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Objective: To investigate whether angiogenic markers of placental function are associated with maternal cardiac function and hemodynamic responses at 19–23 weeks' gestation, controlling for maternal risk factors and pregnancy complications. Methods: This was a prospective study of women with singleton pregnancy attending King's College Hospital, London, UK, for a routine hospital visit at 19–23 weeks' gestation. We recorded maternal characteristics and measured mean arterial pressure (MAP), maternal heart rate, serum placental growth factor (PlGF) and soluble fms‐like tyrosine kinase‐1 (sFlt‐1). We also performed maternal echocardiography to assess cardiac output and peripheral vascular resistance as well as indices of diastolic and systolic function. Results: Our cohort included 4006 women. Lower PlGF values were significantly associated with higher MAP (P < 0.0001), lower maternal heart rate (P < 0.0001), lower mitral valve s′ mean velocity (P = 0.027) and higher left atrial area (P = 0.022) after adjustment for maternal characteristics and pregnancy complications. sFlt‐1 was associated positively with relative wall thickness (P = 0.012), whereas sFlt‐1/PlGF ratio was associated negatively with mitral valve A (P = 0.006) and positively with left atrial area (P = 0.015) and MAP (P = 0.004). The magnitude of these associations was similar in the subgroup of women without any risk factors based on their obstetric and medical history. Conclusions: A continuous association of moderate strength between angiogenic factors and subclinical maternal cardiac function alterations is present in midgestation, independently of pre‐existing maternal risk factors and pregnancy complications. Impaired placental function appears to be related to mild systolic and diastolic dysfunction and cardiac remodeling. © 2024 International Society of Ultrasound in Obstetrics and Gynecology. [ABSTRACT FROM AUTHOR]

Muscle sympathetic nerve activity (MSNA) increases during hyperinsulinemia, primarily attributed to central nervous system effects. Whether peripheral vasodilation induced by insulin further contributes to increased MSNA via arterial baroreflex-mediated mechanisms requires further investigation. Accordingly, we examined baroreflex modulation of the MSNA response to hyperinsulinemia. We hypothesized that rescuing peripheral resistance with coinfusion of the vasoconstrictor phenylephrine would attenuate the MSNA response to hyperinsulinemia. We further hypothesized that the insulin-mediated increase in MSNA would be recapitulated with another vasodilator (sodium nitroprusside, SNP). In 33 young healthy adults (28 M/5F), MSNA (microneurography) and arterial blood pressure (BP, Finometer/brachial catheter) were measured, and total peripheral resistance (TPR, ModelFlow) and baroreflex sensitivity were calculated at rest and during intravenous infusion of insulin (n = 20) or SNP (n = 13). A subset of participants receiving insulin (n = 7) was coinfused with phenylephrine. Insulin infusion decreased TPR (P = 0.01) and increased MSNA (P < 0.01), with no effect on arterial baroreflex sensitivity or BP (P > 0.05). Coinfusion with phenylephrine returned TPR and MSNA to baseline, with no effect on arterial baroreflex sensitivity (P > 0.05). Similar to insulin, SNP decreased TPR (P < 0.02) and increased MSNA (P < 0.01), with no effect on arterial baroreflex sensitivity (P > 0.12). Acute hyperinsulinemia shifts the baroreflex stimulus-response curve to higher MSNA without changing sensitivity, likely due to insulin's peripheral vasodilatory effects. Results show that peripheral vasodilation induced by insulin contributes to increased MSNA during hyperinsulinemia. [ABSTRACT FROM AUTHOR]

Background and Objectives: Previously, the diastolic section of the pulse wave was most often analyzed as the result of reflection of a direct wave from the elements of peripheral vessels. However, measurements of the negative linear velocity of blood flow using ultrasound dopplerograms clearly indicate the presence of reverse blood flow in the arteries. The aim of the work was to establish the relationship of the second derivative of the pulse pressure wave with the value of the reverse blood flow in the arterial bed. Materials and Methods: The shape of the pressure pulse wave was calculated based on the two-element windkessel model. The calculation of the second derivative of the pulse pressure wave was performed taking into account the direct and reverse blood flow occurring in the arteries at different values of the reverse blood flow. Results: The linear dependence of the second derivative of the pulse wave on the value of the blood volume of the reverse wave on the diastole is obtained. Conclusions: It is concluded that the second derivative of the pulse pressure wave can be used to estimate the value of the reverse blood flow in the artery, which depends on the state of the peripheral vascular system.

Background: The ophthalmic artery, which is the first branch of the internal carotid artery, has a Doppler velocity waveform with 2 systolic peaks. The ratio of the peak systolic velocity of the second wave divided by that of the first wave is used to reflect increased peripheral resistance. Previous studies in the first, second, and third trimesters of pregnancy have reported that in pregnant women who subsequently develop preeclampsia, the peak systolic velocity ratio is increased. Both preeclampsia and gestational diabetes mellitus are associated with endothelial dysfunction and an increased risk for cardiovascular diseases during the first decade after pregnancy., Objective: This study aimed to compare the ophthalmic artery peak systolic velocity ratio at 11 to 13 weeks' gestation of women who subsequently develop gestational diabetes mellitus with that of unaffected pregnant women and those who develop preeclampsia., Study Design: This was a prospective observational study of women who attended the King's College Hospital, London, United Kingdom, for a routine hospital visit at 11 +0 to 13 +6 weeks' gestation. This visit included recording of the maternal demographic characteristics and medical history, an ultrasound examination for fetal anatomy and growth, assessment of the flow velocity waveforms from the maternal ophthalmic arteries, calculation of the peak systolic velocity ratio, and measurement of the mean arterial pressure. Linear regression was performed to predict the ophthalmic artery peak systolic velocity ratio based on maternal characteristics and the mean arterial pressure. The peak systolic velocity ratio in the group with gestational diabetes mellitus was compared with that of preeclamptic and unaffected pregnancies., Results: A total of 3999 women were included in this study, including 375 (9.8%) who developed gestational diabetes mellitus and 101 (2.5%) who developed preeclampsia. In the gestational diabetes mellitus group, 161 (43.3%) were treated by diet alone, 130 (34.1%) were treated with metformin, and 84 (22.6%) received insulin with or without metformin. Prediction of peak systolic velocity ratio was provided by development of preeclampsia, maternal age, body mass index, mean arterial pressure, first-degree family history of diabetes mellitus, family history of preeclampsia, Asian ethnicity, and smoking. There was no significant contribution from gestational diabetes mellitus. Among women who developed gestational diabetes mellitus that required insulin treatment, the ophthalmic artery peak systolic velocity ratio (0.67±0.09) was higher (P<.001) than that in unaffected pregnancies (0.63±0.10), but it was not significantly different from that in the preeclampsia group (0.69±0.10; P=.90)., Conclusion: Among women who developed severe gestational diabetes mellitus that required insulin treatment, there was evidence of increased peripheral resistance, which was apparent from the first trimester of pregnancy., (Copyright © 2024. Published by Elsevier Inc.)

Introduction: According to many studies, hypertension is considered as the second leading risk factor for coronary artery disease (CAD) and cardiac infarction after smoking The purpose of the present study was to investigate the effect of four weeks of Isometric Handgrip (IHG) Training on peripheral resistance and hypertension among hypertensive women. Methods: 14 middle aged women, aged 40 to 55 years old, were randomly selected. The training program included 4 sets of 2 minute IHG training with 1 minute resting between each period, performed 3 days a week for four weeks. Doppler ultrasound method was used to measure the vascular resistance. Data were analyzed using paired t-test. Results: According to the results, there was a significant difference between systolic blood pressure (p=0.006) and diastolic blood pressure (p=0.001) after 4 weeks of training. However, no significant difference was observed in vascular resistance (p=0.66). Conclusion: These results demonstrate that IHG training can reduce blood pressure in the hypertensive patients 24 hours after the last training session. It is also revealed that reduced blood pressure is not always associated with reduced vascular resistance and other influential factors may play a role in this regard.

This study presents a database of central blood pressure waveforms according to cardiovascular health conditions, to supplement the lack of clinical data in cardiovascular health research, constructed by a cardiovascular simulator. Blood pressure (BP) is the most frequently measured biomarker, and in addition to systolic and diastolic pressure, its waveform represents the various conditions of cardiovascular health. A BP waveform is formed by overlapping the forward and reflected waves, which are affected by the pulse wave velocity (PWV). The increase in vascular stiffness with aging increases PWV, and the PWV-age distribution curve is called vascular age. For cardiovascular health research, extensive data of central BP waveform is essential, but the clinical data published so far are insufficient and imbalanced in quantity and quality. This study reproduces the central BP waveform using a cardiovascular hardware simulator and artificial aortas, which mimic the physiological structure and properties of the human. The simulator can adjust cardiovascular health conditions to the same level as humans, such as heart rate of 40-100 BPM, stroke volume of 40-100 mL, and peripheral resistance of 12 steps. Also, 6 artificial aortas with vascular ages in the 20-70 were fabricated to reproduce the increase in vascular stiffness due to aging. Vascular age calculated from measured stiffness of artificial aorta and central BP waveform showed an error of less than 3 years from the clinical value. Through this, a total of 636 waveforms were created to construct a central BP waveform database according to controlled various cardiovascular health conditions., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Background/Aims: Intradialytic hypertension (IH) occurs frequently in some hemodialysis patients and increases mortality risk. We simultaneously compared pre-dialysis, post-dialysis and changes in extracellular volume and hemodynamics in recurrent IH patients and controls. Methods: We performed a case-control study among prevalent hemodialysis patients with recurrent IH and hypertensive hemodialysis controls. We used bioimpedance spectroscopy and impedance cardiography to compare pre-dialysis, post-dialysis, and intradialytic change in total body water (TBW) and extracellular water (ECW), as well as cardiac index (CI) and total peripheral resistance index (TPRI). Results: The ECW/TBW was 0.453 (0.05) pre-dialysis and 0.427 (0.04) post-dialysis in controls vs. 0.478 (0.03) and 0.461 (0.03) in IH patients (p=0.01 post-dialysis). The ECW/TBW change was -0.027 (0.03) in controls and -0.013 (0.02) in IH patients (p=0.1). In controls, pre- and post-dialysis TPRI were 3254 (994) and 2469 (529) dynes/sec/cm2/m2 vs. 2983 (747) and 3408 (980) dynes/sec/cm2/m2 in IH patients (p=0.002 post-dialysis). There were between-group differences in TPRI change (0=0.0001), but not CI (p=0.09). Conclusions: Recurrent intradialytic hypertension is associated with higher post-dialysis extracellular volume and TPRI. Intradialytic TPRI surges account for the vasoconstrictive state post-dialysis, but intradialytic fluid shifts may contribute to post-hemodialysis volume expansion.

Maternal cardiovascular changes during pregnancy include an expansion of plasma volume, increased cardiac output, decreased peripheral resistance, and increased uteroplacental blood flow. These adaptations facilitate the progressive increase in uteroplacental perfusion that is required for normal fetal growth and development, prevent the development of hypertension, and provide a reserve of blood in anticipation of the significant blood loss associated with parturition. Each woman's genotype and phenotype determine her ability to adapt in response to molecular signals that emanate from the fetoplacental unit. Here, we provide an overview of the major hemodynamic and cardiac changes and then consider regional changes in the splanchnic, renal, cerebral, and uterine circulations in terms of endothelial and vascular smooth muscle cell plasticity. Although consideration of gestational disease is beyond the scope of this review, aberrant signaling and/or maternal responsiveness contribute to the etiology of several common gestational diseases such as preeclampsia, intrauterine growth restriction, and gestational diabetes. [ABSTRACT FROM AUTHOR]

Hypertension is a condition characterized by pressure and/or volume overloads and echocardiography is helpful and feasible to understand hemodynamic mechanisms. Echocardiographic information is sometimes critical and susceptible of modifying decision making. In this review, we provide detailed descriptions of the parameters that can be derived from a standard transthoracic echocardiogram, including some more recent techniques. We will also explain how each parameter might have impact in the evaluation of the hypertensive patient and give indications on when to refer patients to echo-labs, which parameters are critical and which ones might be redundant, and how to use the information obtained in the report. Cardiac geometry, LV systolic and diastolic function, LV pump performance, output impedance and left atrial function are parameters that might be altered in arterial hypertension, but not necessarily doctors need the whole information for decision making. The critical measures are provided. [ABSTRACT FROM AUTHOR]

A significant number of patients with essential thrombocythemia (ET) complain of symptoms including distal parts of the extremities (e.g., paresthesias or Raynaud's phenomenon). The aim of the present study was to examine peripheral circulation in the upper extremities of individuals with ET. The study included 45 ET patients and 30 control subjects. All participants were subjected to thermography, photoplethysmography, impedance plethysmography, and applanation tonometry pulse wave analysis. The patients with ET differed significantly from the control subjects in terms of 3rd finger skin temperature (mean 31.04 vs. 32.45 °C), skin temperature gradient (mean 1.82 vs. 0.11 °C), photoplethysmographic amplitude (median 0.25 vs. 0.74%), and pulse waveform in the radial artery (more frequent occurrence of type B waveform). Pulse wave parameters correlated with the skin temperature gradient. The study findings imply the altered regulation of peripheral circulation in ET, including a decreased flow and an increased resistance. [ABSTRACT FROM AUTHOR]

Systemic vascular pressure in vertebrates is regulated by a range of factors: one key element of control is peripheral resistance in tissue capillary beds. Many aspects of the relationship between central control of vascular flow and peripheral resistance are unclear. An important example of this is the relationship between hypoxic response in individual tissues, and the effect that response has on systemic cardiovascular adaptation to oxygen deprivation. We show here how hypoxic response via the HIF transcription factors in one large vascular bed, that underlying the skin, influences cardiovascular response to hypoxia in mice. We show that the response of the skin to hypoxia feeds back on a wide range of cardiovascular parameters, including heart rate, arterial pressures, and body temperature. These data represent the first demonstration of a dynamic role for oxygen sensing in a peripheral tissue directly modifying cardiovascular response to the challenge of hypoxia.

This article reviews the pathophysiology and sonographic findings of peripheral arterial lesions, with emphasis on the spectral Doppler waveforms encountered in each. It discusses the characteristic features of the Doppler spectra in obstructive conditions, including thromboembolism, atherosclerotic disease, bypass graft occlusion, dissection, trauma, and compartment syndrome, as well as non-obstructive conditions, including hyperemia, pseudoaneurysm, and arteriovenous fistula. Familiarity with the commonly-encountered spectral waveforms in the setting of these lesions is necessary for timely and accurate diagnosis and treatment. [ABSTRACT FROM AUTHOR]

Purpose: The dynamics of the postulated phenomenon of exercise baroreflex resetting is poorly understood, but can be investigated using closed-loop procedures. To shed light on some mechanisms and temporal relationships participating in the resetting process, we studied the time course of the relationship between the R-R interval (RRi) and arterial pressure with a closed-loop approach.Methods: On ten young volunteers at rest and during light exercise in supine and upright position, we continuously determined, on single-beat basis, RRi (electrocardiography), and arterial pressure (non-invasive finger pressure cuff). From pulse pressure profiles, we determined cardiac output (CO) by Modelflow, computed mean arterial pressure (MAP), and calculated total peripheral resistance (TPR).Results: At exercise start, RRi was lower than in quiet rest. As exercise started, MAP fell to a minimum (MAPm) of 72.8 ± 9.6 mmHg upright and 73.9 ± 6.2 supine, while RRi dropped. The initial RRi versus MAP relationship was linear, with flatter slope than resting baroreflex sensitivity, in both postures. TPR fell and CO increased. After MAPm, RRi and MAP varied in opposite direction toward exercise steady state, with further CO increase.Conclusion: These results suggest that, initially, the MAP fall was corrected by a RRi reduction along a baroreflex curve, with lower sensitivity than at rest, but eventually in the same pressure range as at rest. After attainment of MAPm, a second phase started, where the postulated baroreflex resetting might have occurred. In conclusion, the change in baroreflex sensitivity and the resetting process are distinct phenomena, under different control systems. [ABSTRACT FROM AUTHOR]

We examined the effects of acute and chronic exercise under hypobaric hypoxia on cardiovascular responses/adaptations to test the hypothesis that cardiovascular adaptations are more effective after exercise under hypobaric hypoxia than under normobaric normoxia. First, we found that a decrease in peripheral resistance and blood pressure (BP) concomitant with an increase in stroke volume (SV) and cardiac output (CO) could be more effectively induced by chronic exercise under hypobaric hypoxia, than under normoxia. Also, the decrease in peripheral resistance and BP might be attributable to a decrease in arterial stiffness and enhanced vasodilatory activity. Second, the effects of acute hypoxic exposure and exercise on arterial stiffness and vasodilatory activity were examined. Arterial stiffness decreased after acute exercise alone, but not after acute hypoxic exposure alone. However, vasodilatory activity was enhanced by hypoxic stimulus, and to greater extent after hypoxic exercise. These findings suggested that stimulation with concomitant exercise and hypoxia could bring about more beneficial vascular responses. Finally, the time course of cardiovascular adaptations to hypobaric hypoxic exercise were accessed, and we found that a significant decrease in BP, accompanied by an increase in SV and CO, occurs within one week of starting the exercise; and that there is a significant decrease in arterial stiffness by the end of the second week. These changes in cardiovascular responses persisted until the end of the training period. Our findings suggest that exercise under hypobaric hypoxia brings about more rapid and effective beneficial cardiovascular adaptations than that under normoxia.

BackgroundEven if sodium sensitivity represents a risk factor at any blood pressure (BP) level, limited evidence is available that it may influence cardiovascular control in normotensives, particularly in white individuals. Therefore, the aim of the study was to investigate whether sodium sensitivity alters hemodynamic or autonomic responses to salt in normotensives. Methods and ResultsWe evaluated the Sodium‐Sensitivity Index (SS‐Index) in 71 white normotensives after 5 days of high‐ and low‐sodium diets. We measured BP continuously at the end of each period, estimating hemodynamic indices from BP waveform analysis, and autonomic indices from heart rate (HR) and BP variability. According to the SS‐Index distribution, we defined 1 sodium‐sensitive group (SS, with SS‐Index >15 mm Hg/[mmol·day]), 1 sodium‐resistant group, (unresponsive to sodium load with −15≤ SS‐Index ≤+15), and 1 inverse sodium‐sensitive group, responsive to sodium by decreasing BP, with SS‐Index