Arterial Wave Research Articles

Pulmonary artery wave intensity analysis in pulmonary hypertension associated with heart failure and reduced left ventricular ejection fraction.

Wave intensity analysis (WIA) uses simultaneous changes in pressure and flow velocity to determine wave energy, type, and timing of traveling waves in the circulation. In this study, we characterized wave propagation in the pulmonary artery in patients with pulmonary hypertension associated with left-sided heart disease (PHLHD) and the effects of dobutamine. During right heart catheterization, pressure and velocity data were acquired using a dual-tipped pressure and Doppler flow sensor wire (Combowire; Phillips Volcano), and processed offline using customized Matlab software (MathWorks). Patients with low cardiac output underwent dobutamine challenge. Twenty patients with PHLHD (all heart failure with reduced left ventricular ejection fraction) were studied. Right ventricular systole produced a forward compression wave (FCW), followed by a forward decompression wave (FDW) during diastole. Wave reflection manifesting as backward compression wave (BCW) following the FCW was observed in 14 patients. Compared to patients without BCW, patients with BCW had higher mean pulmonary artery pressure (28.7 ± 6.12 vs. 38.6 ± 6.5 mmHg, p = 0.005), and lower pulmonary arterial capacitance (PAC: 2.88 ± 1.75 vs. 1.73 ± 1.16, p = 0.002). Pulmonary vascular resistance was comparable. Mean pulmonary artery pressure of 34.5 mmHg (area under the curve [AUC]: 0.881) and PAC of 2.29 mL/mmHg (AUC: 0.833) predicted BCW. The magnitude of the FCW increased with dobutamine (n = 11) and correlated with pulmonary artery wedge pressure. Wave reflection in PHLHD is more likely at higher pulmonary artery pressures and lower PAC and the magnitude of reflected waves correlated with pulmonary artery wedge pressure. Dobutamine increased FCW but did not affect wave reflection.

Seated Elliptical Exercise, But Not Periodic Standing, Alleviates Sitting-Induced Changes to Arterial Wave Reflections.

Sedentary behavior may contribute to increased central wave reflection due to associated peripheral vasoconstriction, yet its impact on central hemodynamics and the mitigating effects of interventional strategies have not been thoroughly investigated. We tested whether standing or seated elliptical breaks alleviate the deleterious effects of prolonged sitting on central wave reflections. Eighteen healthy adults (9 9 females, 25 ± 3 yr) completed three 3-h protocols on separate days: uninterrupted sitting, sitting with periodic standing, and sitting with periodic seated elliptical activity. Central wave reflection, central pulse wave velocity, and lower-limb pulse wave velocity were measured before and after each intervention. Central relative wave reflection magnitude (RM) increased during sitting (0.31 ± 0.05 to 0.35 ± 0.05; P < 0.01) but did not change after standing (0.30 ± 0.05 to 0.32 ± 0.04; P = 0.19) or elliptical protocols (0.30 ± 0.05 to 0.30 ± 0.04; P > 0.99). The change in RM during prolonged sitting (ΔRM) was attenuated with elliptical activity (0.04 ± 0.05 vs 0.00 ± 0.03; P = 0.02) but not with periodic standing (0.04 ± 0.04 vs 0.02 ± 0.05; P = 0.54). In addition, augmentation index and central pulse wave velocity increased after sitting (both P < 0.01) and periodic standing (both P < 0.01) but were unchanged after elliptical activity. Lower limb pulse wave velocity did not change after sitting ( P = 0.73) or standing ( P = 0.21) but did decrease after elliptical activity ( P = 0.03). Prolonged sitting without interruptions increased central wave reflection, whereas elliptical but not standing interruptions were able to ameliorate multiple sitting-induced vascular consequences. More work is required to examine the long-term effectiveness of interruption strategies, as well as the optimal type, frequency, and duration for reducing vascular risk associated with sedentary behaviors.

Peripheral pulse harmonic analysis and its clinical application: A systematic review

IntroductionPulse harmonic analysis is a quantitative and objective methodology within traditional Chinese medicine (TCM) used to evaluate pulse characteristics. However, interpreting pulse wave data is challenging due to its inherent complexity. This study aims to provide a comprehensive review and comparison of existing human pulse wave harmonic analysis methods to elucidate their patterns and characteristics. MethodsA systematic review of clinical research reports published from 1990 to 2021 was conducted, focusing on variations in harmonic characteristics across different medical conditions and physiological states. Keyword searches included terms related to analysis methods (e.g., "Pulse Spectrum," "harmonic analysis," "harmonic index") and measured indicators (e.g., "vascular response," "PPG," "Photoplethysmography," "aortic," "arterial," "blood pressure"). Supplementary research using PubMed's Mesh terms specifically targeted "Pulse wave analysis" within the methods and statistical analysis domain. Articles were filtered based on predefined criteria, including human participants and research related to pulse pressure or vascular volume changes. Conference papers, animal studies, and irrelevant research were excluded, with literature evaluation scales selected based on the retrieved research reports. ResultsInitially, 6487 research reports were identified, and after screening, 50 reports were included in the review. The analysis revealed that low-frequency harmonics increase following vigorous activity or sympathetic excitation but decrease during rest or parasympathetic excitation. Cardiovascular patients exhibited elevated first harmonics associated with the liver meridian, while diabetes patients displayed weakened third harmonics related to the spleen meridian. Liver dysfunction was linked to changes in the first harmonic, and cancer patients showed signs of liver and kidney yin deficiency in the first and second harmonics. These findings underscore the potential of harmonic analysis for TCM disease diagnosis and organ assessment. Moreover, individuals with conditions such as liver dysfunction, cancer, and gynecological disorders displayed distinct intensity patterns across harmonics one through ten compared to healthy controls, albeit with some variations. Heterogeneity in these studies mainly stemmed from differences in measurement methods and study populations. Additionally, research suggested that factors like blood circulation and cognitive activity influenced harmonic intensity. ConclusionsIn summary, this report consolidates prior research on pulse wave harmonics analysis, revealing unique patterns associated with various physiological conditions. Despite limitations, such as limited sample sizes in previous studies, the observed associations between physiological states and harmonics hold promise for potential clinical applications. This study lays a solid foundation for future applications of arterial wave harmonics analysis, promoting wider adoption of this analytical approach.

Worse glycemic control is associated with an impaired arterial energy transfer pattern in elderly with diabetes

Abstract Background Worse glycaemic control is known to exacerbate endothelial insult, increasing macro- and microvascular complication risks in diabetes. Impaired intracranial haemodynamics have been frequently reported in patients with diabetes alongside with malperfusion causing structural abnormalities, and poor cognitive and cortical functionality (1-2).Assessment of the alterations in energy transfer characteristics derived from hemodynamic signals may provide novel mechanistic information about how worse glycaemic control may affect cerebrovascular perfusion. Wave reflection index(WRI) is a previously proposed measure of arterial energy transfer efficiency which reflects distal impedance mismatch(3-4). Purpose We aim to interrogate potential relationship between a worse glycaemic control and a less efficient arterial energy transfer, which could enhance our understanding of the cerebrovascular-cortical functional coupling on a mechanistic basis in elderly with diabetes. Methods Left middle cerebral artery wave intensity (WI) was computed with arterial blood pressure and flow velocity (transcranial Doppler) signal as previously described (WI = (dP/dt)*(dU/dt)) (Figure 1). Standard statistical tests were used to interrogate the relationship between glycated haemoglobin levels (HbA1c) and WI parameters. Results In 36 patients with diabetes mellitus type-2 (DM2) (mean age = 65.7 ± 8.8 years), backward compression wave intensity (BCWI) and wave reflection ratio (WRI= BCWI/FCWI) were significantly correlated with HbA1c levels before (rBCWI: 0.409 pBCWI:0.013; rWRI:0.345 pWRI:0.040) and after (rBCWI: 0.410 pBCWI:0.018, rWRI:0.351 pWRI:0.045) adjusting for age, sex and mean arterial pressure (Figure 2). Conclusion(s) In elderly patient with DM2, higher HbA1c values indicating worse glycaemic control are significantly correlated with altered cerebrovascular energy transfer characteristics as assessed by MCA wave intensity analysis. Continuous relationship between worse glycaemic control and higher wave reflection index (a measure of less efficient energy transfer in arterial system and distal impedance mismatch) may imply that the use of energy transfer related indices alongside with conventional hemodynamic indices may help providing a more comprehensive pathophysiological understanding about how cardiovascular risk factors interfere with perfusion.Computation of Wave IntensityMain Results

THU657 Racing Hearts: A Closer Look At The Connection Between Hyperthyroidism And Coronary Vasospasm

Abstract Disclosure: A. Elahi: None. R.I. Mateo: None. The cardiovascular system is a major target of thyroid hormone action in which subtle changes in thyroid function can lead to cardiac complications such as coronary vasospasm. There are many proposed mechanisms in how this occurs, but further studies are needed to understand the specific pathophysiology. This case illustrates the clinical relevance of encountering a hyperthyroid patient complaining of chest pain and how to address it in real work practice. A 62 year old African American male with history of Graves hyperthyroidism, type 2 diabetes, hypertension, peripheral artery disease, and stroke with residual aphasia presented with acute onset chest pain, shortness of breath, and palpitations. He was noncompliant with his methimazole (MMI) and subsequent labs were significant for free T4 of 2.5 ng/dL, undetectable TSH, and free T3 of 11.53 pg/mL. His high sensitivity troponins were elevated at 29,569 ng/dL. EKG showed sinus tachycardia with T-wave inversions in leads II, III, and AVF with a bedside echo showing inferior lateral wall motion abnormality. He was started on MMI 20mg daily and admitted to the intensive care unit for non-ST elevation myocardial infarction management. Left heart catheterization (LHC) was done after 1 dose of MMI with findings suggestive of vasospasm; specifically, decreased blood flow of the right coronary artery which improved when the catheter was withdrawn and significant dampening of the arterial wave form of the left main coronary artery. Given the unclear differentiation between true coronary artery disease and vasospasm he needed a repeat LHC once his hyperthyroidism was more controlled. His free T3 levels were monitored every 1-2 days with administration of escalating doses of MMI up to 40mg daily. By day 7 of admission, his free T3 level was 4.54 pg/mL, free T4 was 2 ng/dL and repeat LHC was performed showing open vessel lumens with multiple occlusions requiring 2 stents in the right coronary artery and 1 stent in the left circumflex artery. Given that thyroid hormone receptors are present in the myocardium and vascular tissue, alterations in thyroid hormone concentration can affect cardiovascular function. The documentation of coronary spasm, however, is rare and to date, there are only a few limited cases describing the underlying pathophysiology. This case illustrates via cardiac catheterization images and corresponding labs, the positive correlation of coronary vasospasm with thyroid hormone levels in hyperthyroidism. Presentation: Thursday, June 15, 2023

Effect of acute handgrip and aerobic exercise on wasted pressure effort and arterial wave reflections in healthy aging.

Aging increases arterial stiffness and wave reflections that augment left ventricular wasted pressure effort (WPE). A single bout of exercise may be effective at acutely reducing WPE via reductions in arterial wave reflections. In young adults (YA) acute aerobic exercise decreases, whereas handgrip increases, wave reflections. Whether acute exercise mitigates or exacerbates WPE and arterial wave reflection in healthy aging warrants further examination. The purpose of this study was to determine if there are age-related differences in WPE and wave reflection during acute handgrip and aerobic exercise. When compared with baseline, WPE increased substantially in older adults (OA) during handgrip (5,219 ± 2,396 vs. 7,019 ± 2,888 mmHg·ms, P < 0.001). When compared with baseline, there was a robust reduction in WPE in OA during moderate-intensity aerobic exercise (5,428 ± 2,084 vs. 3,290 ± 1,537 mmHg·ms, P < 0.001), despite absolute WPE remaining higher in OA compared with YA during moderate-intensity aerobic exercise (OA 3,290 ± 1,537 vs. YA 1,188 ± 962 mmHg·ms, P < 0.001). There was no change in wave reflection timing indexed to ejection duration in OA during handgrip (40 ± 6 vs. 38 ± 4%, P = 0.41) or moderate-intensity aerobic exercise (40 ± 5 vs. 42 ± 8%, P = 0.99). Conversely, there was an earlier return of wave reflection in YA during handgrip (60 ± 11 vs. 52 ± 6%, P < 0.001) and moderate-intensity aerobic exercise (59 ± 7 vs. 51 ± 9%, P < 0.001). Changes in stroke volume were not different between groups during handgrip (P = 0.08) or aerobic exercise (P = 0.47). The greater increase in WPE during handgrip and decrease in WPE during aerobic exercise suggest that aortic hemodynamic responses to acute exercise are exaggerated with healthy aging without affecting stroke volume.NEW & NOTEWORTHY We demonstrated that acute aerobic exercise attenuated, whereas handgrip augmented, left ventricular hemodynamic load from wave reflections more in healthy older (OA) compared with young adults (YA) without altering stroke volume. These findings suggest an exaggerated aortic hemodynamic response to acute exercise perturbations with aging. They also highlight the importance of considering exercise modality when examining aortic hemodynamic responses to acute exercise in older adults.

Pulmonary artery wave intensity analysis in a pig model of lung resection

Pulmonary artery wave intensity analysis in a pig model of lung resection

Exploring Arterial Wave Frequency Features for Vascular Age Assessment through Supervised Learning with Risk Factor Insights

With aging being a major non-reversible risk factor for cardiovascular disease, the concept of Vascular Age (VA) emerges as a promising alternate measure to assess an individual’s cardiovascular risk and overall health. This study investigated the use of frequency features and Supervised Learning (SL) models for estimating a VA Age-Group (VAAG), as a surrogate of Chronological Age (CHA). Frequency features offer an accessible alternative to temporal and amplitude features, reducing reliance on high sampling frequencies and complex algorithms. Simulated subjects from One-dimensional models were employed to train SL algorithms, complemented with healthy in vivo subjects. Validation with real-world subject data was emphasized to ensure model applicability, using well-known risk factors as a form of cardiovascular health analysis and verification. Random Forest (RF) proved to be the best-performing model, achieving an accuracy/AUC score of 66.5%/0.59 for the in vivo test dataset, and 97.5%/0.99 for the in silico one. This research contributed to preventive medicine strategies, supporting early detection and personalized risk assessment for improved cardiovascular health outcomes across diverse populations.

Pulmonary artery wave intensity analysis in a pig model of lung resection

Pulmonary artery wave intensity analysis in a pig model of lung resection

Dual-network ionogel with pyramidal array microarchitecture as a flexible device for body movement sensing and subtle activity monitoring

Flexible piezoresistive devices with high sensitivity serve as important candidates for wearable sensors in common movements and subtle physiological motions. In this work, a soft material based on ionogel was fabricated into a sheet with pyramidal array architecture on one side (PDNIG), which worked as a pressure sensor in a pair combo state with the pyramidal side contacted each other (di-PDNIG). It demonstrates high sensitivity (10.98 kPa−1) and strong durability, which can work well in monitoring primary limb movements and the subtle physiological signals, including radial artery pulsation and heartbeat, associated with cardiovascular function. The tested radial artery pulse through the sensor presents typical artery wave characteristics. Moreover, the artery pulse rate of the subjects is 72 ∼ 90 beats/min, whilst the heartbeat rate is ∼ 80 beats/min. This di-PDNIG suggests a potential material as soft sensor facing toward wellness status monitoring and artificial intelligence system components.

The Vasopressin Loading for Refractory septic shock (VALOR) study: a prospective observational study

BackgroundVasopressin is a second-line vasoactive agent for refractory septic shock. Vasopressin loading is not generally performed because of the lack of evidence for its effects and safety. However, based on our previous findings, we hypothesized it can predict the responsibility to vasopressin infusion with safety, and prospectively examined it in the present study.MethodsVasopressin loading was performed via the intravenous administration of a bolus of 1 U, followed by its continuous infusion at 1U/h in patients with septic shock treated with ≥ 0.2 μg/kg/min noradrenaline. An arterial pressure wave analysis was conducted, and endocrinological tests were performed immediately prior to vasopressin loading. We classified patients into responders/non-responders based on mean arterial pressure (MAP) changes after vasopressin loading. Based on our previous findings, the lower tertile of MAP changes was selected as the cut-off. The change in the catecholamine index (CAI) after 6 h was assigned as the primary outcome. Digital ischemia, mesenteric ischemia, and myocardial ischemia during the admission period were prospectively and systematically recorded as adverse events.ResultsNinety-two patients were registered during the study period and examined. Sixty-two patients with a MAP change > 22 mmHg were assigned as responders and the others as non-responders. Blood adrenocorticotropic hormone levels were significantly higher in non-responders. Stroke volume variations were higher in responders before loading, while stroke volume and dP/dtmax were higher in responders after loading. Median CAI changes were − 10 in responders and 0 in non-responders, which was significantly lower in the former (p < 0.0001). AUROC of MAP change with vasopressin loading to predict CAI change < 0 after continuous infusion was 0.843 with sensitivity of 0.92 and specificity of 0.77. Ischemia events were observed in 5 cases (5.4%).ConclusionsVasopressin loading may be safely introduced for septic shock. Vasopressin loading may be used to predict responses to its continuous infusion and select appropriate strategies to increase blood pressure.

AUTOMATIC CALCULATION OF THE REFLECTION SITE DISTANCE: IN THE INTERNAL CAROTID

Purpose: The objective of this study is to estimate, in vivo, the effective reflected site of the internal carotid wall (ICA) from the noninvasive determination of the local arterial wave speed (c). Materials: c was calculated in our previous work that uses the measurement of the instantaneous blood velocity at two sites by contrast magnetic resonance, the study having been conducted on 20 healthy subjects. The determination of the effective reflection distance (ERD) requires the measurement of the arrival time of the reflected wave. We have found that the major reflection site in the internal carotid artery was located in the proximity of the measurement site to the circle of Willis. To validate the method proposed in this work, we compared it to the results obtained by using the return time of the foot of the wave. The foot of the wave was determined from the tangent of the abrupt rise of the velocity signal wavefront. Results: A positive correlation between ERD obtained by using the arrival time of the reflected wave and those obtained by the return time of infection point ([Formula: see text]) was obtained. Conclusion: The technique described in this study offers a promising convenient and efficient method to estimate the effective reflection site noninvasively.

Observation of natural flexural pulse waves in retinal and carotid arteries for wall elasticity estimation

The risk of cardiovascular events is linked to arterial elasticity that can be estimated from the pulse wave velocity. This symmetric wave velocity is related to the wall elasticity through the Moens-Korteweg equation. However, ultrasound imaging techniques need improved accuracy, and optical measurements on retinal arteries produce inconsistent results. Here, we report the first observation of an antisymmetric pulse wave: the flexural pulse wave. An optical system performs in vivo wave velocity measurements on retinal arteries and veins. Velocity estimation ranges between 1 and 10 millimeter per second. The theory of guided waves confirms the existence of this wave mode and its low velocity. Natural flexural waves can also be detected at the bigger scale of a carotid artery using ultrafast ultrasound imaging. This second natural pulse wave has great potential of becoming a biomarker of blood vessel aging.

Correlation between pulse wave analysis parameters and left atrial strain and left ventricular myocardial work indices in patients with grade one hypertension

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Central arterial blood pressure and wave reflection characteristics are independent predictors of cardiovascular morbidity and mortality. Pulse wave analysis (PWA) can non-invasively assess these central hemodynamic indices, by deriving central aortic waveform from brachial waveform, and allowing evaluation of central systolic pressure (CSP), Pulse Pressure (PP), augmentation pressure (AP) and augmentation index (AIx), defined as the ratio of AP to central pulse pressure (PP). These parameters are thought to relate to reflected pressure waves. Purpose To investigate whether central hemodynamic indices can impact on left atrial (LA) and left ventricular (LV) performance in patients with grade one hypertension. Materials and Methods 80 pts (male 39; mean age 41 ± 13 years) were prospectively enrolled, distinguishing between not-hypertensives(n=40; male 21; mean age 39 ± 10 years)and newly diagnosed grade one hypertensives(n=40; male 18; mean age 42 ± 11 years), not yet under treatment. All underwent PWA measurement through a standard brachial cuff for measuring CSP (mmHg), PP (mmHg), AP (mmHg), Aix (%) and augmentation index normalized to 75 bpm heart rate (AIx75%). At the same time a complete transthoracic echocardiogram was performed, and LA strain and LV myocardial work parameters were calculated. Results Hypertensives have higher LV mass index(73±16 vs 70±24;p = 0,4) but without any significant difference. On the other hand, hypertensives have significantly higher values of LA volume index (LAVi) (25±6 vs 19±7 ml/mq;p = 0,02). LV global longitudinal strain (GLS) values (−19,4±2 vs −20,3±1,7 %;p = 0,1) don't statistically differ between the two groups. Global work efficiency (GWE) is reduced in Hypertensives than in controls (94±2 vs 96±1,2 %;p = 0,003), while Global wasted work (GWW) is higher in Hypertensives than in controls (146±75 vs 85±27 mmHg%; p = 0,02). Higher values of LAVi are associated with higher values of CSP (r=0,4;p&amp;lt;0,0001), PP (r=0,3;p = 0,01), AP (r=0,4;p&amp;lt;0,0001); Aix (r=0,3;p&amp;lt;0,0001) and Aix75% (r=0,3;p = 0,01). LA reservoir inversely correlates to AP (r=-0,3;p = 0,01), Aix (r=-0,3;p = 0,01) and Aix75% (r=-0,3;p = 0,02). LV mass index directly correlates with PP (r=0,3;p = 0,01), Aix (r=0,3; p = 0,001), AIx75% (r=0,3; p = 0,01) and AP (r=0,4; p&amp;lt;0,0001). Central systolic pressure directly correlates with GLS (r=0,3; p = 0,001) and GWW (r=0,5;p&amp;lt;0,0001) and inversely correlates with GWE (r=-0,5;p&amp;lt;0,0001). Higher values of augmentation pressure are associated with lower values of GWE (r=-0,3;p = 0,01). Higher diastolic dysfunction degrees are associated with higher values of CSP (r=0,5;p&amp;lt;0,0001), PP (r=0,5; p&amp;lt;0,0001), AP (r=0,4;p = 0,0001); Aix (r=0,3; p = 0,002) and Aix75%(r=0,4; p&amp;lt;0,0001). Conclusions: Higher central pressure and reflected pressure waves can impact on LA and LV function leading to an early damage that can be correctly identified by an integrated approach between PWA and Advanced Echocardiography.

Aortopathies: From Etiology to the Role of Arterial Stiffness.

The aorta and aortic wall have a complex biological system of structural, biochemical, biomolecular, and hemodynamic elements. Arterial stiffness could be considered a manifestation of wall structural and functional variations, and it has been revealed to have a strong connection with aortopathies and be a predictor of cardiovascular risk, especially in patients affected by hypertension, diabetes mellitus, and nephropathy. Stiffness affects the function of different organs, especially the brain, kidneys, and heart, promoting remodeling of small arteries and endothelial dysfunction. This parameter could be easily evaluated using different methods, but pulse-wave velocity (PWV), the speed of transmission of arterial pressure waves, is considered the gold standard for a good and precise assessment. An increased PWV value indicates an elevated level of aortic stiffness because of the decline in elastin synthesis and activation of proteolysis and the increase in fibrosis that contributes to parietal rigidity. Higher values of PWV could also be found in some genetic diseases, such as Marfan syndrome (MFS) or Loeys-Dietz syndrome (LDS). Aortic stiffness has emerged as a major new cardiovascular disease (CVD) risk factor, and its evaluation using PWV could be very useful to identify patients with a high cardiovascular risk, giving some important prognostic information but also being used to value the benefits of therapeutic strategies.

MARKED INCREASES IN PROXIMAL AORTIC CHARACTERISTIC IMPEDANCE AND HENCE FORWARD WAVE PRESSURES BEYOND BRACHIAL BLOOD PRESSURE IN ANGIOGRAPHIC PROVEN CORONARY ARTERY DISEASE

Objective: Although indexes of aortic stiffness increase the risk for coronary artery disease (CAD), the extent to which proximal aortic stiffness increases enhance central arterial forward wave pressures beyond changes in peripheral pressures, is uncertain. We aimed to determine whether increases in proximal aortic stiffness, as indexed by aortic characteristic impedance (Zc) translate into an enhanced central arterial pressure for a given brachial BP. Design and method: From central pressure, aortic velocity and outflow tract diameter measurements and echocardiography, we determined Zc and arterial pressure wave morphology in 71 patients with angiographic proven CAD and all other cardiac pathology excluded. We compared central arterial function in these patients with 230 age and sex-matched controls from a community study, and in patients with stroke and CLI (n = 287) diagnosed in a hospital setting. Results: Adjusting for confounders, including mean arterial pressure, and aortic root diameter, as compared to controls, both Zc and the pressures generated by the product of peak aortic flow (Q) and Zc (PQxZc) were markedly increased in patients with CAD (p&lt;0.0001) and those with stroke or CLI (p&lt;0.005). Moreover, compared to patients with stroke and CLI, those with CAD also had marked increases in both Zc and PQxZc (p&lt;0.0001). Consequently, with adjustments for the same confounders, pressures generated by forward wave pressures (Pf) were markedly increased in patients with CAD as compared to controls and to patients with alternative arterial diseases (p&lt;0.0001). Importantly, after further adjustments for brachial PP or SBP, the higher Pf values in patients with CAD were retained (p&lt;0.005 to &lt;0.0001). However, with adjustments for brachial SBP and confounders, central aortic PP did not differ between groups. Conclusions: Independent of confounders and aortic root diameter, a marked increase in proximal aortic Zc occurs in patients with CAD as compared to both controls and patients with arterial disease in alternative beds. This translates into a greater central arterial pulsatile load determined by forward travelling pressure waves, but not peak central PP than that predicted by brachial BP measurements. These data support a need for intense brachial BP lowering in CAD.

IMPACT OF BODY POSITION ON ARTERIAL STIFFNESS OF ELASTIC AND MUSCULAR ARTERIES

Objective: Arterial stiffness is assessed through determination of pulse wave velocity (PWV) over an arterial segment of interest. Measurements are traditionally done in a supine position, which is both practical for high quality arterial pressure wave recordings, and the stability of pressure exerted on the arterial wall along the arterial path. The aim of this project was to study the effect of body position on the stiffness of elastic and muscular arteries. Design and method: This study was conducted with healthy adults. Aortic (cf-PWV) and brachial stiffness (CR-PWV) were repeatedly measured in three different positions (supine, 30̊ and 60̊) using the Complior Analyse. Brachial blood pressure (Mobil-O-graph) was also measured in each position. Generalized Estimating Equations in SPSS were performed to establish changes of PWV between positions. Results: In 23 healthy individuals (65% female, mean age of 36±15 years, and mean systolic (SBP) and diastolic blood pressures (DBP) of 120±2 mmHg and 76±2 mmHg, respectively), CF-PWV increased progressively with body tilting (8.7 (CI95% = 8.0–9.4) m/s supine, 9.4 (CI95% = 8.8–10.0) m/s at 30̊ and 9.5 (CI95% = 8.8–10.1) m/s at 60̊) (p&lt;0.001)). On the other hand, CR-PWV didn’t significantly change with body tilting (8.7 (CI95% = 8.0–9.3) m/s supine, 8.8 (CI95% = 8.0–9.6) m/s at 30̊ and 8.9 (CI95% = 8.1–9.6) m/s at 60̊). SBP didn’t significantly change with body tilting (120 (CI95% = 116-125) mmHg supine, 121 (CI95% = 116–125) mmHg at 30̊ and 122 (CI95% = 117-126) mmHg at 60̊), while DBP increased (76 (CI95% = 71-80) mmHg supine, 78 (CI95% = 73–83) mmHg at 30̊ (p&lt;0.022) and 81 (CI95% = 77-85) mmHg at 60̊ (p&lt;0.001)). Heart rate also increased with body tilting (68 (CI95% = 64–72) BPM supine, 69 (CI95% = 65–73) BPM at 30̊ and 77 (CI95% = 72–82) BPM at 60̊ (p&lt;0.001)). Conclusions: These preliminary results show that elastic and muscular arteries tend to react differently to body positions, without significant changes in arterial stiffness of medium muscular arteries in the arm.

Radial arterial waves for chemotherapy- and radiotherapy-related myocardial damage identification in patients with breast cancer.

Chemotherapy and radiation therapy for breast cancer cause side effects, such as cardiovascular changes, which can be monitored with echocardiography. However, more convenient methods are always encouraged. Radial arterial waves that are used to detect cardiovascular changes can be used to assist in confirming cardiovascular changes. This retrospective study aimed to analyze the frequency and time domains of the radial artery pulse wave in patients with breast cancer to understand its effectiveness in identifying cardiovascular changes. Patients with breast cancer were screened from the pulse examination records in Changhua Christian Hospital and divided into the treatment and remission groups. After unlinking the data, the pulse data were analyzed for the breast cancer treatment and remission group, including the average value of the parameters of four consecutive pulse diagnosis records in four consecutive months to test the difference in pulse waves due to breast cancer treatment between the two groups. Additionally, the pulse wave stability of the two groups was compared using the coefficient of variation. The comparison of the pulse wave data between 19 patients in the treatment group and 40 patients in the remission group revealed 45 parameters in time and 50 in frequency domains. D3, ND3, NA1, and NT1 are the four parameters with significant differences (p < 0.05), which are all related to heart function, and mainly related to cardiac output and peripheral resistance, indicating that patients in the treatment period have poor heart function. No difference was found in the degree of data dispersion between the two groups. Cardiovascular side effects caused by breast cancer treatment can mainly be shown in the pulse wave time domain.

The effects of nordic walking, high-intensity interval training, and moderate-to-vigorous intensity continuous training on arterial stiffness in patients with coronary artery disease

Abstract Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): The investigator-initiated research was supported by the Innovations Fund of the Alternate Funding Plan for the Academic Health Sciences Centres of the Ministry of Ontario (PIs: Pipe, Reed) and Heart and Stroke Foundation of Canada (PI: Reid). Background Coronary artery disease (CAD) is a leading cause of mortality worldwide. Arterial stiffness, a process associated with aging, arteriosclerosis, and arterial remodeling, is a strong and independent predictor of cardiovascular and all-cause mortality in patients with CAD. Moderate-to-vigorous intensity continuous training (MICT) has been shown to improve arterial stiffness parameters, including pulse wave velocity (PWV, i.e., the speed at which arterial pressure waves travel along the aorta and large arteries) and augmentation index (AIx: i.e., aortic pressure waveform) in the CAD population. Yet, the role of alternative exercise training approaches on arterial stiffness in patients with CAD has not been elucidated. Our recent study demonstrated greater improvements following Nordic walking (NW) compared to high-intensity interval training (HIIT) and MICT in functional capacity, quality of life, and depression severity in patients with CAD. No previous trial has compared the efficacy of NW, HIIT, and MICT in improving arterial stiffness in patients with CAD. Alternatives to traditional MICT, such as NW and HIIT, may provide superior understudied benefits on vascular health in patients with CAD. Purpose We compared the effects of 12 weeks of NW, HIIT, and MICT on arterial stiffness in patients with CAD. Methods Patients with CAD were randomly assigned to: (1) NW (walking with NW poles at a resting heart rate [RHR] + 20–40 bpm), (2) HIIT (aerobic exercise equipment: 4 × 4-min of high-intensity work periods at 85%–95% peak HR), or (3) MICT (aerobic exercise equipment: RHR + 20–40 bpm) twice weekly for 12 weeks. At baseline and week 12, aortic stiffness parameters were measured using a non-invasive device by stroke volume (SV), total vascular resistance (TVR), AIx with and without normalization for a HR of 75 bpm (AIX@75), and PWV. Linear mixed-effects models with repeated measures were used to compare groups over time. Results A total of 130 patients with CAD (aged 61 ± 7 years; male: 85%) were randomized to NW (n = 43), HIIT (n = 43), or MICT (n = 44). Table 1 shows that significant main effects of time were observed for SV (∆: 5.485 m/L, F = 8.530, p = 0.004), with a time × group interaction (F = 3.710, p = 0.027) revealing a greater improvement in SV following NW compared to HIIT (F = 5.748, p = 0.019) and MICT (F = 5.494, p = 0.022). A significant time × group interaction (F = 3.700, p = 0.028) was observed in AIx@75, with a greater reduction following NW than MICT (F = 7.388, p = 0.008). No significant differences were observed in TVR, AIx, and PWV. Conclusion Our findings show that NW facilitated greater improvements in SV and AIx@75 parameters of arterial stiffness, an important predictor of future cardiovascular events, when compared to HIIT and MICT in patients with CAD. NW may be considered as an alternative exercise training to improve vascular health in those with CAD.

Harmonics of Pulsatile Pressure At Different Ages and Its Effect On Other Pulsatile Parameters and Waveform-based Clinical Indices

Abstract Pulsatile pressure at an artery is a collection of harmonics of the heartbeat. This study examines harmonics of pulsatile pressure at different ages and its effect on other pulsatile parameters and waveform-based clinical indices. Based on a vibrating-string model of the arterial tree, wave velocity and characteristic impedance are related to arterial stiffness and radius. Blood velocity, wall shear stress (WSS), and driving force on the left ventricle (LV) are related to pulsatile pressure. Reflection magnitude and return time are related to input impedance. These relations are applied to pulsatile pressure and blood velocity at the ascending aorta (AA) and the carotid artery (CA) at different ages in a database to calculate harmonics of all the pulsatile parameters and reflection magnitude and return time at each harmonic. Harmonics of pulsatile pressure varies with aging and between the two arteries. Reflection magnitude and return time vary between harmonics. While wave reflection manifests the arterial tree (i.e., arterial stiffness and radius) and termination, harmonics of pulsatile pressure is a combination of the LV, the arterial tree, and termination. Harmonics of pulsatile pressure dictates harmonics of WSS and affects endothelial function. Harmonics of pulsatile pressure needs to serve as an independent clinical index indicative of the LV function and endothelial function. Reflection magnitude and return time of the 1st harmonic of pulsatile pressure serve as clinical indices indicative of arterial stiffness and radius.