One of the major challenges for hypertension research is to identify the mechanisms that cause the comorbidities encountered in many hypertensive patients, as seen in the metabolic syndrome. An emerging body of evidence suggests that human and experimental hypertensives may exhibit uncontrolled activity of proteinases, including the family of matrix ...

The clinically used sulfonamide carbonic anhydrase (CA, EC 4.2.1.1) inhibitor dorzolamide (DRZ), a new sulfonamide CA inhibitor also incorporating NO-donating moieties, NCX250, and isosorbide mononitrate (ISMN) (an NO-donating compound with no CA inhibitory properties) were investigated for their intraocular pressure (IOP) lowering effects in rabbits with carbomer-induced glaucoma. NCX250 was ...

Lactobacillus delbrueckii ssp. bulgaricus, Streptococcus salivarius ssp. thermophilus, and Lactobacillus acidophilus are dairy cultures widely used in the manufacture of cultured dairy products. Commonly used homogenization pressures in the dairy industry are 13.80 MPa or less. It is not known whether low homogenization pressures can stimulate bacteria to improve their ...

To assess the effectiveness of sodium nitroprusside (SNP)-"enhanced" cardiopulmonary resuscitation (SNPeCPR) on 24-hr survival rates compared to standard CPR in animals after cardiac arrest. SNPeCPR consists of large intravenous SNP bolus doses during CPR enhanced by active compression-decompression CPR, an inspiratory impedance threshold device (ITD), and abdominal binding (AB). The ...

OBJECTIVE: Cardiovascular variability is a complex physiological phenomenon associated with the outcome of cardiovascular diseases. Blood pressure oscillations may cause cardiovascular complications, which, however, are also claimed to have antihypertensive effects. The physiological understanding is limited. This study evaluates whether oscillations in heart rate (HR) and cardiac output (CO) buffer ...

Aim:To identify the role of metformin in cardiac hypertrophy and investigate the possible mechanism underlying this effect.Methods:Wild type and AMPKα2 knockout (AMPKα2(-/-)) littermates were subjected to left ventricular pressure overload caused by transverse aortic constriction. After administration of metformin (200 mg·kg(-1)·d(-1)) for 6 weeks, the degree of cardiac hypertrophy was ...

The cross-correlation function (CCF) yields the correlation coefficient between spontaneous fluctuations of heart period and blood pressure as a function of the time shift between these variables. Two CCF patterns occur in humans: I) positive correlation between heart period and previous pressure values; II) negative correlation between heart period and ...

BACKGROUND: This study aims to evaluate the effect of weight loss on the physical capacity and the structure and function of the heart after bariatric surgery. METHODS: Forty-three adult obese patients, 31 women (72.1%) and 12 men (27.9%), were submitted to electrocardiogram, ergometric test, and echo Doppler cardiogram at presurgical ...

The heart accommodates to rapid changes in demands. This review elucidates the adaptive control of cardiac function by loading conditions, and integrates the sarcomeric control of contraction (SCC) with isolated trabeculae and in vivo whole-heart studies. The SCC includes two feedback mechanisms: (1) cooperativity that regulates cross-bridge (XB) recruitment and ...

We assessed the contribution of angiotensin-(1-7) [Ang-(1-7)] to captopril-induced cardiovascular protection in spontaneously hypertensive rats (SHRs) chronically treated with the nitric oxide synthesis inhibitor NG-nitro-L-arginine methyl ester (SHR-l). NG-nitro-L-arginine methyl ester (80 mg/L) administration for 3 weeks increased mean arterial pressure (MAP) from 196 ± 6 to 229 ± 3 ...

The optimum method of intraoperative monitoring in patients undergoing off-pump coronary bypass remains debatable. Using capnography and end-tidal carbon dioxide pressure may be a helpful method of monitoring cardiac output trends, especially when grafting posterior and lateral vessels. After repositioning the heart, End-tidal carbon dioxide pressures that continue to trend ...

Evaluation of ambulatory blood pressure monitoring (ABPM), two-dimensional (2D) echo and clinical variables in predicting cardiac death and acute decompensated heart failure in patients with ischaemic cardiomyopathy and receiving a cardioverter-defibrillator implantation. We studied 180 consecutive patients (169 men) on an out-patient basis, with systolic dysfunction (ejection fraction ≤35%) and ...

OBJECTIVE:: Fluid therapy after resuscitation from cardiac arrest is challenging since both hypovolemia and fluid overload may cause circulatory failure. Therefore, prediction of fluid responsiveness is a major issue in optimizing hemodynamic therapy. The aim of the present study was to evaluate the performance of stroke volume variation, pulse pressure ...

OBJECTIVES: To assess the prevalence of cardiovascular signs and symptoms in a large group of patients with Hunter syndrome, an X-linked metabolic disorder caused by a deficiency of the lysosomal enzyme iduronate-2-sulfatase. STUDY DESIGN: The Hunter Outcome Survey was established to characterize the natural history of Hunter syndrome and to ...

Scuba diving may elicit acute changes to human cardiovascular function. Environmental stresses such as immersion, cold, and venous gas microbubbles all have been shown to contribute to right ventricular overload and impaired left ventricular filling after single dives. We investigated cardiac function after simulated dry chamber dives. Twenty male divers ...

Octreotide is a somatostatin analog which constricts the splanchnic circulation thereby improving orthostatic tolerance. We tested the hypotheses that octreotide improves orthostatic tolerance by: 1)increasing cardiac filling (right atrial) pressure via reductions in vascular capacity; 2) by causing an upward (i.e. cranial) shift of the hydrostatic indifferent point; and 3) ...

PURPOSE OF REVIEW: The fluid challenge is used in the fluid management of many sick patients. The principle behind the fluid challenge technique is that by giving a small amount of fluid in a short period of time, the clinician can assess whether the patient has a preload reserve that ...

PURPOSE: Beta-2 adrenoceptor agonistic drugs like ritodrine have been the reference tocolytic drugs, but are associated with cardiovascular side-effects. Atosiban, a newer drug, is a competitive antagonist of oxytocin and has been claimed to have fewer cardiovascular side effects. Until now, there has mainly been a subjective reporting of adverse ...

Aims: The Raf-MEK1/2-ERK1/2 signaling cascade is crucial in triggering cardiac responses to different stress stimuli. Scaffold proteins are key elements in coordinating signaling molecules for their appropriate spatiotemporal activation. Here we investigated the role of IQGAP1, a scaffold for the ERK1/2 cascade, in heart function and remodeling in response to ...

Haemodynamic responses during parabolic flight were studied. The hypothesis that haemodynamic changes may be counteracted by a transient vagal reflex during acute gravity transitions was tested. ECG, arterial pressure and respiration were recorded continuously in seven male subjects during parabolic flight. Beat-to-beat haemodynamic parameters were estimated. In the supine position ...

Aortic stiffness (pulse wave velocity, PWV) and pressure wave reflections (augmentation index, AI) are two interrelated markers of mortality. Their potential synergistic effect on mortality has never been studied. We sought to investigate the association as well as the combined effect of PWV and AI on mortality in a cohort ...

The waffle procedure is performed in patients with marked thickening and calcification of the epicardium and no substantial improvement in hemodynamic parameters after pericardiectomy. We retrospectively investigated the efficacy of the waffle procedure in 6 of 11 patients who underwent pericardiectomy. These 6 patients showed no improvement in central venous ...

The purpose of this study was to determine the effects of combined low-dose ketamine and etomidate on hemodynamics during cardiac catheterization in children with congenital cardiac shunts. Sixty children undergoing routine diagnostic cardiac catheterization were included: 30 had a right-to-left shunt, and 30 had a left-to-right shunt. Both groups were ...

Sympathetic activation characterizes essential hypertension, contributing to the development and progression of the high blood pressure state. Throughout the years, evidence has been accumulated to show that adrenergic overdrive also participates in the pathogenesis of the end-organ damage associated with hypertension, including cardiac hypertrophy, left ventricular diastolic dysfunction, and heart ...

The purpose of this study was to develop an automated surveillance system, using pressure-based hemodynamic factors that would detect which patients were making the transition from compensated to decompensated heart failure before they developed worsening symptoms and required acute medical care. Intracardiac pressures in 274 patients with heart failure were measured ...

BACKGROUND: /st> Predicting the response of cardiac output (CO) to volume administration remains difficult, in particular in patients with acutely compromised cardiac function, where, even small amounts of i.v. fluids can lead to volume overload. We compared the ability to predict volume responsiveness of different functional haemodynamic parameters, such as ...

BACKGROUND: /st> Arterial pressure waveform analysis of cardiac output (APCO) without external calibration (FloTrac/Vigileo™) is critically dependent upon computation of vascular tone that has necessitated several refinements of the underlying software algorithms. We hypothesized that changes in vascular tone induced by high-dose vasopressor therapy affect the accuracy of APCO measurements ...

Although blood pressure effects have been reported for adrenomedullin 5 (AM-5), a newly identified member of the CGRP super-family, little is known about other biological actions. We report the integrated hemodynamic, hormonal and renal actions of AM-5 (10 and 100 ng/kg/min each for 90 min) in normal conscious sheep. AM-5 ...

This paper describes the use of brandy and other forms of alcohol in the latter part of the 19th and early 20th centuries. Its prime use was as a cardiac stimulant as it seemed to increase the cardiac output and blood pressure. However it was also recognised as a depressant ...

A single bout of exercise is associated with postexercise hypotension, transient decreases in autonomic function, and changes in baroreflex sensitivity. The baroreflex is less sensitive to falling blood pressure than to rising blood pressure; we characterized the cardiac baroreflex in terms of hysteresis and its mechanical and neural components. We ...

Aim To study the effect of positional change on inferior vena cava (IVC) diameter. The influence of positional change on IVC size is not well studied. Although the American Society of Echocardiography guidelines for chamber quantification recommend imaging the IVC in the left lateral position, many labs routinely image the ...

The critical closing pressure (CrCP) of cerebral circulation is normally estimated by extrapolation of instantaneous velocity-pressure curves. Different methods of estimation were analysed to assess their robustness and reproducibility in both static and dynamic applications. In ten healthy subjects (mean ± SD age 37.5 ± 9.2 years) continuous recordings of ...

Background- Diastolic dysfunction associated with high blood pressure (BP) leads to cardiac remodeling and fibrosis and progression to congestive heart failure. B-type natriuretic peptide (BNP) has BP-lowering, antifibrotic, and antihypertrophic properties, which makes BNP an attractive agent for attenuating the adverse cardiac remodeling associated with hypertension. In the current study, ...

Doppler echocardiography is currently applied for the assessment of left ventricular and right ventricular hemodynamics in patients with cardiovascular disease. However, there are conflicting reports about its accuracy in patients with unstable decompensated heart failure. The objective of this study was to evaluate the accuracy of the technique in patients ...

Background: Pericardial constraint and ventricular interaction influence left ventricular (LV) performance when preload is high. However, it is unclear if these constraining forces modulate LV filling when the heart is unloaded, such as during upright posture, in humans. Methods and Results: Fifty healthy individuals underwent right heart catheterization to measure ...

Increased activity of the sympathetic system is an important feature contributing to the pathogenesis and progression of chronic heart failure. While the mechanisms and consequences of enhanced norepinephrine release from sympathetic nerves have been intensely studied, the role of the adrenal gland in the development of cardiac hypertrophy and progression ...

OBJECTIVES: Patients with cirrhosis often exhibit abnormalities in cardiovascular regulation and oxygenation. Many of these patients are treated with β-blockers and aldosterone antagonists that may influence the regulation of systemic haemodynamics, but the specific effects on systemic haemodynamics and oxygenation are less studied. We therefore investigated systemic haemodynamics and oxygenation ...

BACKGROUND: Abnormal left ventricular (LV) structure and diastolic function are frequently detected in a variety of heart diseases, and insulin resistance has been suggested to be associated with LV diastolic dysfunction (LVDD). The aims of this study were to determine the association between LVDD or LV structure and metabolic syndrome ...

Natriuretic peptides are controregulatory hormones associated with cardiac remodeling, namely, left ventricular hypertrophy and systolic/diastolic dysfunction. We intended to address the prognostic value of N-terminal pro-brain natriuretic peptide (NT-proBNP) in hypertension. We prospectively studied the relationship between plasma NT-proBNP and all-cause mortality in 684 hypertensive patients with no history or ...

The activated renin-angiotensin-aldosterone system increases blood pressure and intracellular signals, thus leading to cardiac fibrosis. Whether increased blood pressure or angiotensin II-activated signaling is responsible for elevated angiotensin II-induced cardiac remodeling is unknown. Here, we aimed to determine whether lowering blood pressure with hydralazine might prevent inflammation and cardiac fibrosis ...

To determine the effects of muscle pump function on cardiac autonomic activity in response to quiet standing, we simulated the muscle pump effect by rhythmic lower leg cuff inflation (RCI) with 4 cuff pressures of 0 (sham), 40, 80, and 120 mmHg at 5 cycles/min. The R-R interval (RRI) and ...

BACKGROUND:: Respiratory change in pre-ejection period (ΔPEP) has been described as a potential parameter for monitoring cardiac preload dependency in critically ill patients. This study was designed to describe the relationship between ΔPEP and pulse pressure variation (PPV) in pigs submitted to severe hemorrhagic shock. METHODS:: In 17 paralyzed, anesthetized ...

Background/Aims: Dual renin-angiotensin system (RAS) blockade has no more efficiency to decrease cardiovascular mortality than mono-blockade. Our goal was to explore differences between other cardiovascular markers in patients with RAS blockade. Methods: We analyzed two groups of patients treated with a long-term ACE inhibitor (MONO-group, n = 20) and an ...

BACKGROUND: Elevated blood pressure is a risk factor for cardiovascular disease and may be detected by left ventricular hypertrophy (LVH) in electrocardiogram (ECG). Pre-western Inuit had frequent signs of LVH in ECG predominantly in the 3rd decade while a low occurrence of ischemic heart disease. METHODS: We evaluated the association ...

Pulse pressure variation (PPV) is an accepted measure of intravascular filling. It can now be estimated automatically. However, there is limited knowledge of the epidemiology and associations of such estimates in cardiac surgery patients. We conducted a pilot prospective observational study of the epidemiology and associations of automatically estimated PPV ...

We describe the case history of a 42-year-old man with cardiac cirrhosis, portal hypertension, and life-threatening variceal bleeding after Fontan revision surgery. Direct pressure measurements in the portal vein, though high, demonstrated only a modest portosystemic gradient (PSG), 9 mm Hg. A transjugular intrahepatic portosystemic shunt procedure was performed. This reduced the ...

Nonhuman primates are used frequently in cardiovascular research. Cardiac time intervals derived by phonocardiography have long been used to assess left ventricular function. Electronic stethoscopes are simple low-cost systems that display heart sound signals. We assessed the use of an electronic stethoscope to measure cardiac time intervals in 48 healthy ...

Total liquid ventilation (TLV) is a promising treatment for severe lung injury and heart resuscitation. We aim to investigate the hemodynamic effect of TLV in piglets with preexisting cardiac dysfunction. After onset of cardiopulmonary dysfunction induced by cardiopulmonary bypass (CPB), piglets were randomly treated with TLV (n = 6) or conventional gas ...

Laboratory exposures to smoking cues have been shown to reliably induce self-reported cigarette cravings among smokers, a model of environmentally triggered urges to smoke that can contribute to poorer cessation success. Several studies have also demonstrated that cue exposures give rise to changes in heart rate and blood pressure. Few ...

Cardiac pulsatility and aortic compliance may result in aortic area and diameter changes throughout the cardiac cycle in the entire aorta. Until this moment these dynamic changes could never be established in the aortic root (aortic annulus, sinuses of Valsalva and sinotubular junction). The aim of this study was to ...