Cardiovascular disease of connective tissue origin

Aortic Dysfunction in Mitral Regurgitation Due to Floppy Mitral Valve/Mitral Valve Prolapse

BACKGROUND

 Floppy mitral valve/mitral valve prolapse (FMV/MVP), a heritable disorder of connective tissue, often leads to mitral regurgitation (MR) and is the most common cause for mitral valve surgery in developed countries. Connective tissue disorders may affect aortic function, and a stiff aorta may increase the severity of MR. Aortic function, however, has not been studied in FMV/MVP with MR.

METHODS

 A total of 17 patients (11 men, 6 women) with FMV/MVP and significant MR were compared with 20 controls matched for age and gender. Aortic diameters (AoD) were measured from left ventriculograms at 2 and 4 cm above the aortic valve. Aortic pressures were measured directly using fluid-filled catheters. Aortic distensibility was calculated using the formula: 2(systolic AoD-diastolic AoD)/(diastolic AoD x pulse pressure).

RESULTS

 Aortic distensibility was significantly lower in FMV/MVP compared with control at 2 cm above the aortic valve (1.00 ± 0.19 versus 3.78 ± 1.10 10^-3 mm Hg^-1, respectively; p = 0.027) and 4 cm above the aortic valve (0.89 ± 0.16 versus 3.22 ± 0.19 10^-3 mm Hg^-1, respectively; p = 0.007). FMV/MVP patients had greater left ventricular (LV) end-systolic (88 ± 72 mL versus 35 ± 15 mL, p = 0.002) and end-diastolic (165 ± 89 mL versus 100 ± 41 mL, p = 0.005) volumes, and lower LV ejection fraction, compared with control (50 ± 12% versus 57 ± 6%, p = 0.034).

CONCLUSION

 Aortic distensibility is decreased (consistent with a stiff aorta) in patients with FMV/MVP and MR. A stiff aorta may increase the severity of MR. Thus, abnormal aortic function, which also deteriorates with age, may play an important role in the natural history of MR due to FMV/MVP.

Matrix Metalloproteinase Polymorphisms in Patients with Floppy Mitral Valve/Mitral Valve Prolapse (FMV/MVP) and FMV/MVP Syndrome

BACKGROUND

It has been suggested that collagen abnormalities of the mitral valve are present in patients with floppy mitral valve (FMV)/mitral valve prolapse (MVP). Genetic factors determining collagen synthesis and degradation have not been well defined in these patients. This study was undertaken to determine whether selective polymorphisms of matrix metalloproteinase-2 (MMP2) or transforming growth factor-β (TGFβ), with known or putative effects on collagen turnover, are more frequent in FMV/MVP.

METHODS

Single nucleotide polymorphisms (SNPs) in select genes related to collagen turnover, including MMP2 rs2285053, MMP2 rs243865, TGFβ1 rs1800469, and TGFβ2 rs900, were determined in 98 patients with FMV/MVP who had severe mitral regurgitation and compared to 99 controls.

RESULTS

MMP2 rs243865 was the only SNP significantly associated with FMV/MVP as compared to the control (odds ratio 2.07, 95% CI 1.23-3.50, p = 0.006). MMP2 rs228503 was the only SNP significantly associated with the FMV/MVP syndrome as compared to patients with FMV/MVP without the syndrome (odds ratio 2.41, 95% CI 1.08-5.40, p = 0.032).

CONCLUSION

The frequency of certain MMP2 polymorphisms is higher in patients with the FMV/MVP syndrome and patients with FMV/MVP without the syndrome. The data suggest that a genetic predisposition that alters collagen turnover may play a role in the pathogenesis and development of FMV/MVP.

Piezogenic Pedal Papules with Mitral Valve Prolapse

Piezogenic pedal papules (PPP) are herniations of subcutaneous adipose tissue into the dermis. PPP are skin-colored to yellowish papules and nodules on lateral surfaces of feet that typically become apparent when the patient stands flat on his/her feet. Some connective tissue diseases and syndromes have been reported in association with PPP. Mitral valve prolapse (MVP) is a myxomatous degeneration of the mitral valve, characterized by the displacement of an abnormally thickened mitral valve leaflet into the left atrium during systole. MVP may be isolated or part of a heritable connective tissue disorder. PPP, which is generally considered as an isolated lesion, might be also a predictor of some cardiac diseases associated with connective tissue abnormalities such as MVP. A detailed systemic investigation including cardiac examination should be done in patients with PPP. Since in the literature, there are no case reports of association of PPP with MVP, we report these cases.

Echocardiographic evaluation in subjects with α1-Antitrypsin deficiency

BACKGROUND

α1-Antitrypsin (AAT) deficiency (AATD) is a genetic condition associated with early-onset panacinar emphysema and, less often, vascular disease. Recently, abnormal elastic properties of ascending aortic wall were described in ZZ genotype AATD subjects who incidentally showed an increased left ventricular mass.

MATERIALS AND METHODS

To evaluate biventricular dimensions, valvular apparatus, systolic and diastolic function, 33 AATD subjects with ZZ genotype and 33 healthy subjects matched for age and sex underwent a complete echocardiographic assessment.

RESULTS

Compared to controls, AATD subjects showed increased left ventricular mass (160 ± 59 g vs. 121 ± 70 g, P < 0.001), a higher incidence of left and right ventricular diastolic dysfunction (30% vs. 16%, P < 0.001 and 45% vs. 20%, P < 0.001, respectively) and mitral valve prolapse (35% vs. 6%, P < 0.001). In contrast, there was no difference between the two groups in diameters and systolic function of both ventricles and in the ejection fraction of left ventricle. The functions of aortic and tricuspidal valves were also similar.

CONCLUSIONS

In the presence of greater left ventricular mass, a significantly higher incidence of left and right ventricular diastolic dysfunction and mitral valve prolapse occurs in AATD subjects (ZZ genotype). These findings strongly suggest an abnormal remodelling process in cardiac tissue in AATD.

Vasculopathies of Neurofibromatosis Type 1 (von Recklinghausen Disease)

Vasculopathies are the least publicized but most important manifestation of neurofibromatosis type 1 (NF1, or, von Recklinghausen disease) as the cause of morbidity and mortality in children and young adults afflicted with the disease. Occlusive or aneurysmal disease of arteries of all sizes may occur almost anywhere in the body. Coarctation or segmental hypoplasia of the abdominal aorta with or without renal artery ostial stenosis is a common cause of renovascular hypertension. Although rare, occlusive coronary artery disease in NF1 may result in myocardial infarction and sudden unexpected death. Visceral vasculopathy causes ischemic bowel disease; and catastrophic retroperitoneal or abdominal hemorrhage has been attributed to spontaneously ruptured arterial aneurysms. Peripheral vascular disease in NF1 with limb ischemia requiring an amputation is described for the first time here. Scanty information exists in the current pathology literature on NF1 vasculopathies, hence the presentation of this review.

Mitral valve prolapse in young healthy individuals. An early index of autoimmunity?

Mitral valve prolapse (MVP) is a benign valvular abnormality. However, an increased prevalence of MVP is reported in patients with systemic lupus erythematosus and autoimmune thyroid disease. Our aim was to evaluate whether the presence of MVP in healthy individuals might indicate a premature index of subclinical autoimmune disorder. A total of 75 individuals with MVP and 44 individuals without MVP were identified by echocardiography. Serum samples were examined for various organ and non-organ specific autoantibodies. In all, 35 of the 75 individuals with MVP had at least one autoantibody. ANA were detected in 17/75 in MVP(+) versus 1/44 in the MVP(-), (P < 0.05), and anti-ENA in 6/75 in the MVP(+) versus 0/44 in the control group, P = ns. In the MVP(+) group, thyroid autoantibodies, IgA and IgG RF were found at a statistically significant higher incidence, 16/75, 11/75 and 10/75 versus 1/44, 0/44 and 0/44 in the MVP(-)group, respectively (P < 0.05). The levels of IgG anticardiolipin antibodies were significantly higher in the MVP(+) group, P < 0.05. The presence of organ and non-organ specific autoantibodies in young healthy MVP(+) individuals insinuate the presence of subclinical autoimmunity and might suggest that autoimmune mechanisms might be involved in its pathogenesis. A follow-up of these individuals might elucidate whether MVP constitutes an early index of autoimmunity.

Ruptured femoropopliteal artery aneurysms in von Recklinghausen neurofibromatosis

A 38-year-old woman with neurofibromatosis type 1 was referred for massive swelling of the left thigh, pain, and anemia. Angiography demonstrated three saccular aneurysms of the femoropopliteal artery. The largest measured 3 cm in diameter. Resection of the aneurysms and femoropopliteal interposition grafting using reversed saphenous vein was performed through a medial surgical approach. Arterial involvement in neurofibromatosis is a well known but infrequent occurrence. Stenotic lesions predominate. Aneurysmal defects are less common, and rupture of peripheral arteries is exceptional. Neurofibromatous invasion and dysplasia of the tunica media of the femoropopliteal vessel were confirmed by means of pathologic study. We think this is the second reported case of a femoropopliteal artery aneurysm and rupture associated with neurofibromatosis.

Is mitral valve prolapse due to cardiac entrapment in the chest Cavity? A CT view

BACKGROUND

Mitral valve prolapse (MVP) is the most frequently diagnosed valvular disease, but its pathophysiology remains elusive. Its complete absence in 1,734 neonatal echocardiographic studies suggests that this may be an acquired rather than a congenital disease. We observed several patients with distorted cardiac and valvular anatomies on electron beam CT (EBCT) images of the chest who reported symptoms reminiscent of MVP. In these patients, the heart is compressed between the spine and the anterior chest wall and it appears trapped in a chest cavity that is too small for its size.

METHODS

We performed EBCT in 66 patients with echocardiographically proven MVP and no clinical pectus excavatum (group A; 80% were women; mean age, 48 +/- 12 years) and in 96 control patients without MVP by echocardiography (group B; 72% were women; mean age, 49 +/- 10 years). EBCT alone was also performed on 200 patients who had reported atypical chest discomfort and palpitations to their physicians (group C) and on 200 asymptomatic patients (group D). The EBCT measurements included the following: anteroposterior chest diameter (APD); the angle formed by the confluence of the mitral valve ring with the interatrial septum (ANGLE); and the contact area between the posterior surface of the anterior chest wall and the myocardium (CA). Entrapment was considered present if the individual patient's measurements varied by more than two SDs compared to measurements made in control subjects (group B).

RESULTS

EBCT images demonstrated cardiac entrapment in 82% of group A patients and in 4.2% of group B patients (p < 0.001). ANGLE and CA were significantly larger in MVP patients than in group B patients (114 +/- 9 degrees vs 91 +/- 5 degrees and 6,230 +/- 2,020 mm(2) vs 476 +/- 1,009 mm(2), respectively; p < 0.001 for both comparisons), while APD was significantly smaller (91 +/- 16 mm vs 128 +/- 17 mm, respectively; p < 0.001). The prevalence of entrapment was significantly greater in group C patients than in group D patients (22% vs 6.5%; p < 0. 001).

CONCLUSIONS

MVP may be an acquired condition caused by a growth disproportion between the heart and the chest cavity, with distortion of the mitral valve annulus and subsequent leaflet prolapse. A narrow APD, a wide ANGLE, and a large CA characterize this condition. Similar findings are found in a sizable proportion of patients with atypical chest pain symptoms and palpitations.

Mitral valve prolapse in autoimmune thyroid disease: an index of systemic autoimmunity?

A coexistence of mitral valve prolapse (MVP) with autoimmune thyroid disease (AITD) has been described, but there are not sufficient data to explain this association. The aim of the present study was to investigate the prevalence of MVP in patients with AITD and to evaluate whether any correlation between MVP and certain immunological parameters exists. M-mode, two-dimensional Doppler echocardiography was performed in 29 patients with Graves' disease (GD), 35 with Hashimoto's thyroiditis (HT), 20 with nonautoimmune goiter, and 30 normal controls. Serum samples were examined for antinuclear antibodies (ANA), antibodies against extractable nuclear antigen (ENA), antiphospholipid antibodies (aCL), rheumatoid factor (RF), thyroid autoantibodies (TAAb), immunoglobulins and C3, C4. Eight of 29 GD patients and 8 of 35 HT patients had MVP, while none of the control group and 2 of 20 of the simple goiter group had MVP (p < 0.05). ANA were detected at low titers in 5 of 8 in MVP(+) GD versus 3 of 21 in MVP(-) GD (p < 0.05). In the HT group the MVP(+) patients had a significantly higher incidence of ANA and ENA, 5 of 8 and 2 of 8 versus 5 of 27 and 0 of 27 of MVP(-) patients, respectively, p < 0.05. A statistically significant higher incidence of aCL was found in HT MVP(+) patients. (3/8) versus HT MVP(-) 1/27, p < 0.05. RF levels (immunoglobulin A [IgA]) were significantly higher in MVP(+) patients. The association of MVP with nonorgan-specific autoantibodies indicates that MVP may also be an autoimmune disease. It is possible that patients with AITD who also have MVP may be at an increased risk to develop systemic autoimmunity.

The Marfan syndrome: cardiovascular physical findings and diagnostic correlates

Correlations among cardiac symptoms and auscultatory and phonoechocardiographic findings in Marfan syndrome have not been completely defined. A total of 24 patients with Marfan syndrome (16 men and 8 women; mean age 28.2 +/- 8.6 years) were studied. Mitral valve prolapse was noted in 22, of whom 19 had either nonejection systolic click or mitral regurgitation murmur. Mitral regurgitation was noted in 12 patients by Doppler imaging. Aortic root dilatation was noted in 20 patients and aortic regurgitation in six, five of whom had aortic regurgitation murmur (5 of 20 patients had undergone surgery). Proximal aortic dissection was noted in two. Dyspnea (n = 12) was associated with progressive mitral or aortic regurgitation in four, but in the others dyspnea could not be explained by valvular or ventricular abnormalities. Chest pain was related to pneumothorax in five and aortic dissection in two but was not associated with either in 15 patients. Palpitations (n = 12) and lightheadedness (n = 6) were not associated with specific arrhythmias. In conclusion, mitral valve prolapse and aortic root dilatation were the most common cardiovascular abnormalities in Marfan syndrome. Mitral valve prolapse was frequently associated with typical auscultatory findings and symptoms including dyspnea, chest pain, palpitations, and lightheadedness, whereas aortic root dilatation could be clinically silent unless complicated by aortic regurgitation or aortic dissection.

Echocardiographic evaluation of the aortic root and mitral valve in children and adolescents with isolated pectus excavatum: comparison with Marfan patients

Pectus excavatum, mitral valve prolapse (MVP), and dilated aortic root occur frequently in patients with Marfan's syndrome (MS). Patients with isolated pectus excavatum (IPE) have a high prevalence of MVP, but it is not known whether aortic root dilatation is a risk in those patients. To test the hypothesis that IPE and MS represent a spectrum of connective tissue dystrophy with MV and aortic root involvement, two-dimensional (2D) echocardiography was used to measure the aortic root diameter and assess for MVP in IPE (n = 31), MS (n = 14), and normal (n = 16) gender- and age-matched patients. Aortic root was measured in parasternal long- and short-axis views, just above the aortic sinuses, at end systole, in six cardiac cycles, and averaged. Parasternal long-axis view was used to assess for MVP. Aortic root diameter in IPE patients was not different from that in normal subjects, 24 +/- 4 mm vs 22 +/- 4 mm (p = NS), respectively, both were significantly smaller than that in MS patients (30 +/- 5 mm; p less than 0.05). MVP was present in 17 of 31 (55%) IPE patients vs 12 of 14 (86%) MS patients (p = NS) and in only 1 of 16 (6%) normal subjects (p less than 0.05) vs both IPE and MS. We conclude that young patients with IPE represent an isolated form of connective tissue abnormality because of the presence of pectus excavatum and MVP, but this is different from the systemic involvement of MS because of the lack of other systemic findings, including aortic root dilatation and changes in body habitus.

The Marfan syndrome: abnormal aortic elastic properties

Aortic distensibility and aortic stiffness index were measured at the ascending aorta (3 cm above the aortic valve) and the mid-portion of the abdominal aorta from the changes in echocardiographic diameters and pulse pressure in 14 patients with the Marfan syndrome and 15 age- and gender-matched normal control subjects. The following formulas were used: 1) Aortic distensibility = 2(Changes in aortic diameter)/(Diastolic aortic diameter) (Pulse pressure); and 2) Aortic stiffness index = ln(Systolic blood pressure)/(Diastolic blood pressure)(Changes in aortic diameter)/Diastolic aortic diameter. Pulse wave velocity was also measured. Compared with normal subjects, patients with the Marfan syndrome had decreased aortic distensibility in the ascending and the abdominal aorta (2.9 +/- 1.3 vs. 5.6 +/- 1.4 cm2 dynes-1, p less than 0.001 and 4.5 +/- 2.1, vs. 7.7 +/- 2.5, cm2 dynes-1, p less than 0.001, respectively) and had an increased aortic stiffness index in the ascending and the abdominal aorta (10.9 +/- 5.6 vs. 5.9 +/- 2.2, p less than 0.005 and 7.1 +/- 3.1 vs. 3.9 +/- 1.2, p less than 0.005, respectively). Aortic diameters in the ascending aorta were larger in these patients than in normal subjects, but those in the abdominal aorta were similar in the two groups. Linear correlations for both aortic distensibility and stiffness index were found between the ascending and the abdominal aorta (r = 0.85 and 0.71, respectively). Pulse wave velocity was more rapid in the patients than in the normal subjects (11.6 +/- 2.5 vs. 9.5 +/- 1.4 m/s, respectively, p less than 0.01). Thus, aortic elastic properties are abnormal in patients with the Marfan syndrome irrespective of the aortic diameter, which suggests an intrinsic abnormality of the aortic arterial wall.

Mediastinal haematoma in Ehlers-Danlos syndrome

A patient with Ehlers-Danlos syndrome presented acutely with clinical and radiological features suggestive of aortic dissection. Further investigations including computerised tomography and aortography showed mediastinal haematoma with no evidence of aortic dissection. He was treated conservatively with no complications. The typical clinical and radiological features are reviewed and an emphasis is made on accurate diagnosis to allow prompt, appropriate management.