Aortic Mean Arterial Pressure Research Articles

Acute inflammation elicits decreased blood pressure but similar arterial stiffness in young African American adults.

African Americans (AA) have a higher risk for cardiovascular disease (CVD) as compared to their White (W) counterparts. CVD is characterized by increased blood pressure (BP), arterial stiffness and systemic inflammation. An acute inflammatory stimulus may explain physiological manifestations responsible for amplified CVD in AA that are not apparent at rest. The purpose of this study was to evaluate central and peripheral BP, central and local arterial stiffness, and indices of pulse wave morphology in young healthy AA and W participants in response to acute inflammation. Concentrations of the inflammatory cytokine interleukin-6 (IL-6) and measures of central and peripheral BP, central arterial stiffness (carotid-femoral pulse wave velocity (cfPWV)), local carotid arterial stiffness (β-stiffness, elastic modulus (Ep)), and indices of pulse wave morphology were assessed in 28 participants (21±2years, AA: n = 11) at baseline (BL), 24h and 48h post-inflammation. Changes in IL-6 concentrations (ΔIL-6) were significantly greater at 24h as compared to 48h post-inflammation (0.652±0.644 vs. -0.146±0.532pg/μl, P≤0.0001). Among AA participants, central and peripheral diastolic BP were significantly decreased at 24h post-inflammation as compared to BL (aortic diastolic BP: -4±4mmHg, P=0.016; brachial diastolic BP: -4±4mmHg, P=0.014). AA participants also experienced a significant decrease in central and peripheral mean arterial BP at 48h post-inflammation as compared to BL (aortic mean arterial pressure: -4±4mmHg, P=0.009; brachial mean arterial pressure: -4±4mmHg, P=0.012). Despite haemodynamic changes, there were no differences in central or local carotid arterial stiffness or indices of pulse wave morphology.

Impact of a Novel Training Approach on Hemodynamic and Vascular Profiles in Older Adults.

Exercise training beneficially moderates the effects of vascular aging. This study compared the efficacy of Peripheral Remodeling through Intermittent Muscular Exercise (PRIME), a novel training regimen, versus aerobic training on hemodynamic profiles in participants ≥70years at risk for losing functional independence. Seventy-five participants (52 females, age: 76 ± 5years) were assessed for hemodynamic and vascular function at baseline, after 4 weeks of either PRIME or aerobic training (Phase 1) and again after a further 8 weeks of aerobic and resistance training (Phase 2). Data were analyzed using 2 × 2 repeated-measures analysis of variance models on the change in each dependent variable. PRIME demonstrated reductions in brachial and aortic mean arterial pressure and diastolic blood pressure (p < .05) from baseline after Phase 1, which were sustained throughout Phase 2. Earlier and greater reductions in blood pressure following PRIME support the proposal that peripheral muscular training could beneficial for older individuals commencing an exercise program.

Aortic haemodynamics: the effects of habitual endurance exercise, age and muscle sympathetic vasomotor outflow in healthy men

PurposeWe determined the effect of habitual endurance exercise and age on aortic pulse wave velocity (aPWV), augmentation pressure (AP) and systolic blood pressure (aSBP), with statistical adjustments of aPWV and AP for heart rate and aortic mean arterial pressure, when appropriate. Furthermore, we assessed whether muscle sympathetic nerve activity (MSNA) correlates with AP in young and middle-aged men.MethodsAortic PWV, AP, aortic blood pressure (applanation tonometry; SphygmoCor) and MSNA (peroneal microneurography) were recorded in 46 normotensive men who were either young or middle-aged and endurance-trained runners or recreationally active nonrunners (10 nonrunners and 13 runners within each age-group). Between-group differences and relationships between variables were assessed via ANOVA/ANCOVA and Pearson product-moment correlation coefficients, respectively.ResultsAdjusted aPWV and adjusted AP were similar between runners and nonrunners in both age groups (all, P > 0.05), but higher with age (all, P < 0.001), with a greater effect size for the age-related difference in AP in runners (Hedges’ g, 3.6 vs 2.6). aSBP was lower in young (P = 0.009; g = 2.6), but not middle-aged (P = 0.341; g = 1.1), runners compared to nonrunners. MSNA burst frequency did not correlate with AP in either age group (young: r = 0.00, P = 0.994; middle-aged: r = − 0.11, P = 0.604).ConclusionThere is an age-dependent effect of habitual exercise on aortic haemodynamics, with lower aSBP in young runners compared to nonrunners only. Statistical adjustment of aPWV and AP markedly influenced the outcomes of this study, highlighting the importance of performing these analyses. Further, peripheral sympathetic vasomotor outflow and AP were not correlated in young or middle-aged normotensive men.

Abstract 260: Aortic Pulse Wave Characteristics and Coronary Blood Flow Responses to Plantar Flexion in Peripheral Arterial Diseases Patients

Peripheral arterial diseases (PAD) is an atherosclerotic occlusive disease in the periphery affecting 8-12 million U.S.adults. It has been reported that the PAD patients have attenuated coronary blood flow response to stress, however how the diseases influence aortic arterial pulse wave properties during exercise, and its relationship with coronary perfusion in this patient population is unknown. Accordingly, the primary aim of this study was to examine myocardial supply and demand relationship by investigating aortic pulse wave properties and their relationship with coronary perfusion during exercise in PAD. Methods: 13 PADpatients and 13 healthy (age, sex, BMI-matched) control subjects performed rhythmic plantar flexion for 14 minutes or until fatigue (30 contractions per minute). The workload started at 2 kg and increased by 1 kg every minute up to12 kg. Brachial (oscillometric cuff) and aortic (SphygmoCor, utilizing transfer function and brachial blood pressures) blood pressures were measured during supine rest and plantar flexion exercise as well as aortic pulse wave properties from derived-aortic pulse waveforms. On a separate visit, coronary blood flow velocity was measured non-invasively during rest and exercise. Results: Due to earlier arrival of reflected wave (140.9± 2.3 vs. 150.5± 3.4 ms; P =0.0289), baseline augmented pressure (15.9± 2.4 vs. 9.3± 1.7 mmHg; AP, P =0.0380), augmentation index (27.2± 2.7 vs. 19.1± 2.2 %; AI, P =0.0263), and cardiac wasted energy (4625± 590 vs. 2875± 491 s· dyne· cm 2 ; E w , P =0.0321) were greater compared to healthy control. During exercise, changes in aortic mean arterial pressure(21.90± 5.04 vs. 9.36± 2.20 mmHg; ΔaMAP, P =0.0041), end-systolic pressure (133.38± 4.85 vs. 111.46± 4.97 mmHg; ΔESP, P =0.0043), and the tension time index (1027± 216 vs. 504± 117 mmHg· S -1 · min -1 ; ΔTTI, P =0.0035) were significantly greater in PAD while ΔAI was not different. Intriguingly, despite the augmented TTI, the first and second peaks of CBV during exercise were not different between the groups leading to significantly attenuated subendocardial viability ratio responses to exercise (-34.66± 4.19 vs. -23.03± 3.37 %; ΔSEVR, P =0.0164). Conclusions: At this peak workload for PAD patients, the patients had a greater myocardial demand compared to healthy control. However, despite the increase in the myocardial demand and the accompanying increase in initial coronary perfusion pressure (ESP), CBV of PAD patients was not different from that seen in healthy control indicating limited myocardial supply during exercise in PAD. Consequently, PAD exhibited a greater mismatch of myocardial demand and supply at the peak workload. This suggests that, in PAD patients, there are mechanisms aside from changes in coronary perfusion pressure that limit myocardial supply during exercise (i.e. a greater coronary vascular tone and diastolic dysfunction).

Preliminary Study Of Ethnic Differences In Hemodynamic Responses Following High Intensity Exercise: Wave Separation Analysis

The Hispanic population is at a high risk of developing cardiovascular disease (CVD), especially cerebrovascular disease. High blood pressure (BP) and inadequate BP regulation are related to future CVD events. Sympathoexcitatory stimulation through high intensity exercise temporarily increases risk of cardiovascular events and alters hemodynamics. It is unknown whether there is an ethnic difference in the regulation of BP and pulse wave characteristics—including forward or reflected pressure waves—between Hispanic and White populations. PURPOSE: To investigate the ethnic differences in BP and pulse wave characteristics measured with wave separation analysis in response to high intensity exercise. METHODS: 10 male volunteers (9 Hispanic; 23 ± 3 yr, 1 White; 21 yr) completed the study. Aerobic capacity was measured by indirect calorimetry and a treadmill graded exercise test (GXT). Brachial BP was measured by an automated BP monitor. Central hemodynamic variables and pulse waves were obtained by tonometer at baseline, 15-minute, and 30-minute after high intensity treadmill exercise (GXT). Pulse waves were further separated into forward pulse height (FH) and reflected pulse height (RH) for analysis. A 2 x 3 repeated measure analysis of variance was performed to investigate ethnic differences in BP and pulse wave responses to high intensity exercise. RESULTS: (See table 1) There were no significant ethnic differences in brachial systolic BP, brachial diastolic BP, aortic systolic BP, aortic diastolic BP, and aortic mean arterial pressure (p > 0.05 for all). Furthermore, FH and RH were not statistically different between Hispanic and White males at rest and following high intensity exercise (p > 0.05). CONCLUSION: Results suggest that blood pressure, forward and reflected pulse height exhibited similar at rest and following high intensity exercise in young, healthy, casually active Hispanic and white males.

Association between diet and measures of arterial stiffness in type 1 diabetes – Focus on dietary patterns and macronutrient substitutions

Background and aimsIncreased arterial stiffness contributes to diabetic vascular complications. We identified dietary factors related to arterial stiffness in individuals with type 1 diabetes, a population with high risk of cardiovascular disease. Methods and resultsAltogether, 612 participants (40% men, mean ± standard deviation age 45 ± 13 years) completed a validated diet questionnaire and underwent measurements of arterial stiffness. Of these, 470 additionally completed a food record. Exploratory factor analysis was applied to identify dietary patterns from the diet questionnaires, and nutrient intakes were calculated from food record entries. Arterial stiffness was measured by applanation tonometry. Of the seven dietary factors formed, the factor scores of “Full-fat cheese and eggs” and “Sweet” patterns were negatively associated with measures of arterial stiffness. In the multivariable macronutrient substitution models, favouring carbohydrates over fats was associated with higher aortic mean arterial pressure and aortic pulse wave velocity. When carbohydrates were consumed in place of proteins, higher aortic pulse pressure, aortic mean arterial pressure, and augmentation index were recorded. Replacing energy from alcohol with proteins, was associated with lower aortic pulse pressure, aortic mean arterial pressure, and augmentation index. Relative distributions of dietary fatty acids were neutral with respect to the measures of arterial stiffness. ConclusionThe macronutrient distribution of the diet is likely to affect the resilience of the arteries. Our observations suggest that reducing energy intake from carbohydrates and alcohol may be beneficial. These observations, especially those dealing with dietary patterns, need to be confirmed in a longitudinal study.

Acute Effects of External Pneumatic Compression on Peripheral and Central Hemodynamics

Use of external pneumatic compression (EPC) to improve recovery after exercise is increasing. However, the acute hemodynamic effects of EPC have not been determined. The purpose of this study was to investigate the acute effects of EPC on the aortic pressure waveform (AoPW) during EPC therapy. Twenty (n=20) young participants (23.5±3.9 years) were included in this study. Analysis of the AoPW was evaluated continuously using applanation tonometry before, during, and after a single 1‐hr therapeutic session of EPC. A sequential EPC device was employed with target inflation pressures of ~100 mmHg of compression. Peripheral systolic blood pressure was increased by 5.8±1.3 mmHg during EPC and remained elevated 10 minutes post treatment, p&lt;0.05. Aortic systolic blood pressure was increased by 5.9±1.1 mmHg during EPC and remained elevated 10 minutes post treatment, p&lt;0.01. Both peripheral and aortic diastolic blood pressure were significantly increased by 5.1±0.9 and 4.8±0.9 mmHg, respectively, during EPC and remained elevated 10 minutes post treatment, p&lt;0.05. Peripheral and aortic mean arterial pressure were increased by 4.2±1.0 and 4.3±1.1 mmHg, respectively, during EPC and remained elevated 10 minutes post treatment when compared to baseline values, p&lt;0.05. EPC at target inflation pressures of 100mmHg increases total peripheral resistance to lower limb blood flow which results in increases in peripheral and central blood pressures during therapy and persists at least 10 minutes post treatment.

Hepatic and systemic hemodynamic derangements predict early mortality and recovery in patients with acute‐on‐chronic liver failure

Acute-on-chronic liver failure (ACLF) is a clinical entity where there is a potential for reversibility of hepatic dysfunction once the acute hepatic insult resolves. The portal and systemic hemodynamics in ACLF patients to study its relevance in determining the clinical outcomes was studied. Clinical, laboratory, portal, and systemic hemodynamic assessments were done at admission and after 3 months. Standard medical care was given to all the patients. Fifty-seven patients with ACLF were enrolled, and they underwent baseline hepatic venous pressure gradient (HVPG) measurement. Twenty-six (46%) patients died during the 3-month follow-up. Presence of high HVPG and hepatic encephalopathy were found to be independent baseline predictors of mortality. Of the 31 surviving patients, 24 consented for a repeat HVPG. The baseline HVPG reduced from 16 (range 12-30) to 13 (range 6-21) mmHg; (P < 0.05). The reduction in HVPG correlated with clinical and biochemical recovery, and reduction in Child-Turcotte-Pugh score score (P < 0.05), while the aortic mean arterial pressure, cardiac index and systemic vascular resistance index improved significantly (< 0.05). Six (25%) patients developed upper gastrointestinal bleed; the median HVPG between bleeders and non-bleeders was not different possibly because of early onset of bleed (median 20 [15-45 days]). Baseline HVPG is an independent predictor of mortality in ACLF patients. The portal and systemic circulatory anomalies regress substantially by 90 days and correlate with clinical recovery. However, in the initial phase, the raised portal pressure predisposes these patients to high risk of variceal bleeding.

659U-shaped association between alcohol and arterial stiffness in young adults

659U-shaped association between alcohol and arterial stiffness in young adults