Transesophageal Doppler echocardiography in the diagnosis of dissecting aortic aneurysm

Transesophageal Doppler echocardiography (TEDE) was performed in three patients with proven or suspected DeBakey type I and type III aortic dissection. Case 1: A 66-year-old woman, with DeBakey type I aortic dissection. Clear images of a widened dissected aorta and an intimal flap were obtained in both the ascending and descending aorta, including the aortic arch. The site of an entry into the false lumen was identified by the defect of the intimal flap and the pulsatile entry flow through it. The reentry into the true lumen was also identified near the orifice of the celiac trunk. In this case, the observation was performed using this technique during the operation; i.e., replacement of the ascending aorta with an artificial graft. Case 2: A 77-year-old man, DeBakey type III aortic dissection. The study was performed after surgery which consisted of replacement of the descending aorta with an artificial graft. TEDE provided clear images of the artificial graft, the aorta, and their boundaries. The remaining intimal flap was clearly confirmed. Case 3: An 80-year-old man, DeBakey type III aortic dissection. In this case, though abdominal echography suggested aortic dissection, angiography and X-ray CT failed to facilitate the diagnosis. Only TEDE confirmed the diagnosis. The abnormal flow via the entry directing toward the false lumen was clearly demonstrated on the color Doppler images. We therefore conclude that TEDE is a useful and reliable means of diagnosing dissecting aortic aneurysm.     

Echocardiographic Findings Mimicking Type A Aortic Dissection

BACKGROUND: Type A aortic dissection is a rare, but life-threatening disease. The prognosis is determined by an accurate and immediate diagnosis. CASE STUDY: A patient with suspected type A dissection based on outward transesophageal echocardiography (TEE) findings is reported. Renewed TEE showed dilation of the ascending aorta with pronounced wall thickness. A membrane-like structure was found in the ascending aorta. M-mode technique revealed movement of the suspected membrane that was partially in parallel to the aortic wall. Thus, there were severe doubts on the presence of type A dissection. By contrast, typical intimal rupture was found in the descending aorta. Computed tomography (CT) and angiography showed aortic dilation and an extended wall hematoma deriving from the entry at the descending part. There was no evidence of type A dissection. CONCLUSION: TEE is a noninvasive diagnostic tool to assess aortic dissection of type A with a sensitivity of 90-98% that is equal to CT or magnetic resonance imaging (MRI) solely. Complementary use of CT or MRI could improve the diagnostic accuracy. False-positive findings could result from echocardiographic artifacts concealing an intimal flap in the ascending aorta. Echo reverberations in dilated or calcified aortas had been judged to account for this phenomenon. In the present case, it could be assumed that the extended wall hematoma in accordance with vessel dilation mimicked the membrane-like structure. Oscillation or flutter of the suspicious intimal flap independently of aortal wall movement seem to be mandatory to avoid false-positive diagnoses. Ancillary findings such as flow signals, intimal fenestration or thrombosis are helpful to enhance the diagnostic specificity of TEE.     

Unusual complication of aortic dissections: intimo–intimal intussusception

Angiography with a pre-diagnosis of acute coronary syndrome was performed in a 76-year-old female patient presenting to another hospital with symptoms of chest pain and syncope. Upon determination of type III aortic dissection, the patient was referred to our clinic. On CT angiography, the ascending aortic diameter was 57 mm and no dissection flap was observed. There was a filling defect suggestive of intimo–intimal intussusception at the level of the aortic arch, occlusion of the left arteria carotid communis, and a double-channel aorta extending from the left subclavian artery to the iliac artery. On transoesophageal echocardiography, the ascending aorta was seen to be larger than normal and no dissection flap was observed. There were findings suggestive of haematoma and intimo–intimal intussusception at the proximal part of the aortic arch. The dissection flap causing occlusion in the vascular structures was resected. Supracoronary graft replacement of the ascending aorta was performed. Transoesophageal echocardiography is an invasive investigative method with high sensitivity and specificity for the diagnosis of intimo–intimal intussusception.     

Acute aortic dissection and peripheral ischemia. Diagnostic and therapeutic problems. Remote control using nuclear magnetic resonance

This study concerns 7 cases of acute aortic dissection associated with visceral and/or lower limb ischemia. Only those cases are included which raised diagnostic and therapeutic problems. Patients were excluded who had purely angiographic involvement of an aortic branch and minor rapidly resolving ischemic syndromes. Five of the 7 patients presented type B (type III or distal) and 2 type A (type I or proximal) dissection. All patients received anti-hypertensor medical treatment. All but one had undergone surgery at least once at the acute stage. Five had been followed up and monitored by magnetic resonance imaging (MRI). One type A and 4 type B dissections were thus reviewed between the 15th month and the 9th year. Diagnostically, aortography was found to be inaccurate twice because of incomplete exploration of the thoracoabdominal aorta. Therapeutically, a case of intraoperative death occurred during replacement of the ascending aorta. Thus, out of the 6 patients who survived the acute stage, 4 are alive and asymptomatic, one has been lost sight of and the other died in year 5 after surgery for chronic dissecting aneurysm of the aortic arch. Among the 5 patients examined by MRI, 4 presented aortic ectasia, chronic dissecting aneurysm of the aortic arch and/or a descending aorta with a diameter between 45 and 65 mm. The patient with subnormal aortic diameter had his ascending aorta replaced (the follow-up period at this writing is only 27 months). Among 3 patients who were examined twice, one showed improvement after a year's interval, with a 5-mm increase in the caliber of the dissected aorta.(ABSTRACT TRUNCATED AT 250 WORDS)     

Color Doppler echocardiography in the diagnosis of aortic dissection and aortic wall abscesses

In eleven patients with aortic dissection or perforated endocarditic aortic wall abscess cavity, the diagnostic usefulness of Color Doppler Echocardiography (CDE) for the identification of true and false lumen as well as the perforation jet was assessed by comparison with the findings of angiography, digital subtraction angiography, computed tomography and surgery. The information gained in addition to that of these procedures, as well as to that of the four conventional echocardiographic techniques was evaluated. Six patients had aortic dissections of DeBakey type I or III; in all of them the diagnosis had been established with conventional ultrasonic techniques. Similarly, in all patients with aortic dissection of DeBakey type I, a clear differentiation between true and false lumen in the aortic root and ascending aorta could already be made by grey-scaled echocardiography. In these patients, however, CDE made the additional demonstration of the perforation jet into the false lumen possible. In those three patients with aortic dissection of DeBakey type III as well as in the abdominal aortic region of DeBakey type I, color Doppler echocardiography was the only method to define true and false lumen and to clearly localize the perforation sites. Two further patients were found to have a small, local dissection, which could only be assumed by conventional echocardiography; the color Doppler M-mode image led to a clear diagnosis. In three patients an endocarditic abscess cavity of the aortic wall could be detected by conventional echocardiography. Two-dimensional color Doppler echocardiography additionally enabled us to visualize the presence and the course of perforation flows. In two patients color-coded Doppler echocardiography made it possible to detect perforations in regions which could not be localized either with conventional echocardiographic techniques or the above-mentioned control procedures.     

Application of thoracic endovascular dissecting aneurysm repair for secondary type B aortic dissection

Type A aortic dissection is an emergency condition that requires immediate surgery. Graft replacement of the ascending aorta is the main treatment for this disorder. However, after ascending aortic replacement, the dissection flap may progress to the distal side (to the descending aorta) and a new intimal tear may develop. In this study, we report on a 66-year-old woman who had a history of ascending aortic replacement six months earlier. She was admitted to hospital with a new onset of back pain. Computed tomography revealed a new dissection tear originating from the distal side of the subclavian artery orifice. Thoracic endovascular dissecting aneurysm repair (TEVDAR) was carried out on the patient. Additional complications were not observed in the postoperative period. Complete cure was provided and the patient was discharged on the fourth day after the operation. TEVDAR may be safe and effective in preventing progression of the aortic flap and the formation of a new intimal tear in type A aortic dissections. Optional hybrid interventions could ameliorate the outcomes in aortic dissection cases.     

Risk factors for aortic dissection: a necropsy study of 161 cases

Among 161 necropsy cases of aortic dissection, 87 (54%) were type I, 34 (21%) type II, and 40 (25%) type III, and an intimal tear was identified in each. Systemic hypertension had been present in 63 of 121 cases (52%) with type I or II dissection and in 30 of 40 (75%) with type III dissection. Aortic dissection involved 7 of 16 cases (44%) with the Marfan syndrome. In the 154 cases without the Marfan syndrome, grade 3 or 4 medial degeneration (cystic medial necrosis) was observed in the ascending aorta in only 27 (18%). The risk of aortic dissection in persons with congenitally bicuspid and unicommissural aortic valves, respectively, was 9 and 18 times that in subjects with tricuspid aortic valves. The mean age of those with aortic dissection and tricuspid, bicuspid and unicommissural aortic valves was 63, 55 and 40 years, respectively, and aortic dissection was more common in men than in women. Grade 3 or 4 atherosclerosis involved the intimal tear in only 11 of 121 type I or II dissections (9%) but 32 of 40 type III dissections (80%). Accordingly, the major risk factors for aortic dissection were systemic hypertension, the Marfan syndrome, and, for type I and II dissections, congenitally bicuspid or unicommissural aortic valves. Aortic medial degeneration was a less important risk factor. Rupture of ulcerocalcific aortic atheromas may have initiated the intimal tear in some type III dissections.     

Diagnosis of aneurysm of the thoracic aorta. Comparison between two non invasive techniques: two-dimensional echocardiography and computed tomography

In order to assess the respective values of two-dimensionalechocardiography (2D echo) and computed tomography (CT) in theevaluation of aneurysms of the thoracic aorta, 14 patients withangiographically proven aneurysms of the thoracic aorta (threeof which were dissecting aneurysms) were studied. The entire thoracic aorta was visualized in 10/14 patients by2D Echo and in all patients by CT. An intimal flap was recognized by 2D echo in each case witha dissection whereas such a recognition was never possible withCT. CT identified calcification of the wall of an huge aneurysmof the ascending aorta in one case and a thrombotic stratificationin the lumen of the descending thoracic aorta in another case;both abnormalities were missed by echocardiography probablybecause of inappropriate gain setting. In conclusion, 2D Echo and CT are both useful in the evaluationof aneurysms of the thoracic aorta: 2D echo appears to be superiorin the recognition of an intimal flap due to dissection whereasCT allows a better recognition of the configuration, extensionand tissue modifications of the aneurysm.     

Dynamic aortic obstruction in a patient with acute type B dissection

There are at least 7000 aortic dissections diagnosed in the United States each year. Type B dissections accounted for 38% of cases enrolled in the prospective International Registry of Aortic Dissection. We report a case of a 48-year-old hypertensive woman with an acute type B aortic dissection causing significant dynamic obstruction of the aorta. Intravascular ultrasound of her aorta revealed a mobile intimal flap nearly obliterating the true lumen with each systolic contraction. Simultaneous pressure tracings obtained from her ascending aorta and femoral artery demonstrated a systolic pressure gradient in excess of 100 mm Hg. The patient developed progressive renal failure and ultimately underwent successful operative replacement of the proximal descending thoracic aorta with a Dacron graft. In this case presentation, we highlight the unusual physiology exemplified by this case and explore contemporary management strategies for complicated type B aortic dissection, including surgery and catheter-based techniques.     

Color Doppler evaluation of aortic dissection

Color Doppler studies were performed in 16 adult patients with proven DeBakey type I and III aortic dissection. Simultaneous opacification of both aortic lumina with oppositely directed flow was noted by color Doppler in at least one aortic segment in 14 of 16 patients (12 type I, two type III). In two patients (one type I, one type III), flow was seen in one lumen only, with clot demonstrated in the other lumen in one of them. Of 12 patients in whom communication between two aortic dissection channels was shown by angiography/surgery, color Doppler correctly identified them in nine patients (four ascending aorta, two aortic arch, and three descending aorta), either by direct visualization of flow moving from one lumen into the other (six patients) or indirectly by analyzing differences in timing of opacification of the two lumina and flow direction (three patients). Also, color Doppler correctly diagnosed aortic regurgitation as severe (aortic regurgitation jet occupying more than 75% of left ventricular outflow) in three patients and moderate in four patients. Color Doppler provides comprehensive evaluation of flow dynamics in aortic dissection.     

Visualization of thoracic dissecting aortic aneurysm by transesophageal Doppler color flow mapping

Real-time color flow mapping by two-dimensional Doppler has now come into widespread use. However, its application via conventional transcutaneous approaches to dissecting aortic aneurysm has some limitations where visualization of the descending aorta is concerned. Its transesophageal approach to this disorder has hitherto remained unreported except by the authors. Transesophageal Doppler color flow mapping has been performed in twelve patients for diagnosis of dissecting aortic aneurysm, and the clinical significance of this method was evaluated. The system used for transesophageal color flow mapping was an Aloka SSD-880 ultrasound scanner with a 5 MHz probe. In all cases, the entire thoracic aorta except for the upper ascending aorta was visualized and both, real-time flow dynamics and structural information, were ascertained. Differentiation of the type of dissection, identification of the entry, and differentiation of the true and false lumina were performed in all cases. Information concerning the reentry was gained in seven cases (58%); aortic regurgitation was graded in three cases, in two of which prolapse of the intimal flap was observed. In five cases, aortography was needed in order to delineate the involvement of aortic branches in the dissection; and in the other seven cases, transesophageal Doppler information was sufficient. In four cases who were operated, the postoperative state was well evaluated. Transesophageal Doppler color flow mapping was found to be a useful method for visualization of the whole thoracic aorta apart from the upper ascending section, and for precise evaluation of the structure and hemodynamics of dissecting aortic aneurysms.     

Diagnostic goals in aortic dissection. Value of transthoracic and transesophageal echocardiography]

The combination of different ultrasound techniques like transthoracic, suprasternal, subcostal and transesophageal echocardiography have a high sensitivity and specificity in the diagnosis of aortic dissection. The limitation of this combined ultrasound technique is related to the visualization of the ascending part of the aortic arch which, cause of the interposition of the trachea, can not be visualized completely. The beginning or the end of a dissection in this part of the aorta may be misinterpreted. False negative results are rare. False positive results due to artefacts resulting from reverberations in an ectatic ascending aorta have to be taken into account. The most important diagnostic aims in acute or chronic aortic dissection can be described: 1. confirmation of the diagnosis by visualization of the intima membrane, 2. the differentiation of the true and false lumen depending on visualization of spontaneous echocardiographic contrast thrombus formation, slow or reduced reversed flow, systolic diameter reduction and signs of entry jet into the false lumen, 3. detection of intimal tear, demonstrating communication by two-dimensional or color Doppler echocardiography, 4. determination of the extent of the dissection with classification according to DeBakey type I, II and III or Stanford A and B with differentiation to communicating or non-communicating dissection, antegrade or retrograde dissection limited to the descending aorta or expanding to the ascending aorta, 5. detection of wall motion abnormalities as a sign of preexisting coronary artery disease or myocardial ischemia due to ostium occlusion by an intimal flap, coronary artery rupture or collapse of the true lumen during diastole, 6. detection and grading of aortic insufficiency, 7. detection of side branch involvement by suprasternal, subcostal and abdominal sonography, which will gain the information which side can be chosen for cannulation or catheterization at the femoral artery, 8. detection of pericardial pleural effusion and mediastinal hematoma as a sign of emergency as rupture can occur within minutes. Without surgical intervention have be performed. Based on these informations, surgery can be performed in all acute situations in type A dissection without further investigations. This decision is particularly important in patients with signs of emergency like pericardial or pleural effusion or mediastinal hematoma.     

Acute and subacute dissection of the thoracic aorta: diagnostic importance of magnetic resonance tomography]

The purpose of this study was to retrospectively assess the reliability of ECG-triggered magnetic resonance imaging (MRI) for the diagnosis of acute and subacute thoracic aortic dissection and associated clinical epiphenomena. 67 patients were subjected to MRI; the diagnostic results were compared with morphological standards. 25 patients had type A, 12 patients type B dissection. In 30 cases a dissection was excluded. 17 patients with aortic dissection had acute onset of symptoms, 10 patients had subacute onset of symptoms. 17 patients revealed thrombosis of the false lumen, which was found in the descending aorta in 59% of the cases. Aortic regurgitation and pericardial effusion was most often associated with type A dissection (Table 1). Three patients were studied while on mechanical ventilation. Scan time for MRI ranged from 15 to 71 minutes with an average of 46 +/- 18 minutes. In this series no deleterious events were encountered related to MRI diagnostics. In contrast to previously published data using other noninvasive techniques the sensitivity of MRI was 100% for detecting a dissection in the ascending segment of the thoracic aorta. Moreover, the specificity of MRI for a dissection was 100% and thus higher than previously published data using transesophageal echocardiography. Sensitivity and specificity for detection and correct classification of type B dissection was 100% and 100% respectively (Table 2). In addition, MRI proved to be sensitive in detecting the formation of thrombus material in the false lumen of the ascending aorta (92%), the aortic arch (100%) and the descending segment (88%). Specificity for exclusion of suspected thrombus material even proved to be slightly higher with 100% in the ascending and descending aorta and 96.1% in the aortic arch (Table 3). The site of entry to a dissection was detected in 78%, with a sensitivity of 76% in the ascending and 92% in the descending aorta. The involvement of side branches in the dissecting process was identified in 60%. There were no false positive findings concerning side branch involvement. Aortic regurgitation and pericardial effusion were detected in 100% and 100%, respectively (Tables 1 and 2). MRI performed even in acute cases proved to be a atraumatic, safe and highly sensitive method to identify and classify acute and subacute dissections of the entire thoracic aorta. Limited patient access was not associated with an increased risk and mechanical ventilation did not interfere with MRI. These results may establish MRI as a valid and promising noninvasive technique to establish the diagnosis in patients with thoracic aortic dissection.(ABSTRACT TRUNCATED AT 400 WORDS)     

Combination of color Doppler and transesophageal echocardiography in emergency diagnosis of type I aortic dissections

We report on the use of colour Doppler- and transesophageal echocardiography in 2 patients with acute type I aortic dissection according to DeBakey. Using transesophageal echocardiography we obtained information on the extension and the entry site of the dissection without interfering with respiration and external thorax configuration. Using colour Doppler we were able to differentiate between the true and false lumen in the thoracic and abdominal aorta due to characteristic phasic flow patterns. In one patient the site of the entry tear of the intimal flap was localized by this method. Furthermore, a noninvasive semiquantitative evaluation of accompanying aortic regurgitation was possible. Colour Doppler gives additional information in the emergency diagnosis of patients with aortic dissection.     

Stanford B型主动脉夹层动脉瘤腔内修复的实验研究

目的 探讨一种较为理想的、稳定可靠的Stanford B型主动脉夹层动脉瘤腔内修复（thoracic endovascular aortic repair,TEVAR）模型的构建方法.方法 18条犬左侧开胸后侧壁阻断降主动脉近端,环形切开外膜、中膜约1/2周径,找到动脉壁分层裂隙,沿裂隙用特制剥离子向下、侧方、向上分离.再环形剪开内膜约1/2周径,将已切开的内膜下唇双角处分别缝合固定于邻近的侧动脉壁,即内膜片双角进行缝合,然后将远端外膜及中膜缝合于近端主动脉壁上.再行下腹部正中切口,经腹主动脉前壁穿刺,用Omnipaque造影剂以10～15 mL/s速度经猪尾巴导管DSA造影及彩超跟踪检查.再经穿刺点置入覆膜支架至主动脉弓降部夹层裂口处,准确定位后释放.结果 直视下、术中彩超影像跟踪、即时DSA造影均显示动脉夹层立即形成并向远端撕裂,置入覆膜支架后夹层裂口被完全修复.结论 应用主动脉内膜片双角缝合法,可建立与人体Stanford B型主动脉夹层动脉瘤（aortic dissection,AD）病理过程相似的动物模型[1,2],经覆膜支架置入后形成腔内修复模型.     

29例主动脉夹层动脉瘤治疗分析

目的总结29例主动脉夹层动脉瘤外科治疗经验。方法29例患者中,DeBakey分型,Ⅰ型16例,Ⅱ型4例,Ⅲ型9例。21例手术治疗,其中6例行Bentall术,2例行Wheat术,5例行升主动脉置换(同时主动脉瓣成形4例),1例行胸主动脉置换,7例置入支撑型人工血管;8例不接受手术。结果手术死亡2例,其中1例为胸主动脉置换术后并发吻合口出血死亡,1例为支撑型人工血管置入后内漏瘤破裂猝死。非手术8例中,4例死亡,4例转慢性化趋稳定出院。结论对主动脉夹层动脉瘤应积极手术,Ⅰ、Ⅱ型可急诊手术,Ⅲ型可置入支撑型人工血管。早诊断,快速急诊手术是抢救成功的关键。     

Two-dimensional and Doppler echocardiographic evaluation of aortic aneurysm and dissection

Ten patients with nondissecting aortic aneurysm and 10 with aortic dissection proved by angiography, surgery or both, were studied by real-time, 2-dimensional echocardiography. Multiple transducer positions were used to visualize various aortic segments so that a composite image of the aorta could be formulated. Using this comprehensive approach, the site, size and extent of all nondissecting aneurysms were correctly delineated (2 ascending aorta, 3 ascending aorta plus aortic root and 5 aortic arch with brachiocephalic involvement). In all patients with aortic dissection, the condition was identified by the presence of prominent, flap-like, undulating motion of the inner dissected wall or marked parallel wall widening (greater than or equal to 15 mm) and correctly categorized into DeBakey type I (4 cases), II (2 cases) or III (4 cases). Pulsed Doppler studies were useful in diagnosing reopening of dissection in a patient with previous surgical obliteration of the false channel.     

Aortic dissection detected by transoesophageal echocardiography

Summary The diagnostic value of transoesophageal echocardiography was evaluated in 24 patients with aortic dissection and compared to transthoracic two-dimensional echocardiography, computer tomography, aortography, surgery and autopsy.Using transoesophageal echocardiography we found in 5 patients a type I dissection, in 5 patients a type II and in 14 patients a type III dissection. Transthoracic two-dimensional echocardiography was positive in 3/5 type I, 2/5 in type II and 2/14 in type III dissections. Computer tomography was unable to demonstrate an intimal flap in 1/2 patients with type I, 2/3 type II and 1/11 type III dissections. Aortography was negative in 1/4 type I, 3/5 type II and 3/12 patients with type III dissection.Additional information concerning thrombus formation, localisation of the entry tear, differentiation between true and false lumen, flow dynamics within the true and false lumen as well as accompaning aortic regurgitation may be obtained by transoesophageal echocardography.This paper contains parts of the doctoral dissertation of D. Steller.     

Intimal tear without hematoma: an important variant of aortic dissection that can elude current imaging techniques

BACKGROUND: The modern imaging techniques of transesophageal echocardiography, CT, and MRI are reported to have up to 100% sensitivity in detecting the classic class of aortic dissection; however, anecdotal reports of patient deaths from a missed diagnosis of subtle classes of variants are increasingly being noted. METHODS AND RESULTS: In a series of 181 consecutive patients who had ascending or aortic arch repairs, 9 patients (5%) had subtle aortic dissection not diagnosed preoperatively. All preoperative studies in patients with missed aortic dissection were reviewed in detail. All 9 patients (2 with Marfan syndrome, 1 with Takayasu's disease) with undiagnosed aortic dissection had undergone >/=3 imaging techniques, with the finding of ascending aortic dilatation (4.7 to 9 cm) in all 9 and significant aortic valve regurgitation in 7. In 6 patients, an eccentric ascending aortic bulge was present but not diagnostic of aortic dissection on aortography. At operation, aortic dissection tears were limited in extent and involved the intima without extensive undermining of the intima or an intimal "flap." Eight had composite valve grafts inserted, and all survived. Of the larger series of 181 patients, 98% (179 of 181) were 30-day survivors. CONCLUSIONS: In patients with suspected aortic dissection not proven by modern noninvasive imaging techniques, further study should be performed, including multiple views of the ascending aorta by aortography. If patients have an ascending aneurysm, particularly if eccentric on aortography and associated with aortic valve regurgitation, an urgent surgical repair should be considered, with excellent results expected.     

Accuracy of M-mode and two-dimensional echocardiography in the diagnosis of aortic dissection: an experience with 128 cases

The accuracy of combined M-mode and two-dimensional echocardiography in the diagnosis of aortic dissection was evaluated in 673 patients with a clinical suspicion of aortic dissection, over a six-year period. In 128 cases, the diagnosis of aortic dissection was confirmed by angiographic, tomographic (CT scan), or autopsy findings, or during surgery. Two echocardiographic features were found to support a diagnosis of aortic dissection: a dilation of at least one segment of the aorta (sensitivity 95%, specificity 51%) and a typical abnormal linear intraluminal echo corresponding to the intimal flap (sensitivity 67%, specificity 100%). This pathognomonic intimal flap was observed in 86 cases, of which three types could be distinguished: (1) a long oscillating flap (n = 15), (2) a long but minimally mobile linear echo which was duplicated and parallel to one or two aortic walls (n = 64), (3) a short, double linear image with a rapid systolic motion and high frequency oscillations. These features were found to have a high sensitivity in type I aortic dissection (88%), although in types II and III the sensitivity was much lower. In some cases, a fourth type of abnormal image could be detected: a small intraluminal echo moving in parallel to the aortic wall. This feature should be interpreted with caution since its predictive value for a positive examination was low (48%). Out of 23 cases in which the diagnosis of aortic dissection was suspected on the basis of this doubtful abnormal echo, it was confirmed in only 11 patients. The results in these 128 cases of aortic dissection indicate that two-dimensional echocardiography, which is easily performed at the patient's bedside, could take priority in investigations of this condition. It is extremely sensitive in the diagnosis of ascending aortic dissection, but much less so in the diagnosis of descending aortic dissection.