mitral valve disease in which surgical decisions were altered from the information obtained from transesophageal echocardiography. A new team (cardiologists, anesthesiologists, and cardiac surgeons) was formed focusing on transesophageal echocardiography. This imaging modality of great diagnostic potential affecting patient care could not be limited just to outpatient or intraoperative settings. Extending from the operating room to the emergency department and intensive care environment was the next obvious step. These acute critically ill patients could only benefit from its use. Accurate and expeditious decisions must be made in these environments. Transesophageal echocardiography can assist in the most fundamental of all questions dealing with these patients, for example, preload and ventricular performance. Treatment can be initiated and altered by its use. In the hemodynamically compromised patient, contrasting pathologic states (severe left ventricular dysfunction, pericardial tamponade, and severe hypovolemia) can have similar and misleading clinical findings. Transesophageal echocardiography can immediately delineate these pathologies. Aortic disease is not unknown to the intensivist. Transesophageal echocardiography can easily evaluate the aorta for acute dissection or aneurysm by passing more invasive studies. In the acute traumatic situation, identification of aortic injury is crucial. In the initial examination (ER or ICU), a complete interrogation may identify this life-threatening pathology. Even though atherosclerotic disease is well known it was not totally appreciated until the advent of transesophageal echocardiography. Its extent, including debris of the aorta, is now recognized as an embolic source for central and peripheral end-organ damage. Other embolic sources are now being recognized by transesophageal echocardiography (i.e., atrial and atrial appendage thrombi, vegetations and thrombi associated with prosthetic valves, especially in the mitral valve position). The association and development of intracardiac thrombi in patients with atrial fibrillation, mitral stenosis, and atrial septal aneurysm are depicted better than by transthoracic echocardiography. Patent foramen ovale may be a harbinger for hypoxia and paradoxical embolization and its extent is now being appreciated by transesophageal echocardiography, especially in the critically ill when loading conditions on the atria, both mechanical and physiologic, can amplify the right-to-left shunt. Pulmonary embolism is a disease entity that continues to perplex us in its diagnosis. Transesophageal echocardiography may identify the hemodynamic effects of pulmonary embolism or even the presence of the thrombi. Transesophageal echocardiography can delineate most valvular defects. Besides the anatomic description (normal versus abnormal), the physician must totally understand the normal progression of valvular heart disease, the technical aspects in its interpretation, and the principles of Doppler and color-flow echocardiography. Several studies have shown the efficacy of transesophageal echocardiography in the critically ill. Overall, the management has been altered in 17% to 60% of the cases whereas surgical intervention was instituted in 18% to 29% of them. In a retrospective study, the information obtained from the pulmonary artery catheter was significantly less useful than the information provided by transesophageal echocardiography. Altogether, approximately 40% to 50% of the patients studied with transesophageal echocardiography will have beneficial information that may assist in their management. This issue deals with most of the pathologies that present to the intensivist in which transesophageal echocardiography can be beneficial. A basic anatomic description, as well as the pitfalls in the interpretation of echocardiography, is presented. Echocardiography or transesophageal echocardiography is not inclusive but ever changing. Thus, this field does incorporate intravascular and intracardiac echocardiography and stress echocardiography with discussion of tissue characterization. As the development of contrast agents continues, it will not be limited just to the heart, but to other organs (i.e., the kidney and the liver). Computer software and hardware development will have a major effect on echocardiography (three-dimensional reconstruction) and directly affect the intensivist's understanding of volume and ventricular performance. Is the construction pressure/volume relationship possible with echocardiography? In the editor's opinion, the answer is "Yes." Echocardiography in congenital heart disease was not bypassed by this editor. Unfortunately, because of logistic reasons, this topic is not presented. A major pathology in which transesophageal echocardiography has greatly influenced diagnosis and management is aortic disease. This article will be presented by Professor Raimund Erbel in a later issue of Critical Care Clinics. Transesophageal echocardiography has extended beyond the operating room suite to the intensive care environment where a new team now encompasses the intensivist. Transesophageal echocardiography should be one of the diagnostic instruments used and initiated by the intensivist. They (the critical care physicians) should be part of an institution's echocardiography team in which they are immediately available. However, each physician should be adequately trained so that a high-quality and efficient service can be rendered to the patient, especially in the ever-changing health care atmosphere. There is a continued explosion of information with echocardiography (transesophageal echocardiography), and the physician is challenged with this new field and its application. The outcome of patients can be altered from its use. This issue only touches the surface; however. it provides at least a basis for further knowledge. Bibliography Feigenbaum H: Echocardiography, ed 5. Malvern, Lea & Febiger, 1994 Foster E, Schiller NB: The role of transesophageal echocardiography in critical care: USCF experience. J Am Soc Echocardiogr 5:368, 1992 Heidenreich P, Stainback R, Redberg R, et al: Transesophageal echocardiography predicts mortality in critically ill patients with unexplained hypotension. J Am Coll Card 26:152, 1995 Hwang J, Shyu K, Chen J, et al: Usefulness of transesophageal echocardiography in the treatment of critically ill patients. Chest 104:861, 1993 Khoury AF, Afridi I, Quinones MA, et al: Transesophageal echocardiography in critically ill patients: Feasibility, safety, and impact on management. Am Heart J 127:1363, 1994 Oh JK, Seward JB, Khandheria BK, et al: Transesophageal echocardiography in critically ill patients. Am J Cardiol 66:1492, 1990 Pavlides GS, Hause AM, Stewart JR, et al: Contribution of transesophageal echocardiography to patient diagnosis and treatment: A prospective analysis. Am Heart J 120:910, 1990 Pearson AC, Castello R, Labovitz AJ, et al: Safety and utility of transesophageal echocardiography in the critically ill patient. Am Heart J 119:1083, 1990 Poelart JI, Trouerbach J, De Buyzere M, et al: Evaluation of transesophageal echocardiography as a diagnostic and therapeutic aid in critical care setting. Chest 107:774, 1995 Porembka DT: Transesophageal echocardiography in the critically ill. Critical Care: State of the Art, vol 15. Anaheim, CA, Society of Critical Care Medicine, 1995, p 269 Sohn D, Shin G, Oh J, et al: Role of transesophageal echocardiography in hemodynamically unstable patients. Mayo Clin Proc 70:925, 1995 Vignon P, Mentec H, Terre S, et al: Diagnostic accuracy and therapeutic impact of transthoracic and transesophageal echocardiography in mechanically ventilated patients in the ICU. Chest 106:1829, 1994 Weyman AE: Principles and Practice of Echocardiography, ed 2. Malvern, Lea & Febiger, 1994 Wolfe LT, Rossi A, Ritter SB: Transesophageal echocardiography in infants and children: Use and importance in the cardiac intensive care unit. J Am Soc Echocardiogr 6:286, 1993