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UNLABELLED: Transesophageal echocardiography (TEE) may improve intraoperative decision-making and patient outcome if it is performed and interpreted correctly. After revising our TEE examination to fulfill the published guidelines for basic TEE practitioners, we prospectively evaluated the ability of our cardiac anesthesiologists (all very experienced with TEE) to record and interpret this revised examination. Educational aids and regular TEE performance feedback were provided to the anesthesiologists. Their interpretations were compared with the independently determined results of experts. Compared with their own historical controls (42% recording rate), all anesthesiologists showed significant improvement in their ability to record a basic intraoperative TEE examination resulting in 81% (P < 0.0001) of all required images being recorded: 88% before cardiopulmonary bypass, 77% immediately after bypass, and 64% after chest closure. Seventy-nine percent of the images recorded at baseline were correctly interpreted, 6% were incorrectly interpreted, and 15% were not evaluated. Our attempt to assess compliance with published guidelines for basic intraoperative TEE resulted in a marked improvement in our intraoperative TEE practice. Most, but not all, standard cross-sections are recorded or interpreted correctly, even by highly experienced and motivated practitioners. IMPLICATIONS: Experienced cardiac anesthesiologists can obtain and correctly interpret most basic intraoperative transesophageal echocardiograms.

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UNLABELLED: We tested the hypothesis that sevoflurane is a safer and more effective anesthetic than halothane during the induction and maintenance of anesthesia for infants and children with congenital heart disease undergoing cardiac surgery. With a background of fentanyl (5 microg/kg bolus, then 5 microg. kg(-1). h(-1)), the two inhaled anesthetics were directly compared in a randomized, double-blinded, open-label study involving 180 infants and children. Primary outcome variables included severe hypotension, bradycardia, and oxygen desaturation, defined as a 30% decrease in the resting mean arterial blood pressure or heart rate, or a 20% decrease in the resting arterial oxygen saturation, for at least 30 s. There were no differences in the incidence of these variables; however, patients receiving halothane experienced twice as many episodes of severe hypotension as those who received sevoflurane (P = 0.03). These recurrences of hypotension occurred despite an increased incidence of vasopressor use in the halothane-treated patients than in the sevoflurane-treated patients. Multivariate stepwise logistic regression demonstrated that patients less than 1 yr old were at increased risk for hypotension compared with older children (P = 0.0004), and patients with preoperative cyanosis were at increased risk for developing severe desaturation (P = 0.049). Sevoflurane may have hemodynamic advantages over halothane in infants and children with congenital heart disease. IMPLICATIONS: In infants and children with congenital heart disease, anesthesia with sevoflurane may result in fewer episodes of severe hypotension and less emergent drug use than anesthesia with halothane.

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BACKGROUND: Digital acquisition and storage of echocardiographic studies offer many advantages over analog recordings, but the amount of computer memory required may be large. "Computer compression" of data is done by machines with various algorithms. "Clinical compression" involves limiting the recordings to 1-beat loops, and although it is commonly used, its diagnostic validity has not been demonstrated in the operating room. METHODS: This prospective pilot study looked at 51 patients undergoing transesophageal echocardiography during cardiac surgery. During continuous videocassette recording, we captured digital loops to demonstrate wall motion abnormalities, ventricular systolic function, aortic insufficiency, and mitral regurgitation. Experts reviewed the loops and tapes. We then compared the diagnoses from the 2 methods. RESULTS: There were major differences in the diagnosis of wall motion between loops and tapes in only 3.4% of myocardial segments. No major differences were seen in the diagnosis of systolic function, aortic insufficiency, or mitral regurgitation in any patients. CONCLUSION: We conclude that clinical compression is a suitable method to compress data in the operating room. Large numbers of patients are required to definitively demonstrate the small differences.

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UNLABELLED: Mitral regurgitation (MR) is a major determinant of outcome in cardiac surgery. The location and mechanism of mitral lesions determine the approach to various repairs and their feasibility. Because of incomplete evaluations or change in patient condition, detailed intraoperative transesophageal echocardiography (TEE) examination of the mitral valve may be required. We hypothesized that a systematic TEE mitral valve examination would allow precise identification of the anatomic location and mechanism of MR in patients undergoing mitral surgery. We designed a systematic mitral valve examination consisting of six views: five-chamber, four-chamber, two-chamber anterior, two-chamber mid, two-chamber posterior and short-axis. We used this examination prospectively in 13 patients undergoing mitral valve surgery for severe MR and compared the results with the surgical findings. We then retrospectively interpreted 11 similar patients who had undergone intraoperative TEE studies before this examination. TEE correctly diagnosed the mechanism and precise location of pathology in 12 of 13 patients in the prospective group, but in only 6 of 10 patients in the retrospective group. TEE also correctly identified 75 of 78 mitral segments (96%) as being normal or abnormal. In the retrospective group, only 42 of 60 segments (70%) were correctly identified (P < 0.001). We conclude that this systematic TEE mitral valve examination improves identification of mitral segments and precise localization of pathologies and may also improve the diagnosis of the mechanism of MR. IMPLICATIONS: In this article, we describe how a systematic examination of the mitral valve by using transesophageal echocardiography allows identification of the different segments of the mitral valve, precise localization of pathology, and helps to diagnose the mechanism of mitral regurgitation. This is important in determining an approach to mitral valve repair and its feasibility.

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UNLABELLED: The role of inhaled nitric oxide in the immediate post-bypass period after surgical repair of congenital heart disease is uncertain. In a controlled, randomized, double-blind study, we tested the hypothesis that inhaled nitric oxide (NO) would reduce pulmonary hypertension immediately after surgical repair of congenital heart disease in 40 patients with preoperative evidence of pulmonary hypertension (mean pulmonary arterial pressure [MPAP] exceeding 50% of mean systemic arterial pressure [MSAP]). Patients were then followed in the intensive care unit (ICU) to document the incidence of severe pulmonary hypertension. Of the patients, 36% (n = 13) emerged from bypass with MPAP > 50% MSAP. In these patients, inhaled NO reduced MPAP by 19% (P = 0.008) versus an increase of 9% in the placebo group. No effect on MPAP was observed in patients emerging from bypass without pulmonary hypertension (n = 23). Inhaled NO was required five times in the ICU, always in the patients who had emerged from cardiopulmonary bypass with pulmonary hypertension (5 of 13 [38%] versus 0 of 23). We conclude that, in infants and children undergoing congenital heart surgery, inhaled NO selectively reduces MPAP in patients who emerge from cardiopulmonary bypass with pulmonary hypertension and has no effect on those who emerge without it. IMPLICATIONS: In a randomized double-blind study, inhaled nitric oxide selectively reduced pulmonary artery pressures in pediatric patients who developed pulmonary hypertension (high blood pressure in the lungs) immediately after cardiopulmonary bypass and surgical repair.

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INTRODUCTION: We hypothesized that simultaneous right and left ventricular apical pacing would result in improvement in left ventricular function due to improved coordination of segmental ventricular contraction. Structural changes in ventricular muscle present in dilated cardiomyopathy compromise ventricular excitation and mechanical contraction. METHODS AND RESULTS: Eleven patients with depressed left ventricular function having cardiac surgery underwent epicardial multisite pacing with continuous transesophageal echocardiographic imaging. Quantitative measurement of percent fractional area change was performed, and segmental changes in contraction sequence resulting from simultaneous right and left ventricular pacing were assessed by application of phase analysis to recorded transesophageal images. There was no statistically significant difference between the paced QRS duration achieved with simultaneous right and left ventricular apical pacing and the native QRS duration (139+/-39 msec vs 106+/-18 msec, P = NS), but all other paced modes resulted in longer QRS durations. Percent fractional area change improved with simultaneous right and left ventricular apical pacing but not with other paced modes (41.5+/-11.9 vs 34.3+/-9.7, P < 0.01). Phase analysis demonstrated a resequencing of segmental left ventricular activation/contraction when compared to baseline ventricular activation. CONCLUSION: Simultaneous right and left ventricular apical pacing results in acute improvements in global ventricular performance in patients with depressed ventricular function. Improvements may result from pacing-induced global coordination through recruitment of left and right ventricular apical and septal segments critical to effective ventricular contraction.

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UNLABELLED: New segmental wall motion abnormalities (SWMA) detected by echocardiography are considered sensitive and specific markers of myocardial ischemia. However, we have observed new SWMA during pacing-induced reductions in left ventricular filling, which resolved immediately with cessation of the atrial pacing and simultaneous restoration of filling. Therefore, we designed this study to determine whether acute reduction in filling can induce new SWMA in the absence of ischemia. Institution of cardiopulmonary bypass was used as a clinical model of acute reduction in filling, and a beat-by-beat analysis of left ventricular contraction, filling, blood pressures, and electrocardiogram was performed when the drainage of blood to the cardiopulmonary bypass machine rapidly emptied the heart. Acute reduction in filling induced new SWMA in 4 of 38 study patients. All 4 patients had preexisting abnormalities of left ventricular contraction, but translocation of these preexisting SWMA did not explain the new SWMA, nor did myocardial ischemia. We conclude that acute reduction in left ventricular filling can cause new SWMA in the absence of ischemia. This finding limits the usefulness of new SWMA as a marker of ischemia in the presence of acute reduction in filling, such as that secondary to severe hypovolemia. IMPLICATIONS: This study documented that acute reduction in cardiac filling can be associated with new systolic wall motion abnormalities detected by transesophageal echocardiography in the absence of documented myocardial ischemia. These findings indicate that segmental wall motion may not be a valid marker for ischemia in the setting of acute hypovolemia.

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A stress test that can be performed intraoperatively might be valuable for cardiac risk stratification in patients needing urgent noncardiac surgery and for early evaluation of coronary reserve in patients undergoing aortocoronary bypass surgery. Therefore, we evaluated the sensitivity and safety of rapid atrial pacing combined with electrocardiography and transesophageal echocardiography for inducing and detecting provokable demand ischemia in 20 anesthetized patients with multivessel coronary artery disease. Rapid atrial pacing induced ST segment changes or new segmental wall motion abnormalities (SWMA), which were defined as evidence of induced ischemia in 15 of the 20 patients. Unexpectedly, the new SWMA normalized during the first beat after abrupt cessation of pacing in three patients who did not show any ST segment changes. Simultaneously, left ventricular preload was severely decreased during pacing and recovered to baseline immediately when pacing was abruptly discontinued. Rapid atrial pacing was safe in all patients, but the target heart rate could not be achieved because of heart block or arterial hypotension in 4 of the 20 patients. These findings raise the question of whether rapid atrial pacing is the most appropriate approach for inducing provokable demand ischemia in anesthetized patients. However, its potential usefulness for predicting adverse cardiac outcomes has not been evaluated and would require larger studies. In addition, the immediate normalization of new SWMA after abrupt cessation of pacing in some patients calls into question the validity of new SWMA as evidence of myocardial ischemia when left ventricular preload is severely decreased.

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Because biplane and multiplane transesophageal echocardiography (TEE) are more complex and expensive than single-plane TEE, we performed this study to determine whether the use of multiple single-plane (transverse) cross sections is as reliable for detection of left ventricular segmental wall-motion abnormalities (SWMA) as biplane TEE. We used biplane TEE to acquire nine standard cross sections of the left ventricle in 41 consecutive adults undergoing cardiac or vascular surgery. Six of these cross sections were in the transverse plane (i.e., achievable with single-plane TEE) and three in the longitudinal plane (i.e., achievable only with biplane or multiplane TEE). Each cross section was divided into myocardial segments for analysis. A total of 1810 segments were analyzed by independent investigators using a standardized evaluation system. Seventeen percent of all SWMA detected in this study were in the midpapillary transverse-plane cross section, an additional 48% in other transverse-plane cross sections, and 35% exclusively in the longitudinal-plane cross sections. Thus, most (65%), but not all, SWMA were in cross sections achievable with single-plane TEE. We conclude that the MP-T cross section should be the foundation for assessment of segmental function, but additional cross sections in the transverse and longitudinal planes are required for detection of the majority of segmental wall-motion abnormalities.

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An infant with pulmonary atresia and intact ventricular septum is presented who, after initial patch reconstruction of the right ventricular outflow tract and bidirectional cavopulmonary anastomosis through a fifth median sternotomy, underwent an echocardiographically guided closed atrial septotomy, which resulted in marked long-term clinical improvement. The technique of intraoperative transesophageal echocardiography as used in the presented case represents an expanded role for this diagnostic modality in congenital cardiac surgery.

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This article evaluates the costs and outcomes associated with TEE during and after cardiac surgery. The costs include the direct and indirect costs--the complications of TEE. The outcomes include the positive consequences or the benefits: money and lives saved. The article uses liberal (high) estimates of the direct and indirect costs of TEE and conservative (low) estimates of the benefits. The exact cost or benefit depends on the number of cases performed. The analysis shows that patients having surgery for congenital heart disease derive the greatest overall benefit: around $600 per case studied. Patients having valvular repair surgery derive the next greatest benefit: around $450 per case studied. In contrast patients having valve replacement have an overall cost of around $150 per case studied. Patients having surgery for coronary artery disease also derive an overall benefit: around $100-$300 per case studied, depending upon assumptions regarding TEE's role in prevention of intraoperative strokes. This analysis indicates that the financial benefits of TEE are substantial and frequently outweigh costs in patients requiring cardiac surgery.

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Qualitative TEE assessment is used to guide administration of fluids and inotropic drugs and to monitor left ventricular function intraoperatively. Left ventricular hypovolemia or depression is easily recognized by directly noting a small end-diastolic area or low ejection fraction. Appropriate therapy can be instituted and continuously monitored. In contrast, pulmonary artery pressure monitoring does not accurately indicate loading conditions during major cardiovascular procedures or whenever left ventricular compliance is impaired, mitral valve dysfunction is present, or right ventricular distention occurs. New applications and technical improvements in TEE are being developed at a remarkable rate. Future versions of ABD technology are likely to address the problem of anisotropy, require less user intervention, and incorporate 3-D information from multiplane probes to produce real-time estimates of left ventricular volumes. The raw information in the returning signal will most likely be further analyzed to allow characterization of ischemic but still viable tissue. Coupled with the ability to assess regional myocardial perfusion by contrast echocardiography, the clinician will be able to institute more timely and appropriate medical and surgical therapy. TEE assessment of mitral valve function has become the standard of care after mitral valve repair, and in a similar fashion, assessment of myocardial perfusion by TEE may become the standard of care during cardiac and major noncardiac surgery.

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OBJECTIVES: We hypothesized that the directional movement of the interatrial septum and its curvature may reflect the pressure relations between the left and right atria. BACKGROUND: Interventricular septal shape is primarily dependent on the pressure gradient between the left and the right ventricle. No analogous study has carefully evaluated the determinants of interatrial septum shape and motion. METHODS: Patients (n = 52) undergoing cardiac or vascular surgery were studied intraoperatively at multiple intervals with transesophageal echocardiography and simultaneous measurement of central venous pressure, pulmonary capillary wedge pressure and airway pressure. RESULTS: Overall interatrial septum shape, which usually curved toward the right atrium, changed concordantly with the interatrial pressure gradient (pulmonary capillary wedge pressure-central venous pressure difference). The degree of interatrial septum curvature was also primarily dependent on the interatrial pressure gradient and, to a lesser extent, was affected by changes in left atrial size (F = 130.4 vs. F = 14.1). During passive mechanical expiration, the interatrial pressure gradient, usually positive, often reverses transiently and the interatrial septum momentarily bows toward the left atrium. Midsystolic reversal was seen in 64 of 72 episodes when the pulmonary capillary wedge pressure was < or = 15 mm Hg but in only 2 of 40 episodes when it was > 15 mm Hg (sensitivity = 0.89, specificity = 0.95, positive predictive value = 0.97). CONCLUSIONS: These findings suggest that overall interatrial septum shape depends on the pressure gradient between the left and right atria. Midsystolic reversal of the interatrial septum, which probably reflects the increased venous return in the right relative to the left atrium during mechanical expiration, may be a useful indicator of the pulmonary capillary wedge pressure.

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BACKGROUND: Although transesophageal echocardiography (TEE) produces real-time images depicting left ventricular (LV) filling and ejection, the quantitative analysis of these images has been too time consuming to be of practical value in the operating room. Therefore, the authors investigated whether a new automated border detection system (ABD) could track the endocardial border continuously and compute the cross-sectional area of the LV cavity. METHODS: Using data from 25 patients who were monitored with TEE as part of their routine clinical care, the authors compared ABD estimates of LV end-diastolic area (EDA in square centimeters), end-systolic area (ESA in square centimeters), and fractional area change (FAC) with the laboratory measurements made independently by an expert. RESULTS: ABD slightly underestimated EDA (10.7 +/- 1.0 vs. 11.2 +/- 1.0 cm2) and slightly overestimated ESA (5.6 +/- 0.7 vs. 4.8 +/- 0.6 cm2, mean +/- standard error). However, when ABD tracking of the endocardial border was judged as "good" or "excellent" (84% of the patients at end diastole and 72% at end systole), the limits of agreement between ABD and the expert's findings were within the limits expected for two experts. By contrast, ABD significantly underestimated FAC (0.44 +/- 0.03 vs. 0.56 +/- 0.03) and the limits of agreement between ABD and the expert were more than twice as great as expected for experts, even when ABD performance was judged as "excellent." CONCLUSION: The authors conclude that, when ABD appears to be performing adequately, it underestimates LV FAC, but provides valid real-time estimates of LV EDA and ESA. Thus, it warrants further evaluation as a potentially powerful clinical and research tool.

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