Transesophageal two-dimensional echocardiography: comparison of ultrasonic and anatomic sections

Focused Transthoracic Echocardiography in the Perioperative Period

Ultrasound applications in perioperative medicine have expanded enormously over the past decade. Transoesophageal echocardiography has been performed by anaesthetists during cardiac surgery for over 20 years. With the increasing availability of portable ultrasound systems, the use of ultrasound to assist in vascular cannulation and regional anaesthesia has been well described. Portable ultrasound systems come with a range of probes for different applications, including transthoracic echocardiography. While transthoracic echocardiography has traditionally been the domain of cardiologists, its use has been increasing in critical care, the emergency room and, recently, by anaesthetists in the perioperative period. Unlike formal cardiology-based transthoracic echocardiography, focused, goal-directed transthoracic echocardiography is often more appropriate in the perioperative period to address a particular question and can be performed in just a few minutes. Transthoracic echocardiography allows rapid, noninvasive, point-of-care assessment of ventricular function, valvular integrity, volume status and fluid responsiveness. It can help distinguish undifferentiated systolic murmurs preoperatively, give valuable information on the aetiology of unexplained hypotension and cardiovascular collapse and assess response to therapeutic interventions such as vasoactive drugs and volume resuscitation. Focused transthoracic echocardiography should include qualitative assessment of left and right ventricular function, an estimate of aortic valve gradient, right ventricular systolic pressure and intravascular volume status as minimum requirements. Transthoracic echocardiography is a valuable tool in the perioperative period and ideally the equipment and expertise should be available in all operating rooms.

Field-by-field evaluation of intraoperative transoesophageal echocardiography interpretative skills

A quality assurance system is essential for the credibility and structured growth of anaesthesiology-based transoesophageal echocardiography (TEE) programmes. We have developed software (Q/A Kappa), involving a 400-line source code, capable of directly reporting kappa correlation coefficient values, using external reviewer interpretations as the 'gold standard', and thereby allowing systematic assessment of the validity of intraoperative echocardiographic interpretation. This paper presents assessment of the validity of 240 intraoperative anaesthesiologists' echocardiographic interpretations, and, in addition, the results of field testing of this prototypical software. Data, derived from consecutive cardiac surgery patients, consisted of standardized two-dimensional transoesophageal echocardiographic, colour flow and Doppler imaging sequences. Intraoperative and off-line 'gold standard' TEE interpretations were compared for 19 fields or variables using the Q/A Kappa program. The kappa correlation coefficients were highly variable and dependent on the examination field, ranging from 0.08 for apical regional wall motion scores to 1.00 for tricuspid regurgitation grade, left atrial measurement, aortic valve anatomy and left ventricular long axis and short axis global function. The correlation coefficients were also operator dependent. These data (480 interpretations) were also manually integrated into the equation required for calculation of values of the variable kappa correlation coefficient. The relationship between Q/A Kappa-derived values and manually calculated values was highly significant (p < 0.001; r = 1.0). The implications and possible explanations of the results for particular examination fields are discussed. This study also demonstrates successful seamless functioning of this software program from data entry, segmentation into tables and valid statistical analysis. These findings suggest that it is practical to provide sophisticated continuous quality improvement TEE data on a routine basis.

Treatment of intraoperative refractory hypotension with terlipressin in patients chronically treated with an antagonist of the renin-angiotensin system

The goal of the present study was to determine whether terlipressin, an agonist of the vasopressin system, could counteract perioperative hypotension refractory to common vasopressor therapy and to analyze its circulatory effects. We enrolled 51 consecutive vascular surgical patients chronically treated with angiotensin-converting enzyme inhibitors or antagonists of the receptor of angiotensin II, who received a standardized opioid-propofol anesthetic. Of these 51 patients, 32 had at least one episode of hypotension, which responded to epinephrine or phenylephrine. In 10 other patients, systolic arterial pressure (SAP) did not remain above 100 mm Hg for 1 min, despite three bolus doses of ephedrine or phenylephrine. In these patients, we injected a bolus of 1 mg of terlipressin, repeated twice if necessary. Hemodynamic and echocardiographic variables were recorded every 30 s over 6 min. In eight patients, arterial pressure was restored with one injection of terlipressin; in two other patients, three injections were necessary. One minute after the last injection of terlipressin, the SAP increased from 88+/-3 to 100+/-4 mm Hg and reached 117+/-5 mm Hg (P = 0.001) 3 min after the injection and remained stable around this value. This increase in SAP was associated with significant changes in left ventricular end-diastolic area (17.9+/-2 vs 20.2+/-2.2 cm2; P = 0.003), end-systolic area (8.1+/-1.3 vs 9.6+/-1.5 cm2; P = 0.004), end-systolic wall stress (45+/-8 vs 66+/-12; P = 0.001), and heart rate (60+/-4 vs 55+/-3 bpm; P = 0.001). Fractional area change and velocity of fiber shortening did not change significantly. No additional injection of vasopressor was required during the perioperative period. No change in ST segment was observed after the injection.

IMPLICATIONS

Terlipressin is effective to rapidly correct refractory hypotension in patients chronically treated with antagonists of the renin-angiotensin system without impairing left ventricular function.

Treating anesthesia-induced hypotension by angiotensin II in patients chronically treated with angiotensin-converting enzyme inhibitors

Although angiotensin II bolus administration may be used to increase blood pressure in patients chronically treated with angiotensin-converting enzyme inhibitors (ACEI) who have severe hypotension on anesthetic induction, no data are available describing its time course and its effects on the left ventricular function. Fourteen patients chronically treated with ACEI for hypertension and scheduled for vascular surgery were prospectively studied. Patients with cardiac insufficiency were excluded. A transesophageal echocardiography probe was inserted to assess systolic left ventricular function. When hypotension was observed (systolic arterial pressure [SAP] <85 mm Hg), an I.V. bolus of 2.5 microg of angiotensin II (AII) was given, and hemodynamic variables were recorded each 30 s over 5.5 min. Results are expressed as mean +/- SEM. Sixty seconds after the AII bolus injection, the SAP increased from 78 +/- 3 to 152 +/- 6 mm Hg. SAP remained higher than control until the 5th min. This was associated with significant increases in end-diastolic area (from 15.1 +/- 0.6 to 19.3 +/- 1.0 cm2, P < or = 0.001), end-systolic area (from 6.6 +/- 0.4 to 10.7 +/- 0.7 cm2, P < or = 0.001), end-systolic wall stress (from 32 +/- 0.05 to 82 +/- 7 kdynes/cm2, P < or = 0.001). In addition, a decrease in fiber-shortening velocity (from 1.1 +/- 0.05 to 0.76 +/- 0.04 circ/s, P < or = 0.05) and in fractional area change (from 0.57 +/- 0.02 to 0.44 +/- 0.02, P < or = 0.05) was observed. Heart rate did not significantly change during the study. Increases in preload and afterload were observed. However, the administration of AII causes a transient impairment in left ventricular function. We conclude that AII, given as an I.V. bolus of 2.5 microg, is effective in restoring arterial blood pressure within 60 s in patients chronically treated with ACEI.

IMPLICATIONS

Severe hypotension on anesthetic induction in patients chronically treated with angiotensin-converting enzyme inhibitors for hypertension could be treated with an I.V. bolus of 2.5 microg of angiotensin II.

Transesophageal multiplane imaging of the human pulmonary artery: a comparison of MRI and multiplane transesophageal two-dimensional echocardiography

OBJECTIVE

To evaluate the anatomical relationship between the esophagus and pulmonary artery including assessment of the correct transesophageal Doppler insonation angle into the mid-pulmonary artery trunk.

METHODS

We evaluated the anatomical relationship between the esophagus and pulmonary artery (PA) from comparable magnetic resonance (MR) and transesophageal echocardiographic (TEE) multiple two-dimensional images (0 degree, 45 degrees, 90 degrees and 135 degrees clockwise rotation of the standard transverse scanning plane when seen bearfrom the esophagus) obtained in 10 healthy, young volunteers.

RESULTS

The main PA could be visualized with both techniques in all 10 volunteers and provided highly identical images of good quality. A mean insonation angle of 35 degrees (range 26 degrees-46 degrees) for a fictive esophageal Doppler beam into the main PA was disclosed. The PA trunk was short with a mean length of 23.4 mm (range 17-30 mm).

CONCLUSIONS

These anatomical data contradict the general assumption of alignment of the pulmonary artery and the transesophageal Doppler beam. Angle correction should be applied in the clinical setting using MTEE by rotation of the scanning plane to approximately 45 degrees. Ignoring the insonation angle of approximately 35 degrees may cause 20% underestimation of blood flow velocity and cardiac output in the PA.

Continuous transoesophageal echocardiography monitoring during weaning from cardiopulmonary bypass in children

The purpose of this study was to evaluate the effectiveness of transoesophageal echocardiography monitoring during weaning from cardiopulmonary bypass after intracardiac repair in children. The left ventricular ejection fraction, left ventricular end-diastolic volume and left ventricle wall motion were monitored continuously by transoesophageal echocardiography in controls weaned easily from cardiopulmonary bypass (group A, n = 25), and those weaned with difficulty from cardiopulmonary bypass after mechanically assisted circulation (group B, n = 16). In group A, left ventricular ejection fraction and left ventricle wall motion were within normal range, and did not change significantly during weaning after cardiopulmonary bypass when compared with pre-bypass data. In contrast, left ventricular ejection fraction, left ventricular end-diastolic volume and left ventricle wall motion in group B during the first trial of weaning from bypass were significantly worsened. Hence, assisted circulation was performed until the data obtained via transoesophageal echocardiography improved with regard to maintenance of fluid balance, catecholamine dosage and assisted pump flow. All cases in group B were weaned safely from cardiopulmonary bypass despite their critical condition. In conclusion, continuous transoesophageal echocardiography monitoring may be a useful tool in children with severe heart failure for safe weaning from cardiopulmonary bypass after intracardiac repair.

Intraoperative echocardiography: techniques and current applications

Intraoperative echocardiography has opened new dimensions in the evaluation of cardiac surgical patients, and has contributed significantly to the improved surgical results. The use of intraoperative echocardiography has enabled the surgeon to image the working heart, to define the operative anatomy and physiology, and to evaluate the results immediately before the patients leave the operating room. This review summarizes the current status and applications of intraoperative echocardiography in the practice of cardiac surgery.

An integrated software system for quality assurance-related kappa coefficient analysis of intraoperative transesophageal echocardiography interpretive skills

This report describes the development of a quality assurance-oriented integrated software system designed for an anesthesiology-based intraoperative transesophageal echocardiography service. Entry data include patient and operation demographics, two-dimensional echocardiographic, saline-contrast, and color flow/pulsed Doppler assessments of the heart and great vessels, presented in a defined sequence. A statistical analysis component (kappa coefficient analysis) allows for comparison of intraoperative real-time interpretations with laboratory interpretations made by experienced full-time echocardiographers on a field-by-field basis. This provides a means of quantifying expertise in each individual aspect of the patient examination sequence. We believe that such self-appraisal data are essential for delineating the status and tracking the progress of service being provided.

Effect of phenylephrine bolus administration on left ventricular function during postural hypotension in anesthetized patients

STUDY OBJECTIVE

To investigate the effect of intravenous (IV) phenylephrine (PHE) bolus administration on left ventricular function in patients who developed postural hypotension during isoflurane anesthesia in the head-up tilt (reverse Trendelenburg) position.

DESIGN

Prospective "before-after" trial.

SETTING

Operation theater of a university medical center.

PATIENTS

15 ASA physical status I and II patients without cardiovascular disorders.

INTERVENTIONS

The anesthetized patients were tilted from a supine horizontal to a 30-degree reverse-Trendelenburg position. Once a steady state was achieved, PHE 3 micrograms/kg was administered as an IV bolus dose.

MEASUREMENTS AND MAIN RESULTS

Transesophageal echocardiography was used to assess left ventricular function. We measured blood pressure (BP); heart rate; left ventricular end-systolic and end-diastolic area, diameter, and wall thickness; and ejection time at baseline and after tilt, immediately before and for a period of 3 minutes after PHE injection. We calculated fractional area change (FAC), mean velocity of circumferential fiber shortening (mVcf), and end-systolic wall stress. Head-up tilt caused a reduction of mean arterial pressure [from 68 to 54 mmHg (mean)], end-systolic and end-diastolic left ventricular area (from 9.7 to 6.5 cm2 and from 19.2 to 13.1 cm2, respectively) and end-systolic wall stress (from 56 to 33 10(3).dyne/cm2). FAC and mVcf remained unaltered. PHE administration restored baseline values or overcompensated the changes caused by tilt. FAC slightly decreased in response to PHE (from 0.51 to 0.43), end-systolic wall stress increased to 83 10(3).dyne/cm2, and mVcf remained unchanged.

CONCLUSION

PHE bolus administration effectively restored BP and cardiac filling, which were reduced after head-up tilt, without causing a relevant impairment of left ventricular function or an increase in end-systolic wall stress above the upper normal limit.

Perivalvular abscesses associated with endocarditis. Clinical features and diagnostic accuracy of two-dimensional echocardiography

OBJECTIVE

To determine the clinical implications of the development of a perivalvular abscess in the course of an infective endocarditis and evaluate the utility of two-dimensional echocardiography in the diagnosis of this complication.

DESIGN

Retrospective clinical review. Investigator-blinded comparative echographic case-control study.

SETTING

Tertiary referral center.

PATIENTS

Forty patients with infective endocarditis and a histologically proved diagnosis of perivalvular abscess.

INTERVENTION

Two-dimensional echocardiograms corresponding to 36 of these 40 patients were blindly compared with two-dimensional echocardiograms of 20 randomly chosen patients with infective endocarditis in whom myocardial abscesses had not been demonstrated during surgery.

MEASUREMENTS AND MAIN RESULTS

During surgery or at autopsy, 40 patients had a total of 41 definite perivalvular abscesses. Native valve endocarditis was present in 27 patients, and prosthetic valve endocarditis was present in 13 patients. Abscesses were more frequent in aortic-valve endocarditis (57.5 percent) than in infections of other valves, and the infecting organism was more often Staphylococcus (42.5 percent of cases). The hospital mortality rate was 90 percent in the 10 patients who did not receive surgical treatment, as compared with 26.6 percent in the 30 operated-on patient (p < 0.001). Sensitivity and specificity for the detection of abscesses associated with endocarditis were 80.5 percent and 85 percent, respectively, for transthoracic two-dimensional echocardiography.

CONCLUSIONS

Our data indicate that transthoracic echocardiography remains an accurate method for the diagnosis of abscesses associated with endocarditis, even in the presence of a prosthetic valve, and it could help to indicate early surgery in these patients.

Transesophageal two-dimensional echocardiographic analysis of right ventricular systolic performance indices during coronary artery bypass grafting

Sixteen patients (aged 59 +/- 14 years) undergoing coronary artery bypass surgery were evaluated to delineate the intraoperative course of transesophageal echocardiographic right ventricular (RV) systolic performance indices. Pre-induction data included thermodilution RV ejection fraction (RVEFTD), 0.43 +/- 0.13, RV end-diastolic volume index (EDVI), 110 +/- 33 mL/m2, cardiac index (CI), 3.4 +/- 1.0 L/min/m2, RV end-diastolic pressure (EDP), 7.1 +/- 4.2 mmHg, and mean pulmonary artery pressure (PAP), 21 +/- 6 mmHg. Eleven patients had significant right coronary artery (RCA) disease (> 70% occlusion). Five patients arrived with an ongoing nitroglycerin infusion (1 to 3 micrograms/kg/min), which was maintained intraoperatively. Echocardiographic measurements included longitudinal-axis (LA) and short-axis (SA) planimetered area excursion fractions (2DLA and 2DSA, respectively) and LA maximal major and minor axis shortening fractions (max majorLA and max minorLA, respectively). Hemodynamic measurements included RVEFTD, EDVI, CI, EDP, and PAP. Measurements were determined following induction/endotracheal intubation, following sternotomy/pericardiotomy, and after cardiopulmonary bypass (CPB) with the chest open. All patients were maintained on vasodilator therapy post-CPB (nitroglycerin, 1 to 3 micrograms/kg/min [N = 16] and nitroprusside, 0.5 to 4.5 microgram/kg/min [N = 4]) post-CPB. Two patients received inotropic support (epinephrine, 0.2 to 0.3 microgram/kg/min). CPB was associated with significant decreases in max major axisLA and 2DLA (P < 0.05) as compared to measurements determined prior to CPB. Maximum major axisLA values pre-CPB were 0.35 +/- 0.06 and 0.33 +/- 0.08 versus post-CPB values of 0.24 +/- 0.08.(ABSTRACT TRUNCATED AT 250 WORDS)

The relationship between "normal" transesophageal color-flow Doppler-defined tricuspid regurgitation and thermodilution right ventricular ejection fraction measurements

Twenty coronary artery revascularization patients, aged 58 +/- 15 years, were studied intraoperatively to define the impact of Doppler-defined tricuspid regurgitation on measurement of thermodilution right ventricular ejection fraction (50 msec response pulmonary artery catheter). Right ventricular function was also estimated using a measurement technique independent of flow patterns across the tricuspid valve (transesophageal two-dimensional echocardiographic 5.0 MHz phased-array transducer). Measurements included transverse plane long- and short-axis planimetered area ratio, respectively, and tricuspid annular plane systolic excursion ratio (ratio = end-diastolic minus end-systolic value divided by end-diastolic value). Data were expressed as thermodilution-echocardiographic gradients, ie, thermodilution ejection fraction minus long-axis planimetered area ratio, short-axis planimetered area ratio, and tricuspid annular plane systolic excursion ratio, respectively. Tricuspid regurgitation was quantified by color-flow Doppler perimetry of maximal regurgitation jet area and analysis of transduced right atrial pressure waveform. Doppler estimates were expressed as absolute values and as a function of corresponding atrial area (tricuspid regurgitation index = planimetered jet area divided by right atrial area). Data were obtained following endotracheal intubation, sternotomy, pericardiotomy, cardiopulmonary bypass, and chest closure. Data were evaluated by regression analysis, with separate analyses performed for each time period. Profiles were unassociated with right atrial pressure waveform abnormalities. There was no significant relationship between thermodilution ejection fraction variance values and tricuspid regurgitation jet area or regurgitation index, respectively. In each measurement period, thermodilution-echocardiographic gradients were also unrelated to the tricuspid regurgitation estimates.(ABSTRACT TRUNCATED AT 250 WORDS)

Influence of high thoracic epidural anesthesia on left ventricular contractility assessed using the end-systolic pressure-length relationship

The effect of high thoracic epidural anesthesia (TEA on left ventricular contractility was studied in a prospective clinical trial. Forty-eight patients with ASA physical status 1 and 2 and without cardiovascular disease were included in the study. Thirty-six patients scheduled for elective upper abdominal surgery were randomly assigned to Group 1 (TEA, bupivacaine 0.25%, n = 12), Group 2 (TEA, bupivacaine 0.5%, n = 12) or to Group 3 (control without TEA, n = 12). TEA induced a sensory block which extended over all cardiac segments. In order to assess the effect of systemically absorbed bupivacaine, we studied a separate group of patients who received lumbar epidural anesthesia without involvement of the cardiac segments: Group 4 (LEA, bupivacaine 0.5%, n = 10). Left ventricular contractility was assessed using the end-systolic pressure-length relationship. Left ventricular dimensions were measured by transesophageal echocardiography. All hemodynamic measurements were performed under general anesthesia. There was no significant difference in systolic or diastolic arterial pressure, heart rate, left ventricular end-systolic and end-diastolic cross-sectional areas and left ventricular wall stress between the four groups. Left ventricular maximum elastance as a measure of left ventricular contractility was significantly (P < 0.001) reduced in Groups 1 and 2 [8.1 (+/- 3.5) and 9.6 (+/- 4.4) kPa.cm-1, respectively] as compared to Groups 3 and 4 [18.4 (+/- 8.8) and 17.7 (+/- 7.7) kPa.cm-1, respectively]. No significant difference could be demonstrated between Groups 1 and 2 or between Groups 3 and 4. It is concluded that high TEA severely alters left ventricular contractility even in subjects without pre-existing cardiac disease.

Value and limitations of transesophageal echocardiography in the evaluation of aortic prostheses

Results of 34 transesophageal (TEE) studies in patients with suspected aortic prosthetic dysfunction were compared with transthoracic echocardiographic (TTE) results and to anatomic findings. Mass lesions noted at surgery (autopsy) were correctly described in 93% by TEE versus 43% by TTE. Abscesses were detected in 88% by TEE versus 18% by TTE. Bioprosthetic degeneration was visualized in 88% versus 38% and prosthetic obstruction correctly identified in 75% versus 50% by TEE and TTE, respectively. Anatomic aortic regurgitant lesions were identified in 96% by TEE versus 77% by TTE, whereas the correct origin was detected in 88% of cases by TEE versus 54% of cases by TTE. TEE provides valuable additional information on morphologic conditions and flow pathology in aortic valve prostheses.

Transesophageal contrast echocardiography and color flow mapping: methods of choice for the detection of shunts at the atrial level?

The detection of shunts at the atrial level is important, and a reliable means of diagnosis is required. Precordial contrast echocardiography is usually performed to detect such shunts. To investigate the advantages of transesophageal echocardiographic techniques, we studied 167 consecutive patients with both precordial and transesophageal echocardiography, using two-dimensional imaging with contrast techniques (with and without a Valsalva maneuver) and color flow mapping. A patent foramen ovale was diagnosed in 31 patients, an atrial septal defect in 11 (7 with bidirectional shunts), and a pulmonary arteriovenous fistula in 3 patients. All right-to-left shunts were detected with transesophageal contrast echocardiography. With these results used as the gold standard, the sensitivity of combined precordial techniques was 37% and that of transesophageal color flow mapping 46%. All left-to-right shunts were detected by transesophageal color flow mapping. With these results used as the gold standard, the sensitivities of both precordial color flow mapping and a transesophageal negative right atrial contrast study were 27%. We conclude that transesophageal contrast echocardiography is the echocardiographic method of choice for the detection of a right-to-left shunt at the atrial level, which cannot be excluded by negative results on precordial study or on transesophageal color flow map study. A left-to-right shunt at this level is best detected by transesophageal color flow mapping.

Transesophageal color Doppler flow imaging in the evaluation of prosthetic cardiac valves

To determine the value of transesophageal echocardiography in the assessment of prosthetic cardiac valves, 11 patients with clinically suspected cardiac prosthetic valve dysfunction were studied by transesophageal two-dimensional imaging, as well as by color Doppler flow mapping. Among these 11 patients, there were 10 with biological tissue valves and 3 with metallic valves (1 Bjork-Shiley, 2 St. Jude). Nine patients had replacement of mitral valves alone. The remaining two had received both mitral and aortic prostheses. The degree of mitral regurgitation was graded by transesophageal color Doppler according to the area of the regurgitant jet visualized. The degree of aortic regurgitation was graded by the jet height/left ventricular outflow height ratio method. All transesophageal studies were performed without complication and all were well tolerated. The pathological morphology of the cardiac prosthesis was clearly visualized by transesophageal two-dimensional imaging and subsequently proven at surgery. Of those tested, one patient was found to have a torn leaflet, one had a dislodged leaflet, one patient had paravalvular leakage, four had cusp vegetations, and five patients had prosthetic degeneration for other reasons. Mitral regurgitation was graded as absent in one patient, mild in two patients, moderate in two patients, and severe in six patients. Aortic regurgitation was graded as severe in both patients with aortic prostheses. We conclude that in patients with clinically suspected cardiac prosthetic dysfunction, transesophageal two-dimensional imaging combined with color Doppler can provide reliable information that corresponds to surgical findings.

Normal pulmonary venous flow characteristics as assessed by transesophageal pulsed Doppler echocardiography

Twenty-seven subjects without apparent cardiac abnormalities underwent transesophageal echocardiography to evaluate normal Doppler characteristics of pulmonary venous flow. In particular, the effects of normal respiration and straining during the Valsalva maneuver were analyzed. Pulmonary venous flow during systole consisted of one forward flow wave in 15 cases (56%) and of two forward flow waves in 12 cases (44%). In all instances one forward flow wave was seen during early diastole and in 23 subjects (85%) a retrograde wave related to atrial contraction was present. Maximal velocity during systole was 57 +/- 13 cm/sec (mean +/- SD), during early diastole was 58 +/- 19 cm/sec, and during late diastole was 16 +/- 9 cm/sec. Velocity time integral during systole was significantly higher than during early diastole (11.8 +/- 4.9 vs 9.5 +/- 3.9 cm, p < 0.05), while velocity time integral during late diastole was 1.1 +/- 0.7 cm. During normal inspiration both early diastolic velocity and velocity time integral significantly decreased from 59 +/- 15 to 54 +/- 15 cm/sec (p < 0.01) and from 9.5 +/- 3.9 to 8.5 +/- 4.2 cm (p < 0.05), respectively. During normal expiration, systolic and early diastolic velocity time integral significantly increased, from 11.0 +/- 4.1 to 11.8 +/- 4.5 cm (p < 0.001) and from 9.5 +/- 3.9 to 10.1 +/- 4.3 cm (p < 0.05), respectively. Although statistically significant, the differences were small and do not seem of clinical importance. Straining during the Valsalva maneuver, however, obviously decreased pulmonary venous flow velocities. Systolic and early diastolic velocity decreased from 57 +/- 15 to 32 +/- 10 cm/sec and from 59 +/- 18 to 34 +/- 15 cm/sec, respectively, while velocity time integral during systole, early, and late diastole decreased from 12.0 +/- 5.6 to 4.3 +/- 2.6 cm, from 9.9 +/- 4.4 to 5.2 +/- 3.7 cm, and from 1.3 +/- 0.8 to 0.8 +/- 0.7 cm, respectively. In conclusion, pulmonary venous Doppler characteristics can adequately be analyzed with transesophageal echocardiography. Normal respiration only minimally influences pulmonary venous flow velocities in contrast to straining during the Valsalva maneuver; this should be considered when these variables are applied for clinical purposes.

Transoesophageal Doppler echocardiographic measurement of cardiac output by the mitral annulus method

OBJECTIVE

To compare cardiac output measured by the transoesophageal Doppler and thermodilution techniques.

DESIGN

Prospective direct comparison of paired measurements by both techniques in each patient.

SETTING

Intensive care unit in a cardiovascular centre.

PATIENTS

65 patients after open heart surgery (mean (SD) age 53 (12) years).

INTERVENTIONS

Cardiac output was measured simultaneously by the transoesophageal Doppler and thermodilution techniques. Cardiac output was measured again after a mechanical intervention or volume loading.

RESULTS

The limits of agreement were -2.53 to +0.83 1.min-1 for cardiac output measured by the Doppler and thermodilution techniques. This suggests that the Doppler method alone would not be suitable for clinical use. The second measurement of cardiac output by thermodilution was compared with cardiac output estimated from the first and second Doppler measurements and the first thermodilution measurement. The limits of agreement (-0.55 to +0.51 1.min-1) were good enough for clinical use.

CONCLUSIONS

After cardiac output had been measured simultaneously by both the Doppler and thermodilution techniques, subsequent transoesophageal Doppler alone gave a clinically useful measurement of cardiac output.

Baroreflex control of heart rate during high thoracic epidural anaesthesia. A randomised clinical trial on anaesthetised humans

Baroreflex control of heart rate after cardiac sympathectomy induced by thoracic epidural anaesthesia was evaluated in 30 patients who were randomly assigned to group 1 (bupivacaine 0.25%), group 2 (bupivacaine 0.5%) or group 3 (control). Plasma volume expanders were given to equalize preload conditions, as assessed using transoesophageal echocardiography. All measurements were made under general anaesthesia. Baroreflex sensitivity was determined from the heart rate response to phenylephrine and nitroglycerin. There was no difference in cardiac slowing in response to phenylephrine between the three groups. Baroreflex sensitivity, measured as cardiac acceleration in response to nitroglycerin, was significantly lower (p < 0.01) in groups 1 and 2 (1.8 and 1.5 ms.mmHg-1 respectively) compared with group 3 (3.5 ms.mmHg-1) with no differences between the two bupivacaine concentrations. The results suggest that baroreflex-mediated response to decreases in arterial pressure is dependent on the integrity of the sympathetic nervous system.

Cardiac evaluation

Over the past decade there has been a dramatic, rapid development of new imaging modalities used in the evaluation of the cardiac patient. These newer techniques are frequently complex and specialized in their application and interpretation. Nonetheless, the prevalence of cardiac disease in the United States, and the wide application of these diagnostic tests, mandate that the well-rounded clinician has a basic understanding of the utility of these diagnostic modalities. Unfortunately, the burgeoning field of cardiac imaging seems at times to overshadow our most important basic diagnostic tools, namely, the history, physical exam, chest radiograph, and electrocardiogram (ECG). This review will attempt to impart a basic understanding of the newer cardiac diagnostic tests and their utility in various disease states. Emphasis on the importance of the basic clinical exam and the precise integration of specific diagnostic tests into the cardiac evaluation will be emphasized. The article will deliver a basic review of exercise treadmill testing, echocardiography, radionuclide imaging techniques, magnetic resonance imaging, and cardiac catheterization. It is hoped that this review will impart to the noncardiologist clinician a basic understanding of the cardiovascular diagnostic techniques so that an accurate, precise, cost-effective, efficient diagnostic plan for the patient with cardiovascular disease can be developed and applied.

The use of transoesophageal echocardiography for detecting early recurrence of atrial myxoma

A comparison between praecordial and transoesophageal cross-sectional echocardiography was undertaken in the follow-up of 14 patients who had previously undergone surgical excision of atrial myxoma. The mean interval between surgery and follow-up was 39 months. Evidence of recurrent tumour was seen in two patients by transoesophageal echocardiography but went undetected in one of these using the praecordial approach. Clear visualisation of the atria and interatrial septum was possible in all remaining cases using transoesophageal echocardiography and this allowed confident exclusion of tumour recurrence. Using praecordial echocardiography, technically inadequate studies meant that this was not possible in 4 patients. The significant late recurrence rate of excised atrial myxomas, emphasises the need for serial, postoperative echocardiographic studies. Praecordial echocardiography may be unreliable in the detection of recurrent atrial myxoma in its early stages and for this reason transoesophageal echocardiographic follow-up is justified in high risk patients.

Biplane transesophageal echocardiography: an anatomic-ultrasonic-clinical correlative study

In 427 subjects TEE was performed with either a uniplane or biplane transducer; in seven cadavers the cardiac anatomic segments were observed in several levels and directions. Nine transverse and six longitudinal views were compared with the corresponding cardiac anatomic segments. Based on this correlative study, the levels of segments, insertion depth, anatomic structure identification, image characteristics, clinical applications, and the advantages as well as the limitations of biplane TEE are discussed.

Limitations of transoesophageal echocardiography in patients with focal cerebral ischaemic events

OBJECTIVE

To investigate the detection rate of cardiac sources of embolism by transoesophageal echocardiography in patients with focal cerebral ischaemic events and to relate the echocardiographic findings to other clinical findings.

DESIGN

Prospective study with blinded analysis of the echocardiographic data and subsequent comparison with the other clinical findings.

SETTING

Regional cardiothoracic unit based in a teaching hospital.

PATIENTS

131 consecutive patients with focal ischaemic cerebral events (49 with a transient ischaemic attack, 77 with a cerebrovascular accident, and five with a retinal arterial embolus) referred for echocardiography.

INTERVENTIONS

Full M mode, cross sectional, Doppler, and contrast echocardiography by both the precordial and transoesophageal techniques.

RESULTS

Precordial echocardiography detected a cardiac abnormality in 72 patients. Transoesophageal echocardiography confirmed all the precordial findings (except left ventricular hypertrophy, which at present cannot be defined with this technique) and detected other abnormalities in a further 20 patients (18 with potential right-to-left shunts and two with valve vegetations). It also showed spontaneous contrast echoes in 27 of 28 patients with a large left atrium and showed atrial thrombus in three. Cardiac abnormalities were clinically detected in 53 patients, all of which were confirmed or documented by echocardiography. In the 78 patients with no clinically detectable cardiac abnormality six had mitral valve prolapse and one had a regional wall motion defect (identified by precordial echocardiography) and 17 had potential right-to-left shunts (11 of which were identified only by transoesophageal echocardiography).

CONCLUSIONS

Transoesophageal echocardiography is more sensitive than precordial echocardiography in detecting potential sources of embolism in these patients. However, except for the detection of a potential right-to-left shunt, the yield in patients with no cardiac abnormality is low. Moreover, the abnormalities detected in those with previously detected cardiac disease merely confirm the clinical diagnosis. Patients with left atrial spontaneous contrast echoes may benefit from anticoagulation but this requires further study. Until more data are available on this feature and on the role of potential right-to-left shunts in this population, the contribution of echocardiography, precordial or transoesophageal, remains limited.

Assessment of anomalous systemic and pulmonary venous connections by transoesophageal echocardiography in infants and children

OBJECTIVE

To assess the value of transoesophageal echocardiography in the preoperative definition of systemic and pulmonary venous connections.

DESIGN

Transoesophageal echocardiographic studies were performed prospectively under general anaesthesia in 76 consecutive unoperated children. Results were compared with those obtained by earlier transthoracic ultrasound studies (n = 76), cardiac catheterisation (n = 62), and subsequent surgical inspection (n = 58).

SETTING

Two tertiary referral centres.

PATIENTS

76 unoperated infants and children (age 0.2-14.8 years, mean age 4.1 years) with congenital heart disease.

MAIN OUTCOME MEASURE

Identification of anomalous systemic and pulmonary venous connections.

RESULTS

Transoesophageal studies showed anomalous venous connections in 14 patients. Two had both anomalous systemic and pulmonary venous connections. Transoesophageal studies showed 12 anomalous systemic venous connections in nine patients. In eight patients these were confirmed at operation or catheterisation: one patient is awaiting operation. Six anomalous systemic venous connections were missed during earlier transthoracic studies. Anomalous pulmonary venous connections (one mixed total, six partial) were shown in seven patients. These were confirmed at operation in six and by cardiac catheterisation in one. Four of these patients were missed during earlier transthoracic ultrasound studies. No patient defined as having normal venous connections by the transoesophageal study was subsequently shown to have anomalous venous connections at operation or angiography.

CONCLUSIONS

Transoesophageal echocardiography is a highly sensitive tool for the preoperative definition of systemic and pulmonary venous connections. In this series it was better than transthoracic ultrasound and complemented cardiac catheterisation and angiocardiography.

Transesophageal echocardiographic monitoring of interventional cardiac catheterization in children

Transesophageal echocardiography was used prospectively in 22 children scheduled for interventional cardiac catheterization (9 with pulmonary valvuloplasty, 5 with aortic valvuloplasty, 1 with pulmonary angioplasty, 2 with aortic angioplasty, 2 with patent ductus arteriosus occlusion and 3 with Mustard baffle dilation) to determine its potential value as a monitoring technique. The patients ranged in age from 0.9 to 14.6 years (mean 5.4) and in weight from 9.5 to 49.2 kg (mean 21.1). Studies were completed in all patients without complications. Preintervention studies provided important new information in two patients, leading to cancellation of the planned procedure. Major contributions of transesophageal monitoring included 1) a real time assessment of catheter placement across either atrioventricular valve and the aortic valve during balloon valvuloplasty; 2) immediate assessment of aortic valve and aortic wall morphology during balloon dilation; and 3) detailed morphologic and hemodynamic information together with enhanced catheter guidance during Mustard baffle dilation. After pulmonary valvuloplasty, partial chordal rupture of the tricuspid valve was documented in one patient. In two patients, balloon catheter position was modified according to the transesophageal findings. The assessment of changes in pulmonary valve morphology and transcatheter occlusion of a patent ductus arteriosus was not enhanced by single-plane transesophageal monitoring. Pulsed wave Doppler studies contributed additional information in the assessment of immediate hemodynamic changes after interventional procedures. Transesophageal echocardiography is a new important guiding and monitoring technique during interventional cardiac catheterization procedures in children. It can provide additional real time imaging information, immediate identification of complications and assessment of hemodynamic changes.

Intraoperative transesophageal echocardiography of atrioventricular septal defect

To determine the accuracy and utility of single-plane transesophageal echocardiography in analyzing atrioventricular (AV) septal defect, intraoperative transesophageal echocardiography was performed before and after institution of cardiopulmonary bypass in 16 patients (age 24 days to 14 years, weight 3 to 47 kg). Prebypass transesophageal echocardiography (including two-dimensional echocardiography, Doppler color flow mapping and pulsed wave Doppler ultrasound) correctly diagnosed divided AV valve, common AV valve and unbalanced AV valve, as well as atrial or ventricular septal defect, or both, in all cases. It correctly analyzed AV valve regurgitation in all 10 patients with right and all 14 with left AV valve regurgitation and correctly analyzed 30 of 33 additional cardiac anomalies. Transesophageal echocardiography was able to detect the absence of normal pulmonary venous connections but failed to demonstrate all of the complex anomalous pulmonary venous connections in three patients with atrial isomerism. Postbypass transesophageal echocardiography documented the absence of a significant residual shunt in 11 of 11 patients undergoing corrective surgery and verified residual AV valve regurgitation in 7 of 9 patients with tricuspid regurgitation and 11 of 13 with mitral regurgitation. Transesophageal echocardiographic information that altered or refined the surgical treatment was obtained in 5 (31%) of 16 patients. Epicardial and transesophageal echocardiography results were concordant in all 13 patients in whom both were performed. Transesophageal echocardiography provides useful and accurate imaging of the important two-dimensional, pulsed wave Doppler ultrasound and Doppler color flow mapping features in AV septal defect.

Biplane transesophageal echocardiography: imaging sections and anatomic segments

In order to recognize correctly the images of transesophageal echocardiography (TEE), in 410 subjects TEE was performed with uniplane or biplane transducer, and in 7 corpses the cardiac anatomic segments were observed, at various levels and in different directions, 9 transverse and 6 longitudinal views were compared with the corresponding cardiac anatomic segments. Based on this study, the authors reported the levels of segments, insertion depth, anatomic structure identification, image characteristics and clinical application of TEE, and the advantages of biplane TEE are discussed.

Hemodynamic effects of different ventilatory patterns. A prospective clinical trial

We compared the hemodynamic effects of three different ventilatory patterns including two variations of the I:E ratio (2:1 and 3:1) and a PEEP-pattern with the MAWP being equal in all three patterns. The study was performed on 15 patients without lung or cardiovascular disease who were ventilated after elective abdominal surgery. Each of the patients was subjected to the three different pressure wave curves. The IPPV served as control. Hemodynamic measurements included TEE registration of the LV cross-sectional areas, diameters and wall thickness as well as arterial blood pressure and heart rate. As a result, we found no significant differences in the hemodynamic effects of all three patterns. Compared with IPPV, they showed a reduction of systolic and diastolic blood pressure, LV dimensions and systolic wall stress. Assessed with the end systolic quotient, LV contractility remained constant.

Effects of prolonged transesophageal echocardiographic imaging and probe manipulation on the esophagus--an echocardiographic-pathologic study

Transesophageal echocardiography is being increasingly utilized in the operating room and intensive care and ambulatory settings. However, to date no data are available concerning possible trauma of the transesophageal echocardiographic technique to the esophagus due to probe insertion, manipulation or direct ultrasound energy transmission. To test the hypothesis that transesophageal manipulations caused no traumatic or thermal injury to the esophageal mucosa, 12 animals were studied with continuous transesophageal echocardiography for a period of variable duration (mean 4.6 h +/- 51 min). The study group consisted of four monkeys (mean weight 5.7 +/- 0.6 kg and eight mongrel dogs (mean weight 29.8 +/- 1.4 kg). The eight dogs were studied during right heart bypass with full heparinization for 6.6 +/- 0.2 h, whereas the four monkeys were studied for 60 to 90 min in the absence of cardiopulmonary bypass and anticoagulation. Immediately after completion of transesophageal echocardiography in each case, the esophagus was entirely excised. Detailed macroscopic and microscopic examination of the esophagus revealed no significant mucosal or thermal injury. This preliminary animal study suggests that transesophageal echocardiography is safe for the esophageal mucosa in animals as small as 5 kg in weight, despite prolonged use and in the presence of systemic anticoagulation.

Biplane transesophageal echocardiography: clinical applications of the long-axis plane

Tomography of the heart and great vessels is limited during conventional transesophageal echocardiography by the inability to rotate the transducer at the end of the transesophageal echocardiographic endoscope. A biplane transesophageal echocardiographic probe has been developed recently with a second transducer capable of long-axis imaging that yields long-axis views in addition to the familiar short-axis views. We describe our experience with 37 patients with a variety of cardiovascular diseases. In 17 patients new diagnostic information was obtained, although management was not changed. Long-axis scanning was particularly useful in the assessment of diseases of the thoracic aorta, valvular morphology and regurgitation, and congenital heart disease. Important limitations of the biplane imaging system include reduced image quality and a continued inability to rotate the transducer to obtain any desired plane of imaging. Nonetheless, biplane imaging enhances the versatility of transesophageal echocardiography and improves three-dimensional conceptualization of cardiac disease.

The value of transesophageal echocardiography in children with congenital heart disease

With the use of dedicated pediatric single-plane probes, transesophageal echocardiography was performed prospectively in 102 children to determine the potential value of this new technique in the diagnosis (40 patients) and the follow-up of congenital heart disease (29 patients) and as a monitoring technique during the perioperative period or interventional cardiac catheterization (33 patients). The findings were correlated with precordial studies (102 patients), cardiac catheterization (82 patients), epicardial ultrasound findings (18 patients), or surgical inspection (34 patients). The age at investigation ranged from 2.5 months to 14.9 years (mean age, 5.2 years); weight ranged from 3.7 to 52 kg (mean weight, 19.1 kg). Additional information was obtained in 49 patients (48.4%) and was relevant for patient management in 21 patients (20.6%). Major areas of improved diagnostic insight included the following: (1) systemic and pulmonary venous return, (2) atrial morphology, (3) atrioventricular junction abnormalities, (4) left ventricular outflow tract disease, (5) atrial baffle function, and (6) the Fontan circulation. Inherent limitations were as follows: (1) the semiinvasive character of the procedure, (2) the need for heavy sedation or general anesthesia, and (3) the limited imaging planes provided. Transesophageal echocardiography in children can provide important additional diagnostic information on a wide spectrum of congenital heart lesions. The technique would appear to be a highly valuable adjunct to the diagnostic armentarium of the pediatric cardiologist.

The flail mitral valve: echocardiographic findings by precordial and transesophageal imaging and Doppler color flow mapping

To determine the echocardiographic and Doppler characteristics of mitral regurgitation associated with a flail mitral valve, precordial and transesophageal echocardiography with pulsed wave and Doppler color flow mapping was performed in 17 patients with a flail mitral valve leaflet due to ruptured chordae tendineae (Group I) and 22 patients with moderate or severe mitral regurgitation due to other causes (Group II). Echocardiograms were performed before or during cardiac surgery; cardiac catheterization was also performed in 28 patients (72%). Mitral valve disease was confirmed at cardiac surgery in all patients. By echocardiography, the presence of a flail mitral valve leaflet was defined by the presence of abnormal mitral leaflet coaptation or ruptured chordae. Using these criteria, transesophageal imaging showed a trend toward greater sensitivity and specificity than precordial imaging in the diagnosis of flail mitral valve leaflet. By Doppler color flow mapping, a flail mitral valve leaflet was also characterized by an eccentric, peripheral, circular mitral regurgitant jet that closely adhered to the walls of the left atrium. The direction of flow of the eccentric jet in the left atrium distinguished a flail anterior from a flail posterior leaflet. By transesophageal echocardiography with Doppler color flow mapping, the ratio of mitral regurgitant jet arc length to radius of curvature was significantly higher in Group I than Group II patients (5.0 +/- 2.3 versus 0.7 +/- 0.6, p less than 0.001); all of the Group I patients and none of the Group II patients had a ratio greater than 2.5.(ABSTRACT TRUNCATED AT 250 WORDS)

Echocardiographic evaluation of patients with clinically suspected arterial emboli

153 patients (mean age 42 years, range 16-60) who had arterial embolic events were examined prospectively by transthoracic and transoesophageal echocardiography. Patients older than 60 years and those with evidence of extracranial carotid artery occlusive disease were excluded. 84 patients had a cerebral ischaemic event, 50 patients had embolic events in an abdominal organ or limb, and 19 patients had acute retinal ischaemia. The transthoracic echocardiographic examination was normal in 92 patients (60%), whereas only 65 patients (42%) had normal findings after both transthoracic and transoesophageal examination (p less than 0.005). Intracardiac masses, including valvular vegetations, were found in 39 patients (25%), including 27% of patients with cerebral embolism and 32% of these with peripheral embolism, but in none of the patients with retinal ischaemia (p less than 0.001). 47 patients (31%) had valvular disease, 10 (7%) had wall motion abnormalities, 23 (15%) had abnormalities of the interatrial septum, and 9 patients (6%) had diseases of the thoracic aorta. Cardiovascular abnormalities were frequently found by echocardiography in patients with arterial emboli. The transesophageal technique significantly increased the chance of detecting such abnormalities, especially intracardiac masses.

The clinical role of transoesophageal echocardiography

The role of transoesophageal echocardiography (TEE) was evaluated in a consecutive series of 100 procedures performed in 86 patients (age 17-81, mean 56 years). All patients had prior transthoracic echocardiography (TTE). TEE was performed with a 5 MHz phased array transoesophageal transducer with pulsed wave Doppler and colour flow mapping capability. Forty-four per cent of patients received intravenous sedation and 36% received antibiotic prophylaxis. There were no complications of TEE. The TTE and TEE findings were compared. In patients referred for possible cardiac source of embolism, left atrial thrombi were detected in 8/27 TEE studies but in none of 27 TTE studies. In 12 patients with prosthetic valve dysfunction TEE distinguished prosthetic from periprosthetic regurgitation in 9/12 studies compared to 3/12 with TTE. In 11 patients with suspected aortic dissection TEE correctly detected dissection in all seven cases in which the diagnosis was subsequently confirmed, whereas TTE showed only equivocal findings in two cases. Vegetations were detected by TEE in 4/5 studies in patients with proven native valve endocarditis and by TTE in 2/5. No vegetations were detected by TTE or TEE in five studies in patients with proven prosthetic valve endocarditis. Compared with other investigations there were no false positive TEE studies and one possible false negative study. We conclude that TEE is a safe procedure which often provides additional clinical information to transthoracic echocardiography.

The anatomical location of the transesophageal echocardiographic transducer during a short-axis view of the left ventricle

This study was performed to clarify the location of a transesophageal echocardiographic (TEE) transducer when obtaining the short-axis view of the left ventricle (S-LV). The depth of the probe tip from the incisors when obtaining a S-LV, the relationship to the diaphragm, and the location of the cardia of the stomach using a gastroscope attached to the TEE probe were measured in 24 patients undergoing coronary artery bypass grafting. The location of the transducer relative to the cardia and diaphragm was determined. The study demonstrated that when obtaining a S-LV, the transducer was in the stomach in 72.7%, at the cardia in 13.6%, and in the esophagus in 13.6% of the patients. The predominantly intragastric position of the transducer suggests that gastric diseases should be included as contraindications to TEE. When the probe was advanced about 40 cm from the incisors, some resistance was often encountered by the TEE operator at about the level of the diaphragm. Careful manipulation is mandatory to avoid tissue damage by the probe. Visualization of the S-LV can be disturbed by gas in the stomach. This is a specific problem in anesthetized patients because gas is often pushed into the stomach at the time of induction.

Intraoperative echocardiography in infants and children with congenital cardiac shunt lesions: transesophageal versus epicardial echocardiography

To determine the utility and limitations of intraoperative transesophageal echocardiography in infants and children with congenital intracardiac shunts, intraoperative transesophageal (n = 50) and epicardial (n = 49) echocardiograms were performed before and after cardiopulmonary bypass in children from 4 days to 16 years old and 3 to 45 kg in body weight. A miniaturized transesophageal probe (6.9 mm maximal diameter) was used in 36 patients weighting less than or equal to 20 kg. Epicardial imaging was performed with a 5 MHz precordial probe. The intraoperative transesophageal echocardiographic findings before and after cardiopulmonary bypass were correct and complete in 94% of patients. Transesophageal echocardiography correctly identified atrial septal defects, most types of ventricular septal defects, anomalous pulmonary veins, atrioventricular septal defects, tetralogy of Fallot, truncus arteriosus and double inlet ventricles. It failed to provide a correct diagnosis in only three patients, all of whom had doubly committed subarterial ventricular septal defects. Epicardial echocardiography identified all cases that had a doubly committed subarterial ventricular septal defect. A correct and complete intraoperative diagnosis was obtained with the use of epicardial imaging in 92% before and after cardiopulmonary bypass, but this technique required interruption of surgery and could not be completed in three patients because of induced arrhythmias and hypotension. These results demonstrated that intraoperative transesophageal echocardiography consistently defined important morphologic, color and pulsed Doppler ultrasound features of most congenital shunt lesions. Lesions that involved the right ventricular outflow tract are sometimes difficult to image with uniplane transesophageal echocardiography. There were no complications in any of the 50 subjects.

Direct visualization of ruptured chordae tendineae by transesophageal two-dimensional echocardiography

To determine the value of transesophageal echocardiography in the detection of ruptured chordae tendineae, 28 patients who had surgical therapy for pure mitral regurgitation were evaluated prospectively by conventional transthoracic and transesophageal two-dimensional echocardiography. Seventeen patients (Group I) had ruptured chordae tendineae and 11 (Group II) had intact chordae tendineae. Transthoracic echocardiography detected ruptured chordae tendineae in 6 patients from Group I (sensitivity 35%) and flail leaflets in 11 patients from Group I (sensitivity 65%). Transesophageal echocardiography disclosed ruptured chordae tendineae in all 17 Group I patients (sensitivity 100%); the sensitivity was significantly higher than that of transthoracic echocardiography. No abnormal chordal echoes were visualized in any patient from Group II by either transthoracic or transesophageal echocardiography (specificity 100%). Transesophageal echocardiography is a highly sensitive method for detecting ruptured chordae tendineae and is superior to transthoracic echocardiography in establishing its diagnosis.

Transesophageal echocardiography in the awake elderly patient: its role in the clinical decision-making process

To assess the impact on the management and safety of transesophageal echocardiography (TEE) in the elderly population, the results and limitations of this technique were retrospectively analyzed in 88 patients. TEE was indicated whenever the transthoracic approach was not diagnostic or was inconsistent with the clinical setting. The most frequent clinical indications were to investigate the source of emboli, assess valvular regurgitation, and identify valvular vegetations. In 72 patients (82%) TEE significantly influenced management decisions. In selected patients TEE avoided the use of more invasive diagnostic procedures. Adverse effects included occasional premature atrial or ventricular beats (11 patients), sinus bradycardia (six patients), and protracted nausea (one patient). We conclude that in elderly patients with cardiovascular diseases, TEE plays a significant role in the decision-making process without adding a significant risk.

Anatomic correlations of the long-axis views in biplane transesophageal echocardiography

The number of views obtainable during transesophageal echocardiography (TE) has been limited by the fixed position of the transducer at the end of the probe. This has confined standard TE studies to short-axis tomography of the heart and aorta. Recently, a biplane TE probe has become available that is capable of both long- and short-axis imaging. This study prospectively assessed the application of the long-axis plane of the biplane probe in providing complementary long-axis views in ambulatory patients. Six standard long-axis views could be obtained and were compared with corresponding anatomic sections to illustrate anatomic relations and facilitate structure identification. The long-axis views provide a better appreciation of the 3-dimensional nature of cardiac anatomy and function, especially in demonstrating the relation of vertically aligned structures.

Contribution of transesophageal echocardiography to patient diagnosis and treatment: a prospective analysis

The capability of transesophageal (TEE) versus transthoracic (TTE) echocardiography as a diagnostic tool in clinical practice was prospectively examined in 86 consecutive cases. A conclusive diagnosis was possible in 95% with TEE, whereas the same result was achieved in 48% by TTE. Specifically, TEE provided a conclusive diagnosis in 14 of 16 cases of infective endocarditis, while TTE gave this result in 4 of the 16 cases (p less than 0.001). Similarly, TEE allowed a conclusive diagnosis in 11 of 11 instances of aortic dissection, while TTE gave this indication in two cases (p less than 0.001). TEE was similarly effective in eight of eight cases of atrial thrombi, whereas TTE gave the diagnosis in three of eight cases (p less than 0.01). In five subjects with intracardiac masses, TEE gave a conclusive diagnosis in all five, whereas TTE was able to diagnose conclusively in one subject (p less than 0.02). In seven patients with mitral regurgitation, TEE gave the conclusive diagnosis in all seven and TTE was able to provide this information in four (p = NS). TEE was able to provide a conclusive diagnosis in four patients with aortic insufficiency, and TTE gave the same information in two of the four (p = NS). In 14 patients with prosthetic valve dysfunction, TEE gave the diagnosis in 12 and TTE gave it in eight patients (p = NS). Both methods gave a conclusive diagnosis in 13 out of 13 cases of mitral stenosis (p = NS). Also, TEE provided a conclusive diagnosis in eight of eight patients with adult congenital heart disease and TTE gave this information in four (p = NS).(ABSTRACT TRUNCATED AT 250 WORDS)

Onset of altered interventricular septal motion during cardiac surgery. Assessment by continuous intraoperative transesophageal echocardiography

Abnormal motion of the interventricular septum is frequently observed after uncomplicated cardiac surgery. We sought to elucidate the mechanism underlying this phenomenon by using continuous echocardiographic imaging of the heart from a constant transesophageal location in 21 patients undergoing their first cardiac operation. Quantitative global and regional functional analyses were performed in each patient at baseline (stage 1), after median sternotomy (stage 2), after sternal retraction (stage 3), after pericardiotomy (stage 4), after completion of cardiopulmonary bypass (stage 5), and after chest closure (stage 6). During the first four surgical stages, mean left ventricular fractional shortening varied little among regions with a fixed reference system (maximum range, 31.6-39.2%; p = NS) but changed dramatically after the discontinuation of cardiopulmonary bypass (stage 5). The apparent medial hypokinesis that was observed (4.9 +/- 4.7% [SD]) was accompanied by lateral hyperkinesis (65.2 +/- 4.1%, p less than 0.0001). These regional differences were completely eliminated with a floating reference system (33.6 +/- 2.7% for medial, and 34.8 +/- 1.7% for lateral; p = NS), suggesting cardiac translation. Quantitative curvature analysis supported this conclusion, with preservation of baseline regional curvature seen throughout the procedure. The mean length of individual translational vectors (reflecting systolic movement of the endocardial centroid) remained minimal (less than or equal to 1.0 mm) through stage 4 but increased more than fourfold at stage 5, continuing in a medial direction after chest closure (5.2 +/- 3.0 mm and 271 +/- 6 degrees from anterior). Thus, abnormal postoperative septal motion is not caused by removal of restraining forces of the pericardium or anterior mediastinum but rather appears to be directly related to events occurring during cardiopulmonary bypass.