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Results 501 - 550 of 1548
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Kim B J - - 1998
Constrictive pericarditis following an open cardiac surgery for congenital heart disease is very rarely encountered in children. We report a case of constrictive pericarditis, diagnosed at 22 months after surgical closure of an atrial septal defect, in a 14-year-old boy who presented postpericardiotomy syndrome. Cardiac catheterization revealed uniformity of elevated ...
Abdalla I - - 1998
Transmitral Doppler flow patterns of patients with cardiac amyloidosis evolve from an early impaired relaxation to an advanced restrictive pattern. This reflects increasing severity of diastolic dysfunction and hence left ventricular filling pressures. The duration of the pulmonary venous atrial reversal flow was recently shown to exceed that of the ...
Woods R L - - 1998
Intravenous atrial natriuretic peptide (ANP) usually results in splanchnic vasoconstriction in humans or experimental animals that is accompanied by falls in blood pressure and/or cardiac output. To determine direct in vivo effects in the present study, ANP was infused (12 ng. kg-1. min-1) directly into the mesenteric (iMA) and hepatic ...
McDougall J G - - 1998
1. There is considerable evidence for the existence of an endogenous inhibitor of Na+/K(+)-ATPase. The exact physiological nature and role of this postulated agent remains unclear, although it would be predicted that one of its actions would be stimulation of renal sodium excretion. 2. The natriuretic effect of renal arterial ...
Massoudy P - - 1998
BACKGROUND: In isolated working guinea pig heart preparations using the conventional technique of cannulating the left atrium via the atrial appendage, the resulting cardiac output is often insufficiently low (15-20 ml/min). This is a problem in ischemia reperfusion studies where small absolute differences can be responsible for large relative changes ...
Ceconi C - - 1998
Abnormalities of cytosolic calcium handling and myocyte energetics appear to play an important role in mediating contractile dysfunction in heart failure. Systolic and diastolic dysfunction in the failing heart are related to abnormalities of the excitation-contraction mechanism as well as myofilament calcium sensitivity. These abnormalities can be viewed as a ...
el-Harari M B - - 1998
We describe a case of 1:1 atrial flutter in a patient with coronary disease taking propafenone. In atrial flutter, the atrial rate is usually about 300 beats/min with 2:1 AV conduction and a ventricular rate of 150 beats/min. Class IA antiarrhythmic drugs, especially quinidine and disopyramide, may cause 1:1 AV ...
Murakawa Y - - 1998
INTRODUCTION: In vitro studies have suggested that human atrial natriuretic peptide (ANP) modulates the electrophysiologic properties of myocardial cells. This study assessed whether ANP could influence defibrillation efficacy. METHODS AND RESULTS: In 35 anesthetized dogs, the transcardiac defibrillation threshold (DFT) as well as hemodynamic and electrophysiologic variables were determined before ...
Seta K - - 1998
The present study was undertaken to verify the hypothesis that infusion of atrial natriuretic peptide (ANP) might lower preload and be beneficial in the treatment of pulmonary congestion even without a diuresis in patients with acute renal failure (ARF) secondary to severe congestive heart failure (CHF). We studied 22 patients ...
Kario K - - 1998
OBJECTIVE: The aim of this study was to investigate the relationships between levels of natriuretic peptides and adrenomedullin and 24 h blood pressure levels in elderly hypertensives. DESIGN AND METHODS: We performed both 24 h ambulatory blood pressure monitoring and measurement of plasma levels of atrial natriuretic peptide (ANP), brain ...
Azzam F J - - 1998
PURPOSE: To report the management of junctional ectopic tachycardia after cardiac surgery in an infant. Postoperatively, the patient suffered profound cardiac decompensation secondary to the accelerated rhythm and required extracorporeal membrane oxygenation (ECMO) for haemodynamic support. CLINICAL FEATURES: A 14-day-old, 3.5 kg boy exhibited junctional ectopic tachycardia after cardiopulmonary bypass. ...
Kita H - - 1998
The nocturnal secretion profile of the newly identified natriuretic peptide (NP), brain natriuretic peptide (BNP), was studied in 14 patients with obstructive sleep apnoea syndrome (OSAS) (apnoea hypopnoea index: 60.5 +/- 3.4, mean +/- SE) during two separate nights before and during nasal continuous positive airway pressure (NCPAP) therapy. Plasma ...
Dahle M G - - 1998
OBJECTIVE: The aim was to examine the usefulness of plasma N-terminal proatrial natriuretic factor (N-terminal proANP) as a non-invasive marker of cardiac pressure in patients with normal to mildly elevated serum creatinine. METHODS: Blood samples were drawn at rest from 100 patients with cardiac disease undergoing diagnostic cardiac catheterization. RESULTS: ...
Bauer E P - - 1998
BACKGROUND: Acute or chronic pressure overload may occur during or after cardiac surgical procedures. Typical examples are aortic cross-clamping and pulmonary artery banding. It is well known that mechanical stress induces transcription of different myocardial genes. However, these results were mainly obtained from in vitro studies and experiments with rodents. ...
Rao P S - - 1998
OBJECTIVE: We evaluated the effects of coliform endotoxin on the circulating levels of atrial natriuretic factor and renal function. To understand the direct effects of endotoxin in the release of atrial natriuretic factor by cardiac tissue, studies in isolated rat atria were performed. STUDY DESIGN: In vivo studies were used. ...
Takeichi N - - 1998
To investigate the relationship between left atrial function and secretion of atrial natriuretic peptide (ANP), we analyzed left ventricular inflow and pulmonary venous flow, left atrial dynamics, intracardiac pressures, and plasma ANP level in 92 patients with various cardiac diseases. From the apical four-chamber view, maximal left atrial volume and ...
Barrett C J - - 1998
Experiments were performed on rat right atria maintained at 37 degrees C in oxygenated Krebs-Henseleit solution, at a baseline diastolic transmural pressure of 2 mmHg. A step increment in right atrial pressure caused an increase in atrial rate which reached a steady value after 2-3 min (rate response). An 8-mmHg ...
Takenaga M - - 1998
The effects of dual-chamber pacing therapy in patients with hypertrophic obstructive cardiomyopathy (HOCM) have been reported in short- and long-term studies. Almost all of these studies have reported that the key factor in pacing therapy is the setting of the atrioventricular (AV) interval. However, studies focusing on the effects of ...
Hoit B D - - 1998
The objective of this study was to examine the hypothesis that long-term, rapid atrial pacing produces a model of atrial systolic and diastolic dysfunction but does not alter ventricular function. Eight dogs were atrially paced at 400 beats/min (3:1-5:1 ventricular response) for 6 wk and subsequently instrumented with left atrial ...
Mitaka C C Intensive Care Unit, Tokyo Medical and Dental University, - - 1998
The purpose of this study was to investigate the effect of i.v. infusion of atrial natriuretic peptide (ANP) on hemodynamics, pulmonary gas exchange, and urine volume during mechanical ventilation with positive end-expiratory pressure (PEEP) in patients with acute lung injury. Prospective, randomized, comparable study. ICU of a university hospital. Forty ...
Hornestam B - - 1998
BACKGROUND: Atrial filling pressures are increased in acute atrial fibrillation, which stimulates the release of atrial natriuretic factor pro-hormone, proANF. METHODS: In a randomized trial comparing digoxin with placebo in 216 patients, we investigated whether the baseline plasma level of N-terminal proANF is a predictor for conversion to sinus rhythm ...
Globits S - - 1998
BACKGROUND: The mechanism of atrial natriuretic peptide (ANP) release has been difficult to demonstrate in patient studies because of inaccuracies in measuring atrial volumes using conventional techniques. METHODS: Magnetic resonance imaging was performed in 28 clinically stable patients (New York Heart Association class 3) with chronic heart failure to determine ...
Kallaras C - - 1998
In order to investigate the effects of centrally administered Atrial Natriuretic Peptide (ANP) on plasma ADH and corticosterone levels as well as on blood pressure and on heart rate, 20 male New Zealand White (NZW) rabbits were used. Measurements were made on restrained conscious animals one week after the implantation ...
Borgeson D D - - 1998
Endothelin-1 (ET-1) is a cardiovascular peptide that binds to two distinct receptors, ET(A) and ET(B), resulting in systemic and regional vasoconstriction, alteration in sodium excretion, mitogenesis, and release of other vasoactive peptides such as atrial natriuretic peptide (ANP). A role for ET-1 has been proposed in congestive heart failure (CHF) ...
Fagard R H - - 1998
It has been shown in animal experiments that angiotensin II and aldosterone have mitogenic effects on the cardiovascular system, whereas atrial natriuretic peptide has antimitogenic properties. The aim of the present study was to relate plasma renin activity, angiotensin II, aldosterone and atrial natriuretic peptide to left ventricular structure and ...
Hiramatsu T - - 1998
BACKGROUND: Reduction of pulmonary vascular resistance and maintenance of urine output are important after the modified Fontan procedure. Atrial natriuretic peptide (ANP) has the effects of a vasodilator (including the pulmonary arteries) and a physiologic diuretic, and newly synthesized human ANP is available. We measured plasma ANP levels before and ...
Clemo H F - - 1998
Control of heart rate in critically ill patients who develop atrial fibrillation or atrial flutter can be difficult. Amiodarone may be an alternative agent for heart rate control if conventional measures are ineffective. We retrospectively studied intensive care unit patients (n = 38) who received intravenous amiodarone for heart rate ...
Scapellato F - - 1998
This study demonstrates that a Doppler-derived tricuspid flow velocity pattern provides an accurate, feasible, and noninvasive method of estimating and monitoring mean right atrial pressure in patients with heart failure due to left ventricular systolic dysfunction, and who are both in sinus rhythm and atrial fibrillation. In particular, the acceleration ...
Vervoort G - - 1998
BACKGROUND: Atrial natriuretic factor increases urinary sodium and water excretion. It also causes an increase in albuminuria. Angiotensin converting enzyme inhibition attenuates the effects of atrial natriuretic factor on renal sodium and water handling; however, it is not known whether this effect is mediated by the accompanied decrease in blood ...
Stefanadis C - - 1998
OBJECTIVES: This study sought to validate and apply a new method for obtaining the left atrial (LA) pressure-area relation. BACKGROUND: In physiologic investigations, the pressure-area relation is the most accurate and representative index of LA hemodynamic status. METHODS: We applied real-time two-dimensional echocardiographic imaging with automatic boundary detection to estimate ...
Fontana F - - 1998
Two groups of patients with acute congestive heart failure (CHF), New York Heart Association class III, presenting elevated plasma values of beta-endorphin, norepinephrine, atrial natriuretic factor (ANF) and endothelin-1, underwent the Mental Arithmetic Test (MAT) during placebo (n = 10) and naloxone hydrochloride (n = 10) infusion. The MAT during ...
Dev B R - - 1998
The effect of locally perfused atrial natriuretic peptide (ANP) into the nucleus of the solitary tract (NST) was studied by monitoring the changes in the extracellular neurotransmitters and the cardiovascular functions in urethane anesthetized Sprague-Dawley rats. Perfusion of ANP was accomplished by using in vivo microdialysis probe unilaterally and stereotaxically ...
Massin M M - - 1998
The aim of this study was to assess heart rate variability, a noninvasive parameter for studying the neurohumoral control of heart rate, in children with atrial septal defect. We examined five time-domain and three frequency-domain indices of heart rate variability determined from 24-hour Holter recordings in 20 children, aged 3-14 ...
Hayano J - - 1998
OBJECTIVES: We examined the circadian variations in atrioventricular (AV) conduction properties during atrial fibrillation (AF) by a technique based on the Lorenz plot of successive ventricular response (VR) intervals and analyzed their relations with clinical features. BACKGROUND: The VR interval in chronic AF shows circadian variation, which is attenuated in ...
Lurie K G - - 1998
As part of a new effort to develop an implantable drug infusion/pacing system to treat atrial fibrillation, this study examined the effects of rapid intracardiac procainamide infusion in humans with pacing-induced atrial fibrillation. Twenty patients with atrial fibrillation for > 5 minutes during an EP study received 500 mg of ...
Dernellis J M - - 1998
BACKGROUND: Investigations of the left atrial (LA) distensibility have revealed that it plays a major role in atrial function; however, LA distensibility has not as yet been studied in congestive heart failure (CHF). HYPOTHESIS: The study was undertaken to determine the effects of acute administration of esmolol, isosorbide dinitrate, dobutamine, ...
Ota K - - 1998
To assess the interaction of endothelin (ET) with nitric oxide (NO) and the effects on venous circulation and handling of renal water and electrolytes, ET (1.0 ng/kg/min) or saline was administered with or without three doses (0.27, 2.7 and 27 ng/kg/min for 40 min) of N omega-nitro-L-arginine methyl ester (L-NAME), ...
Oliver P M - - 1997
Natriuretic peptides, produced in the heart, bind to the natriuretic peptide receptor A (NPRA) and cause vasodilation and natriuresis important in the regulation of blood pressure. We here report that mice lacking a functional Npr1 gene coding for NPRA have elevated blood pressures and hearts exhibiting marked hypertrophy with interstitial ...
Stein J H - - 1997
Clinical estimates of right atrial pressure from the jugular venous pulse were accurate when right atrial pressure was normal, but systematically underestimated elevated right atrial pressures. Because the increased distance from the mid-right atrium to the sternal angle is not accounted for, apparently normal right atrial pressure estimates by this ...
Videbaek R - - 1997
The hypothesis was tested that human cardiac filling pressures increase and the left atrium is distended during 20-s periods of microgravity (microG) created by parabolic flights, compared with values of the 1-G supine position. Left atrial diameter (n = 8, echocardiography) increased significantly during microG from 26.8 +/- 1.2 to ...
Van der Ent M - - 1997
BACKGROUND: Currently evaluated positive inotropic agents that act predominantly through phosphodiesterase III-inhibiting properties, have been disappointing in the treatment of heart failure. Lack of efficacy as a result of diminished cellular cyclic adenosine monophosphate and vasodilating tolerance and side effects are prevalent. In contrast, calcium sensitization is preserved in heart ...
Cheung B M - - 1997
1. The plasma brain natriuretic peptide (BNP) concentration is elevated in patients with essential hypertension and normal systolic function. This may be related to left ventricular hypertrophy or diastolic dysfunction, both of which commonly occur in hypertension. 2. Echocardiography was performed on 32 patients with newly diagnosed untreated mild-to-moderate hypertension ...
Lovett E G - - 1997
A time-frequency coherence estimator is developed and applied to study changes in signal characteristics as atrial fibrillation converts to sinus rhythm during administration of procainamide. A coherence spectrogram (CS) using multiple sinusoidal tapers is used in this study to assess phase relations between electrogram recordings at multiple atrial sites of ...
Rademaker M T - - 1997
The effects of separate and combined endopeptidase inhibition (by SCH-32615) and natriuretic peptide receptor C blockade [by C-ANP-(4-23)] on the clearance and bioactivity of atrial (ANP) and brain (BNP) natriuretic peptides was investigated in eight sheep with heart failure. SCH-32615 and C-ANP-(4-23) administered separately induced significant and proportionate dose-dependent rises ...
Hopkins W E - - 1997
BACKGROUND: Many adults with cyanotic congenital heart disease are characterized by reduced ventricular filling pressures and decreased systemic oxygen transport. Data from animals suggest that hypoxia can induce synthesis and secretion of atrial natriuretic peptide. METHODS AND RESULTS: We measured plasma N-terminal (1-98) proatrial natriuretic peptide (proANP) in 26 cyanotic ...
Mannaerts H - - 1997
AIMS: The study set out to assess the relative contributions of donor heart rate, respiration and recipient atrial contraction on the mean of pulsed wave transmitral Doppler flow indices in orthotopic heart transplant recipients. This would provide information on the theoretical usefulness of pacemaker synchronization of recipient atrial contraction, as ...
Akdemir G - - 1997
The effect of intraventricular atrial natriuretic peptide (ANP) on elevated intracranial pressure (ICP) was evaluated in a rodent model of global ischemia and reperfusion. ANP administration into the lateral ventricle 30 minutes after reperfusion statistically significantly reduced ICP compared with both vehicle treated animals (p < 0.001) and pretreatment pressures ...
Shimizu W - - 1997
INTRODUCTION: Sympathetic stimulation plays an important role in the genesis of QT(U) prolongation and ventricular arrhythmias in congenital long QT syndrome (LQTS). Permanent pacemaker as well as beta blockers are reported to be effective in the management of this syndrome. The purpose of this study was to examine influence of ...
Lopez M J - - 1997
A genetic model of salt-resistant hypertension has been developed recently through disruption of the guanylyl cyclase-A (GC-A) natriuretic peptide receptor gene (Lopez, M. J., Wong, S. K., Kishimoto, I., Dubois, S., Mach, V., Friesen, J., Garbers, D. L., and Beuve, A. (1995) Nature 378, 65-68). These genetically altered mice were ...
Ravelli F - - 1997
BACKGROUND: Atrial fibrillation (AF) is frequently observed under conditions that are associated with atrial dilatation. The aim of this study was to investigate the effects of atrial dilatation on the substrate of AF. METHODS AND RESULTS: In 15 Langendorff-perfused rabbit hearts, the interatrial septum was perforated, and after occlusion of ...
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