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Results 451 - 500 of 1543
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Ingemansson M P - - 2000
AIMS: To investigate the effects of parenteral administration of MgSO4, and glucose, insulin, and potassium (GIK), on the dominant atrial cycle length during chronic atrial fibrillation (CAF). METHODS AND RESULTS: The length of the dominant atrial cycle (DACL) in the power-frequency spectrum of the QRST-suppressed lead V1 ECG was identified ...
Suzuki T - - 2000
Early diagnosis and treatment of heart failure lead to improved survival; pre-clinical detection would thus be beneficial. A non-invasive biochemical testing method would indeed be ideal to screen for the condition. In the present study, we sought to determine whether circulating levels of B-type natriuretic peptide (BNP) correlate with cardiac ...
McConnell P I - - 2000
BACKGROUND: Endothelin-1 (ET-1) is a potent vasoconstrictor peptide elaborated by many cell types. Plasma ET-1 levels are significantly augmented in patients and experimental animals with heart failure. Enhanced levels of ET-1 may contribute to myocardial depression and alterations in sympathetic nerve activity in the setting of chronic heart failure. The ...
Hiasa G - - 2000
A 58-year-old male patient had apical hypertrophic cardiomyopathy (HCM) associated with a life-threatening tachycardia due to atrial flutter. Following palpitation and dyspnea for 2-3 h, he became unconscious because of circulatory catastrophe, but was fully resuscitated. An electrocardiogram recorded just before the loss of consciousness revealed atrial flutter at a ...
Qi W - - 2000
To describe the differential dynamic responses of atrial natriuretic peptide (ANP), N-terminal proatrial natriuretic peptide (Nt-proANP) and brain natriuretic peptide (BNP) to acute changes in atrial pressure, 6 pigs were studied during and after a 24-h period of rapid atrial pacing (225 bpm). During pacing, left atrial pressure increased acutely. ...
Zaki A - - 2000
This study was conducted to assess right and left atrial hemostatic function in patients with mitral stenosis (MS) and to investigate the immediate effect of balloon mitral valvuloplasty (BMV) on hemostatic function. BMV was performed in 28 patients with MS (age 29 +/- 8 years) who had sinus rhythm and ...
Azevedo E R - - 2000
Previous studies have shown that atrial natriuretic peptide (ANP) has relative sympathoinhibitory effects that are of potential benefit in patients with congestive heart failure (CHF). In this study, cardiac and systemic sympathetic responses to ANP were evaluated and compared with responses to sodium nitroprusside (SNP) in patients with CHF. Right- ...
Friedrich M - - 2000
BACKGROUND: ANF is a potent diuretic, natriuretic and vasorelaxant hormone. The objective of the present study was to examine the effect of opioid receptor stimulation by morphine after surgery on endogenous ANF production and diuresis. METHODS: Prospectively, 11 women undergoing surgery for either uterine leiomyomas, chronic pelvic discomfort or desire ...
Friedrich M - - 2000
OBJECTIVE: ANF is a potent diuretic, natriuretic and vasorelaxant hormone. The objective of the present study was to examine the effect of opioid receptor stimulation by morphine on endogenous ANF production and diuresis after surgery. METHODS: Prospectively, nine women undergoing surgery for either uterine leiomyomas, chronic pelvic discomfort or desire ...
Li Y G - - 2000
INTRODUCTION: Recent observations suggest that the circuit of AV nodal reentrant tachycardia (AVNRT) may extend down to the His bundle. The purpose of this study was to develop a quantitative model indicating the location of the lower turnaround point in AVNRT. METHODS AND RESULTS: Slow pathway modification was performed in ...
Ommen S R SR Division of Cardiovascular Diseases and Internal Medicine, Mayo Clinic Rochester, Minn 55905, - - 2000
To derive a clinically useful, noninvasive determination of right atrial pressure. Noninvasive assessment of right ventricular systolic pressure from Doppler-derived tricuspid regurgitant velocity requires an accurate assumption of right atrial pressure. Seventy-one patients were studied in the cardiac catheterization laboratory, comparing right atrial pressure (measured at mid systole) with simultaneous ...
Mehmanesh H - - 1999
Supraventricular and ventricular tachycardias are common and serious postoperative complications early after cardiac surgery. We introduce a completely removable temporary adjustable defibrillation electrode (TADE) for low energy cardioversion/defibrillation of postoperative atrial and ventricular tachyarrhythmias. The electrode consists of three loops of steel wires connected to one steel wire, which are ...
Efremidis M - - 1999
BACKGROUND: There is evidence suggesting that atrial fibrillation (AF) may be induced by acute increase of atrial pressure. The aim of the present study was to investigate the effect of alterations in atrial pressure, induced by varying the atrioventricular (AV) interval, on atrial refractoriness, and on the frequency of induction ...
Mychaskiw G G - - 1999
We report an interaction of a transesophageal atrial pacemaker (TAP) with a permanently implanted pacemaker in a cardiac patient who had undergone ablative therapy for atrial tachyarrhythmia 5 years earlier. The patient's permanent A-V pacemaker was completely inhibited by the TAP, and there was loss of ventricular contractions and blood ...
Barrett C J - - 1999
BACKGROUND: It has been suggested that a blunted sympathoinhibitory response to atrial natriuretic peptide (ANP) may contribute to the elevation of sympathetic activity seen in heart failure. METHODS AND RESULTS: Experiments were performed in anesthetized rats 6 to 9 weeks after coronary ligation to induce heart failure. Responses to intravenous ...
Ohki S - - 1999
BACKGROUND: A cardiac hormone, alpha-human atrial natriuretic polypeptide (alpha-hANP), acts as a vasodilator and a diuretic by activating cyclic GMP formation. We studied the hemodynamic effects of continuous intravenous infusion of alpha-hANP on patients undergoing open-heart surgery. METHODS: A total of 15 patients, including 7 with CABG, 4 with AVR, ...
Pitzalis M V - - 1999
Previous studies have found that respiratory variations of ventricular response in atrial fibrillation are infrequent and inconsistent. This asynchrony between heart rate and respiration may characterize the physiological mechanisms coupling heart rate and systolic blood pressure oscillations in the respiratory band. The aim of this study was to evaluate whether ...
Hayashi K - - 1999
A 55-year-old Japanese man was hospitalized for palpitations and severe chest oppression one hour after he ingested about 1500 ml of beer and sildenafil (Viagra) 50 mg. At 43 years of age, he had been diagnosed with intermittent WPW syndrome following a paroxysmal supraventricular tachycardia (PSVT) attack. He took a ...
Szukiewicz D - - 1999
The number of placental vascular guanylate-coupled receptors. corresponding to bioactive natriuretic peptide receptors is greater in preeclampsia. but there are no clear data about atrial natriuretic peptide (ANP) concentration in preeclampsia. The influence of various doses of ANP and urodilatin (URO) on placental perfusion pressure in preeclampsia was investigated by ...
Brunner-La Rocca H P - - 1999
OBJECTIVES: To investigate the relationship of the BP response to the Valsalva maneuver (VM) to parameters of congestive heart failure (CHF) other than hemodynamic measures. DESIGN: Comparison of neurohormones (atrial natriuretic peptide [ANP], brain natriuretic peptide [BNP], norepinephrine [NE]), parameters of spiroergometry, and clinical parameters with BP response to the ...
Anselmo-Franci J A - - 1999
Extracellular volume expansion (EVE) was performed in intact rats and 24 h after locus coeruleus (LC) lesions or sham-operation. Blood pressure was registered 5 min before and after EVE. At the end of the experiment the animals were decapitated and blood was collected from the trunk for quantification of plasma ...
Hayabuchi Y - - 1999
We examined the plasma concentrations of atrial and brain natriuretic peptides (ANP and BNP) and cyclic guanosine monophosphate (cGMP) during dobutamine infusion and their relationship with hemodynamic parameters in 14 patients with surgically repaired tetralogy of Fallot (TOF). Dobutamine was infused at an initial dose of 5 microgram/kg/min and increased ...
Fugelseth D - - 1999
AIMS: To investigate the ductus venosus flow velocity (DVFV) in infants with persistent pulmonary hypertension of the newborn (PPHN); to evaluate the DVFV pattern as a possible diagnostic supplement in neonates with PPHN and other conditions with increased right atrial pressure. METHODS: DVFV was studied in 16 neonates with PPHN ...
Ylitalo K - - 1999
Plasma atrial natriuretic peptide (ANP) concentration increases during ventricular arrhythmias and rapid ventricular pacing but less is known about plasma brain natriuretic peptide (BNP) and endothelin (ET-1). In the present study concentrations of ANP, the amino terminal part of the proANP (NT-proANP), BNP, and ET-1 were measured in the coronary ...
Mills R M - - 1999
OBJECTIVES: The goal of this study was to further define the role of nesiritide (human b-type natriuretic peptide) in the therapy of decompensated heart failure (HF) by assessing the hemodynamic effects of three doses (0.015, 0.03 and 0.06 microg/kg/min) administered by continuous intravenous (IV) infusion over 24 h as compared ...
Lai L P - - 1999
INTRODUCTION: The funny current (I(f)) contributes to phase IV spontaneous depolarization in cardiac pacemaker tissue. Enhanced I(f) activity in myocardial tissue may lead to increased automaticity and therefore tachyarrhythmia. We measured the amount of I(f) activity in the messenger ribonucleic acid (mRNA) in human atrial tissue and correlated the mRNA ...
Cunningham M W - - 1999
Ostium secundum atrial septal defects (ASDs) were observed in six (3 M, 3 F) of 33 (20 M, 13 F) (18%) Florida panthers (Puma concolor coryi) necropsied by veterinary pathologists between 1985 and 1998. A seventh ASD was found in a female panther necropsied in the field and is included ...
Kitashiro S - - 1999
A short-term treatment of atrial natriuretic peptide (ANP), a circulating hormone of cardiac origin, is reported to improve cardiac performance in patients with chronic heart failure. However, clinical usefulness of long-term administration of ANP in patients with congestive heart failure has not been reported. We studied 36 patients with severe ...
Woods R L - - 1999
Cardiovascular responses were compared with equimolar infusions of B-type (BNP) and C-type (CNP) with atrial natriuretic peptide (ANP) in conscious, instrumented dogs. On separate days, each natriuretic peptide or vehicle was infused (intravenously) at step-up doses of 2, 5, 10, and 20 pmol. kg-1. min-1 (20 min each dose) to ...
Asano K - - 1999
Plasma concentrations of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) were measured in 6 dogs with experimental mitral regurgitation (MR) and 19 canine patients with asymptomatic and symptomatic congestive heart failure (CHF). In dogs with experimental MR, ANP and BNP concentrations were significantly correlated with pulmonary capillary wedge ...
Abramson B L - - 1999
BACKGROUND: The purpose of this study was to determine if atrial natriuretic peptide (ANP) exerts a relative inhibitory effect on muscle sympathetic nerve activity (MSNA) at rest and during nonhypotensive lower body negative pressure (LBNP) in heart failure, as in healthy subjects. METHODS AND RESULTS: Fifteen men (age 39+/-2 years ...
Parker J D - - 1999
Levels of endothelin-1 (ET-1) are elevated in many disease states, although its total body kinetics of elimination are poorly understood. Therefore, it remains uncertain whether the presence of elevated levels of ET-1 in the setting of disease are secondary to changes in production or clearance or some combination thereof. Using ...
Alboni P - - 1999
The hemodynamic effects of atrial flutter (AF) are unknown. The purpose of the present study was to investigate the changes in atrial and ventricular pressures after induction of AF. In 23 patients with paroxysmal AF (age 59 +/- 9 years), a hemodynamic study was performed both during sinus rhythm and ...
Wu M H - - 1999
AIMS: The aims of this study were to define the changes of cardiac conduction properties after selective IK1 blockade in isolated hearts. METHODS AND RESULTS: Intracardiac recording and stimulation in Langendorff-perfused rabbit hearts were used to define cardiac conduction properties after Ba2+, a well known IK1 blocker. Ba2+ prolonged the ...
Bolter C P - - 1999
We have recently shown that the intrinsic rate response to an increase in right atrial pressure is augmented when cardiac muscarinic receptors are activated. This present study examines the cardiac pacemaker response to vagal stimulation at different values of right atrial pressure in isolated rat right atrium and in the ...
Bandali K S - - 1999
Atrial natriuretic peptide (ANP) can excite cardiac nerve endings and invoke a decrease in arterial blood pressure and a reduction in renal sympathetic nerve activity. Our laboratory has previously demonstrated that this renal depressor reflex was invoked by systemic injection of ANP and not by the direct application of ANP ...
Holmström H - - 1999
We postulated previously that variables related to pulmonary flow are independent predictors of levels of atrial natriuretic peptide in children with congenital heart disease. The aim of this study was to test this hypothesis in relation to other hemodynamic and clinical variables. During catheterization we measured the levels of plasma ...
Pitts W R - - 1999
Neither "prominent" right atrial V waves nor an elevated mean right atrial pressure reliably predicts the presence of moderate or severe tricuspid regurgitation. On the other hand, the absence of prominent right atrial V waves and an elevated mean right atrial pressure are relatively specific for the absence of moderate ...
Stefanadis Christodoulos - - 1999
In most clinical studies, evaluation of left atrial (LA) function evolved from estimation of LA size on chest radiograph, electrocardiographic P wave abnormalities, LA diameter determined at fluoroscopy or by echocardiography, LA pressure recordings, blood flow velocity with Doppler echocardiography, and measurements of LA volume based on echocardiographic, cineangiographic, radionuclide, ...
Kamijo T - - 1999
The pharmacologic profiles of nicorandil in the cardiovascular system have been characterized by K-channel opening and nitrate activities. However, the effects of nicorandil on acute heart failure have yet to be elucidated. To investigate the effects of nicorandil under such pathophysiologic conditions, we administered nicorandil intravenously to dogs with acute ...
Campbell A R - - 1999
The effect of moderate left atrial (LA) hypertension on alveolar liquid clearance (ALC) was investigated in anesthetized, ventilated sheep, surgically prepared to measure lung lymph flow as well as hemodynamics. To simulate alveolar edema, 3-4 ml/kg of isosmolar 5% albumin in Ringer lactate were instilled into each lower lobe, and ...
Nakano H - - 1998
To investigate the role on the right ventricular function of the parasympathetic nerves in discrete cardiac regions, we studied the effects of stimulation of the intracardiac parasympathetic nerves to the atrioventricular (AV) nodal area (AVPS) or sinoatrial (SA) nodal area (SAPS), and stimulation of the cervical vagus nerves (CVS) on ...
Tayama K - - 1998
BACKGROUND: Natriuretic peptides are vasodilator hormones involved in the regulation of blood pressure and volume homeostasis. However, the mechanism of these peptides after pneumonectomy remains obscure. METHODS: We investigated changes in the pulmonary arterial pressure and the localization and changes in the atrial (A-type) natriuretic peptide (ANP) and the C-type ...
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 ...
La Vecchia L - - 1998
BACKGROUND: Although a large number of studies have investigated the relationship between atrial natriuretic peptide (ANP) concentrations and circulatory abnormalities, it is presently unsettled as to whether this parameter provides valuable information in unselected patients with heart disease of different etiologies regardless of the presence of left ventricular dysfunction or ...
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 ...
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 ...
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 ...
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