Increased aortic stiffness in patients with coronary artery ectasia

OBJECTIVE: Alterations in aortic stiffness may reflect the elastic properties of the larger arteries. In many diseases, aortic elastic properties have been investigated to show whether the larger arteries are involved. The elastic properties of aorta in patients with coronary artery ectasia, however, have not been studied yet. We aimed to investigate aortic stiffness parameters in patients with coronary artery ectasia and to compare patients with coronary artery ectasia and coronary artery disease with the control group. METHOD: Thirty-three patients with coronary artery ectasia, 31 patients with coronary artery disease and 30 patients with angiographically normal coronary arteries were included in this study. Aortic diameters were measured on the M-mode tracing obtained at a level 3 cm beyond the aortic valve at parasternal long-axis view. Aortic diameter change, aortic strain, aortic distensibility and stiffness parameters were measured as aortic stiffness parameters. RESULTS: Aortic diameter changes were fewer in the coronary artery ectasia and coronary artery disease group than in the control group (0.4 +/- 0.1 and 0.3 +/- 0.1 vs. 0.8 +/- 0.2; P < 0.001). Aortic distensibility and aortic strain were significantly lower in patients with coronary artery ectasia and coronary artery disease than in the controls (for aortic distensibility P < 0.001 and for aortic strain P < 0.001, < 0.001, respectively). In contrast, a significantly higher aortic stiffness index was observed in patients with coronary artery ectasia and coronary artery disease than in the control group (14.2+/-2.6 and 18.1 +/- 2.9 vs. 5.9 +/- 1.8; P < 0.001, respectively). CONCLUSIONS: The impairment in aortic elastic properties in patients with coronary artery ectasia indicates that this disease is a generalized disease rather than a localized disease of the coronary arteries.     

Aortic distensibility associates with increased ascending thoracic aorta diameter and left ventricular diastolic dysfunction in patients with coronary artery ectasia

Coronary artery ectasia is usually linked to coronary atherosclerosis. Its primary defect is a destruction of vascular media, which leads to coronary dilatation. The aim of the present study is to evaluate whether ascending aorta present anatomical and functional wall changes in patients with coronary ectasia compared with patients without ectasia. Forty patients with known coronary ectasia (group A) underwent echocardiography in order to study aortic lumen diameter and wall properties (distensibility and stiffness index). Twenty-five patients with coronary artery disease (group B) and 40 individuals with normal coronary arteries (group C) served as control groups. Both ascending aorta diameter and ascending aorta index were significantly increased in group A compared with groups B and C (P < 0.05 and P < 0.001, respectively). Furthermore, in patients with ectatic coronary arteries ascending aorta index, systolic blood pressure and diastolic dysfunction independently associate with aortic distensibility. In patients with coronary artery ectasia, ascending aortic diameter could be enlarged while aortic stiffness is related to diastolic dysfunction. We suggest that coronary ectasia is not an isolated lesion but a reflection of a generalized vascular media defect, and should not be recognized as a benign entity.     

Decreased aortic distensibility and coronary flow velocity reserve in patients with significant aortic valve stenosis with normal epicardial coronary arteries

BACKGROUND AND AIM OF THE STUDY: A number of clinical and experimental studies have suggested that aortic valve stenosis (AS) is a manifestation of atherosclerotic process. Previous studies have revealed a decreased coronary flow velocity reserve (CFR) in AS patients in consequence of left ventricular hypertrophy. The hypothesis was tested that the elastic properties of the descending aorta of AS patients might indicate signs of stiffness of the aorta. METHODS: The CFR and indices of aortic distensibility as functional markers of the descending aorta were compared in three different patient populations: (i) control subjects without valvular and coronary artery disease; (ii) patients with AS with normal epicardial coronary arteries; and (iii) patients with significant left anterior descending coronary artery (LAD) stenosis. CFR measurements were carried out according to a standard protocol, using vasodilatory stimulation with dipyridamole (0.56 mg/kg for 4 min), and peak diastolic velocity measurements at 6 min. The elastic properties of the aorta were calculated from echocardiographic parameters and blood pressure data. RESULTS: The CFR in AS patients was decreased to a similar extent as in patients with LAD stenosis. The aortic distensibility indices were similarly significantly increased in patients with AS and normal epicardial coronary arteries and with LAD stenosis, as compared with controls. CONCLUSION: These results indicate that the descending aorta exhibits appreciable increased stiffness in AS patients with normal epicardial coronary arteries.     

Aortic Upper Wall Tissue Doppler Image Velocity: Relation to Aortic Elasticity and Left Ventricular Diastolic Function

Background: Aortic stiffening contributes to the left ventricular (LV) afterload, hypertrophy, and substrate for diastolic dysfunction. It is also known that aortic elastic properties could be investigated with color tissue Doppler imaging (TDI) in aortic upper wall. The purpose of this study is to evaluate the relation of aortic upper wall TDI and aortic stiffness and other parameters of LV diastolic function. Methods: We examined aortic upper wall by TDI at the 3 cm above the aortic valves because of patient's chest discomfort or dyspnea. We excluded the patient with arterial hypertension or reduced left ventricular ejection fraction (LVEF) or significant valvular heart disease. So a total of 126 (mean age 53.8 ± 13.9 years, male 49.2%) patients were enrolled in this study and divided normal LV filling group (N = 31) and abnormal LV filling group (N = 95). Results: Aortic upper wall early systolic velocity and late diastolic velocity were not different between the two groups. Only aortic upper wall early diastolic velocity (AWEDV) was related to aortic stiffness index (r =−0.25, P = 0.008), distensibility (r = 0.28, P = 0.003), early diastolic (Em) (r = 0.45, P = 0.001), E/Em (r =−0.26, P = 0.003), and significantly reduced in abnormal LV filling group (6.19 ± 2.50 vs 8.18 ± 2.87, P = 0.001). Conclusions: AWEDV is decreased significantly in abnormal LV filling patients. It is statistically related to aortic stiffness, distensibility and parameters of abnormal LV filling, Em, E/Em. TDI velocity of the aortic upper wall can be a helpful tool for evaluating aortic stiffness, distensibility, and diastolic function.     

Aortic distensibility abnormalities in coronary artery disease

Vasodilatory capacity of nonstenotic arteries in experimental animals with atherosclerosis is decreased. It was postulated that aortic distensibility may be abnormal in patients with coronary artery disease (CAD). Aortic distensibility was determined in 24 normotensive patients with CAD and an angiographically normal aorta and values were compared with those in 18 age-matched normal subjects. Aortic diameters were measured at 3 levels--2, 4 and 6 cm above the aortic valve--by angiographic techniques. The area of the first 6 cm of the aorta above the aortic valve was planimetered and mean aortic diameters were calculated. Distensibility was calculated using the formula: [2 X (changes of the aortic diameter)/(diastolic aortic diameter) X (changes of the aortic pressure)]. CAD patients had similar aortic pressures but markedly lower distensibility than normal subjects: 0.7 +/- 0.2 vs 1.7 +/- 0.3 (p less than 0.02); 1.5 +/- 0.3 vs 4.0 +/- 0.6 (p less than 0.02); and 1.2 +/- 0.2 vs 5.3 +/- 0.6 (p less than 0.001) at 2, 4 and 6 cm above the aortic valve, respectively. Distensibility was also calculated from the mean aortic diameters and was greater in normal subjects than in CAD patients (3.4 +/- 0.4 vs 1.6 +/- 0.1, p less than 0.001). Decreased aortic distensibility in CAD may be related to the common atherosclerotic process or to reduced ascending aorta vasa vasorum flow from coronary arteries.     

Prognostic value of coronary flow reserve and aortic distensibility indices in patients with suspected coronary artery disease

In recent studies it has been demonstrated that a reduced coronary flow reserve (CFR) is independently associated with a less benign long-term outcome. Aortic stiffness is one of the most important cardiovascular risk factors predicting cardiovascular morbidity and mortality. Vasodilator stress transesophageal echocardiography (TEE) is a suitable method to evaluate simultaneously CFR and elastic properties of the descending thoracic aorta. The aim of the present study was to assess the relative prognostic value of simultaneously measured CFR and aortic elastic properties by pulsed-wave Doppler TEE in patients with suspected or known coronary artery disease (CAD). The study comprised 157 in-hospital patients with chest pain. In all patients, stress TEE was used for the simultaneous evaluation of CFR and aortic distensibility indices [elastic modulus E(p) and Young's circumferential static elastic modulus E(s)]. During a mean follow-up of 48 +/- 8 months, 13 patients suffered cardiovascular death. By univariate analysis older age, diabetes mellitus, increased left ventricular (LV) end-diastolic diameter, increased LV mass index, lower LV ejection fraction, and lower CFR were significant predictors of cardiovascular survival. Multivariate regression analysis showed that only CFR (hazard ratio [HR] 10.31, P = 0.04), age (HR 1.20, P = 0.001), and increased left ventricular (LV) end-diastolic diameter (HR 1.14, P = 0.02) were independent predictors of cardiovascular survival. Only in the small number of patients without CAD and abnormal CFR aortic distensibility seemed to provide complementary prognostic information over CFR. In the majority of patients aortic distensibility did not offer complementary prognostic information to CFR during vasodilator stress TEE testing.     

Color Doppler tissue imaging in assessing the elastic properties of the aorta and in predicting coronary artery disease

We hypothesized that the change in aortic elastic properties could directly be shown with color Doppler tissue imaging (CDTI), that these findings could be related to aortic stiffness and distensibility and that, through these, coronary artery disease (CAD) could be predicted. One hundred and twenty six patients (group I: 83 with CAD, mean age 54+/-10 years, 18 female, 65 male; group II: 43 without CAD, mean age 53+/-10 years, 27 female, 16 male) having been evaluated for coronary artery disease by angiography were examined by echocardiography. Arterial pressure was measured immediately before echocardiographic evaluation. Internal aortic systolic and diastolic diameters by M-mode echocardiography and aortic upper wall tissue velocities (Aortic S, E, A, m/sec) by CDTI were measured 3 cm above the aortic valve. Lateral mitral annulus tissue velocities (Annulus S, E, A, m/sec) were also recorded. Aortic distensibility (cm2 x dynes(-1)) and aortic stiffness index were calculated using formulas. In the statistical analyses, CAD risk factors and left ventricular ejection fraction were used for adjustment. Aortic stiffness (2.79+/-3.49 vs 1.62+/-1.31, P=0.03), distensibility (1.55+/-1.46 vs 2.37+/-3.08, P=0.04), and aortic S velocity (0.057+/-0.016 vs 0.064+/-0.015, P=0.02) differed significantly between groups I and II. After adjustment, while aortic stiffness and S velocity were still statistically different (P=0.04; P=0.03 respectively), the significance of the difference in aortic distensibility disappeared (P=0.051). Aortic stiffness and aortic S velocity (0.06 m/sec<) were important CAD determinants (Odds ratio=1.4 P=0.03; Odds ratio=3.6 P=0.01, respectively), but aortic distensibility was not. Aortic stiffness was correlated only with aortic S velocity (r=-0.28, P=0.01), and aortic distensibility had a significantly positive correlation with aortic S velocity (r=0.20, P=0.02). The interobserver and intraobserver correlation coefficients for aortic S velocities were 0.65 and 0.71, respectively (P<0.05). Elastic properties of the aorta can directly be assessed by reproducibly measuring the movements in the upper wall of the aorta by CDTI. Reduced aortic S velocity is associated with increased aortic stiffness. Increased aortic stiffness and reduced aortic S velocity are important predictors of CAD.     

Effect of obstructive sleep apnea on aortic elastic parameters: relationship to left ventricular mass and function.

BACKGROUND: Obstructive sleep apnea (OSA) syndrome has a critical association with cardiovascular mortality and morbidity. Aortic elastic parameters are important markers for left ventricular (LV) function and are deteriorated in cardiovascular disease. METHODS AND RESULTS: Aortic elastic parameters and LV functions and mass were investigated in 40 patients with OSA (apnea - hypopnea index (AHI) >or=5) (mean age 51.3 +/-9 years, 32 males) and 24 controls (AHI <5) (mean age 51.9+/-5.2 years, 19 males). All subjects underwent polysomnographic examination and recordings were obtained during sleep. They also underwent a complete echocardiographic examination and systolic and diastolic aortic measurements were noted from M-mode traces of the aortic root. There were no significant differences in the demographic data of the patients with OSA and the controls. Subjects with OSA demonstrated higher values of aortic stiffness (7.1+/-1.88 vs 6.42+/-1.56, p=0.0001), but lower distensibility (9.47+/-1.33 vs 11.8+/-3.36, p=0.0001) than the controls. LV ejection fraction was significantly lower in patients with OSA when compared with the control group (61.3+/-5.2% vs 65.9+/-8.4%, p=0.0001). LV diastolic parameters were also compared and were worse in the subjects with OSA than in the control subjects (mitral E/A: 0.91 +/-0.42 vs 1.35+/-0.66, p=0.001; Em/Am: 0.86+/-0.54 vs 1.23+/-0.59, p=0.021). Respiratory disturbance index had a positive correlation with aortic stiffness (r=0.63, p=0.0001 and negative correlation with distensibility (r=-0.41, p=0.001). CONCLUSION: Aortic elastic parameters are deteriorated in OSA, which has an extremely high association with cardiovascular disease. Increased aortic stiffness might be responsible for the LV systolic and diastolic deterioration in OSA syndrome.     

Aortic distensibility in post-stenotic aortic dilatation: the effect of co-existing coronary artery disease

Aortic distensibility is decreased in patients with coronary artery disease (CAD) and the angiographically normal aorta. To determine if the same is true in patients with aortic stenosis and post-stenotic dilatation, two groups were studied. Group A consisted of 15 patients with post-stenotic aortic dilatation and normal coronary arteries, and group B, 14 patients with post-stenotic aortic dilatation and CAD. The patients were compared to 18 normal subjects. The area of the first 6 cm of the aorta above the valve obtained by aortography was planimetered and the mean diameters were calculated. Distensibility was calculated using the formula: (formula; see text) Distensibility was greater in group A (2.5 +- .4 cm2.dynes-1) compared to group B (1.0 +- 8 cm2.dynes-1, p less than 0.001). Distensibility in normal subjects reported recently from this laboratory (3.4 +- .4 cm2.dynes-1) was greater compared to both groups A and B (p less than 0.001). Thus, distensibility was decreased in patients with post-stenotic aortic dilatation. The further decrease in distensibility in patients with co-existing coronary artery disease may be partially related to abnormal nutrition of the arterial wall since the vasa vasorum of the ascending aorta are derived from the coronary arteries.     

Coronary flow velocity reserve and indices describing aortic distensibility in patients after coronary angiography

BACKGROUND: The purpose of this study was to assess the elastic properties of the descending aorta and the coronary flow velocity reserve (CFR) in patients after coronary angiography. METHODS AND PATIENTS: We recruited 112 subjects with stable angina pectoris without a previous myocardial infarction: 17 consecutive patients with anatomically normal coronary arteries, 24 patients with non-significant coronary artery disease (CAD), 31 patients with significant left anterior descending coronary artery (LAD) disease and 40 patients with multivessel disease (MVD). Transoesophageal echocardiography (TEE) is useful for evaluation of the elastic properties of the descending aorta. The physical behaviour of vessels in response to an intraluminal force is described by the elastic modulus (E(p)) and Young's circumferential static elastic modulus (E(s)). Coronary flow velocities can be measured in the LAD under baseline conditions and during dipyridamole stress. The CFR was calculated as the ratio of the average peak diastolic flow velocity during hyperaemia to that at rest. RESULTS: The indices of aortic distensibility, CFR and mean CFR, were different in patients with LAD disease and in those with normal coronary angiograms. There were no further changes in these parameters in cases with MVD. In patients with non-significant CAD, the CFR, mean CFR and stiffness moduli lie between those for negative cases and those for patients with LAD disease/MVD. CONCLUSIONS: When there was significant stenosis of the LAD, the CFR was significantly decreased, while indices of aortic distensibility were increased as compared with the negative controls. Interestingly, not only the CFR, but also E(p) and E(s) displayed no further changes in cases with MVD as compared with LAD disease.     

Reduced aortic distensibility and coronary flow velocity reserve in diabetes mellitus patients with a negative coronary angiogram

BACKGROUND: Structural and functional abnormalities of the aortic wall and disturbances of the coronary circulation with presumed microvascular complications have been reported in patients with diabetes mellitus. OBJECTIVES: To simultaneously establish the coronary flow velocity reserve (CFVR) and aortic distensibility indexes in type 2 diabetes mellitus patients who have normal epicardial coronary arteries by stress transesophageal echocardiography (STEE). METHODS: The elastic properties of the descending aorta and the CFVR were evaluated simultaneously in 18 type 2 diabetes mellitus patients who had negative coronary angiograms. These results were compared with those of 21 nondiabetic subjects with normal epicardial coronary arteries and 24 patients with left anterior descending coronary artery (LAD) stenosis. STEE was used for the evaluation of elastic moduli of the descending aorta. The CFVR was calculated as the ratio of the average peak diastolic flow velocity during hyperemia to that at rest. RESULTS: The CFVR of diabetic patients with normal epicardial coronary arteries and those with LAD stenosis was similarly decreased compared with the controls (2.10+/-0.63 and 1.78+/-0.47 versus 2.76+/-1.25, P<0.05 and P<0.001, respectively). The elastic modulus (in 103 mmHg) was similarly increased in patients with diabetes mellitus and normal epicardial coronary arteries, and in those with LAD stenosis, compared with the control subjects (0.94+/-0.82 and 0.91+/-0.59 versus 0.49+/-0.19, P<0.05 and P<0.05, respectively). CONCLUSIONS: It may be stated that reduced aortic distensibility (increased elastic modulus) and the CFVR were demonstrated simultaneously during STEE in diabetic patients compared with nondiabetic subjects with negative coronary angiograms.     

Elastic properties of the ascending aorta in young children after successful coarctoplasty in infancy

BACKGROUND: Based on the hypothesis that vascular dysfunction in the ascending aorta can cause morbidity, we undertook this study on the elastic properties of ascending aorta and left ventricular (LV) function in young children who received coarctoplasty in early infancy. METHODS: Blood pressures (BP) in the right arm and ascending aortic internal diameters determined by M-mode ultrasound at rest and after exercise were measured in 25 patients (mean age, 6.4+/-3 years) and 22 control subjects (mean age, 5.8+/-2.4 years). Ascending aortic stiffness index and distensibility were calculated using BP measurements and ascending aortic internal diameters. In addition, LV parameters (systolic and diastolic function, mass index) were evaluated. RESULTS: Compared with control subjects, patients had increased stiffness index (at rest: 4.87+/-1.94 versus 3.57+/-1.19, P=0.021; after exercise: 4.33+/-1.91 versus 3.2+/-1.26, P=0.034) and decreased distensibility (at rest: 6.90+/-3.15 versus 8.72+/-2.77, P=0.02; after exercise: 5.69+/-2.39 versus 7.88+/-3.44 cm2 dyn(-1) 10(-6), P=0.023). BP and LV parameters showed no consistent differences between the two groups. In patients, distensibility was significantly correlated with systolic BP (at rest: P=0.008; after exercise: P=0.014) and pulse pressure (at rest: P=0.013; after exercise: P=0.001). CONCLUSIONS: This study suggests that vasculopathy of ascending aorta is possible in some young children despite early correction. However, long-term tracking study is needed to clarify the significance of the study.     

The relationship between aortic stiffness and left ventricular function in patients with Cushing's disease: aortic stiffness in Cushing's disease

We aimed to investigate the aortic function and to evaluate the relationship between aortic stiffness and systolic and diastolic functions of the left ventricle in patients with Cushing's disease (CD). Fourteen women and one man with newly diagnosed CD, and 17 control cases were enrolled in this study. All subjects underwent echocardiography and systolic and diastolic aortic measurements were noted from M-mode aortic root. Aortic elastic parameters, aortic strain, and distensibility were calculated. Left ventricle functions were measured using echocardiography including, two-dimensional, M-mode, conventional Doppler, and tissue Doppler imaging. Aortic strain (7.4 ± 1.9 vs. 12.3 ± 2.4%; P < 0.001), and aortic distensibility (3.2 ± 1.1 × 10?? vs. 5.6 ± 1.4 × 10?? cm2 dyn?1; P < 0.001) were significantly decreased in patient group compared with control group. Mitral E velocity and the ratio of E/A were significantly lower and deceleration time of E was significantly prolonged in patients with CD. We also observed that patients with CD had markedly lower early diastolic myocardial peak velocity (Em) and Em/Am ratio and higher Tei index than in control group. Aortic elastic parameters are deranged in patients with CD and there is a significant correlation between left ventricular parameters determined by tissue Doppler echocardiography and aortic elastic parameters in these patients. We think that patients with CD should also be evaluated with aortic stiffness known to be an early marker for atherosclerosis.     

Relationship between aortic stiffness and the development of coronary collateral in patients with coronary artery disease

Large artery stiffness is an independent predictor of cardiovascular mortality and a major determinant of pulse pressure. The stiff aorta may result in greater systolic, lower diastolic, and wider pulse pressures, which may decrease coronary artery perfusion. Shear stress has been implicated in the development of coronary collateral. Decreased coronary perfusion may reduce shear stress and thus collateral formation. The goal of this study was to assess the relationship between the development of coronary collateral and aortic stiffness in patients with coronary artery disease. In 106 patients with at least one coronary artery stenosis of 90% or greater, collateral vessels were assessed angiographically by the Rentrop grading (grade 0-3), establishing two groups: 50 patients with poor collateral vessels (Rentrop grade 0 or 1), and 56 patients with good collateral vessels (Rentrop grade 2 or 3). Internal aortic root diameters were measured at 3 cm above the aortic valve by use of two-dimensional guided M-mode transthoracic echocardiography, and arterial pressure was measured simultaneously at the brachial artery by sphygmomanometry. Two indexes of the aortic elastic properties were measured: aortic distensibility index was calculated by use of the formula: 2 x (systolic diameter - diastolic diameter)/(diastolic diameter) x (pulse pressure) in cm(- 2)dyn(-1)10(-6). The aortic stiffness index was calculated by: (systolic blood pressure/diastolic blood pressure)/pulsatile change in diameter/diastolic diameter. The aortic distensibility index and the aortic stiffness index were not significantly different between the patients with poor collateral vessels and those with good collateral vessels (5.1 +/-2.3 vs 5.7 +/-3.3 cm(-2)dyn( -1)10(-6), p = 0.31; 4.02 +/-2.3 vs 4.43 +/-3.7, p = 0.49, respectively). There were no significant differences regarding the aortic elastic properties between the patients with poor collateral vessels and those with good collateral vessels, suggesting that collateral formation is a complex phenomenon consisting of several distinct processes.     

Aortic stiffness in patients with cardiac syndrome X

AIM: Recently, the close relationship between aortic stiffness and cardiovascular mortality has aroused the interest of investigators in carrying out studies related to aortic stiffness. This study aims to investigate the aortic stiffness parameters in patients with cardiac syndrome X, a disorder that is believed to be a generalized disturbance of the vasodilator function of small arteries. MATERIAL AND METHODS: 18 patients with typical chest pain and angiographically normal coronary arteries associated with a positive exercise test were included in the study. The control group consisted of 27 patients with angiographically normal coronary arteries and no ischaemia on exercise testing. Antianginal medication was withheld 4 weeks before the study and transthoracic echocardiography was performed using a Hewlett-Packard Sonos 1500 instrument with a 2.5 MHz phased array transducer. Ascending aorta diameters were measured on the M-mode tracing at a level 3 cm above the aortic valve. Diameter change, pulse pressure, aortic strain and distensibility were measured as aortic stiffness parameters. RESULTS: The aortic diameter change was less in the syndrome X group than in the control group (0.15 +/- 0.04 cm/m2 vs. 0.28 +/- 0.12 cm/m2, p < 0.001). Likewise, aortic strain (9 +/- 3% vs. 18 +/- 8%, p < 0.001) and distensibility (4.01 +/- 1.71 cm2 x dyn(-1) x 10(-3) vs. 9.95 +/- 5.08 cm2 x dyn(-1) x 10(-3), p < 0.001) was significantly lower in the syndrome X group than in the control group. CONCLUSION: The deterioration in aortic elasticity properties in patients with cardiac syndrome X suggests that this disease may be a more generalized disturbance of the vasculature.     

Diminished coronary flow velocity reserve and aortic distensibility in elderly patients with chest pain and negative coronary angiograms

BACKGROUND AND AIMS: Aging is a dominant process that alters vascular stiffness, endothelial function and coronary flow regulation. The objective of our work was to assess simultaneously the elastic properties of the descending aorta and coronary flow velocity reserve (CFR) during the same transesophageal echocardiography (TEE) in elderly patients. METHODS: The following patients with normal epicardial coronary arteries were compared: 30 subjects under 55 years of age (group 1) and 17 patients over 55 years (group 2). A complete TEE examination was carried out in all patients, and the following aortic elastic properties were calculated from aortic diameter and blood pressure data: aortic elastic modulus [E(p)] and Young's circumferential static elastic modulus [E(s)]. Doppler evaluation of left anterior descending coronary flow velocity was performed in resting conditions and after administration of 0.56 mg/Kg dipyridamole over 4 min. Peak coronary flow velocities were measured at the 6th minute at maximum vasodilation. CFR was estimated as the ratio of hyperemic to basal peak diastolic coronary flow velocities. RESULTS: Peak hyperemic diastolic coronary flow velocities were significantly decreased (139.1+/-35.6 cm/s vs 105.7+/-39.7 cm/s, p<0.01) in patients >55 years. CFR was decreased (2.67+/-1.05 vs 2.13+/-0.56, p<0.05), whereas E(p) (in 103 mmHg, 0.59+/-0.49 vs 0.94+/-0.65, p<0.05) and E(s) (in 103 mmHg, 5.70+/-4.30 vs 8.47+/-5.14, p<0.05) were increased in patients >55 years. A correlation was found between CFR and E(p) (r=-0.20, p<0.05). CONCLUSIONS: CFR and aortic distensibility are altered in elderly patients. There is a relationship between these functional parameters.     

Effects of normal blood pressure, prehypertension and hypertension on left ventricular diastolic function and aortic elastic properties

Background. The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (BP) provides guideline for the new category of BP levels as normal, prehypertension (PHT), and hypertension. Although PHT is associated with a markedly increased risk of developing hypertension within 4 years, its prognostic significance and predisposition to target-organ damage is unknown. Accordingly, we evaluated the effects of normal BP, PHT and hypertension on left ventricular (LV) diastolic function and aortic elasticity, which are sensitive indicators of target-organ damage. Methods. We evaluated LV diastolic function and aortic elastic properties of 60 subjects with PHT, 70 patients with hypertension and 50 normotensive healthy volunteers using transthoracic echocardiography. None of the subjects had any systemic disease. Results. LV diastolic function was more significantly impaired in the hypertension group than in the PHT group compared with controls, but it was not strongly different between the PHT and control group. Aortic distensibility was significantly lower, and aortic stiffness index was significantly higher in both the hypertension and the PHT group than those in the control group. However, aortic elastic properties did not significantly differ between the PHT and hypertension groups. Furthermore, we found that the presence of the PHT was significant predictor of impaired aortic elasticity in a multivariable model that adjusted for other variables. Conclusions. Aortic elastic properties are significantly and LV diastolic function is slightly impaired in subjects with PHT, and impairment of aortic elasticity is as severe as that in hypertension.     

Usefulness of colour tissue Doppler imaging in assessing aortic elastic properties in Type 1 diabetic patients.

AIMS: Diabetes mellitus (DM) is associated with macrovascular disease and impaired aortic function. We hypothesized that the change in aortic elastic properties could be investigated with colour tissue Doppler imaging (CTDI) in Type 1 diabetic patients and that these findings could be related to the aortic stiffness index. METHODS: We examined by echocardiography 66 patients with Type 1 DM (mean age 35 +/- 10 years, mean duration of disease 20 +/- 9 years) without a history of arterial hypertension or coronary artery disease (negative thallium-201 stress test) and 66 age- and sex-matched normal subjects. Arterial pressure was measured before echocardiography was performed. Internal aortic systolic and diastolic diameters by M-mode echocardiography and aortic systolic upper wall tissue velocity (Sao, cm/s) by CTDI were measured 3 cm above the aortic valve. Aortic distensibility and aortic stiffness index were calculated using accepted formulae. RESULTS: Aortic stiffness, distensibility and Sao velocity differed significantly between the studied groups. In the diabetic group, duration of diabetes correlated with aortic stiffness (r = 0.53, P < 0.001), distensibility (r = -0.61, P < 0.001) and Sao velocity (r = -0.48, P < 0.001). There was a negative correlation between aortic stiffness and Sao velocity (r = -0.49, P < 0.001). Multiple stepwise linear regression analysis in the diabetic group revealed that aortic S velocity (beta = 0.30, P = 0.005) and duration of diabetes (beta = -0.49, P = 0.001) were the main predictors of aortic distensibility (overall R(2) = 0.48). CONCLUSIONS: Aortic elastic properties can be directly assessed by measuring the movements in the upper aortic wall. Reduced aortic S velocity is associated with increased aortic stiffness in Type 1 diabetic patients.     

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.     

The Effect of Non-dipper and Dipper Blood Pressure Patterns on Aortic Elasticity in Patients with Metabolic Syndrome

The purpose of this study was to evaluate the effect of blood pressure (BP) rhythm on aortic functions in patients with metabolic syndrome. Seventy patients with newly diagnosed hypertension who fulfilled the metabolic syndrome criteria according to the Third Report of the National Cholesterol Education Program Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (NCEP/ATP-III) were evaluated with 24-hour BP holter monitoring. According to BP rhythm, 35 patients with dipper BP pattern and 35 patients with non-dipper BP pattern were enrolled as two groups in our study. Systolic and diastolic diameters of the ascending aorta were measured by M-mode echocardiography and aortic functions (aortic strain, distensibility, and stiffness index) were calculated. The nocturnal systolic and diastolic BPs were significantly higher in non-dipper patients than the dipper group. According to clinical parameters including age, gender, height, weight, body mass index, waist circumference, clinical systolic, and diastolic BPs, we did not find significantly difference between the two groups. Aortic strain was significantly higher (6.63 ± 3.37 vs. 1.81 ± 0.92; P < .0001) and aortic distensibility was lower (2.38 ± 1.18 cm^?2/dyn/10^?6 and 6.66 ± 3.67 cm^?2/dyn/10^?6; P < .001) in non-dipper group. These findings suggest that aortic functions were prominently deteriorated in non-dipper hypertensive patients than dippers with metabolic syndrome.