stevenson hemodynamic profiles

BACKGROUND: Pulmonary arterial hypertension (PAH) is characterized by persistently increased pressure in the pulmonary arteries. New defining criteria for the different hemodynamic types of pulmonary hypertension (PH) that occur with left heart disease have been proposed by the task force on PH. After consideration of the changes in the general definition of PH in left heart disease, the proposed hemodynamic definition was: (1) isolated postcapillary PH: pulmonary artery wedge pressure >15 mm Hg and mean pulmonary arterial pressure (mPAP) >20 mm Hg and pulmonary vascular resistance (PVR) <3 Woods units (WU); and (2) combined post- and precapillary PH: pulmonary artery wedge pressure >15 mm Hg, mPAP >20 mm Hg, and PVR ≥3 WU...

BACKGROUND: High-G acceleration experienced during launch and re-entry of suborbital spaceflights may present challenges for older or medically susceptible participants. A detailed understanding of the associated physiological responses would support the development of an evidence-based medical approach to commercial suborbital spaceflight. METHODS: There were 24 healthy subjects recruited into 'younger' (18-44 yr), 'intermediate' (45-64 yr) and 'older' (65-80 yr) age groups. Cardiovascular and respiratory variables were measured continuously during dynamic combinations of +Gx (chest-to-back) and +Gz (head-to-foot) acceleration that simulated suborbital G profiles for spaceplane and rocket/capsule platforms...

The renal outer medullary potassium (ROMK) channel mediates potassium recycling and facilitates sodium reabsorption through the Na+ /K+ /2Cl- cotransporter in the loop of Henle and potassium secretion at the cortical collecting duct. Evidence from the phenotype of humans and rodents with functional ROMK deficiency supports the contention that selective ROMK inhibitors (ROMKi) will represent a novel diuretic with potential of therapeutic benefit for hypertension. ROMKi have recently been synthesized by Merck & Co, Inc...

BACKGROUND: Patients perceive different symptoms of heart failure decompensation. It is not known whether the nature of the worst symptom relates to hemodynamic profile, response to therapy, or improvement in clinical trials. METHODS AND RESULTS: Patients in the Evaluation Study of Congestive Heart Failure and Pulmonary Artery Catheterization Effectiveness trial were hospitalized with advanced heart failure, ejection fraction ≤30%, and at least 1 sign and 1 symptom of elevated filling pressures...

BACKGROUND: Impedance cardiography (ICG) is a noninvasive modality that uses changes in impedance across the thorax to assess hemodynamic parameters, including cardiac output (CO). The utility of ICG in patients hospitalized with heart failure is uncertain. METHODS: The BioImpedance CardioGraphy in Advanced Heart Failure study was a prospective substudy of the Evaluation Study of Congestive Heart Failure and Pulmonary Artery Catheterization Effectiveness. A total of 170 subjects underwent blinded ICG measurements using BioZ (CardioDynamics, San Diego, CA); of these, 82 underwent right heart catheterization...

Advanced heart failure (HF) is associated with frequent hospitalizations, poor quality of life, and increased mortality. Despite optimal medical management, readmission rates remain high and account for approximately two thirds of all costs related to HF management. Evaluation of patients with HF is critical for the appropriate selection and monitoring of therapy as well as for the prevention of recurrent hospitalizations. This evaluation can be complex and relies on integration of the bedside evaluation and information available from invasive and other noninvasive diagnostic techniques...

Advanced heart failure has been defined as persistent symptoms (NYHA class III-IV) that limit daily life despite routine therapy with agents of known benefit. Although these symptoms can occur both with low and preserved ejection fraction, the majority of reported experience is with low ejection fraction, usually <25%. For this population with expected one year mortality of 30-50%, over twice the mortality of the landmark trials of medical therapy, there is little trial data to guide management, which is based largely on collected experience...

OBJECTIVES: This study was designed to determine the relevance of a proposed classification for advanced heart failure (HF). Profiles based on clinical assessment of congestion and perfusion at the time of hospitalization were compared with subsequent outcomes. BACKGROUND: Optimal design of therapy and trials for advanced HF remains limited by the lack of simple clinical profiles to characterize patients. METHODS: Prospective analysis was performed for 452 patients admitted to the cardiomyopathy service at the Brigham and Women's Hospital with a diagnosis of HF...

CONTEXT: Advanced heart failure, defined as persistence of limiting symptoms despite therapy with agents of proven efficacy, accounts for the majority of morbidity and mortality in heart failure. OBJECTIVE: To review current medical therapy for advanced heart failure. DATA SOURCES: We searched MEDLINE for all articles containing the term advanced heart failure that were published between 1980 and 2001; EMBASE was searched from 1987-1999, Best Evidence from 1991-1998, and Evidence-Based Medicine from 1995-1999...

BACKGROUND: Advanced heart failure is characterized by activation of the sympathetic nervous system and intense vasoconstriction. Biofeedback-relaxation techniques have been used successfully to treat conditions with similar pathophysiological features. OBJECTIVES: The purpose of this study was to determine if conscious control of skin temperature via a biofeedback-relaxation technique could produce vasodilation and alter central hemodynamic status and circulating levels of catecholamines in patients with heart failure...

OBJECTIVES: We attempted to determine whether changes in heart failure therapy since 1989 have altered the prognostic significance of atrial fibrillation. BACKGROUND: Atrial fibrillation occurs in 15% to 30% of patients with heart failure. Despite the recognized potential for adverse effects, the impact of atrial fibrillation on prognosis is controversial. METHODS: Two-year survival for 750 consecutive patients discharged from a single hospital after evaluation for heart transplantation from 1985 to 1989 (Group I, n = 359) and from 1990 to April 1993 (Group II, n = 391) was analyzed in relation to atrial fibrillation...

BACKGROUND: Patients with advanced heart failure often cannot undergo cardiac transplantation soon enough to prevent fatal hemodynamic deterioration or sudden death. The approach to these patients includes tailoring of medical therapy with vasodilators and diuretics, which allows stabilization of 60% to 80% of potential candidates. Current criteria for mechanical support before transplantation currently focus on the identification of hospitalized patients with at least 30% chance of death before transplantation...

OBJECTIVES: The purpose of this investigation was to determine how often left ventricular function improves in recent onset dilated cardiomyopathy of sufficient severity to cause referral for heart transplantation and how to predict this improvement at the time of evaluation for transplantation. BACKGROUND: Improvement has been reported to occur frequently in patients with acute dilated cardiomyopathy but has not been described specifically in these patients referred for transplantation...

The need for better low-profile mechanical valves led to the design and development of the Medtronic-Hall (formerly known as the Hall-Kaster valve) pivoting disc heart valve prosthesis in 1976. In vitro flow studies indicate that it has improved pressure drop characteristics compared to the Lillehei-Kaster and convexoconcave Björk-Shiley (60 degrees model) tilting disc valves. It does, however, have a somewhat larger regurgitant volume compared to the Björk-Shiley valve design. Velocity measurements with a laser-Doppler anemometer in the immediate downstream vicinity of the Medtronic-Hall valve indicate no region of stagnation near the outflow face of the disc...

The haemodynamic and neurohumeral response to a novel vasodilator calcitonin gene-related peptide was assessed in 11 patients with severe chronic heart failure. To assess tolerance, a continuous 48-h infusion (n = 6) was compared with a regimen of two successive 8-h infusions (n = 5). Haemodynamic response profiles were similar for both regimens, though the continuous infusion was poorly tolerated. Reductions in afterload reflected by changes in systemic vascular resistance and systemic blood pressure led to increases in cardiac index of at least 24%...

Over the past 25 years, the concept of circulation in heart failure has evolved from that of a simple circuit with a weak pump and high pressures to a complex integrated system of cellular modification, cardiac compensation and systemic neurohumoral responses. The original model of cardiac afterload as the systemic vascular resistance has been refined to reflect the interdependence of preload and afterload and the central role of atrioventricular valve regurgitation. It is becoming increasingly apparent that the impact of vasodilator therapy far exceeds the direct haemodynamic effects on preload and afterload, and depends on the mechanism by which vasodilation is achieved, with increasing emphasis on those agents which oppose neurohumoral activation...