Bicuspid Aortic Valve and Aortic Root Disease

Bicuspid aortic valve (BAV) is the most common form of congenital heart disease, with frequent and premature occurrence of cardiac events, dominated by significant valvular dysfunction. BAV has a high prevalence of aortic wall abnormalities such as ascending aortic dilatation. Because more rapid aortic dilatation can occur, once the ascending aorta reaches 40 mm, annual imaging with echocardiography or other imaging techniques is indicated. The most feared complication is aortic dissection. However, the actual incidence of this complication is low (4%). Although limited data exist regarding prophylactic intervention, it is suggested that elective surgical repair of BAV-associated aortic dilatation should be more aggressively recommended. In patients with BAV, the decision to indicate surgical treatment in aortic diameters between 50 and 55 mm should be based on patient age, body size, comorbidities, type of surgery, and the presence of additional risk factors.     

主动脉夹层

主动脉夹层是一种严重的心血管疾病 ,大多数未经治疗的Ⅰ型和Ⅱ型病人 (近端解离 )和半数以上Ⅲ型 (远端解离 )病人在 1年内死亡。大多数死亡发生在 2周以内 ,死亡原因为主动脉破裂、主动脉瓣关闭不全和主动脉分支阻塞。本病并不少见 ,我国台湾省台北市一家医院 ,1989～ 1994年间 ,收治胸主动脉夹层病人 10 9例 ,可见国人并不少见[1] 。1　定义[2 ]主动脉夹层动脉瘤为发生于主动脉中层的解离过程。解离的主动脉动脉瘤呈纺锤形 ,或者由于假腔外壁的扩张 ,或者在先前纺锤形动脉瘤上重叠发生主动脉中层解离。解离过程呈急性或慢性 ,症状出现后 …     

主动脉夹层和主动脉瘤与高血浆同型半胱氨酸

目的观察主动脉夹层及主动脉瘤患者血浆同型半胱氨酸(Hcy)的水平。方法病例组为确诊的106例主动脉夹层患者及38例主动脉瘤患者,对照组为199例在性别、高血压病史、饮酒史等与病例组相匹配的门诊查体者。常规检测血生化指标,高效液相方法测定血浆同型半胱氨酸。结果主动脉夹层合并主动脉瘤组血浆Hcy水平较对照组增高,分别为(19.75±12.77)μmol/L和(13.43±5.15)μmol/L,(P<0.001),病例组高血浆同型半胱氨酸患者的比率高于对照组,分别为67.4%和38.5%(P<0.01)。主动脉夹层组血浆Hcy水平较主动脉瘤组稍高,分别为(20.25±13.96)μmol/L和(18.76±8.55)μmol/L,但差异不显著。主动脉夹层急性期与慢性期组的血浆Hcy水平无差别。将病例组按性别分层后,血浆Hcy水平与对照组相比,仅女性主动脉瘤组无差异,其余各组均显著增高(P<0.01或P<0.05)。结论主动脉夹层合并主动脉瘤组血浆Hcy水平较对照组增高,高血浆Hcy与主动脉夹层合并主动脉瘤的发生、发展密切相关。     

Subvalvular Aortic Membrane Masquerading as Valvular Aortic Stenosis

Discrete subvalvular aortic membrane is an unusual cause of left ventricular outflow tract obstruction. While commonly presenting during childhood, one quarter of the individuals are asymptomatic in childhood but remain vulnerable to progressive outflow tract obstruction as well as bacterial endocarditis in adulthood. Unfortunately, because the condition is so uncommon in adults, the diagnosis of subvalvular membrane is often missed or delayed. We recently had the opportunity to care for an adult patient who finally had subvalvular membrane identified as the cause of a left ventricular outflow obstruction, only after a protracted series of diagnostic investigations. Pitfalls in the noninvasive and invasive diagnosis of this condition are reviewed.     

Aortic dissection

Aortic root enlargement is generally asymptomatic, with few clinical clues, but may be observed as an incidental finding on a chest x-ray, echocardiogram, or contrast-enhanced computerized tomogram of the chest. Aortic dissection is one of the most feared complications of hypertension. A history of hypertension is commonly present, but the systolic blood pressure in type A dissection (proximal to the left subclavian artery) has been found to be less than 150 mm Hg in 64% of patients. However, 71% of type B dissections (distal to the left subclavian artery) present with a systolic blood pressure 150 mm Hg or higher (International Registry of Acute Aortic Dissection). Most frequently, onset of symptoms is in the daytime, especially between 6 a.m. and noon. Severe sharp chest pain that is abrupt in onset is the most likely presentation. Migrating pain is uncommon. Although a pulse deficit with decreased or absent carotid, brachial, or femoral pulses occurs in only 30% of patients, three or more deficits predict an in-house mortality of about 60%. A chest x-ray finding of a widened mediastinum is present in 62.6% of type A and 56% of type B dissections. Contrast-enhanced computerized tomography or transesophageal echocardiography is the most commonly performed procedure for diagnosis. In-house mortality has been found to be 32.5% in type A dissections and 13% in type B dissections.     

Aortic stenosis

Choice of the best surgical option for aortic stenosis (AS) must be individualized and requires discussion among patient, cardiologist, and surgeon to weigh the risks and benefits of different options. Mechanical valves have been preferred for young patients, for those with a life expectancy of more than 10 to 15 years, or for those who require anticoagulation. Bioprosthetic valves have been preferred for elderly patients, for patients with limited life expectancy, or for patients who are unable to be anticoagulated. Newer tissue valves (eg, the stentless porcine aortic bioprosthesis and homografts) as well as newer techniques (eg, the Ross procedure) have increased the number of available options and the complexity of the decision-making process.     

Aortic Stenosis

Noninvasive assessment of aortic valve area by echocardiography has become the standard of practice over the past few years. The advent of transesophageal echocardiography (TEE) has provided a new method for the assessment of aortic valve area (AVA) using planimetry by two-dimensional imaging. Clear visualization of the anatomy of the valve, as well as accuracy of AVA assessment, makes TEE an invaluable tool for the evaluation of aortic valve stenosis. TEE is especially helpful in clinical settings when there is a discrepancy between the AVA obtained by transthoracic echocardiography and cardiac catheterization. TEE is particularly helpful in the assessment of the aortic valve during intraoperative echocardiography. This review discusses the techniques, imaging planes, and details for assessing AVA by TEE. The role of TEE in AVA assessment is described, with specific clinical case examples cited.