Aortic Wave Reflection Research Articles

Os valores da pressão arterial aórtica e índice de aumentação central em indivíduos com hipertensão da bata branca são mais próximos dos indivíduos normotensos do que dos hipertensos tratados para idênticas idades, género e pressão noturna

IntroductionThere is disagreement whether white coat hypertensives (WCH) have different hemodynamic and structural characteristics compared to normotensives (NT) and hypertensives (HT). MethodsWe compared cardiovascular prognostic markers (pulse wave velocity [PWV] and aortic stiffness index [ASI]) and data on central hemodynamics and central pressures (augmentation index [AIx], augmentation pressure [AugP] and pulse pressure amplification [PPA]) from aortic pulse wave analysis between NT (n=175), WCH (n=315) and treated HT (n=691), all with 24‐h blood pressure (BP) <130/80 and nocturnal BP <120/70 mmHg after matching for age, gender, body mass index (BMI) and and nocturnal BP. The groups were also compared separately in terms of 24‐h systolic BP <120 mmHg and 120‐129 mmHg. ResultsThe percentage of non‐dippers was 40.1% in NT, 34.5% in WCH and 38.3 in HT. For similar 24‐h and nocturnal systolic BP (NT 109/64±7/5, WCH 110/66±7/6, HT 109/64±7/5 mmHg), aortic stiffness was greater in HT (n=691, PWV 10.8±2.6 m/s and ASI 0.33±0.16, p<0.01) than in WCH (n=316, PWV 9.7±2.4 m/s and ASI 0.28±0.17) and NT (n=175, PWV 9.5±2.0 m/s and ASI 0.29±0.15); AugP and AIx were higher (p<0.01) in HT (13.9±8.2 and 29.6±12.6 mmHg) than in WCH (11.5±8.5 mmHg and 24.9±15.2) and NT (11.0±6.4 mmHg and 26.6±11.5). PPA was lower (p<0.01) in HT (11.3±5.5 mmHg) than in WCH (13.2±7.1 mmHg) and in NT (12.4±4.9 mmHg). The findings were similar when the 24‐h systolic BP <120 mmHg and 120‐129 mmHg subgroups were analyzed separately. ConclusionOur data suggest that for similar age, gender distribution, BMI, and 24‐h and nocturnal BP, aortic stiffness, central aortic pressures and wave reflection in WCH are closer to those of NT than to those with treated HT. This supports the idea that white coat hypertension may be a more benign condition than treated hypertension for similar 24‐h and particularly nocturnal BP levels.

Effects of acute dietary nitrate supplementation on aortic blood pressure and aortic augmentation index in young and older adults

PurposeAging is associated with elevated blood pressure (peripheral and aortic; BP) and aortic augmentation index (AIx) which may contribute to aortic BP. Although inorganic nitrate consumption reduces peripheral BP in both young and older adults, the effects of nitrate consumption on aortic BP and wave reflection in young and older adults is unknown. Therefore, we sought to characterize the effects of nitrate consumption on aortic BP and AIx in young and older adults. MethodsNoninvasive aortic pressure waveforms were synthesized from high-fidelity radial pressure waveforms via applanation tonometry before and following (60, 90, 120, 150, and 180 min) consumption of a nitrate-rich beetroot juice in 26 healthy adults (young: 25 ± 4 years, n = 14; older: 64 ± 5 years, n = 12). Aortic BP and indices of aortic wave reflection (AIx and AIx normalized for heart rate; AIx@75bpm) were calculated from the generated aortic pressure waveform. ResultsNitrate consumption increased plasma nitrite in both groups 60–180 min following beetroot consumption (P < 0.001). Nitrate consumption reduced peripheral and aortic BP in both young and older adults (P < 0.05), with the change being similar between age groups. Conversely, indices of aortic wave reflection were reduced only in young adults following nitrate consumption (range of change from baseline over time: AIx@75bpm, −4.3 to −8.8%, P < 0.05), whereas aortic AIx remained unchanged in the older adults. ConclusionsTaken together, our results suggest that acute dietary nitrate supplementation reduces peripheral and aortic BP similarly in young and older adults despite differential effects on aortic AIx between age groups.

Cardiac Diastolic Dysfunction is Associated With Aortic Wave Reflection, but Not Stiffness in a Predominantly Young-to-Middle-Aged Community Sample.

Whether the impact of backward wave pressures (Pbs) on left ventricular (LV) diastolic dysfunction (DD) antedates the effects of aortic stiffness is uncertain. We compared the relative contribution of various aortic hemodynamic parameters to preclinical DD in a predominantly young-to-middle-aged community-based sample. In 524 randomly selected participants of African ancestry (mean age = 46.8±18.4 years), we assessed central aortic pulse pressure (PPc), forward wave pressure (Pf), Pb, augmented pressure (Pa), the time-to-wave reflection (Rt), and aortic pulse wave velocity (PWV) using applanation tonometry (SphygmoCor software). LV mass index (LVMI), early to late transmitral velocity (E/A), and E/velocity of myocardial tissue lengthening (E/e') were determined using echocardiography. Independent of age, sex, mean arterial pressure, body mass index, diabetes mellitus and/or HbA1c > 6.1%, regular smoking, regular alcohol intake, treatment for hypertension, pulse rate, and LVMI; PPc (P < 0.002), Pb (P < 0.0005), Pa (P < 0.002), and Pf (P < 0.02), but not Rt or PWV were independently associated with E/e' (but not with E/A). With adjustments for confounders, PPc (P < 0.005), Pb (P < 0.002), and Pa (P < 0.001), but not Pf, Rt, or PWV were independently associated with E/e' ≥ 12 (moderate-to-severe DD, n = 69). The independent relations between PPc and E/e' or moderate-to-severe DD were not affected by adjustments for PWV, Pf, or Rt, but were abolished with adjustments for Pb. In a predominantly young-to-middle-aged community sample, the impact of Pbs on LV DD antedates the effects of aortic stiffness, the time-to-wave reflection, or Pfs.

Post-exercise effects on aortic wave reflection derived from wave separation analysis in young-to middle-aged pre-hypertensives and hypertensives.

Decreases in brachial blood pressure (BP) may occur for several hours following a bout of exercise. Although aortic backward waves predict cardiovascular damage independent of brachial BP, whether decreases in aortic backward waves also occur post-exercise in young-to-middle-aged hypertensives, the extent to which these changes exceed brachial BP changes, and the best method of identifying these changes is uncertain. We examined aortic function at baseline and 15-min post-exercise in 20 pre-hypertensive or hypertensive men and women (age 45±7years). Central aortic pressure, forward (Pf) and backward (Pb) wave pressures, the reflection index (RI) and augmentation pressure (AP) and index (AIx) were determined using applanation tonometry, and SphygmoCor software. Decreases in central aortic (p<0.001) but not brachial systolic BP and pulse pressure (PP) occurred post-exercise. In addition, decreases in post-exercise (baseline versus post-exercise) Pb (19±4 vs 13±3mm Hg p<0.0001), RI (72.9±22.1 vs 47.6±12.8%, p<0.0001), AIx (26.3±10.8 vs 7.8±11.6%, p<0.0001) and AP (9.9±3.9 vs 2.8±3.9mm Hg, p<0.0001), but not Pf, were noted. However, decreases in AIx were not correlated with decreases in Pb, and whilst decreases in aortic PP correlated with decreases in Pb (p<0.0001), no correlations were noted with decreases in AP or AIx. In young-to-middle-aged pre-hypertensive and hypertensive individuals, aortic backward waves decrease post-exercise; this change is not reflected in brachial BP measurements and is poorly indexed by measures of pressure augmentation.

L-Citrulline supplementation attenuates blood pressure, wave reflection and arterial stiffness responses to metaboreflex and cold stress in overweight men.

Combined isometric exercise or metaboreflex activation (post-exercise muscle ischaemia (PEMI)) and cold pressor test (CPT) increase cardiac afterload, which may lead to adverse cardiovascular events. l-Citrulline supplementation (l-CIT) reduces systemic arterial stiffness (brachial-ankle pulse wave velocity (baPWV)) at rest and aortic haemodynamic responses to CPT. The aim of this study was to determine the effect of l-CIT on aortic haemodynamic and baPWV responses to PEMI+CPT. In all, sixteen healthy, overweight/obese males (age 24 (sem 6) years; BMI 29·3 (sem 4·0) kg/m2) were randomly assigned to placebo or l-CIT (6 g/d) for 14 d in a cross-over design. Brachial and aortic systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean arterial pressure (MAP), aortic augmented pressure (AP), augmentation index (AIx), baPWV, reflection timing (Tr) and heart rate (HR) were evaluated at rest and during isometric handgrip exercise (IHG), PEMI and PEMI+CPT at baseline and after 14 d. No significant effects were evident after l-CIT at rest. l-CIT attenuated the increases in aortic SBP and wave reflection (AP and AIx) during IHG, aortic DBP, MAP and AIx during PEMI, and aortic SBP, DBP, MAP, AP, AIx and baPWV during PEMI+CPT compared with placebo. HR and Tr were unaffected by l-CIT in all conditions. Our findings demonstrate that l-CIT attenuates aortic blood pressure and wave reflection responses to exercise-related metabolites. Moreover, l-CIT attenuates the exaggerated arterial stiffness response to combined metaboreflex activation and cold exposure, suggesting a protective effect against increased cardiac afterload during physical stress.

Ambulatory (24 h) blood pressure and arterial stiffness measurement in Marfan syndrome patients: a case control feasibility and pilot study.

BackgroundThe aim of this work is the investigation of measures of ambulatory brachial and aortic blood pressure and indices of arterial stiffness and aortic wave reflection in Marfan patients.MethodsA case-control study was conducted including patients with diagnosed Marfan syndrome following Ghent2 nosology and healthy controls matched for sex, age and daytime brachial systolic blood pressure. For each subject a 24 h ambulatory blood pressure and 24 h pulse wave analysis measurement was performed.ResultsAll parameters showed a circadian pattern whereby pressure dipping was more pronounced in Marfan patients. During daytime only Marfan patients with aortic root surgery showed increased pulse wave velocity. In contrast, various nighttime measurements, wave reflection determinants and circadian patterns showed a significant difference.ConclusionsThe findings of our study provide evidence that ambulatory measurement of arterial stiffness parameters is feasible and that these determinants are significantly different in Marfan syndrome patients compared to controls in particular at nighttime. Further investigation is therefore indicated.

Influence of the cold pressor test upon aortic pulse wave reflection in individuals with increased arterial stiffness

Aortic pulse wave reflection is an indicator of LV after load, myocardial O2 demand and a predictor of cardiovascular events and is partly determined by muscular and elastic artery stiffness and pulse wave velocity. Acute stimulation of the sympathetic nervous system increases the vascular resistance of the muscular arteries thereby influencing arterial stiffness. The aim of this study was to examine the influence of acute sympathetic stimulation via the cold pressor test upon aortic pulse wave reflection in individuals with and without increased arterial stiffness. Eleven participants (4 males, 31±12yrs; 172±10cm; 75±15kg) completed a cold pressor test (CPT) wherein the left hand was immersed up to the wrist in 2–4°C water for 3 minutes. Blood pressure (mean arterial pressure; MAP) and pulse wave reflection (radial tonometry) were measured throughout. Stroke volume was calculated (photoplethysmography; NexFin) and heart rate measured (ECG; HR) throughout to provide cardiac output (Q). Aortic pulse wave velocity was measured before the CPT (Mobil‐O‐Graph®; aPWV). Pulse wave reflection was referenced to a heart rate of 75 bpm (augmentation index; Aix75). At baseline heart rate was 66±8 bpm and the change during CPT was variable between participants (Range: −11 to +14 bpm). Prior to CPT, Aix75 was 0±19% (Range −31 to 31%) and MAP was 87±10 mmHg. During the CPT Aix75 increased to 17±13% while MAP increased to 102±7 mmHg (both P ≤ 0.05). The change in Aix75 during CPT correlated poorly with age (R2 = 0.13), baseline MAP (R2 = 0.03), the change in MAP during CPT (R2 = 0.05) and baseline aPWV (R2 = 0.08) (all P &gt; 0.05). However, the increase in Aix75 during the CPT correlated moderately with baseline Aix75 (R2 = 0.75; P = 0.0006) and the change in Q during CPT (R2 = 0.40; P = 0.049). Increases in aortic pulse wave reflection during the cold pressor test were inversely related to baseline aortic pulse wave reflection. This may be indicative of a ceiling effect where individuals with evidence of existing arterial stiffening demonstrate a reduced increase in pulse wave reflection during sympathetic stimulation via cold pressor test. Nevertheless individuals with evidence of increased arterial stiffness still experience acute increases in pulse wave reflection during sympathetic stimulation via the cold pressor test.

Higher augmentation index is associated with tension-type headache and migraine in middle-aged/older humans with obesity.

Obesity is a major risk factor for chronic daily headaches, including migraine and tension-type headache (TTH). Although migraine is associated with increased risk of cardiovascular diseases (CVD), a relation between TTH and CVD risk has not been established. It was hypothesized that higher carotid-femoral pulse wave velocity (CFPWV) and augmentation index (AI), measures of aortic stiffness and pressure wave reflection, respectively, and biomarkers of CVD risk, would be higher among adults with obesity and migraine or TTH compared with those with no headache. Adults with obesity (n = 93; body mass index ≥30 kg/m(2) ) who were between 40 and 75 years old with at least one additional CVD risk factor were enrolled. Subjects had CFPWV and AI assessed and a complete neurological exam for diagnosis of headache in the past 12 months. Adults with obesity and TTH (P = 0.018), but not migraine (P = 0.29), had significantly higher AI compared with those with no headache. When both CFPWV and AI were considered in a logistic regression model with migraine or TTH, only AI was associated with TTH (P = 0.008) and migraine (P = 0.032) but could not distinguish between the two headache phenotypes. Increased aortic AI but not stiffness is associated with TTH and migraine among middle-aged/older adults with obesity and high CVD risk.

Circulating resistin concentrations are independently associated with aortic pulse wave velocity in a community sample.

The role of the adipokine, resistin in mediating increases in aortic stiffness is uncertain. We aimed to determine independent relations between circulating resistin concentrations and aortic pulse wave velocity (PWV) and wave reflection in a community-based sample with a high prevalence of untreated hypertension and obesity. Plasma resistin, adiponectin, and C-reactive protein concentrations (ELISA); carotid-femoral (aortic) PWV and the aortic reflected wave index (applanation tonometry and SphygmoCor software) were determined in 683 randomly selected participants of African ancestry from SOWETO, South Africa who had never received antihypertensive therapy. Resistin concentrations were not independently associated with office or 24-h (n = 492) blood pressure (BP). In a stepwise regression model with BMI included in the model, age (P < 0.0001), mean arterial pressure (P < 0.0001), plasma resistin concentrations (P < 0.005), female sex (P = 0.01), and creatinine concentrations (P < 0.01) contributed independently to variations in PWV. Independent relations between resistin concentrations and PWV persisted with further adjustments for C-reactive protein concentrations (P < 0.005), and the homeostasis model of insulin resistance (P < 0.02). Similar relations were noted with waist circumference rather than BMI in the model. Resistin concentrations were not independently associated with aortic reflected wave index or aortic BP. Resistin is independently and directly associated with aortic stiffness and these effects occur beyond BP, insulin resistance, and general inflammation.

Why the radial augmentation index is low in patients with diabetes: The J-HOP study

BackgroundRadial augmentation index (rAI), a marker of aortic wave reflection, is usually lower in patients with diabetes (DM) than in non-DM subjects, even though atherosclerotic change is advanced in DM. ObjectiveWe sought to explore why rAI in DM is lower than in non-DM. MethodsWe performed radial applanation tonometry in 1787 subjects who had at least one cardiovascular risk factor. The rAI was defined as [late systolic shoulder pressure amplitude (PP2)]/[radial pulse pressure (rPP)]. The late systolic shoulder blood pressure (SBP2) and PP2 of a radial pressure wave were used as estimates of the central SBP and PP (cPP), respectively. ResultsThe age (65.8 ± 9.8 vs. 65.8 ± 12.1 yrs) and mean brachial SBP (141 ± 16 vs. 141 ± 17 mmHg) were similar between the DM and non-DM groups. The rAI was significantly lower in the DM group (83.3 ± 14.1 vs. 87.3 ± 15.7%, p < 0.001), but clinic PP (62 ± 14 vs. 59 ± 14 mmHg, p < 0.001) and cPP (51 ± 15 vs. 49 ± 15 mmHg, p = 0.019) were significantly greater in the DM group than in the non-DM group. In multivariable analyses adjusting for covariates, the significant determinants of rAI were the estimated glomerular filtration rate (eGFR) (β = 0.17, p < 0.001) in the DM group, and the log-transformed homeostatic model assessment of insulin resistance (HOMA-IR) (β = −0.15, p < 0.001) in the non-DM group. The same trends were also seen for central SBP and cPP. ConclusionsThe lower rAI in DM associated with higher cPP compared to non-DM suggests proximal conduit–predominant arterial stiffening causing reduced reflection coefficients at systemic reflection sites. As renal function decreases, a cPP increase may overcome the increase of augmentation pressure in the DM group.

Hemodialysis patients with intradialytic rise in blood pressure display higher baseline aortic stiffness and negligible drop in augmentation index with dialysis.

In hemodialysis patients, the intradialytic rise in blood pressure (BP) is associated with increased mortality risk. However, the mechanisms of this adverse effect are not yet elucidated. This study examined whether intradialytic rise in BP is associated with increased arterial stiffness and wave reflections, which are powerful cardiovascular risk predictors in hemodialysis. The pattern of intradialytic hemodynamic response was evaluated in 70 prevalent hemodialysis patients, by measuring seated brachial BP before and after the mid-week dialysis session. All patients had pre- and post-dialysis determination of aortic pulse wave velocity (PWV) and heart rate-adjusted augmentation index [AIx(75)], as measures of arterial stiffness and wave reflections, with the Sphygmocor device. Intradialytic rise in brachial systolic BP (SBP) was evident in 17 patients, whereas intradialytic change in SBP (ΔSBP) of -10 to 0 mmHg was observed in 23 and ΔSBP greater than -10 mmHg in 30 patients. Participants with intradialytic SBP rise had significantly higher pre-dialysis aortic PWV (10.4 ± 1.6 vs 8.3 ± 1.9 vs 9.4 ± 2.4 m/s, P < 0.01) and AIx(75) (28.1 ± 7.3 vs 21.7 ± 8.6 vs 25.8 ± 8.2%, P < 0.05) than those experiencing intradialytic ΔSBP of -10 to 0 and greater than -10 mmHg, respectively. Patients with rise in SBP during dialysis exhibited also lower intradialytic reduction in AIx(75) (-1.5 ± 4.9 vs -5.4 ± 5.9 vs -6.7 ± 5.3%, P < 0.001). This study shows that aortic stiffness and wave reflections are higher and not affected by dialysis procedure in patients with intradialytic SBP rise, suggesting that accelerated arteriosclerosis may be one possible explanation for the heightened cardiovascular risk associated with intradialytic hypertension.

Evaluation of effect of highly standardized aqueous extract of roots and leaves of Withania somnifera on cold pressor test induced cardiovascular changes in healthy human subjects

Background: Stress is an important cardiovascular risk factor. Cold pressor test (CPT) is a simple, validated, non-invasive test used to measure stress induced changes in cardiovascular parameters. The objective of this study was to evaluate effect of Withania somnifera extract on cold pressor stress test induced changes on cardiovascular parameters and aortic wave reflections in healthy human subjects. Methods: This was a double-blind, placebo controlled, crossover study. Participants were randomized to receive either two capsules of Withania somnifera extract 250 mg or two capsules of placebo twice daily for 14 days. Pharmacodynamic parameters heart rate, aortic pressure, augmentation index (AIx), subendocardial viability ratio (SEVR), radial and aortic blood pressure (BP) were recorded before and after CPT at baseline and at end of treatment. After washout period of 10 days, subjects crossed over to other treatment group and same procedure was repeated. Safety assessments were done at baseline and at end of treatment. Results: A total of 20 volunteers completed the study. Compared with baseline and placebo, Withania somnifera extract produced a significant decrease in mean percent change of arterial stiffness indices (AIx, radial and aortic BP). SEVR with CPT increased, however it was non-significant compared to baseline and placebo. Both treatments were well-tolerated and no serious adverse events were reported. Conclusions: Withania somnifera extract showed a significant decrease in cold pressor stress test induced changes on aortic wave reflections, suggesting its beneficial effects in reducing stress induced cardiovascular changes. However, further clinical studies are warranted to evaluate these effects in patients with cardiovascular and other associated diseases.

Office blood pressure is a predictor of aortic elastic properties and urinary protein excretion in subjects with white coat hypertension

BackgroundWhite coat hypertension (WCH) is related to target organ damage and increased cardiovascular risk. Arterial elastic properties and urinary protein excretion are determinants of cardiovascular performance and predictors of outcomes. We investigated whether office blood pressure (BP) is a better determinant of arterial and renal function than the ambulatory BP in WCH patients. MethodsWe studied 440 consecutive untreated non-diabetic patients with WCH (office BP >140/90mmHg, mean daytime ambulatory BP <135/85mmHg). Arterial function was evaluated with carotid–femoral pulse wave velocity (cfPWV), an index of aortic stiffness, and aortic augmentation index (AIx), a composite marker of aortic stiffness and wave reflections. In 24-hour urine, albumin excretion and albumin/creatinine ratio (ACR) were measured as markers of glomerular function and urinary α1-microglobulin was measured as a marker of renal tubular function. ResultsIn univariate analysis, office systolic BP correlated significantly with cfPWV (r=0.245, P<0.001), AIx (r=0.31, P<0.001), albumin (r=0.134, P=0.005), ACR (r=0.199, P<0.001) and α1-microglobulin (r=0.118, P=0.013). In contrast, mean ambulatory systolic BP did not correlate with arterial function or urinary proteins (all P>0.5). Hierarchical multilevel linear regression analysis showed that office systolic BP is an independent determinant of cfPWV (P=0.050), AIx (P=0.029), albumin (P=0.002) and ACR (P=0.001) and has a borderline association with α1-microglobulin (P=0.088). ConclusionsIn non-diabetic WCH individuals, office systolic BP is an independent predictor of aortic elastic properties and urinary protein excretion, whereas ambulatory BP is not. This finding suggests that office BP may be a marker of cardiovascular risk in subjects with WCH.

Association of aortic stiffness and wave reflections with coronary flow reserve in women without obstructive coronary artery disease: An ancillary study from the National Heart, Lung, and Blood Institute–sponsored Women’s Ischemia Syndrome Evaluation (WISE)

Increased aortic stiffness and reduced coronary flow reserve (CFR) independently predict adverse outcomes. But information about relationships between arterial properties and CFR in subjects without obstructive coronary artery disease (CAD) is limited. CFR was measured (Doppler flow wire and intracoronary adenosine) in 50 women (age 53 ± 11 years) with symptoms and signs of myocardial ischemia without obstructive CAD. Aortic pulse wave velocity (aPWV), a measure of aortic stiffness, was obtained via catheter pullback; radial artery pressure waves were measured by applanation tonometry and central aortic pressure synthesized. Overall, CFR (mean 2.61 ± 0.47) was significantly correlated with aPWV (r = -0.51), pulse wave amplification (r = 0.45), augmented pressure (r = -0.48), augmentation index (AIx, r = -0.44), aortic systolic pressure (r = -0.49), left ventricular wasted energy (LVEw, r = -0.47) (all P < .001), systolic pressure time index (r = -0.37, P < .008), and rate pressure product (r = -0.29, P < .04). In the multiple regression model including aPWV, CFR was still significantly correlated with aPWV (P < .008) and aortic systolic pressure (P < .01). No other measures contributed significant additional information. Women with CFR ≤2.5 versus those with CFR >2.5 had greater aPWV (894 ± 117 vs 747 ± 93 cm/s, P < .001), augmented pressure (14 ± 4.9 vs 11 ± 4.1 mmHg, P < .008), AIx (32 ± 6.6 vs 27 ± 6.6%, P < .003), LVEw (30 ± 12 vs 21 ± 10 dyne-s/cm(2) × 10(2), P < .02) and reduced pulse pressure amplification (1.20 ± .07 vs 1.26 ± .10, P < .008) and pressure wave travel time (133 ± 7.3 vs 138 ± 6.9 milliseconds, P < .04). Among symptomatic women without obstructive CAD, CFR was inversely related to aortic systolic pressure and indices of aortic stiffness. These changes in arterial properties increase left ventricular afterload requiring the ventricle to generate additional, but wasted, energy that increases indices of myocardial oxygen demand, reduces CFR and increases vulnerability to ischemia.

Relationship between muscle sympathetic nerve activity and aortic wave reflection characteristics in aerobic- and resistance-trained subjects.

Increased arterial stiffness is associated with an impairment of ventricular-vascular coupling efficiency and increased risk of cardiovascular mortality. Recently, it has been suggested that an increase in arterial stiffness is associated with resistance exercise training. Therefore, the aims of this study were to compare augmentation index (AIx) and left ventricular wasted pressure energy (LVEW) as markers of arterial stiffness and ventricular-vascular coupling efficiency in young aerobic-trained (AT) and resistance (RT)-trained subjects. We also investigated the relationship of muscle sympathetic nerve activity (MSNA) and flow-mediated dilation (FMD) to AIx in both sets of subjects to determine if endothelial function or sympathetic outflow could explain any differences in arterial stiffness. To achieve our aims, we measured MSNA in 15 male subjects (8 RT, 7 AT) using microneurography. We also used applanation tonometry of the radial pressure waveform to noninvasively synthesize aortic pressure waveforms. FMD was calculated as percent dilation of the radial artery from baseline following a 5 min occlusion. RT subjects had an increased AIx (12 ± 3 vs. -7 ± 2; P < 0.01), LVEW (429 ± 111 vs. -360 ± 77; P < 0.01) and MSNA burst incidence (34 ± 4 vs. 26 ± 4; P < 0.01) when compared with AT subjects. There was no difference in FMD between groups. MSNA burst incidence was also significantly related to AIx in subjects (R (2) = 0.61; P < 0.01) with a distinct demarcation between RT and AT subjects. These results confirm previous reports of a positive association between MSNA and AIx in young male resistance-trained subjects. Furthermore, RT is associated with increased arterial stiffness and elevated sympathetic outflow.

Impact of age on aortic wave reflection responses to metaboreflex activation and its relationship with leg lean mass in post-menopausal women

Wave reflection (augmentation pressure [AP] and index [AIx]) is greater in older women than men. Resting AP is a better wave reflection index than AIx in older adults. The negative relationship between wave reflection and lean mass (LM) has been inconsistent. We investigated the impact of age and LM on aortic hemodynamic responses to metaboreflex activation in post-menopausal women. Post-menopausal women, younger and older (n=20 per group) than 60years, performed 2-min isometric handgrip at 30% of maximal force followed by 3-min post-exercise muscle ischemia (PEMI). We measured carotid–femoral pulse wave velocity (cfPWV) and femoral-ankle PWV (faPWV) at rest, and aortic systolic blood pressure (aSBP), pulse pressure (aPP), AP, AIx, and AIx-adjusted for heart rate (AIx@75) at rest and during PEMI using tonometry. Arm and leg LM were measured by DEXA. Resting cfPWV, aSBP, and aPP were higher, while AIx@75 and leg LM were lower in older than younger women. aSBP and aPP increased similarly during PEMI in both groups. Increases in AP (P<0.05), AIx (P<0.05), and AIx@75 (P<0.01) during PEMI were greater in older than younger women. From these responses, only AP during PEMI was correlated (P<0.05) positively with aSBP and aPP responses, and negatively with leg LM. Resting faPWV, but not cfPWV, was correlated (P<0.01) with AP, aSBP, and aPP during PEMI. Therefore, PEMI induces greater wave reflection responses in older than younger post-menopausal women. Our findings suggest that the increased AP response to PEMI is related to leg arterial stiffness and muscle loss in older women.

Letter in response to: Elastin fracture and enhanced aortic pressure wave reflection in adult patients with congenital heart disease

Letter in response to: Elastin fracture and enhanced aortic pressure wave reflection in adult patients with congenital heart disease

PP.28.25

Objective: Several single nucleotide polymorphisms (SNP) have been associated with arterial hypertension (HT). Design and method: We investigated in a representative sample of the Portuguese adult population (PHYSA study) the distribution and the association with HT phenotypes of 16 variants of 10 genes that have been considered as susceptibility loci for HT and salt sensitivity. Study subjects comprised 3,720 individuals (2,152 normotensives and 1,568 hypertensives, 394 untreated). The genotypes of SNPs were determined by high-throughput DNA Microchip platform using iPlex MassAssay system from Sequenom. PCR Malditof mass spectrometry. Results: Multivariable logistic regression analysis with adjustment for age, gender, body mass index and smoking status revealed that polymorphisms of gene GRK4_CM025430 encoding G protein-coupled receptor kinase4 and of gene SCL12A3_RS13306673 encoding Na+ Channel/amiloride-sensitive were independent risk factors for HT (P = 0.025, OR = 1.257, 95%CI [1.029–1.535]; P = 0.048, OR = 1.343, [1.076–1.676]; respectively), whereas polymorphism of gene NOS3_CM981388 encoding NO synthase was protective against this condition (P = 0.022, OR = 0.718, 95%CI [0.540–0.953]. Polymorphism of adducin gene, ADD1_CM021240 was independently associated with an increased risk of cardiovascular event (P = 0.016, OR = 1.079, 95%CI [1.007–1.158]). Quantitative trait analysis indicated that the untreated cases with NOS3_CM981388 polymorphisms had vs the population without it a lower systolic blood pressure (SBP) (126.3 + 18.4 vs 129.5 + 16.9 mm Hg, P = 0.021 and a lower diastolic BP (75.8 + 10.3 vs 74.3 + 10.6 mm Hg, P = 0.046) confirming the protective influence of this polymorphism. In contrast, untreated cases with variant polymorphisms of the angiotensinogen gene (AGT_CM920009 and AGT_CM920010) showed vs the population carriers of wild alleles, respectively a higher SBP (128.8 + 17.9 vs 126.3 + 17.4 mm Hg, P = 0.029) and a higher diastolic BP (74.6 + 10.3 vs 73.6 + 10.4 mm Hg, P = 0.023). Conclusions: Our data suggest that for similar age, gender distribution, and 24 h and nighttime BP the values of aortic stiffness, central aortic pressures and wave reflection of subjects with WCHT are more close to those of normotensives than to those of treated HT reinforcing the concept that WCHT may be a much more benign condition than treated true hypertensive patients for similar 24 h and nighttime BP levels.

Elastin fracture localized in ascending aorta could be one of the mechanisms of enhanced aortic pressure wave reflection in adult patients with congenital heart disease

Elastin fracture localized in ascending aorta could be one of the mechanisms of enhanced aortic pressure wave reflection in adult patients with congenital heart disease

Relationship Between Endothelial Function and Aortic Wave Reflection Characteristics in Aerobic and Resistance Athletes

Relationship Between Endothelial Function and Aortic Wave Reflection Characteristics in Aerobic and Resistance Athletes