Critical velocity (CV)

NEW FINDINGS: What is the central question of this study? Gonadal hormones modulate cerebrovascular function while insulin-like growth factor 1 (IGF-1) facilitates exercise-mediated cerebral angiogenesis; puberty is a critical period of neurodevelopment alongside elevated gonadal hormone and IGF-1 activity: but whether exercise training across puberty enhances cerebrovascular function is unkown. What is the main finding and its importance? Cerebral blood flow is elevated in endurance trained adolescent males when compared to untrained counterparts...

Left atrial (LA) inflow propagation velocity from the pulmonary vein (LAIF-PV) has been proposed as a novel measure of LA reservoir function and is associated with pulmonary capillary wedge pressure in critically ill patients. However, data on LAIF-PV in acute heart failure (AHF) are lacking. We sought to examine the feasibility of measuring LAIF-PV and evaluate clinical and echocardiographic correlates of LAIF-PV in AHF. In a prospective cohort study of adults hospitalized for AHF, we used color M-mode Doppler of the pulmonary veins to obtain LAIF-PV in systole...

Background: Cardiac output (CO) assessment is essential for management of patients with circulatory failure. Among the different techniques used for their assessment, pulsed-wave Doppler cardiac output (PWD-CO) has proven to be an accurate and useful tool. Despite this, assessment of PWD-CO could have some technical difficulties, especially in the measurement of left ventricular outflow tract diameter (LVOTd). The use of a parameter such as minute distance (MD) which avoids LVOTd in the PWD-CO formula could be a simple and useful way to assess the CO in critically ill patients...

IMPORTANCE: Valsartan has shown promise in attenuating cardiac remodeling in patients with early-stage sarcomeric hypertrophic cardiomyopathy (HCM). Genetic testing can identify individuals at risk of HCM in a subclinical stage who could benefit from therapies that prevent disease progression. OBJECTIVE: To explore the potential for valsartan to modify disease development, and to characterize short-term phenotypic progression in subclinical HCM. DESIGN, SETTING, AND PARTICIPANTS: The multicenter, double-blind, placebo-controlled Valsartan for Attenuating Disease Evolution in Early Sarcomeric Hypertrophic Cardiomyopathy (VANISH) randomized clinical trial was conducted from April 2014 to July 2019 at 17 sites in 4 countries (Brazil, Canada, Denmark, and the US), with 2 years of follow-up...

The fluctuations in resting-state beat-to-beat blood pressure (BP) are physiologically complex, and the degree of such BP complexity is believed to reflect the multiscale regulation of this critical physiologic process. Hypertension (HTN), one common age-related condition, is associated with altered BP regulation and diminished system responsiveness to perturbations such as orthostatic change. We thus aimed to characterize the impact of HTN on resting-state BP complexity, as well as the relationship between BP complexity and both adaptive capacity and underlying vascular characteristics...

BACKGROUND: Gore Cardioform Atrial Septal Defect Occluder (GCA) is composed of a platinum-filled nitinol wire frame covered with expanded polytetrafluoroethylene (ePTFE). This makes the device highly occlusive and resistant to residual shunts through the device, as well as conforming well to the surrounding anatomy. In defects with poor rims to hold a device for closure or where one of the 'rims' is the free wall of the left ventricle, such as in a post-infarct apical ventricular septal defect (VSD), successful closure with standard nitinol mesh devices can be unachievable...

OBJECTIVES: To compare the glycemic index(GI),obesity,echocardiographic,and arterial stiffness measurements with the healthy control group to evaluate the cardiovascular risk of pediatric classical phenylketonuria(PKU). METHODS: The study was a prospective observational,involving 104 pediatric volunteers between 2019 and 2020.Two groups were formed:the PKU patient group and the healthy control group.These two groups were further divided into three subgroups:obese,overweight,and normal weight...

AIMS: Inflammatory cytokines play a critical role in the progression of calcific aortic valve disease (CAVD), for which there is currently no pharmacological treatment. The aim of this study was to test the hypothesis that interleukin-8 (IL-8), known to be involved in arterial calcification, also promotes aortic valve calcification (AVC) and to evaluate whether pharmacologically blocking the IL-8 receptor, CXC motif chemokine receptor 2 (CXCR2), could be effective in preventing AVC progression...

OBJECTIVE: Peripheral arterial stenoses (PAS) are commonly investigated with duplex ultrasound (DUS) and angiography, but these are not functional tests. Fractional flow reserve (FFR), a pressure based index, functionally assesses the ischaemic potential of coronary stenoses, but its utility in PAS is unknown. FFR in the peripheral vasculature in patients with limb ischaemia was investigated. METHODS: Patients scheduled for angioplasty/stenting of isolated iliac and superficial femoral artery stenoses were recruited...

BACKGROUND: In patients with symptomatic cerebral vasospasm (CV) following aneurysmal subarachnoid hemorrhage who do not respond to medical therapy, urgent treatment escalation has been suggested to be beneficial for brain tissue at risk. In our routine clinical care setting, we implemented stellate ganglion block (SGB) as a rescue therapy with subsequent escalation to intraarterial spasmolysis (IAS) with milrinone for refractory CV. METHODS: In this retrospective analysis from 2012 to 2021, patients with CV following aneurysmal subarachnoid hemorrhage who received an SGB or IAS were identified...

Blood flow in stenosed arteries is a common cause of cardiovascular diseases, leading to serious health problems. The present study aims to investigate the unsteady Womersley blood flow in a stenosed, porous saturated artery under the influence of acceleration and magnetic fields. The study utilizes a Carreau constitutive equation to model blood rheology and employs the finite difference technique to compute the governing equations under the assumption of unsteady, unidirectional, and laminar flow. The importance of this study lies in its potential to provide a better understanding of the complex behavior of hemodynamic flow in the presence of external fields and porous media, which has significant implications for the control and management of cardiovascular diseases...

Pregnant women with cardiovascular risk (CVR) factors are highly prone to develop cardiovascular disease later in life. Thus, recent guidelines suggest extending the follow-up period to 1 yr after delivery. We aimed to evaluate cardiovascular remodeling during pregnancy and determine which CVR factors and potential biomarkers predict postpartum cardiac and vascular reverse remodeling (RR). Our study included a prospective cohort of 76 healthy and 54 obese and/or hypertensive and/or with gestational diabetes pregnant women who underwent transthoracic echocardiography, pulse-wave velocity (PWV), and blood collection at the 1st trimester (1T) and 3rd trimester (3T) of pregnancy as well as at the 1st/6th/12th mo after delivery...

BACKGROUND: Despite benefits of endovascular treatment (EVT) for large vessel occlusion (LVO) ischemic stroke, space-occupying brain edema (BE) represents a detrimental complication. In critical-care settings, CT-imaging is needed for monitoring these patients. Yet, bed-side techniques with the potential to predict whether patients develop BE or not would facilitate a time- and cost-efficient patient care. We assessed clinical significance of automated pupillometry in the follow-up of patients undergoing EVT...

Pathophysiological conditions such as endothelial dysfunction and arterial stiffness, characterized by low nitric oxide bioavailability, deficient endothelium-dependent vasodilation and heart effort, predispose individuals to atherosclerotic lesions and cardiac events. Nitrate (NO3 - ), L-arginine, L-citrulline and potassium (K+ ) can mitigate arterial dysfunction and stiffness by intensifying NO bioavailability. Dietary compounds such as L-arginine, L-citrulline, NO3 - and K+ exert vasoactive effects as demonstrated in clinical interventions by noninvasive flow-mediated vasodilation (FMD) and pulse-wave velocity (PWV) prognostic techniques...

BACKGROUND: Chronic obstructive pulmonary disease (COPD) often causes cardiopulmonary dysfunction, which deteriorates exercise capacity. Cardiopulmonary exercise testing (CPET) and echocardiography are common tools for evaluating cardiovascular function. No studies have analyzed the correlation between echocardiography-derived parameters and cardiopulmonary response during exercise. OBJECTIVES: We analyzed the correlation between echocardiographic parameters such as tricuspid regurgitation peak gradient (TRPG), tricuspid annular plane systolic excursion (TAPSE), TRPG/TAPSE and CPET-derived parameters...

BACKGROUND: Regional myocardial conduction velocity (CV) dispersion has not been studied in postinfarct patients with ventricular tachycardia (VT). OBJECTIVES: This study sought to compare the following: 1) the association of CV dispersion vs repolarization dispersion with VT circuit sites; and 2) myocardial lipomatous metaplasia (LM) vs fibrosis as the anatomic substrate for CV dispersion. METHODS: Among 33 postinfarct patients with VT, we characterized dense and border zone infarct tissue by late gadolinium enhancement cardiac magnetic resonance, and LM by computed tomography, with both images registered with electroanatomic maps...

BACKGROUND: Although cardiovascular disease (CVD) has markedly declined since the early 1960s due to medical advances and better management, this condition persists as the most critical and preventable cause of death in the US. For that reason, the identification and application of more sensitive, specific, validated, and noninvasive biomarkers of cardiovascular functioning in the primary care setting for the early identification of CVD risk at the subclinical level are warranted. AIM: The goal of the present review is twofold: first, to familiarize the primary care practitioner with noninvasive aortic hemodynamic parameters, including how these could be integrated into primary care services and patient management, and second, to propose a model for earlier detection of CVD based on the noninvasive hemodynamic parameters in the primary care setting...

BACKGROUND: Atrial tachycardia (AT) is a commonly encountered rhythm disorder in patients with underlying atrial scar. The role of atrial late activation mapping during sinus rhythm to predict the critical isthmus (CI) of AT has yet to be systematically evaluated. We aimed to investigate the relationship between the functional substrate mapping (FSM) characteristics and the CI of reentrant ATs in patients with underlying atrial low-voltage areas. METHODS: Patients with history of left AT who underwent catheter ablation with 3D mapping using high-density mapping were enrolled...

BACKGROUND: Myocardial lipomatous metaplasia (LM) has been reported to be associated with post-infarct ventricular tachycardia (VT) circuitry. OBJECTIVES: We examined the association of scar versus LM composition with impulse conduction velocity (CV) in putative VT corridors that traverse the infarct zone in post-infarct patients. METHODS: The cohort included 31 post-infarct patients from the prospective INFINITY (Intra-Myocardial Fat Deposition and Ventricular Tachycardia in Cardiomyopathy) study...

Preeclampsia-eclampsia syndrome is a leading cause of maternal mortality. The precise etiology of preeclampsia is still not well-defined and different forms exist, including early and late forms or preeclampsia, which may arise via distinctly different mechanisms. Low-dose aspirin administered at the end of the first trimester in women identified as high risk has been shown to reduce the incidence of early, but not late, preeclampsia; however, current risk factors show only fair predictive capability. There is a pressing need to develop accurate descriptions for the different forms of preeclampsia...