Susanne Mohr-Kahaly

Aortic intramural hemorrhage visualized by transesophageal echocardiography: Findings and prognostic implication

OBJECTIVES This study describes the transesophageal echocardiographic and follow-up findings in patients with aortic intramural hemorrhage. BACKGROUND Localized aortic intramural hemorrhage resulting in layered thickening of the aortic wall seems to represent a variant of acute aortic dissection without communication or a typical moving intimal flap. In autopsy studies this variant, attributed to a rupture of the vasa vasorum, has been described in 5% to 10% of patients with dissection. METHODS In a prospective transesophageal echocardiographic study in patients with aortic dissection performed between 1986 and 1991, the diagnosis of intramural hemorrhage was established in 15 of 114 patients and either confirmed anatomically (7 patients) with an additional diagnostic imaging technique or on the basis of clear follow-up changes (8 patients). RESULTS Elderly patients (mean age 70 years) with a history of hypertension were affected by this variant of dissection. The ascending aorta was involved in 3 patients and the descending aorta in 12. The longitudinal extent varied between 3 and 20 cm, and wall thickness varied between 0.7 and 3 cm. Classic aortic dissection developed in five patients (33%) and rupture in four (27%). Regression of aortic wall thickening was noted in two patients, whereas three patients became asymptomatic without apparent wall changes (33%). Surgery was performed in 5 patients, whereas medical therapy was continued in 10. During a mean follow-up period of 11 months, eight patients (53%) died because of complications of the aortic disease. CONCLUSIONS Intramural hemorrhage represents a variant of aortic dissection and may be an early finding in patients who develop classic aortic dissection or rupture. Transesophageal echocardiography is an excellent method for the detection of intramural hemorrhage and for monitoring these patients.

Ambulatory follow-up of aortic dissection by transesophageal two-dimensional and color-coded Doppler echocardiography.

Follow-up of 18 patients with aortic dissection (five with type I, one with type II, 11 with type III dissection according to DeBakey) by transesophageal, two-dimensional and color-coded Doppler echocardiography showed a persistence of the false lumen in five of seven patients (71%) after surgery and in nine of 11 patients (82%) after medical therapy. In two patients treated with surgery, the dissected part of the aorta had been resected, whereas in two patients treated medically, a progressive and complete obliteration of the false lumen was observed. In the false lumen, thrombus formation was absent in four, localized in four, and progressive in six patients. Flow within the false lumen could be registered in 14 patients, and two distinct flow patterns were differentiated (laminar biphasic flow or slowly circulating flow). Persisting intimal tears were visualized by two-dimensional echocardiography in four patients, whereas color-coded Doppler showed an additional one to three intimal tears in the descending aorta in 10 patients. Flow across these intimal tears was biphasic in 75% of patients; that is, systolic flow was directed from the true to the false lumen with diastolic flow reversal. Unidirectional flow was detected in 25% of the communications, directed in 20% from the true to the false lumen, serving as an entry only and in one (5%) as reentry only. Additional information concerning complications like extension of the dissection (one of 18 patients), localized dilatation of the regurgitation (three of 18 patients) were detected by this method. Concerning the morphologic findings and the detection of flow characteristics, the transesophageal approach was superior to conventional echocardiography especially in the descending thoracic aorta. Thus, transesophageal two-dimensional and color-coded Doppler echocardiography seems to be an ideal method not only for the easy detection of aortic dissection but also for follow-up.

The presence of infection-related antiphospholipid antibodies in infective endocarditis determines a major risk factor for embolic events

OBJECTIVES The impact of infection-associated antiphospholipid antibodies (APA) on endothelial cell activation, blood coagulation and fibrinolysis was evaluated in patients with infective endocarditis with and without major embolic events. BACKGROUND An embolic event is a common and severe complication of infective endocarditis. Despite the fact that APAs are known to be associated with infectious diseases, their pathogenic role in infective endocarditis has not been clearly defined. METHODS The relationship among the occurrence of major embolic events, echocardiographic vegetation size, endothelial cell activation, thrombin generation, fibrinolysis and APA was examined in 91 patients with definite infective endocarditis, including 26 patients with embolic events and 65 control subjects without embolic events. RESULTS Overall, 14.3% of patients exhibited elevated APA levels. Embolic events occurred more frequently in patients with elevated levels of APA than in patients without (61.5% vs. 23.1%; p = 0.008). Patients with elevated levels of APA showed higher levels of prothrombin-fragment F1 +2 (p = 0.005), plasminogen-activator inhibitor 1 (p = 0.0002), von Willebrand factor (p = 0.002) and lower levels of activated protein C (p = 0.001) than patients with normal levels of APA. Thrombin generation and endothelial cell activation were both positively correlated with levels of APA. The occurrence of elevated APA levels was frequently associated with structural valve abnormalities (p = 0.01) and vegetations >1.3 cm (p = 0.002). CONCLUSIONS Infection-associated elevated APA levels in patients with infective endocarditis are related to endothelial cell activation, thrombin generation and impairment of fibrinolysis. This may contribute to the increased risk for major embolic events in these patients.

Measurement of intracardiac dimensions and structures in normal young adult subjects by transesophageal echocardiography

Transesophageal echocardiography (TEE) has proven to be an excellent diagnostic means of diagnosing different cardiac diseases. To distinguish between normal and pathologic findings, standardized measurements of well-defined cross-sectional planes are necessary. Therefore, the 2-dimensional echocardiographic data of 25 healthy volunteers were obtained. In 13 men and 12 women, aged 19 to 30 years, recordings of the left ventricular short-axis view, the 2- or 4-chamber view with the left and right atria, the long axes of the left and right ventricles, the mitral and tricuspid valve ring and the atrial septum were analyzed. Furthermore, the aortic valve plane and the ascending and descending aorta were also measured. All data are given as mean values +/- 2 times the standard deviation. End-diastolic and end-systolic left ventricular anterior-to-posterior diameter of the left ventricular short axis was 2.5 +/- 0.3 cm/m2 and 1.7 +/- 0.3 cm/m2, with the fractional shortening ranging from 27 to 42%. The end-systolic lateral diameter was 2.4 +/- 0.5 cm/m2 for the left atrium and 2.4 +/- 0.4 cm/m2 for the right atrium, and the end-systolic anterior-to-posterior diameter was 1.5 +/- 0.6 cm/m2 for the left atrium and 2.1 +/- 0.6 cm/m2 for the right atrium. End-diastolic diameters of 3.4 +/- 0.6 cm/m2 and 2.8 +/- 0.4 cm/m2 were obtained for the long axis of the left ventricle and for the right ventricle. Measurements ranged from 1.5 to 2.2 cm/m2 for the end-diastolic diameter of the mitral ring and from 1.3 to 2.0 cm/m2 for the tricuspid ring.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiovascular Hemodynamics and Exercise Tolerance in Thyroid Disease

The heart is an organ sensitive to the action of thyroid hormone, and measurable changes in cardiovascular performance are detected with small variations in thyroid hormone serum concentrations. Most patients with thyroid disease experience cardiovascular manifestations, and the most serious complications of thyroid dysfunction occur as a result of cardiac involvement. The increased metabolic state and oxygen consumption that occur in hyperthyroid patients require an increased supply of oxygen and removal of metabolic products from the periphery. This is accomplished by increasing the cardiac output to meet the needs of the periphery. Circulation time is decreased in hyperthyroid patients, and a lowered arterial resistance and increased venous resistance promote the return of blood to the heart. Thyroid hormones may significantly decrease the strength of respiratory and skeletal muscles and affect regulatory mechanisms of adaptation to incremental effort. In hyperthyroidism, cardiovascular exercise testing and analysis of respiratory gas exchange demonstrate low efficiency of cardiopulmonary function as well as impaired chronotropic, contractile, and vasodilatatory reserves, which are reversible when euthyroidism is restored. During exercise, the increment (delta) of minute ventilation (respiratory rate x tidal volume), and oxygen pulse (oxygen uptake per heart beat) are significantly lower in dysthyroidism versus euthyroidism. Especially in older patients with thyroid dysfunction, markedly reduced workload, delta ejection fraction, and delta heart rate, both at the anaerobic threshold as well as at maximal exercise, are observed. In thyrotoxicosis, mitochondria oxidative dysfunction during exercise mostly causes intracellular acidosis, whereas in hypothyroidism, inadequate cardiovascular support appears to be one of the principal factors involved. These abnormalities partly explain why subjects with dysthyroidism are intolerant to exertion. Thus, in thyroid disease, both cardiac structures and function may remain normal at rest, however impaired cardiovascular and respiratory adaptation to effort becomes unmasked during exercise.

Improvement of tricuspid regurgitation after pulmonary thromboendarterectomy.

BACKGROUND For patients with chronic thromboembolic pulmonary hypertension who undergo pulmonary thromboendarterectomy (PTE) it has not yet been systematically investigated how operation affects the severity of tricuspid regurgitation (TR). This study sought (1) to evaluate the extent of TR reversibility after operation, (2) to identify potential predictors of the reversibility of TR, and (3) to investigate the influence of geometric and hemodynamic alterations on the extent of TR severity. METHODS Thirty-nine patients (55+/-12 years) undergoing PTE without tricuspid valve repair were investigated before and 13+/-8 days after operation by Doppler color flow mapping. Geometry of the tricuspid valve as well as right ventricular size and function were determined with echocardiography. Mean pulmonary arterial pressure was determined invasively. RESULTS After PTE, mean pulmonary arterial pressure was significantly lower (48+/-10 versus 25+/-7 mm Hg, p < 0.05). Most of the patients had a distinct reduction of TR, and the improvement trend showed on the severity scale: number of patients with 4+TR (23 --> 4), 3+TR (12 --> 12), 2+TR (2 --> 13), and 1+TR (2 --> 10). Examination after PTE revealed profound reduction of right ventricular size and annulus diameter, with a normalization of the valvular geometry. However, none of the study variables were useful as indicators of the postoperative outcome. CONCLUSIONS After PTE without additional valve repair most patients show significantly reduced severity of TR soon afterward; the very few cases in which TR does not improve remain unidentifiable before operation. Our recommendation is consequently to refrain from additional tricuspid repair in patients undergoing PTE.

Direct measurement of left ventricular outflow tract by transthoracic real-time 3D-echocardiography increases accuracy in assessment of aortic valve stenosis

BACKGROUND Evaluation of aortic valve stenosis is a major clinical application of echocardiography. The widely employed continuity equation requires determination of the left ventricular outflow tract (LVOT) area. We aimed at testing whether direct area measurement in a volume data set is superior to conventional calculation from the LVOT diameter. METHODS We performed LVOT measurement in 20 normal subjects and 83 patients with moderate to severe aortic stenosis with a transthoracic real-time three-dimensional echocardiography (3D-TTE) technique in two systolic frames. The off-line 3D-evaluation allows full choice of section planes within the acquired volume data set. The aortic valve area was calculated from systolic LVOT areas. These results were compared to area values obtained by M-mode LVOT-diameters (area=pi(*)(d/2)(2)). In addition, the calculated aortic valve orifices were compared to invasive measurements or direct planimetry in the transthoracic or transesophageal examination. RESULTS Two independent observers found a reduction in LVOT area during systole (p<0.001). Often a more ellipsoid-like shaped LVOT resulted at end-systole which was shown by a reduction (p<0.001) of the LVOT longitudinal to oblique axis ratio. 3D-TTE determination of aortic valve orifice areas (mean difference: -0.04+/-0.09 cm(2)) showed a lesser deviation from the invasively or planimetrically measured areas than conventionally calculated LVOT areas (mean difference: -0.1+/-0.1 cm(2)) using the continuity equation (p<0.001). CONCLUSIONS The tested transthoracic 3D-echocardiography technique offers non-invasive measurement of the LVOT and aortic valve area based on the continuity equation during systole and thus improves accuracy and, additionally, agreement of aortic valvular area determination with invasive and direct measurements.

Quantitative assessment of aortic stenosis by three-dimensional echocardiography☆☆☆★

The purpose of this study was to assess the feasibility of three-dimensional echocardiography in aortic stenosis. Planimetric determination of valve area and dynamic volume-rendered display were performed. Three-dimensional echocardiography permits display of any desired plane of the cardiac structure. Thus in the case of aortic stenosis, the plane used for planimetric evaluation can be positioned exactly through the valve orifice. Dynamic volume-rendered display may provide a spatial demonstration of the stenotic valve. In 48 patients aortic valve area was measured by planimetry. The three-dimensional data set was acquired by a workstation in the course of a multiplane transesophageal examination. Results were compared with those obtained by multiplane transesophageal two-dimensional planimetric technique and invasive measurement. A dynamic three-dimensional reconstruction was displayed. Planimetric determination of valve area was possible in 42 (88%) of 48 cases. Statistical analysis of the data acquired showed a good agreement between three-dimensional echocardiography and transesophageal echocardiography (mean difference +0.018 cm2; SD = 0.086) and between three-dimensional echocardiography and the invasive technique (mean difference +0.012 cm2; SD = 0.12). Dynamic volume-rendered display was possible in 42 of 48 cases. Three-dimensional echocardiography permits accurate and reliable determination of aortic valve area. Preoperative spatial recognition of the stenotic valve is possible by dynamic volume-rendered display.

Exercise echocardiography for the evaluation of patients after nonsurgical coronary artery revascularization

OBJECTIVES The purpose of this study was to demonstrate the accuracy of stress echocardiography for detecting the progression of coronary artery disease after nonsurgical revascularization. BACKGROUND The expanding role of nonsurgical coronary revascularization procedures mandates the development of sensitive noninvasive techniques for the detection of recurrent ischemia. METHODS Bicycle stress echocardiography was performed in a series of 86 patients 6.5 +/- 1.3 months after a revascularization procedure. Seven patients were excluded from analysis because of poor echocardiographic image quality. RESULTS Digital analysis achieved a sensitivity of 83% for the entire group and a specificity of 85% for stress echocardiographic detection of significant coronary artery disease. Sensitivity was greater in patients with (88%) than in those without (75%) prior myocardial infarction, but this difference did not reach statistical significance. Additional analysis using an increase in end-systolic volume index or a decrease in ejection fraction during stress as an additional marker for ischemia tended to enhance sensitivity (90% for the entire group and 93% for the subgroup with prior myocardial infarction). CONCLUSIONS Stress echocardiography is a useful and sensitive method for the follow-up of patients undergoing nonsurgical revascularization procedures. The addition of volume determination to routine wall motion analysis may be helpful in patients with prior infarction who have scar tissue that may be difficult to distinguish from an adjacent exercise-induced wall motion abnormality.

Transthoracic three-dimensional echocardiographic volumetry of distorted left ventricles using rotational scanning☆☆☆★

The purpose of this study was to evaluate the relation of transthoracic three- and two-dimensional echocardiographic left ventricular volumetry to cineventriculographic volumetry. Twenty-five patients with distorted left ventricles were included in the study. To demonstrate the impact of acquiring data by rotational scanning, we performed three- and two-dimensional echocardiography in 36 latex ventricles with data acquisition in different areas of the ultrasound sectors. Interobserver and intraobserver variability were calculated to test for reproducibility. The three-dimensional imaging system consisted of a rotation motor device, a transthoracic 2.5 MHz transducer, a conventional ultrasound unit, and a work-station (TomTec) which provides data acquisition, post-processing, and two- or three-dimensional visualization of digitized data. The transducer moved automatically at 2-degree increments with data acquisition at each tomographic level. The mean investigation time for three-dimensional echocardiography was 21 +/- 6 minutes. In the central near field of the transducer, differences from true volumes in latex ventricles were remarkably smaller for three-dimensional compared with two-dimensional echocardiography (root mean square percent error: three-dimensional echocardiography = 5.3% versus two-dimensional echocardiography = 14.6%). In three-dimensional echocardiography, there was considerable overestimation of volumes in the lateral far field (root mean square percent error = 13.2%) of the ultrasound sector. Differences between two-dimensional echocardiographic human left ventricular volumes and cineventriculography increased with larger volumes. In three-dimensional echocardiography the differences remained constant. Interobserver and intraobserver variability is reduced nearly twofold by three-dimensional echocardiography. Three-dimensional echocardiographic volumetry provides fewer discrepancies to cineventriculography and lesser variability than two-dimensional echocardiography. With the use of rotational scanning, the ventricle has to be positioned in the central near field of the transducer.