Rita A. Longaker

Transesophageal echocardiographic guidance of cardioversion in patients with atrial fibrillation

The role of TEE in the guidance of cardioversion of atrial fibrillation was studied. Thirty-seven (18%) of 206 patients had left atrial thrombus. Cardioversion was attempted in 153 patients receiving no (n = 107) or < 7 days (n = 46) of anticoagulation prophylaxis, in 27 patients after > or = 3 weeks of anticoagulation, and was cancelled in 26 patients, primarily on the basis of TEE findings. Left atrial thrombus was observed in 37 (18%) of 206 patients. No embolic complications occurred over a 4-week follow-up period. In 7 (41%) of 17 patients new left atrial appendage spontaneous echocardiographic contrast developed immediately after electric cardioversion. In this group, significant decreases occurred in the left atrial appendage maximal emptying shear rate (11.1 +/- 11.1 sec-1 vs 5.0 +/- 5.1 sec-1; p < 0.05), maximal filling shear rate (6.7 +/- 5.9 sec-1 vs 3.7 +/- 3.5 sec-1; p < 0.05), and peak emptying velocity (0.38 +/- 0.29 cm/sec vs 0.19 +/- 0.14 cm/sec; p < 0.05). In one patient a left atrial appendage thrombus formed after electric cardioversion. Left atrial thrombus resolved in 1 (5%) of 21 patients and became immobile in 0 (0%) of 16 patients after 3 to 5 weeks of anticoagulation but resolved (n = 9) or became immobile (n = 6) in 15 (71%) of 21 patients after > 5 weeks of anticoagulation. TEE-guided cardioversion was safely done without or with < 7 days of anticoagulation prophylaxis in selected patients, but the potential for left atrial thrombus to form after electric cardioversion makes anticoagulation advisable in all patients. The conventional recommendation of 3 to 4 weeks of anticoagulation prophylaxis before cardioversion is usually inadequate for left atrial thrombus to resolve or to become immobile.

The safety of transesophageal echocardiography in the elderly

The safety of transesophageal echocardiography (TEE) in elderly patients (aged > or = 70 years) and young patients (aged < or = 50 years) was compared in a retrospective study of 283 examinations in each group. A greater percentage of studies was performed in an intensive care unit in the elderly group (22%) as compared with the younger group (13%, p < 0.02). In studies performed in an intensive care unit, 39% (24/61) of patients in the elderly group and 45% (17/38) in the young group were on ventilators. Transient systemic hypotension complicating TEE was 3.5 times more frequent in the elderly (5%) as compared with the young group (1.4%, p < 0.02). Life-threatening complications associated with TEE were rare (< 0.01%) and included third-degree atrioventricular block in one patient and profound vasovagal reaction in one patient in the elderly group and myocardial ischemia in one patient in the young group. Being elderly and on a ventilator were independent predictors of the development of systemic hypotension during TEE. Overall, TEE is a low-risk procedure but is associated with a 3.5 times greater risk of systemic hypotension in elderly patients as compared with younger subjects. The benefit and risk should be assessed in all patients before TEE, particularly in the elderly.

Diastolic dysfunction is a feature of the antiphospholipid syndrome

Recurrent thrombi, thrombocytopenia, pregnancy loss, and stroke in association with medium to high concentrations of anticardiolipin antibodies are well-recognized features of antiphospholipid syndrome. Cardiac manifestations of primary antiphospholipid syndrome (PAPS) also have been documented but involve structural and valvular heart disease. Diastolic dysfunction in PAPS has not been well described. Therefore, 10 patients with PAPS (nine women and one man) of mean age 30 +/- 7 years (range 20 to 46 years) and 10 healthy age-, sex-, weight-, and height-matched control subjects were studied by echocardiography. Anticardiolipin antibody concentrations of patients with PAPS were > 80 immunoglobulin G phospholipid units as determined by enzyme-linked immunosorbent assay. Doppler-derived parameters of left ventricular filling showed a significant association between PAPS and diastolic dysfunction compared with control, as evidenced by a decrease in peak early filling velocity (52 +/- 10 cm/sec vs 67 +/- 12 cm/sec; p < 0.01), a decrease in the ratio of peak early to peak atrial filling velocities (1.03 +/- 0.40 vs 1.52 +/- 0.28; p < 0.005), a decrease in the mean deceleration rate of early filling (338 +/- 75 cm/sec2 vs 590 +/- 227 cm/sec2; p < 0.005), and an increase in the percentage of atrial contribution to filling and deceleration time. Left ventricular mass, diastolic filling time, and heart rate did not differ between groups. Left ventricular systolic function was normal and ejection fraction did not differ between patients with PAPS and control subjects (63% +/- 2% vs 65% +/- 7%; p not significant).(ABSTRACT TRUNCATED AT 250 WORDS)

Doppler transesophageal echocardiographic determination of aortic valve area in adults with aortic stenosis

Two-dimensional transesophageal echocardiography has been shown to be an accurate method of measuring aortic valve area in patients with aortic stenosis. The accuracy of Doppler transesophageal echocardiography for this purpose is unknown. Thus 86 consecutive adult patients (mean age 68 +/- 11 years) with calcific (n = 79) or congenital bicuspid (n = 7) AS were studied by biplane or multiplane transesophageal echocardiography. From the transgastric long-axis view, continuous wave Doppler of peak aortic valve velocity and pulsed Doppler of left ventricular outflow tract velocity were determined. Left ventricular outflow tract diameter was measured from a transesophageal echocardiography long-axis view, and cross-sectional area was calculated. Aortic valve area was calculated by the continuity equation. Two-dimensional transesophageal echocardiography was used to directly measure aortic valve area by planimetry of the minimal orifice from a short-axis view. Aortic valve area determination was less feasible by Doppler (62 of 86 patients, or 72%) versus two-dimensional transesophageal echocardiography (81 of 86 patients, or 94%; p < 0.0025) because of the inability to align the continuous wave Doppler beam with the aorta in 24 patients. The feasibility of obtaining aortic valve area by Doppler transesophageal echocardiography improved from the first 43 patients (24 of 43 patients, or 56%) to the latter 43 patients (38 of 43 patients, or 88%; p < 0.0025) and suggests a significant learning curve. In 62 patients, aortic valve area by Doppler and two-dimensional transesophageal echocardiography did not differ (1.30 +/- 0.54 cm2 vs 1.23 +/- 0.46 cm2, p = not significant) and correlated well (r = 0.88; standard error of the estimate = 0.26 cm2; intercept = 0.02 cm2; slope = 1.04; p = 0.0001). Absolute and percent differences between aortic valve area measured by Doppler and two-dimensional transesophageal echocardiography were small (0.18 +/- 0.20 cm2 and 15% +/- 15%, respectively). Mild, moderate, and severe aortic stenosis by two-dimensional transesophageal echocardiography was correctly identified in 93% (28 of 30), 79% (15 of 19), and 77% (10 of 13) of patients by Doppler transesophageal echocardiography, respectively. Doppler transesophageal echocardiography is an accurate method to measure aortic valve area in patients with aortic stenosis and should complement two-dimensional transesophageal echocardiography. The feasibility of Doppler transesophageal echocardiography for aortic valve area determination has a significant learning curve.

Mobile strands are frequently attached to the St. Jude Medical mitral valve prosthesis as assessed by two-dimensional transesophageal echocardiography

Two-dimensional transesophageal echocardiographic findings are reported in 13 patients with structurally and functionally normal St. Jude Medical bileaflet mitral valve prostheses. Multiple mobile linear echogenic densities attached to the pivot of the prosthesis were present in 9 of 13 patients. These densities may represent fibrin strands. These mobile strands alternatively resolve and reform over a period of 5 to 14 months after mitral valve replacement. No adverse clinical events were attributable to these prosthetic mitral valve strands. We conclude that mobile stands are frequently attached to the structurally and functionally normal St. Jude Medical mitral valve prosthesis. The clinical significance of these prosthetic mitral valve strands requires clarification.

Transesophageal Echocardiography Impacts Management and Evaluation of Patients with Stroke, Transient Ischemic Attack, or Peripheral Embolism

The relative impact of transesophageal echocardiography (TEE) on the management of patients with specific embolic events, namely nonhemorrhagic cerebrovascular accident (CVA), transient ischemic attack (TIA), or peripheral embolism is controversial. The impact of TEE in 234 adult subjects with CVA (n = 141), TIA (n = 59), or peripheral embolism (n = 34) was determined. TEE was diagnostic of a potential embolic source in 61%, 51%, and 62% of patients with CVA, TIA, and peripheral embolism, respectively (P = NS). TEE results changed medication or surgical treatment in 32%, 22%, and 32% of patients with CVA, TIA, and peripheral embolism, respectively (P = NS). Anticoagulation was started on the basis of TEE findings in 11%, 12%, and 18% of patients with CVA, TIA, and peripheral embolism, respectively (P = NS). In 77% of all patients, TEE findings confirmed as appropriate the empiric decision made prior to TEE, to anticoagulate (60%; 12/20) or not to anticoagulate (79%; 168/214). These data demonstrate that TEE findings have a significant and similar impact on the clinical management of patients with various types of potential embolism. Future studies addressing the effectiveness of treatment, guided by TEE findings, in the prevention of recurrent embolic events are needed.

Two-dimensional Transesophageal Echocardiographic Characterization of Ventricular Filling in Real Time by Acoustic Quantification: Comparison with Pulsed Doppler Echocardiography

Little is known about the accuracy of acoustic quantification (AQ) in the assessment of left ventricular diastolic filling. Therefore the objective of this study was to determine the ability of AQ applied to two-dimensional echocardiography to characterize left ventricular diastolic filling compared with Doppler echocardiography. In 80 unselected patients, AQ of left ventricular diastolic filling was performed during two-dimensional transesophageal echocardiography. Pulsed Doppler transthoracic echocardiography was performed at the tips of the mitral valve leaflet and the mitral annulus level. In 53 patients with synchronous systolic wall motion, significant correlations were found between AQ-derived versus Doppler-derived indexes obtained from the level of the mitral annulus of peak rate of increase in left ventricular diastolic area versus peak early filling velocity (r = 0.78; p < 0.0001), peak early/peak atrial rate of change in left ventricular area ratio versus peak early/peak atrial filling velocity ratio (r = 0.80; p < 0.0001), and percent atrial contributions to filling (r = 0.80; p < 0.0001). Correlations between acceleration time and deceleration time derived by AQ versus Doppler echocardiography were poor. Acoustic quantification-derived acceleration and deceleration times significantly underestimated analogous times derived by Doppler echocardiography at the mitral annulus level. Correlations obtained between AQ-derived indexes and Doppler echocardiography were better with pulsed Doppler performed at the mitral annulus level compared with the leaflet tips. In 27 patients with asynchronous systolic wall motion, the correlations between AQ-derived indexes and Doppler-derived indexes of the relative distribution of filling were similar to those of the group of subjects with synchronous wall motion. However, in patients with asynchronous wall motion the correlations between indexes of peak early filling velocity and rate worsened. In addition, no correlations were found between acceleration and deceleration times derived by the two techniques in subjects with asynchronous systolic wall motion. Acoustic quantification assessment of left ventricular diastolic filling accurately characterizes the distribution of diastolic filling compared with Doppler echocardiography. The presence of asynchronous systolic wall motion decreases the accuracy of the AQ method in assessing peak filling rate. The ultimate clinical application of AQ in the assessment of left ventricular diastolic filling is yet to be determined but appears promising.

The role of transesophageal echocardiography in cardiac donor screening

Transthoracic echocardiography has played a useful role in the screening of cardiac transplant donors. However, transthoracic echocardiograms may be suboptimal in many patients on ventilators. The role of transesophageal echocardiography in cardiac donor screening is unknown. Therefore we compared the potential benefit of transesophageal echocardiography combined with transthoracic echocardiography in 24 (16 men and 8 women) consecutive brain-dead patients with a mean age of 29 +/- 9 years (range 16 to 44 years), who were being considered as cardiac transplant donors. Transthoracic echocardiography was performed immediately before or after transesophageal echocardiography. Transthoracic echocardiography was technically difficult in 7 of 24 (29%) patients. Results of transesophageal echocardiography were abnormal in five of the seven patients and demonstrated left (n = 4) and right (n = 3) ventricular wall motion abnormalities and concentric left ventricular hypertrophy (n = 2). The four patients with wall motion abnormalities were eliminated as potential donors. In 16 of 17 patients with technically adequate transthoracic echocardiograms, transesophageal and transthoracic echocardiographic findings agreed and demonstrated normal hearts in 13 patients, left (n = 2) and right (n = 1) ventricular wall motion abnormalities in two patients, and isolated concentric left ventricular hypertrophy in one patient. In 1 of the 17 patients with a technically adequate transthoracic echocardiographic study, a bicuspid aortic valve was demonstrated by transesophageal echocardiography but not diagnosed by transthoracic echocardiography. Overall seven patients were eliminated as cardiac donors on the basis of transesophageal echocardiograms (n = 7), transthoracic echocardiograms (n = 2), or both.(ABSTRACT TRUNCATED AT 250 WORDS)

Transesophageal echocardiography in the pregnant patient

conclusion of TPA treatment, aspirin and heparin therapy were started to prevent further thrombosis. Several days later, her regimen of daily doses of warfarin was resumed, and the heparin therapy was discontinued. The patient tolerated thrombolysis well, with no obvious side effects, and was transferred out of the intensive care unit on day 6. She was discharged on day 16, with no detectable signs of valvular dysfunction. Follow-up examinations 3 and 6 months later revealed no further signs of valvular thrombosis. We chose a lower dose of TPA, approximately l/10 to l/20 the usual adult acute dose, in an attempt to decrease the risk of bleeding and embolization of the thrombi through the patient’s ventricular septal defect. We felt that a continuous infusion would provide the optimum activation of the thrombolyt,ic pathway because it, would allow slow dissolution of the clots’ exposed surfaces and thus would help prevent embolization of a larger piece. The combination of continuous infusion and a half-life of 3 to 10 minutes would, we believed, allow us to terminate the process rapidly if bleeding or cerebral embolism occurred or if the therapy failed and an urgent operation was necessary. The prolonged half-life of streptokinase and urokinase make them less attractive for this reason. There are potentially serious risks associated with thrombolytic agents. There is an 0.4”,’ to 1“;) incidence of intracranial bleeding and as high as a 5”~’ incidence of other organ bleeding. Also, TPA is 10 to 20 times more expensive than the other thrombolyt,ic agents. Despite the potential problems of TPA, its use should be considered for the treatment of life-threatening thrombosis when other agents have failed or have caused allergic reactions, or when an urgent operation will be necessary should medical management fail. Medical management with TPA should only be attempted, however, in institutions where alternative medical and surgical therapies are available in case of emergency.

Transesophageal echocardiography: normal variants and mimickers.

An accurate diagnosis of cardiac pathology using TEE is contingent upon the ability to recognize and differentiate normal cardiac structures and normal variants from pathologic conditions. We describe several normal cardiac structures commonly imaged using TEE of the atria, interatrial septum, aorta, valves, and extracardiac spaces that may mimic diverse pathologic states, such as intracardiac tumor and thrombus, valvular vegetations, mitral and tricuspid valve prolapse, atherosclerotic plaque, and aortic dissection. Methods to aid in the differentiation of normal cardiac structures from pathology are offered.