Aortic wall mechanics in the Marfan syndrome assessed by transesophageal tissue Doppler echocardiography

The aim of this study was to investigate the value of tissue Doppler imaging (TDI) using transesophageal echocardiography (TEE) in assessing the elastic properties of the thoracic aorta in patients with Marfan's syndrome. Aortic distensibility, stiffness index, and pulse-wave velocity were calculated using M-mode data in a TEE short-axis view in 31 patients with Marfan's syndrome and 22 normal controls. Acceleration time, maximum wall expansion velocity (Vmax), and wall strain were determined from TDI tracings. Indexes derived from TDI differed at a greater level of significance than M-mode-derived indexes in patients with dilated and normal aortas. Significant predictors of aortic dilation were systolic blood pressure, aortic stiffness index, Vmax, and strain. Decreased aortic strain and Vmax and increased stiffness index were predictive of aortic dissection (odds ratios 4.5, 3.3, and 2.2). In conclusion, the TDI assessment of aortic wall mechanics is complementary to standard M-mode measurements in discriminating normal subjects from patients with Marfan's syndrome and is accurate in predicting aortic dilation and dissection.

Aortic reflection coefficients and their association with global indexes of wave reflection in healthy controls and patients with Marfan's syndrome

Early return of reflected pressure waves increases the load on central arteries and may increase the risk of aortic rupture in patients with Marfan's syndrome (MFS). To assess whether wave reflection is elevated in MFS, we used ultrasound and MRI to measure central pressure and flow waveforms in 26 patients (13-54 yr of age) and 26 age- and gender-matched controls. Aortic systolic and diastolic cross-sectional areas were measured at the ascending and descending aorta (AA and DA), diaphragm (DIA), and lower abdominal aorta (AB). From these measurements, local characteristic impedance (Z(0-xx)) and local reflection coefficients (Gamma(xx-yy)) were calculated. Calculated global wave reflection indexes were the augmentation index (AIx) and the ratio of backward to forward pressure wave (P(b)/P(f)). The aorta was wider in MFS patients at AA (P < 0.01) and DA (P < 0.01). Aortic pulse wave velocity was 42 cm/s higher in MFS patients (P < 0.05). Z(0-xx) was not different between groups, except at DA, where it was lower in MFS patients. In controls, Gamma(AA-DA) was 0.31 +/- 0.08, Gamma(DA-DIA) was 0.00 +/- 0.11, and Gamma(DIA-AB) was 0.31 +/- 0.16. Mean values of Gamma(xx-yy) were not different between MFS patients and controls. In controls, aging diminished Gamma(AA-DA) but increased Gamma(DIA-AB). Clear age-related patterns were absent in MFS patients. AIx or P(b)/P(f) was not higher in MFS patients than in controls. There were indications for enhanced wave reflection in young MFS patients. Our data demonstrated that the major determinants of AIx were pulse wave velocity and the effective length of the arterial system and, to a lesser degree, HR and P(b)/P(f).

Prenatal Marfan syndrome: report of one case and review of the literature

OBJECTIVES

Our objective was to describe the features of prenatal Marfan syndrome.

METHODS

Doppler fetal echocardiograms were performed. The morphology and rhythm of the fetal heart were examined sequentially.

RESULTS

The case was referred because of cardiomegaly and dilated great vessels. Sequential Doppler echocardiographic evaluation led to the diagnosis of prenatal Marfan syndrome. The main features are cardiomegaly, dysplastic atrioventricular valves with tricuspid regurgitation and dilated great vessels, which can be aneurysmal at their origin. The fetus died in utero at 39 weeks of gestation because of cardiac failure. Pathological study confirmed the Marfan habitus and complications. Molecular genetic study showed a de novo point mutation in exon 26 of the FBN1 gene.

CONCLUSION

We report a case of prenatal Marfan syndrome diagnosed by sequential evaluation of the cardiac signs, which are essential for prenatal diagnosis. The prognosis seems as poor as the neonatal one. The prenatal diagnosis is essential for adequate counselling.

Determinants of rapid progression of aortic root dilatation and complications in Marfan syndrome

BACKGROUND

Progressive aortic dilatation has prognostic significance in the Marfan syndrome.

METHODS

To identify which patients were at high risk of rapid progression, we echocardiographically studied 43 patients (age 22 +/- 14 years) with the mean follow-up period of 5.2 +/- 3.2 years. Aortic diameters, left ventricular (LV) size, fractional shortening, and the severity of aortic and mitral regurgitation were assessed. Transmitral peak early and atrial flow velocities, their ratio and the deceleration time of peak early velocity were also obtained.

RESULTS

Mean annual increases of aortic diameters were 0.4 +/- 0.3 mm at the annulus, 1.5 +/- 1.3 mm at the sinuses of Valsalva, 0.7 +/- 0.6 mm at the supraaortic ridge and 0.4 +/- 0.4 mm at the proximal ascending aorta. Patients were divided into 2 groups according to the aortic growth rate at the sinuses of Valsalva level: rapid (R, >3% per year, 15 patients) or slow (S, < or =3% per year, 28 patients) progression groups. Measured variables did not show significant differences between the 2 groups except older age, higher blood pressure and more severe aortic regurgitation in group R. Multiple regression analysis identified prolonged deceleration time as the most important variable predicting aortic complications. Aortic dissection occurred more frequently in group R (7 patients, 47%) than in group S (0%, P < 0.001).

CONCLUSIONS

Marfan patients at older age, with higher blood pressure, and with significant aortic regurgitation were at high risk of progression of aortic dilatation, with the most remarkable increase at the sinuses of Valsalva. Prolonged deceleration time may relate to an increased risk for aortic complications.

Risk of development of abdominal aortic aneurysm and dissection of thoracic aorta in a postpartum woman with Marfan's syndrome

A 24-year-old pregnant woman with Marfan's syndrome delivered by cesarean section during the 38th week of gestation. Although aortic root dilatation did not increase during pregnancy, three months after delivery, the patient noticed a pulsatile abdominal mass. Aortic aneurysm was diagnosed and surgical replacement of the infrarenal abdominal aorta to the common iliac arteries and reconstruction of the inferior mesenteric artery were performed. Moreover, the patient subsequently developed a Stanford type B thoracic aortic dissection, even after more than four months of beta-blockade.

[Serial clinical and echocardiographic evaluation in children with Marfan syndrome]

OBJECTIVE

To describe the clinical cardiac manifestations and temporal evolution of Marfan syndrome in children; to estimate the incidence of annuloaortic ectasia and mitral valve prolapse; and to evaluate tolerability and efficacy of beta-blockers in these patients.

METHODS

During one year, 21 children with Marfan syndrome underwent serial clinical and echocardiographic examinations. Echocardiograms assessed: the presence of mitral valve prolapse, aortic root diameter, mitral and aortic valves regurgitation, and aortic enlargement during beta-blocker therapy. Eleven patients had two measurements of the aortic root taken one year apart.

RESULTS

The children were asymptomatic throughout the study. Mitral prolapse was found in 11 (52%) children. Annuloaortic ectasia occurred in 16 (76%) patients and found to be mild in 42.8%, moderate in 9.5%, and severe in 23.8%. One of these patients underwent aortic valve replacement and repair of the ascending aorta by the Bentall-De Bono technique, with good results. Heart rate decreased by 13.6% (from 85 to 73 bpm; p < 0.009) with the use of beta-blockers; however, aortic root diameter increased by 1.4 mm/year (p < 0.02). One child could not be given beta-blockers due to bronchial asthma, and no significant side effects were observed in the remaining children, including one who also had bronchial asthma.

CONCLUSION

The children remained asymptomatic throughout the study, the use of beta-blockers led to a significant decrease in heart rate, and no significant adverse effects were observed. Contrary to the literature, incidence of annuloaortic ectasia was high among the study population, greater than that of mitral valve prolapse, even during beta-blocker therapy.

Primary impairment of left ventricular function in Marfan syndrome

BACKGROUND

Cardiovascular involvement in Marfan syndrome is mainly characterized by progressive dilatation of the proximal aorta. Whether left ventricular dysfunction is present in these patients is not clear at present.

OBJECTIVES

Assess left ventricular function in patients with Marfan syndrome, free of significant valvular heart disease, using a combination of MRI and Tissue Doppler imaging (TDI).

METHODS AND RESULTS

A total of 26 Marfan patients (mean age=32.0+/-10.9, 12 men) without significant valvular heart disease, and 26 age- and sex-matched controls were studied. Left ventricular volumes and ejection fraction were measured with magnetic resonance imaging. Systolic and diastolic function parameters were assessed using conventional echocardiography and TDI. When compared to controls, Marfan patients showed impairment of left ventricular contractile function as expressed by a reduced ejection fraction (53.5+/-9.0% vs. 59.6+/-6.7%, p=0.009), an increased end-systolic volume (36.0+/-9.5 vs. 29.5+/-6.7 ml/m(2), p=0.007), and reduced peak systolic velocities at the basal septal and lateral myocardial wall (5.2+/-1.4 vs. 6.4+/-1.3 cm/s, p=0.003 and 6.0+/-2.2 vs. 7.5+/-2.3 cm/s, p=0.03, respectively). Diastolic function was impaired with an increased deceleration time of the E wave (171+/-41 ms vs. 141+/-36 ms, p=0.006). Peak early diastolic velocity at the mitral valve annulus was significantly lower (9.6+/-2.4 cm/s vs. 11.9+/-3.3 cm/s, p=0.006).

CONCLUSION

These data provide evidence for mild, but significant impairment of left ventricular systolic and diastolic function in Marfan patients, not related to valvular heart disease.

Echocardiographic Doppler assessment of the biophysical properties of the aorta in pediatric patients with the Marfan syndrome

In the Marfan syndrome (MS), aortic root involvement is usually clinically monitored according to the aortic sinus of Valsalva dilation. Using an echocardiographic Doppler method in this cross-sectional study, abnormal biophysical properties of the ascending aorta were found in pediatric patients with MS compared with healthy controls but not consistently in association with the aortic sinus of Valsalva dilation.

[3D echocardiography of the ascending aorta in Marfan's syndrome]

Marfan's syndrome is a cause of dilatation of the aorta, the main complication of which is dissection of the aorta. 2D echocardiography is the reference investigation for measuring the ascending aorta. Asymmetry of sinus dilatation makes a 3D approach necessary. Real time 3D echocardiography is a simple, non-invasive method which, by a biplane mode, allows measurement of the 3 sinuses of Valsalva. The aim of the study was to compare the 2D and 3D echocardiographic methods for measuring the ascending aorta. Fifteen patients (average age 12 +/- 8 years) with Marfan's syndrome were studied prospectively. The maximal 3D diameter was significantly greater than the 2D measurement (31.7 +/- 6.8 mm vs 29.9 +/- 6.6 mm, p< 0.005). In 4 patients, the difference was over 3 mm. The diameter between the right coronary and left coronary sinus was greater than the two others (right coronary-non coronary and left coronary-non coronary). The oldest 5 patients had an MRI aortic measurement very similar to that of 3D echocardiography (36.6 vs 36.7 mm). Real time 3D echocardiography in the biplane mode enables reliable and reproducible measurement of the aortic root in patients with Marfan's syndrome. Larger and multicenter studies are required to allow confirmation of the value of 3D echocardiography in the follow-up of these patients.

Diagnostic power of aortic elastic properties in young patients with Marfan syndrome

BACKGROUND

In patients with Marfan syndrome, progressive aortic dilation implicates a still-unpredictable risk of life-threatening aortic dissection and rupture. We sought to quantify aortic wall dysfunction noninvasively, determine the diagnostic power of various aortic parameters, and establish a diagnostic model for the early detection of aortic abnormalities associated with Marfan syndrome.

METHODS

In 19 patients with Marfan syndrome (age, 17.7 +/- 9.5 years) and 19 age- and sex-matched healthy control subjects, computerized ascending and abdominal aortic wall contour analysis with continuous determination of aortic diameters was performed out of transthoracic M-mode echocardiographic tracings. After simultaneous oscillometric blood pressure measurement, aortic elastic properties were determined automatically.

RESULTS

The following ascending aortic elastic parameters showed statistically significant differences between the Marfan group and the control group: (1) decreased aortic distensibility ( P < .001), (2) increased wall stiffness index ( P < .01), (3) decreased systolic diameter increase ( P < .01), and (4) decreased maximum systolic area increase ( P < .001). The diagnostic power of all investigated parameters was tested by single logistic regression models. A multiple logistic regression model including solely aortic parameters yielded a sensitivity of 95% and a specificity of 100%.

CONCLUSIONS

In young patients with Marfan syndrome, a computerized image-analyzing technique revealed decreased aortic elastic properties expressed by parameters showing high diagnostic power. A multiple logistic regression model including merely aortic parameters can serve as useful predictor for Marfan syndrome.

Echocardiometric evaluation of cardiovascular abnormalities in Marfan syndrome

Marfan syndrome is an inherited disorder of connective tissue with manifestations in various organ-systems including cardiovascular system. The aim of this study was to characterize and determine the frequency of cardiovascular alterations by echocardiography in 2 age cohorts of Mexican patients with Marfan syndrome and their comparisons with control groups.

MATERIAL AND METHODS

Sixty six with Marfan syndrome and 33 control patients were evaluated by echocardiography. Segments of the aorta and pulmonary artery were measured at different levels, cardiac valves were examined for prolapse and the interatrial septum was assessed for septal aneurysm. Numeric values were corrected for the body surface area and compared with the control group.

RESULTS

Mean significant values between group I (children) and Group II (adults) were as follows: aortic annulus 16.62 +/- 4.57 mm/m2 vs 12.81 +/- 1.95 (p < 0.001), aortic root 23.30 +/- 7.49 mm/m2 vs 18.36 +/- 2.97 (p < 0.001), sinuses of Valsalva 24.14 +/- 7.29 mm/m2 vs 19.84 +/- 3.59 (p < 0.001), ascending aorta 18.43 +/- 5.90 mm/m2 vs 17.02 +/- 4.79 (p < 0.001), aortic arch 16.12 +/- 4.73 mm/m2 vs 14.20 +/- 2.68 (p < 0.001). Pulmonary valve prolapse was seen in 10/22 (45.5%) vs 7/44 (15.9%), p < or = 0.03. Interatrial septal aneurysm was found in 3/22 (13.6%) vs 20/44 (45.5%), p < or = 0.03. There was a significative diference in the presence of atrial septal aneurysm between the adult group and control group (p < 0.001).

CONCLUSIONS

The incidence of cardiovascular abnormalities in our series is similar to that in the literature with the exception of the very high incidence of pulmonary valve prolapse vs control groups, then it suggests that the clinical manifestations of MFS are strikingly severe in the Mexican population. Also a high incidence of interatrial septal aneurysm (34.9%) in comparison to control groups (18.2%) was found.

Dural ectasia: a likely cause of inadequate spinal anaesthesia in two parturients with Marfan's syndrome

We report two cases of Caesarean section in patients with Marfan's syndrome where continuous subarachnoid anaesthesia failed to provide an adequate surgical block. This was possibly because of dural ectasia, which was confirmed by a computed tomography scan in both cases.

Pregnancy and aortic root growth in the Marfan syndrome: a prospective study

AIMS

In women with Marfan syndrome pregnancy presents an increased risk of dilatation, dissection, and rupture of the aorta. The aim of this study was to investigate the influence of pregnancy on growth of the aortic root.

METHODS AND RESULTS

Between 1993 and 2004 127 women with Marfan syndrome were prospectively followed; 61 women had one or more children; in 23 women, 33 pregnancies could be followed prospectively for aortic dimensions. Only one woman had suffered an aortic complication, a type A dissection (limited to the ascending aorta), before pregnancy. Out of 66 childless women a comparison group of 22 women was selected and individually matched. Mean initial aortic root diameter just before pregnancy was 37+/-5 mm (range 25-45). Before, during, and after pregnancy the overall individual aortic root diameter change (in 31 pregnancies) was not significant (P=0.77). Only the woman with a previous type A dissection developed an aortic complication (type B dissection) during her second pregnancy. No cardiac complications occurred in the other 22 women during their pregnancies. During a median follow-up of 6.4 years, no significant difference in growth of the aortic root was observed between the pregnancy group and the matched childless group (0.28 vs. 0.19 mm/year, P=0.08, respectively).

CONCLUSION

Pregnancy in women with Marfan syndrome seems to be relatively safe up to an aortic root diameter of 45 mm, at least as far as our observed diameter range of 25-45 mm is concerned.

Marfanoid habitus with abnormal situs

Marfanoid habitus suggests abnormal microfibril formation, whereas a situs ambiguus or situs inversus phenotype points to defective left-right axis determination. The concurrence of these two abnormalities has been reported only once in the literature. We report a similar phenotype in two unrelated patients. Documentation of this specific combination of Marfanoid habitus and abnormal situs gives further credence to the notion that the combination may represent a distinct syndrome.

Repair of left coronary artery aneurysm, recurrent ascending aortic aneurysm, and mitral valve prolapse 19 years after Bentall's procedure in a patient with Marfan syndrome

A 45-year-old female with Marfan syndrome had a Bentall's procedure performed 19 years ago. She presented with a 4-year history of gradually worsening dyspnea and decreasing exercise tolerance. Investigations revealed severe mitral valve prolapse, a left main stem coronary artery (LMSCA) aneurysm, and a recurrent aneurysm of the ascending aorta. The mitral valve was replaced and the aortic aneurysmal sac and the LMSCA aneurysm were then repaired by a modified Bentall procedure. The patient made an uneventful recovery and was discharged home.

Usefulness of tissue doppler imaging for assessing aortic wall stiffness in children with the Marfan syndrome

The purpose of this study was to assess wall motion velocities of the abdominal aorta using tissue Doppler imaging (TDI) in 12 patients with Marfan syndrome and 30 age-matched normal controls. The patients with Marfan syndrome displayed an increased aortic stiffness index in the abdominal aorta, and significant relationships were observed between wall motion velocities of the abdominal aorta and the aortic stiffness index. Thus, TDI analyzes aortic expansion and contraction velocities and allows the identification of abdominal aortic stiffness in patients with Marfan syndrome.

Craniofacial structure in Marfan syndrome: A cephalometric study

Marfan syndrome (MFS) is a connective tissue disorder with autosomal dominant inheritance. Mutations in the FBN1 gene cause deficient processing of fibrillin-1, the main constituent of extracellular microfibrils, affecting tissues displaying elastic properties. Clinical manifestations are widespread and involve the skeletal, ocular, cardiovascular and pulmonary systems, skin and integumentum, and dura. A highly arched palate and retrognathia have been assigned to the symptoms with minor diagnostic specificity, although epidemiological data on prevalence are lacking yet. Twenty-six patients with MFS (n = 26) were studied for craniofacial characteristics using cephalometric measurements on lateral cranial radiographs. The purposes of this study were (1) to compare cephalometric variables of MFS group with age- and sex-matched population norms, and (2) to assess differences in palatal vault dimensions among adult MFS (n = 17) and matched controls (n = 32) by means of cephalometric measurements. Significant differences with population norms were found in the structures of the cranial base, the maxillary complex, the mandible body, and the relations of the jaws with respect to the cranial base and to each other. Palatal height and palatal length were significantly larger in MFS, and were significantly correlated to each other and to the height of the maxillo-alveolar processus. The present data disprove in part previously reported findings, possibly due to biased patient selection in these studies or demographic differences. However, a strong correlation was found between maxillary/mandibular retrognathia, long face, highly arched palate, and MFS. A combination of both intrinsic genetic factors and environmental factors is suggested as a possible explanation for specific morphogenetic aspects of the craniofacial complex in MFS.

A novel Doppler echocardiographic method of measuring the biophysical properties of the aorta in pediatric patients

BACKGROUND

This study was performed to: (1) assess the feasibility of measuring pulse wave velocity (PWV) from aortic (AO) Doppler flow and deriving AO input and characteristic impedances and the arterial pressure strain elastic modulus; and (2) compare these indices in pediatric patients with arterial disease to control (C) patients.

METHODS

There were 14 healthy children in the C group, 9 with inflammatory connective tissue diseases (ICTD), and 6 with Marfan syndrome (M). Using standard echocardiographic equipment, the AO annulus, AO root diameter in systole (AO(S)) and diastole (AO(D)), and AO length (L) were measured. The time taken for the Doppler signal to travel from the ascending to descending aorta was measured. AO peak flow was calculated from AO annulus cross-sectional area x peak aortic velocity (AoV); PWV = L/time taken for the Doppler signal to travel from the ascending to descending aorta; input impedance = (systolic - diastolic blood pressure)/(AO cross-sectional area x AoV); characteristic impedance = (PWV x rho)/Ao cross-sectional area (where rho = 1.06); and pressure strain elastic modulus = (systolic - diastolic blood pressure)/[(AO(S) - AO(D))/AO(D)]; beta index = ln (systolic/diastolic blood pressure)/[(AO(S) - AO(D))/AO(D)].

RESULTS

Results for PWV were ICTD = M > C (533, 496, 362 cm/s; P <.02); for input impedance were ICTD > M = C (245, 120, 116; P <.03); for characteristic impedance were ICTD < M = C (249, 107, 142; P <.05); for pressure strain elastic modulus were M > ICTD = C (262, 447, 187; P <.003); and for beta index were M > ICTD > C (2.91, 2.51, 2.13; P <.0006).

CONCLUSIONS

This novel, relatively simple method of assessing the biophysical properties of the aorta shows abnormal function in patients with M and ICTD. This technique may be helpful in the long-term follow up of patients with arterial disease.

Recurrent aortic dissection in Marfan's syndrome: possible effects of anticoagulation

Recent reports support the role of a valve-sparing procedure in ascending aortic dissection in patients with Marfans syndrome. A 49-year-old woman with Marfans syndrome and prior aortic aneurysm repaired with a composite graft presented with sudden-onset chest pain. Following an initial negative computed tomographic (CT) scan, a long dissection involving the descending thoracic and abdominal aorta was discovered on a repeat CT scan a few hours later. Symptoms improved gradually with optimal medical management and the patient was discharged home on anticoagulant therapy. Although no direct cause-and-effect relationship can be established, chronic anticoagulant therapy may accelerate the progression of recurrent dissection in these patients. A valve-sparing procedure should be considered in eligible patients with Marfans syndrome who need operative correction to avoid possible future untoward effects of long-term anticoagulant therapy.