超声评估二叶式主动脉瓣患者升主动脉增宽的影响因素

目的 探讨先天性二叶式主动脉瓣畸形的超声特点及升主动脉增宽的影响因素.方法 二维及彩色多普勒超声观察二叶式主动脉瓣畸形的形态、回声、启闭及血流动力学情况,心脏及主动脉结构的变化.结果 升主动脉内径的增宽与患者年龄关系密切,内径较宽的患者心脏形态学改变较重.结论 二叶式主动脉瓣畸形患者的年龄是升主动脉内径的增宽的重要的影响因素.     

Impaired aortic distensibility and elevated central blood pressure in Turner Syndrome: a cardiovascular magnetic resonance study

Background

Women with Turner Syndrome have an increased risk for aortic dissection. Arterial stiffening is a risk factor for aortic dilatation and dissection. Here we investigate if arterial stiffening can be observed in Turner Syndrome patients and is an initial step in the development of aortic dilatation and subsequent dissection.

Methods

Fifty-seven women with Turner Syndrome (48 years [29–66]) and thirty-six age- and sex-matched controls (49 years [26–68]) were included. Distensibility, blood pressure, carotid-femoral pulse wave velocity (PWV), the augmentation index (Aix) and central blood pressure were determined using cardiovascular magnetic resonance, a 24-h blood pressure measurement and applanation tonometry. Aortic distensibility was determined at three locations: ascending aorta, transverse aortic arch, and descending aorta.

Results

Mean aortic distensibility in the descending aorta was significantly lower in Turner Syndrome compared to healthy controls (P =?0.02), however, this was due to a much lower distensibility among Turner Syndrome with coarctation, while Turner Syndrome without coarctation had similar distensibility as controls. Both the mean heart rate adjusted Aix (31.4% vs. 24.4%; P?=?0.02) and central diastolic blood pressure (78.8 mmHg vs. 73.7 mmHg; P?=?0.02) were higher in Turner Syndrome compared to controls, and these indices correlated significantly with ambulatory night-time diastolic blood pressure. The presence of aortic coarctation (r = ??0.44, P =?0.005) and a higher central systolic blood pressure (r = ??0.34, P =?0.03), age and presence of diabetes were inversely correlated with aortic distensibility in TS.

Conclusion

Aortic wall function in the descending aorta is impaired in Turner Syndrome with lower distensibility among those with coarctation of the aorta, and among all Turner Syndrome higher Aix, and elevated central diastolic blood pressure when compared to sex- and age-matched controls.

Trial registration

The study was registered at ClinicalTrials.gov (#NCT01678274) on September 3, 2012.

     

Association of aortic distensibility and left ventricular function in patients with stenotic bicuspid aortic valve and preserved ejection fraction: a CMR study

The International Journal of Cardiovascular Imaging - To determine the relationship between aortic distensibility and left ventricular (LV) remodeling, myocardial strain and blood biomarkers in...     

Fate of bicuspid aortic valves in patients undergoing aortic root repair or replacement for aortic root enlargement

OBJECTIVE: To better understand the outcome of the bicuspid aortic valve (BAV) after valve-sparing root replacement, we evaluated BAV function after its preservation at the time of the ascending aorta (AA) repair. PATIENTS AND METHODS: From January 1, 1994, through March 31, 2002, BAVs were preserved during repair of AA aneurysms in 21 patients (mean +/- SD age, 45+/-12 years; 13 males). We reviewed the clinical and surgical records of these patients for baseline characteristics, operative procedures, and data at latest follow-up. RESULTS: The primary indication for operation was AA enlargement (median diameter, 55 mm; range, 43-65 mm) in 18 patients and severe aortic regurgitation (AR) in 3 patients. Preoperatively, the BAV exhibited mild or moderate stenosis in 5 patients (mean gradient, 25 mm Hg; range, 19-34 mm Hg), moderate AR in 2, and severe AR in 3. Aortic valve repair was performed in 11 patients. Seventeen patients had excision and graft replacement of the enlarged AA, and 4 patients had primary AA repair. There were no perioperative deaths. Moderate or severe AR was relieved in all patients early postoperatively and during follow-up (median, 2.5 years; maximum, 7.6 years). One patient required aortic valve replacement at 4.8 years for AR. An additional patient had recurrent, severe AR but was asymptomatic and has not undergone reoperation. CONCLUSION: Repair of diseased BAVs or preservation of functionally normal BAVs during surgery for AA aneurysms has a low perioperative risk, and early results are encouraging. Additional observation is necessary to determine whether this strategy has real advantages over early aortic valve replacement.     

MDCT differentiation between bicuspid and tricuspid aortic valves in patients with aortic valvular disease: correlation with surgical findings

To identify multi-detector computed tomographic (MDCT) features discriminating bicuspid aortic valves (BAVs) from tricuspid aortic valves (TAVs) in patients with aortic valvular disease using surgical findings as reference. Forty-five patients underwent ECG-gated cardiac MDCT scans prior to aortic valve replacement. Morphologic patterns of aortic valves on MDCT were classified into: bicuspid without raphe (A), fused valve with a fish-mouth opening (B), fused valve without a fish-mouth opening (C), and tricuspid without fusion (D). To differentiate congenital raphe of BAV from commissural fusion of TAV, MDCT features of patterns B and C were evaluated. Diameters of the aortic root and ascending aorta between patients with BAVs and TAVs were also compared. Patterns A (n = 6) and B (n  = 6) were all bicuspid, in pattern C: 8 of 26 (30.8%) were bicuspid, and pattern D (n  = 7) were all tricuspid. In patterns B and C, uneven cusp size, round-shaped opening and midline calcification at leaflet fusion were strongly associated with BAVs (all, P < 0.05). The mean length of leaflet fusion in BAVs was significantly larger than in TAVs (13.5 vs. 8.7 mm, P < 0.0001), with a cutoff value of 10.3 mm providing a sensitivity of 85.7%, a specificity of 83.3%, and an area under the ROC curve of 0.90. In all patients, the mean diameter of the ascending aorta was larger in patients with BAVs than with TAVs (43.3 vs. 39.7 mm, P < 0.05). MDCT features of uneven cusp size, round-shaped opening, midline calcification, longer leaflet fusion and larger diameter of the ascending aorta can be helpful in distinguishing BAVs from TAVs.     

Influence of beta-blocker therapy on aortic blood flow in patients with bicuspid aortic valve

In patients with bicuspid aortic valve (BAV), beta-blockers (BB) are assumed to slow ascending aorta (AAo) dilation by reducing wall shear stress (WSS) on the aneurysmal segment. The aim of this study was to assess differences in AAo peak velocity and WSS in BAV patients with and without BB therapy. BAV patients receiving BB (BB+, n = 30, age: 47 ± 11 years) or not on BB (BB?, n = 30, age: 46 ± 13 years) and healthy controls (n = 15, age: 43 ± 11 years) underwent 4D flow MRI for the assessment of in vivo aortic 3D blood flow. Peak systolic velocities and 3D WSS were calculated at the anterior and posterior walls of the AAo. Both patient groups had higher maximum and mean WSS relative to the control group (p = 0.001 to p = 0.04). WSS was not reduced in the BB+ group compared to BB? patients in the anterior AAo (maximum: 1.49 ± 0.47 vs. 1.38 ± 0.49 N/m², p = 0.99, mean: 0.76 ± 0.2 vs. 0.74 ± 0.18 N/m², p = 1.00) or posterior AAo (maximum: 1.45 ± 0.42 vs. 1.39 ± 0.58 N/m², p = 1.00; mean: 0.65 ± 0.16 vs. 0.63 ± 0.16 N/m², p = 1.00). AAo peak velocity was elevated in patients compared to controls (p < 0.01) but similar for BB+ and BB? groups (p = 0.42). Linear models identified significant relationships between aortic stenosis severity and increased maximum WSS (β = 0.186, p = 0.007) and between diameter at the sinus of Valsalva and reduced mean WSS (β = ?0.151, p = 0.045). Peak velocity and systolic WSS were similar for BAV patients irrespective of BB therapy. Further prospective studies are needed to investigate the impact of dosage and duration of BB therapy on aortic hemodynamics and development of aortopathy.     

Dilatation of the ascending aorta in bicuspid aortic valve disease: a magnetic resonance imaging study

Background  

Bicuspid aortic valve disease (BAV) is increasingly recognized as a disease of the entire proximal aorta including both valvular and vascular complications. The aim of our study was to assess the dimensions of the thoracic aorta using MRI in a broad spectrum of BAV and tricuspid aortic valve disease (TAV) and to define the prevalence of the dilatation of the ascending aorta (AA) ≥4.5 cm in severe BAV disease.     

Qualitative grading of aortic regurgitation: a pilot study comparing CMR 4D flow and echocardiography

Over the past 10 years there has been intense research in the development of volumetric visualization of intracardiac flow by cardiac magnetic resonance (CMR). This volumetric time resolved technique called CMR 4D flow imaging has several advantages over standard CMR. It offers anatomical, functional and flow information in a single free-breathing, ten-minute acquisition. However, the data obtained is large and its processing requires dedicated software. We evaluated a cloud-based application package that combines volumetric data correction and visualization of CMR 4D flow data, and assessed its accuracy for the detection and grading of aortic valve regurgitation using transthoracic echocardiography as reference. Between June 2014 and January 2015, patients planned for clinical CMR were consecutively approached to undergo the supplementary CMR 4D flow acquisition. Fifty four patients (median age 39 years, 32 males) were included. Detection and grading of the aortic valve regurgitation using CMR 4D flow imaging were evaluated against transthoracic echocardiography. The agreement between 4D flow CMR and transthoracic echocardiography for grading of aortic valve regurgitation was good (κ = 0.73). To identify relevant, more than mild aortic valve regurgitation, CMR 4D flow imaging had a sensitivity of 100 % and specificity of 98 %. Aortic regurgitation can be well visualized, in a similar manner as transthoracic echocardiography, when using CMR 4D flow imaging.     

A simplified continuity equation approach to the quantification of stenotic bicuspid aortic valves using velocity-encoded cardiovascular magnetic resonance.

OBJECTIVE: We aimed to compare velocity-encoded cine cardiac magnetic resonance (CMR) with an established echocardiographic method for noninvasive measurement of aortic valve area (AVA) using the continuity equation. METHODS AND RESULTS: Twenty consecutive young adults with stenotic bicuspid aortic valves were examined with CMR and transthoracic echocardiography (TTE). CMR AVA was calculated by the continuity equation, dividing stroke volume by the aortic velocity-time integral (VTIAorta), the stroke volume measured both by ventricular volume analysis and by phase contrast velocity mapping at 4 levels (1 subvalvar and 3 supravalvar). Stroke volumes measured at all levels correlated well with those from volumetric analysis. The CMR AVAs calculated using volumetric analysis and VTIAorta from jet velocity mapping correlated and agreed well with TTE AVA measurements (R2 = 0.83). When CMR AVA was calculated more rapidly using volume flow and VTIAorta both measured from the same trans-jet velocity acquisition, R2 was 0.74, with a bias and limits of agreement of 0.02 (-0.44, 0.47) cm2. CONCLUSIONS: Continuity equation calculation of the AVA using CMR velocity mapping, with or without ventricular volumetric measurement, correlated and agreed well with the comparable and widely accepted TTE approach.     

Quantification of myocardial blood volume during dipyridamole and doubtamine stress: a perfusion CMR study.

PURPOSE: Myocardial blood volume (MBV) may provide complementary information about myocardial oxygen needs and viability. The aim of this study is to examine a Cardiovascular Magnetic Resonance (CMR) perfusion method to quantify the changes in MBV, in comparison with the radiolabeled 99mTc-Red-Blood-Cell (RBC) method. METHODS: Normal mongrel dogs (n=12) were used in this study. Eight dogs were injected intravenously with dipyridamole, and 4 dogs were given dobutamine during the MR scans. CMR first-pass perfusion imaging was performed at rest and during the pharmacological stress. An intravascular contrast agent, Gadomer (Schering AG, Berlin, Germany), was injected (0.015 mmol/kg) as a bolus during the scans. A perfusion quantification method was applied to obtain MBV maps. Radiolabeled-RBCs were injected at the end of the study to measure reference MBV at rest (n=4), during dipyridamole vasodilation (n=4), and during dobutamine stress (n=4). RESULTS: Myocardial blood flow (MBF) increased approximately 3-fold with both dipyridamole and dobutamine injections. Transmural MBV values measured by CMR were closely correlated with those measured by 99mTc method (CMR:MBV=6.2+/-1.3, 7.2+/-0.8, and 8.3+/-0.5 mL/100 g, at rest, with dipyridamole, and with dobutamine, respectively. 99mTc-RBC: MBV=6.1+/-0.5, 7.0+/-0.9, and 8.6+/-0.7 mL/100 g). Dobutamine stress significantly increased MBV by CMR (33%) and 99mTc methods (35%). During dipyridamole induced vasodilation, MBV increased non-significantly by 14% with the 99mTc method and 1% with CMR method, which agreed well with other reports. CONCLUSION: First-pass perfusion CMR with the injection of intravascular contrast agents is a promising non-invasive approach for the assessment of MBV both at rest and pharmacologically induced stress.     

Ascending aortic dilatation rate after transcatheter aortic valve replacement in patients with bicuspid and tricuspid aortic stenosis: A multidetector computed tomography follow-up study

BACKGROUND: Current data is lacking about the progression of ascending aortic dilatation after transcatheter aortic valve replacement (TAVR) in aortic stenosis (AS) patients with bicuspid aortic valve (BAV) and tricuspid aortic valve (TAV). This study aims to assess the ascending aortic dilatation rate (mm/year) after TAVR in patients with BAV versus TAV using a multidetector computed tomography (MDCT) follow-up and to determine the predictors of ascending aortic dilatation rate.METHODS: Severe AS patients undergoing TAVR from March 2013 to March 2018 at our center with MDCT follow-ups were included. BAV and TAV were identified using baseline MDCT. Baseline and follow-up MDCT images were analyzed, and the diameters of ascending aorta were measured. Study end point is ascending aortic dilatation rate (mm/year). Furthermore, factors predicting ascending aortic dilatation rate were also investigated.RESULTS: Two hundred and eight patients were included, comprised of 86 BAV and 122 TAV patients. Five, 4, 3, 2, and 1-year MDCT follow-ups were achieved in 7, 9, 30, 46, and 116 patients. The ascending aortic diameter was significantly increased after TAVR in both BAV group (43.7±4.4 mm vs. 44.0±4.5 mm; P<0.001) and TAV group (39.1±4.8 mm vs. 39.7±5.1 mm; P<0.001). However, no difference of ascending aortic dilatation rate was found between BAV and TAV groups (0.2±0.8 mm/year vs. 0.3±0.8 mm/year, P=0.592). Multivariate linear regression revealed paravalvular leakage (PVL) grade was independently associated with ascending aortic dilatation rate in the whole population and BAV group, but not TAV group. No aortic events occurred during follow-ups.CONCLUSION: Ascending aortic size continues to grow after TAVR in BAV patients, but the dilatation rate is mild and comparable to that of TAV patients. PVL grade is associated with ascending aortic dilatation rate in BAV patients post-TAVR.     

先天性卵巢发育不全综合征一例的诊断

Turner综合征（TS）又称先天性卵巢发育不全综合征,为女性一条X染色体缺失或者结构异常所致,活产女婴发病率为1/2000-1/2500,典型临床表现为身材矮小和第二性征缺乏.TS患者常合并多种并发症,如自身免疫性疾病、心血管畸形、糖脂代谢异常等,其骨质疏松和骨折、缺血性心肌病、2型糖尿病、高血压和卒中的风险增加.     

Prediction of aortic dilation in Turner syndrome - enhancing the use of serial cardiovascular magnetic resonance

Background

Identification of the subset females with Turner syndrome who face especially high risk of aortic dissection is difficult, and more optimal risk assessment is pivotal in order to improve outcomes. This study aimed to provide comprehensive, dynamic mathematical models of aortic disease in Turner syndrome by use of cardiovascular magnetic resonance (CMR).

Methods

A prospective framework of long-term aortic follow-up was used, which comprised diameters of the thoracic aorta prospectively assessed at nine positions by CMR at the three points in time (baseline [n = 102, age 38 ± 11 years], follow-up [after 2.4 ± 0.4 years, n = 80] and end-of-study [after 4.8 ± 0.5 years, n = 78]). Mathematical models were created that cohesively integrated all measurements at all positions, from all visits and for all participants, and using these models cohesive risk factor analyses were conducted based on which predictive modeling was performed on which predictive modelling was performed.

Results

The cohesive models showed that the variables with effect on aortic diameter were aortic coarctation (P < 0.0001), bicuspid aortic valves (P < 0.0001), age (P < 0.0001), diastolic blood pressure (P = 0.0008), body surface area (P = 0.015) and antihypertensive treatment (P = 0.005). Oestrogen replacement therapy had an effect of borderline significance (P = 0.08). From these data, mathematical models were created that enabled preemption of aortic dilation from CMR derived aortic diameters in scenarios both with and without known risk factors. The fit of the models to the actual data was good.

Conclusion

The presented cohesive model for prediction of aortic diameter in Turner syndrome could help identifying females with rapid growth of aortic diameter, and may enhance clinical decision-making based on serial CMR.     

Exploring myocardial fibrosis in severe aortic stenosis: echo,CMR and histology data from FIB-AS study

The International Journal of Cardiovascular Imaging - Myocardial fibrosis in aortic stenosis is associated with worse survival following aortic valve replacement. We assessed myocardial fibrosis in...     

Dilation of the ascending aorta in Turner syndrome - a prospective cardiovascular magnetic resonance study

Background

The risk of aortic dissection is 100-fold increased in Turner syndrome (TS). Unfortunately, risk stratification is inadequate due to a lack of insight into the natural course of the syndrome-associated aortopathy. Therefore, this study aimed to prospectively assess aortic dimensions in TS.

Methods

Eighty adult TS patients were examined twice with a mean follow-up of 2.4 ± 0.4 years, and 67 healthy age and gender-matched controls were examined once. Aortic dimensions were measured at nine predefined positions using 3D, non-contrast and free-breathing cardiovascular magnetic resonance. Transthoracic echocardiography and 24-hour ambulatory blood pressure were also performed.

Results

At baseline, aortic diameters (body surface area indexed) were larger at all positions in TS. Aortic dilation was more prevalent at all positions excluding the distal transverse aortic arch. Aortic diameter increased in the aortic sinus, at the sinotubular junction and in the mid-ascending aorta with growth rates of 0.1 - 0.4 mm/year. Aortic diameters at all other positions were unchanged. The bicuspid aortic valve conferred higher aortic sinus growth rates (p < 0.05). No other predictors of aortic growth were identified.

Conclusion

A general aortopathy is present in TS with enlargement of the ascending aorta, which is accelerated in the presence of a bicuspid aortic valve.