Robin S. Freedberg

Atrial Septal Aneurysm in Adult Patients A Multicenter Study Using Transthoracic and Transesophageal Echocardiography

BACKGROUND An atrial septal aneurysm (ASA) is a well-recognized abnormality of uncertain clinical relevance. We reevaluated the clinical significance of ASA in a large series of patients. The aims of the study were to define morphological characteristics of ASA by transesophageal echocardiography (TEE), to define the incidence of ASA-associated abnormalities, and to investigate whether certain morphological characteristics of ASA are different in patients with and without previous events compatible with cardiogenic embolism. METHODS AND RESULTS Patients with ASA were enrolled from 11 centers between May 1989 and October 1993. All patients had to undergo transthoracic and transesophageal echocardiography within 24 hours of each other; ASA was defined as a protrusion of the aneurysm > 10 mm beyond the plane of the atrial septum as measured by TEE. Patients with mitral stenosis or prosthesis or after cardiothoracic surgery involving the atrial septum were excluded. Based on these criteria, 195 patients 54.6 +/- 16.0 years old (mean +/- SD) were included in this study. Whereas TEE could visualize the region of the atrial septum and therefore diagnose ASA in all patients, ASA defined by TEE was missed by transthoracic echocardiography in 92 patients (47%). As judged from TEE, ASA involved the entire septum in 100 patients (51%) and was limited to the fossa ovalis in 95 (49%). ASA was an isolated structural defect in 62 patients (32%). In 106 patients (54%), ASA was associated with interatrial shunting (atrial septal defect, n = 38; patent foramen ovale, n = 65; sinus venosus defect, n = 3). In only 2 patients (1%), thrombi attached to the region of the ASA were noted. Prior clinical events compatible with cardiogenic embolism were associated with 87 patients (44%) with ASA; in 21 patients (24%) with prior presumed cardiogenic embolism, no other potential cardiac sources of embolism were present. Length of ASA, extent of bulging, and incidence of spontaneous oscillations were similar in patients with and without previous cardiogenic embolism; however, associated abnormalities such as atrial shunts were significantly more frequent in patients with possible embolism. CONCLUSIONS As shown previously, TEE is superior to the transthoracic approach in the diagnosis of ASA. The most common abnormalities associated with ASA are interatrial shunts, in particular patent foramen ovale. In this retrospective study, patients with ASA (especially with shunts) showed a high frequency of previous clinical events compatible with cardiogenic embolism; in a significant subgroup of patients, ASA appears to be the only source of embolism, as judged by TEE. Our data are consistent with the view that ASA is a risk factor for cardiogenic embolism, but thrombi attached to ASA as detected by TEE are apparently rare.

High risk for vascular events in patients with protruding aortic atheromas: A prospective study

OBJECTIVES The purpose of this study was to prospectively evaluate the risk of vascular events in patients with protruding aortic atheromas. BACKGROUND Protruding atheromas of the thoracic aorta have been shown to be associated with embolic disease in previous retrospective studies. METHODS During a 1-year period, 521 patients had transesophageal echocardiography. Of these, 42 patients had protruding atheromas and no other source of emboli. They were followed up for up to 2 years (mean follow-up 14 months) and compared with a control group without atheromas, matched for age, gender and hypertension. RESULTS Of 42 patients with atheromas, 14 (33%) had 19 vascular events during follow-up (5 brain, 2 eye, 4 kidney, 1 bowel, 7 lower extremity). Of 42 control patients, 3 (7%) had vascular events (2 brain, 1 eye). Univariate analysis identified only protruding atheromas as significantly correlating with events (p = 0.003). There was no positive correlation of events with age, gender, hypertension, smoking, family history, atrial fibrillation, valve replacement, antithrombotic drug use, diabetes or coronary disease. Multivariate analysis showed that only protruding atheromas independently predicted events (p = 0.005, odds ratio 4.3, 95% confidence interval 1.2 to 15.0). Nine patients died in the atheroma group versus six in the control group, but this was not statistically significant (p = 0.39). CONCLUSIONS Protruding atheromas seen on transesophageal echocardiography predict future vascular events.

Effect of treatment on the incidence of stroke and other emboli in 519 patients with severe thoracic aortic plaque

Severe aortic plaques seen on transesophageal echocardiography (TEE) are a high-risk cause of stroke and peripheral embolization. Evidence to guide therapy is lacking. Retrospective information was obtained regarding the occurrence of embolic events (stroke, transient ischemic attacks, or peripheral emboli) in 519 patients with severe thoracic aortic plaque seen on TEE since 1988. Treatment with statins, warfarin, or antiplatelet medications was noted. Treatment was not randomized. In a matched-paired analysis, each patient taking each class of therapy was matched for age, gender, previous embolic event, hypertension, diabetes, congestive failure, and atrial fibrillation to someone not taking that medication. Multivariate analysis was also performed. An embolic event occurred in 111 patients (21%). Multivariate analysis showed that statin use was independently protective against recurrent events (p = 0.0001). Matched analysis also showed a protective effect of statins (p = 0.0004; absolute risk reduction 17%, relative risk reduction 59%, number needed to treat [n = 6]). No protective effect was found for warfarin or antiplatelet drugs. The odds ratio for embolic events was 0.3 (95% confidence interval [CI] 0.2 to 0.6) for statin therapy, 0.7 (95% CI 0.4 to 1.2) for warfarin, and 1.4 (95% CI 0.8 to 2.4) for antiplatelet agents. Thus, there is a protective effect of statin therapy, and no significant benefit of warfarin or antiplatelet drugs on the incidence of stroke and other embolic events in patients with severe thoracic aortic plaque on TEE.

The contribution of magnetic resonance imaging to the evaluation of intracardiac tumors diagnosed by echocardiography.

MAgnetic resonance (MR) imaging was performed in 14 patients with intracavitary cardiac tumors diagnosed by echocardiography. Except in the patients whose echocardiograms were diagnostic of atrial myxomas, this modality contributed important additional anatomic information regarding the tumors relationship to the normal intracardiac structures and/or its extension to the adjacent vascular and mediastinal structures. The MR findings correlated extremely well with the findings in all 12 patients who underwent surgical exploration or postmortem examination, and in the other two patients, MR guided the decision to obtain transvenous biopsy samples of their right heart masses.

Valve strands are strongly associated with systemic embolization: A transesophageal echocardiographic study

OBJECTIVES We attempted to determine the prevalence of strands on native and prosthetic valves, as detected by transesophageal echocardiography, and to assess the relative risk for systemic emboli associated with these strands. BACKGROUND Fine threadlike strands, seen on native and prosthetic valves by transesophageal echocardiography, have been implicated in systemic embolization. METHODS During a 2-year period, 1,559 patients underwent transesophageal echocardiography at our center. Of these, 41 patients had strands and no other identifiable source of systemic emboli. They were matched for age, gender, history of hypertension and history of smoking with a control group of 41 patients without strands who also had no identifiable source of emboli. The risk of embolization in the two groups was compared. RESULTS Of 1,559 patients studied by transesophageal echocardiography, 86 (5.5%) had strands. Strands were far more common on mitral valves than on aortic valves. Of the patients with strands, 38% had had an event consistent with a systemic embolus, whereas 62% had not. Of 597 patients with an embolic event, 63 (10.6%) had strands, whereas only 23 (2.3%) of 962 patients without emboli had strands. In the case-control study, 33 (83%) of the 41 patients with strands without another source of embolism had emboli compared with only 12 (29%) of the 41 control patients without another source (odds ratio 10.0, 95% confidence interval 3.6 to 27.8, p = 0.00001). CONCLUSIONS Valvular strands visualized by transesophageal echocardiography are associated with systemic embolization.

Transesophageal echocardiography is superior to transthoracic echocardiography in the diagnosis of sinus venosus atrial septal defect.

The purpose of this study was to compare transthoracic and transesophageal echocardiography in the diagnosis of various types of atrial septal defects. Forty-one adult patients with the clinical diagnosis of atrial septal defect were studied by transthoracic and transesophageal echocardiography (30 women, 11 men; 18 to 81 years of age). Transthoracic echocardiography demonstrated the atrial septal defect in 33 patients (secundum type in 28, primum type in 3 and sinus venosus type in 2). Transesophageal echocardiography demonstrated the defect in all 41 patients. Thus, in 8 (20%) of 41 patients the atrial septal defect was demonstrated by transesophageal and not by transthoracic echocardiography. Six of the eight had a sinus venosus type atrial septal defect; the other two patients had a secundum atrial septal defect (one of these two had a technically poor transthoracic echocardiogram and the other had a small atrial septal defect). Transthoracic echocardiography, therefore, failed to demonstrate the sinus venosus defect in six (75%) of eight patients. An anomalous venous connection associated with the sinus venosus defect was visualized by transesophageal echocardiography in seven of the eight patients but was not seen on transthoracic echocardiography in any patient. Sinus venosus type atrial septal defects are frequently not visualized in adults by conventional transthoracic echocardiography. Transesophageal echocardiography is recommended when an atrial septal defect is clinically suspected but cannot be visualized by transthoracic echocardiography.

Transesophageal echocardiography to detect atrial clots in candidates for percutaneous transseptal mitral balloon valvuloplasty

Left atrial thrombi are common in patients with mitral stenosis. When percutaneous balloon mitral valvuloplasty is performed on such patients, there is a potential risk of thrombus dislodgment and embolization. In this study conventional transthoracic echocardiography and transesophageal echocardiography were performed for percutaneous balloon mitral valvuloplasty on 19 consecutive candidates (6 men, 13 women, 23 to 81 years old). In five patients (26%), transesophageal echocardiography revealed a left atrial thrombus; in only one of these was there a suspicion of left atrial thrombus on transthoracic echocardiography. Balloon mitral valvuloplasty was canceled in four of the five patients. Three underwent mitral valve surgery that confirmed the echocardiographic findings. Transesophageal echocardiography is better than conventional transthoracic echocardiography in detecting left atrial clots in candidates for balloon mitral valvuloplasty. Because of the potential risk of embolization, transesophageal echocardiography is recommended in all candidates for balloon mitral valvuloplasty.

Exercise Doppler Echocardiography as an Aid to Clinical Decision Making in Mitral Valve Disease

The timing of valve replacement in patients with mitral valve disease, severe resting pulmonary hypertension, and severe symptoms is usually straightforward. However, this may not be true for patients with mild to moderate resting pulmonary pressures and symptoms that are difficult to evaluate. The measurement of hemodynamic parameters with exercise has been useful during cardiac catheterization. The purpose of this study was to evaluate the hemodynamic significance of dyspnea provoked by exercise in patients with mitral valve disease using exercise Doppler echocardiography. Nineteen tests were done in 17 patients (two patients had repeat studies 1 year after the first test). Dyspnea developed in patients during exercise in 11 tests, and the others were limited by fatigue (and angina in one patient). There was a significantly greater increment in pulmonary artery systolic pressure during exercise in the patients who developed dyspnea (24 mm Hg) than in those who did not (15 mm Hg, p = 0.04). The two groups exercised to approximately the same heart rate and blood pressure, but the dyspneic patients had a significantly shorter exercise capacity (p = 0.04). Furthermore, clinical decision making was affected by the test results in 84% (only three tests did not affect patient management) and included a decision to proceed to invasive testing and surgery in seven patients, and a decision to treat the patient medically in nine. In conclusion, exercise Doppler echocardiography is a useful adjunct in the diagnosis and treatment of patients with mitral valve disease and an aid to clinical decision making.

Comparison of cardiac catheterization and Doppler echocardiography in the decision to operate in aortic and mitral valve disease

Clinical decisions utilizing either Doppler echocardiographic or cardiac catheterization data were compared in adult patients with isolated or combined aortic and mitral valve disease. A clinical decision to operate, not operate or remain uncertain was made by experienced cardiologists given either Doppler echocardiographic or cardiac catheterization data. A prospective evaluation was performed on 189 consecutive patients (mean age 67 years) with valvular heart disease who were being considered for surgical treatment on the basis of clinical information. All patients underwent cardiac catheterization and detailed Doppler echocardiographic examination. Three sets of two cardiologist decision makers who did not know patient identity were given clinical information in combination with either Doppler echocardiographic or cardiac catheterization data. The combination of Doppler echocardiographic and clinical data was considered inadequate for clinical decision making in 21% of patients with aortic and 5% of patients with mitral valve disease. The combination of cardiac catheterization and clinical data was considered inadequate in 2% of patients with aortic and 2% of patients with mitral valve disease. Among the remaining patients, the cardiologists using echocardiographic or angiographic data were in agreement on the decision to operate or not operate in 113 (76% overall). When the data were analyzed by specific valve lesion, decisions based on Doppler echocardiography or catheterization were in agreement in 92%, 90%, 83% and 69%, respectively, of patients with aortic regurgitation, mitral stenosis, aortic stenosis and mitral regurgitation. Differences in cardiac output determination, estimation of valvular regurgitation and information concerning coronary anatomy were the main reasons for different clinical management decisions. These results suggest that for most adult patients with aortic or mitral valve disease, alone or in combination, Doppler echocardiographic data enable the clinician to make the same decision reached with catheterization data.

The anatomy of the interatrial septum: A transesophageal echocardiographic study

Transesophageal echocardiography provides a unique view of the IAS. We reviewed results of 119 transesophageal studies (1) to study the detailed anatomy of the IAS, and (2) to determine the thickness of the IAS at different times during the cardiac cycle, (3) the effect of age, and (4) the thickness of the IAS in relation to various disease states. From the transesophageal view the IAS extends from the right posteriorly toward the left and anteriorly. The more inferior aspect of the septum courses in a more direct posteroanterior direction and is more difficult to accurately visualize. The IAS is thickest peripherally and gradually narrows toward the more centrally located fossa ovalis. A region of constant thickness is frequently present between the most peripheral aspect of the IAS and the fossa ovalis. We standardized the measurement of the thickness of the septum by measuring it only at this region of constant thickness in the plane that visualized the fossa ovalis. The mean thickness at this point was 6 +/- 2 mm. The thickness correlated weakly with the age of the patient. These results agree with previously published autopsy findings. Thickness was not affected by the presence of significant disease of the atrioventricular valves, atrial fibrillation, or an atrial septal defect. However, the thickness increased to 7 +/- 2 mm with atrial contraction during sinus rhythm (p less than 0.0001). The mean thickness of the septum primum covering the fossa ovalis was 1.8 +/- 0.7 mm.(ABSTRACT TRUNCATED AT 250 WORDS)