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Results 401 - 450 of 729
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Vanoverschelde J L - - 1991
To determine the effects of a moderately prolonged exercise on left ventricular systolic performance, 23 healthy male subjects, aged 18 to 51 yr (mean 37 yr) were studied. The subjects exercised first on a treadmill (brief exercise) and completed, on a separate day, a 20-km run. M-mode, two-dimensional, and Doppler ...
Yang J C - - 1991
Exercise-induced ventricular tachycardia during exercise testing is considered to increase risk during testing. Moreover, exercise-induced ventricular tachycardia has been considered to confer a poor prognosis although this has not been specifically studied. On a retrospective review of 3351 patients who had undergone routine clinical exercise testing between September 1984 and ...
Rosenheck S - - 1991
The purpose of this study was to determine the effects of quinidine and mexiletine on the adaptation of ventricular refractoriness to a change in heart rate. The ventricular effective refractory period was measured at a basic drive cycle length of 500 msec with basic drive train durations of two beats, ...
Awad S S - - 1991
1. Comparisons of the effects of 4 and 16 weeks of exercise were made on; cardiac output, stroke volume, heart rate, left intraventricular systolic and diastolic pressures, dP/dt, and heart calcium in the Bio 14.6 cardiomyopathic and F1 B hamsters. 2. In the cardiomyopathic hamster the cardiac output, stroke volume, ...
Pirilä T - - 1991
The possible effect of handedness on hearing threshold asymmetry was analysed in a large random population representing a normal population. The left ear was on an average slightly but significantly poorer than the right ear at high frequencies, especially at 4 kHz, while at low frequencies the right ear was ...
Takahashi N - - 1991
Systolic time intervals were obtained from 19 middle-aged noninsulin-dependent diabetic patients without clinically evident cardiovascular disease (8 patients had and 11 did not have retinopathy) and 14 normal subjects using ear densitography. All subjects had neither ischemic electrocardiographic response nor chest pain during maximal treadmill exercise. Although left ventricular ejection ...
Takala T E - - 1991
The effects of endurance training and anabolic steroid (Methandienone 1.5 mg.kg-1 p. o. daily) and their combination on regional collagen biosynthesis and concentration in the hearts of male beagle dogs were studied by measuring prolyl 4-hydroxylase (PH) activity and hydroxyproline (HYP) concentration. The PH (P less than 0.05) and HYP ...
Drory Y - - 1990
This study assesses the persistence of arrhythmia at rest or during exercise tests, or both, after a mean follow-up period of 6.7 years in 76 young men (mean age 21.5 years) without evidence of organic heart disease. The exercise test was performed using a near-maximal protocol based on progressively increasing ...
Jansson K - - 1990
To determine the best way to detect serious ventricular arrhythmia in patients with hypertrophic cardiomyopathy (HCM), 15 patients with HCM performed an exercise test, had Holter monitoring during 24 hours, and programmed electrical stimulation (PES) in a randomized order, and the presence and type of ventricular arrhythmia was noted. During ...
Clifton G D - - 1990
The relationship of left ventricular systolic function and heart rate to serum l-propranolol concentrations was determined in 10 healthy male volunteers during maximal exercise treadmill testing. Peak aortic blood flow acceleration (ACL), measured by Doppler ultrasonography, was used to evaluate left ventricular systolic function. Repeated exercise testing was performed on ...
Navaratnam S - - 1990
1. We previously isolated an extract from porcine left ventricle that possessed digitalis-like properties such as inhibition of cardiac and kidney Na+, K(+)-ATPase, displacement of [3H]-ouabain from its binding sites and cross reactivity with digoxin antibodies. The extract also had a positive inotropic effect on the guinea-pig heart. 2. In ...
Gratama J W - - 1990
We determined maximal exercise capacity and measured hemodynamics in 10 6-wk-old lambs with an aortopulmonary left-to-right shunt [S, 57 +/- 11%, (SD)] and in 9 control lambs (C) during a graded treadmill test 8 days after surgery. Maximal exercise capacity (3.7 +/- 0.2 km/h and 10 +/- 5% inclination vs. ...
Weber S - - 1990
1. Cicloprolol is a partial beta 1-adrenoceptor agonist considered for the treatment of patients with coronary artery disease and impaired left ventricular function. In such patients, digoxin remains in widespread use. 2. We assessed the pharmacokinetic and pharmacodynamic interaction between oral cicloprolol 50 mg day-1 and oral digoxin 0.25 mg ...
Heywood J T - - 1990
The effects of exercise on right ventricular diastolic function were evaluated in 14 patients who underwent supine rest and exercise right ventricular angiography. On the basis of coronary anatomy and exercise left ventricular regional wall motion analysis, these patients were classified into two groups: Group 1 (n = 7) had ...
Pouleur H - - 1990
The relation between global left ventricular function at rest (evaluated during cardiac catheterization) and exercise capacity was examined in a group of 33 untreated patients with a previous anterior myocardial infarction. The resting ejection fraction (range, 24-68%) correlated poorly with exercise duration (r = 0.47) and did not separate patients ...
Rowland T W - - 1990
Previous reports have suggested that children possess limited cardiac functional reserve during exercise compared to young adults. In this study, echocardiography was performed immediately after maximal treadmill exercise to measure left ventricular dimensions and shortening fraction (SF) in college men, and these values were compared to previous results in a ...
Marieb M A - - 1990
Because there is controversy regarding the clinical relevance of exercise-induced ventricular arrhythmias, we analyzed their significance in 383 patients who had undergone both exercise thallium-201 stress-testing and cardiac catheterization. Two-hundred twenty-one patients (58%) had no exercise-induced ventricular arrhythmias while 162 (42%) did. There was no difference between patients with and ...
Trippel D L - - 1990
Twenty children and adolescents treated orally with atenolol for chronic paroxysmal ventricular tachycardia (n = 10) or Long QT Syndrome (n = 10) over a 5 year period were retrospectively evaluated to ascertain the efficacy of arrhythmia suppression, the effective dosage, the cardiovascular effects, and the incidence of adverse effects. ...
Wolfe C L - - 1990
Regional alterations in myocardial substrate uptake and/or utilization have been demonstrated in rats with hypertension. To determine whether alterations in left ventricular fatty acid uptake and/or utilization are present in patients with left ventricular hypertrophy (LVH), we compared the results of rest and exercise iodine-123 phenylpentadecanoic acid (IPPA) myocardial scintigraphy ...
Taguchi H - - 1990
From among subjects who were examined by submaximal exercise testing in 1987, 54 were selected in order to examine the relationship between the blood pressure response during exercise and the tendency to develop left ventricular hypertrophy. Only those subjects having resting systolic blood pressure values between 120 mmHg and 140 ...
Blake J - - 1990
PURPOSE: To elucidate determinants of abnormal left ventricular functional responses to exercise in hypertensive patients. PATIENTS AND METHODS: One hundred twenty-seven patients with uncomplicated essential hypertension were studied by rest and exercise radionuclide angiography and by echocardiography at rest. RESULTS: The 24 patients with subnormal left ventricular ejection fraction at ...
Cheong T H - - 1990
We studied the effect of maximal exercise on the prevalence of arrhythmias in 122 subjects with severe COPD. At rest, ten subjects had supraventricular arrhythmias while 13 had unifocal VPB greater than or equal to 6/min or ventricular bigeminy. At peak exercise, six subjects had supraventricular arrhythmias while 24 had ...
de Feyter P J - - 1990
The effects of xamoterol 0.2 mg kg-1 i.v. and placebo on left ventricular function at rest and on exercise were compared in patients with left ventricular dysfunction due to ischaemic heart disease. Improvements were seen in systolic and diastolic function at rest, and at up to 50% of maximal exercise, ...
Konishi T - - 1990
To assess the effects of age on left ventricular performance, multistage supine ergometer exercise radionuclide ventriculography (RNV) was performed in 92 normal subjects. The subjects ranged in age from 24 to 86 years and were free of cardiopulmonary disease and diabetes. Age-related changes in exercise duration, left ventricular end-diastolic volume ...
Ashmore R C - - 1990
Calcium antagonists are popular therapeutic agents in the treatment of systemic hypertension. Although these agents have similar antihypertensive efficacy, they have varied effects on left ventricular function at rest in hypertensive patients. The effect of different calcium antagonists on left ventricular function during exercise and on exercise performance in patients ...
Lazzari J O - - 1990
To assess the short-term behavior of the right ventricle anterior papillary muscle extrasystoles (APME) based on Holter recording and exercise data, 20 subjects (age 31.5 +/- 13.7 years) with otherwise normal electrocardiogram were studied. APME was diagnosed when it resembled LBBB morphology, with downward oriented AQRS in the frontal plane, ...
Fischer G - - 1990
STUDY OBJECTIVE - The aim of the study was to verify the reproducibility of a canine model of treadmill exercise induced regional myocardial dysfunction designed to mimic exertional angina pectoris in man. DESIGN - Dogs trained to run on a treadmill were chronically instrumented with a microtip manometer in the ...
Candinas R A - - 1990
Exercise testing is an important noninvasive method for the exposure of arrhythmias. It provides complementary information to that obtained from ambulatory monitoring or electrophysiologic testing. By producing a number of important physiologic changes, especially activation of the sympathetic nervous system and an increase in circulating catecholamines, exercise testing provides a ...
de Feyter P J - - 1990
A new cardioselective beta 1-adrenergic receptor agonist xamoterol (Corwin) has been developed for the treatment of heart failure. To study the acute hemodynamic effects of xamoterol, 24 patients, 39-70 years old, with mild-to-moderate postinfarction left ventricular dysfunction entered a double-blind, between-patient comparison of a single 5-minute intravenous infusion of xamoterol ...
Douglas P S - - 1990
To examine the functional consequences of the greater increase in right ventricular work with exercise, the effects of prolonged exercise on the right and left heart chambers were compared in 41 athletes before, at the finish (13 min) and after recovery (28 h) from the Hawaii Ironman Triathlon (3.9 km ...
Thomas G S - - 1990
In order to assess the effect of acute, reversible myocardial ischemia on the outcome of programmed ventricular stimulation (PVS), ventricular stimulation was performed at rest, during exercise, and during recovery in 10 patients with coronary artery disease. Of these ten patients, four were tested while off antiarrhythmic drugs and six ...
Bahler R C - - 1990
The influence of the electrocardiographic diagnosis of left ventricular hypertrophy on exercise performance was assessed in 101 hypertensive patients and 37 control subjects referred to an exercise testing laboratory. Maximal exercise capacity was measured by the duration of a symptom-limited, treadmill test using the modified Bruce protocol. The Romhilt-Estes point ...
Lewis R V - - 1990
We have examined the effects of magnesium replacement therapy upon post-exercise heart rate and incidence of ventricular premature beats (VPB) in digitalised patients with AF. In 11 such patients, all of whom had serum magnesium concentrations of less than 0.85 mmol/l, treatment with magnesium glycerophosphate was associated with a significant ...
Bielen E - - 1990
The maximal aerobic power of endurance athletes is high and their heart is characterized by a larger left ventricular internal dimension than in non-athletes, and a proportional increase of wall thickness; these traits may be inherited and/or the consequence of intense physical training. To assess the influence of inheritance on ...
Yano K - - 1990
A thirty-five-year-old woman without organic heart disease who has exercise-induced ventricular arrhythmias suppressed by propranolol and diltiazem is reported. Treadmill exercise provoked reproducibly nonsustained ventricular tachycardia (NSVT) and salvos of ventricular premature contraction (VPC). QRS morphology of these ventricular arrhythmias showed left bundle branch block pattern and right axis deviation. ...
Nakano A - - 1989
Bunazosin hydrochloride (Detantol) was administrated in 3-mg oral doses to 10 patients (6 males and 4 females, average 49.9 years) with dilated cardiomyopathy (DCM) of class II in the NYHA functional classification. The patients were observed for changes in their hemodynamics at rest, chest X-ray, echocardiography, humoral factors and symptom-limited ...
Le Corre P - - 1989
Electrophysiological effects, antiarrhythmic activity and kinetics of levorotatory disopyramide (R(-) DP) and racemic disopyramide (equimolar mixture of R(-) DP and S(+) DP) were compared in patients with ventricular arrhythmias. This double blind cross-over randomized trial was achieved, at steady-state, following oral administration of 200 mg three times a day. In ...
Hämäläinen H - - 1989
An exercise test was performed in 306 patients who had had acute myocardial infarction one year previously. The five year cumulative coronary heart disease mortality was 40.0%, when the test had to be discontinued because of ventricular arrhythmias but only 13.0% if discontinued because of fatigue (P less than 0.05). ...
Busby M J - - 1989
Frequent or repetitive exercise-induced ventricular ectopic beats are often considered a marker for serious cardiac disease or sudden death, or both. However, the prognostic value of these arrhythmias in an unreferred asymptomatic community-dwelling population over a broad age range is unknown. Of 1,160 subjects aged 21 to 96 years who ...
Koga Y - - 1989
The long-term prognosis for 314 patients with hypertrophic cardiomyopathy (HCM) and 82 with dilated cardiomyopathy (DCM) was investigated in an attempt to elucidate clinical variables predicting sudden death (SD). In the patients with HCM, 68% of cardiac deaths occurred suddenly and unexpectedly. Variables associated with an increased risk to SD ...
Iwase M - - 1989
To assess the accuracy of the exercise-induced decrease in the ratio of peak flow velocity in atrial systole to that in early diastole (A/E) for predicting an elevation of left ventricular filling pressure, supine bicycle ergometer exercise testing was performed in 27 consecutive patients with coronary artery disease. Doppler-derived transmitral ...
Kusama Y - - 1989
In a study of aerobically perfused rat hearts, the in situ photoactivation (530-590 nm) of rose bengal (a process that leads to the production of singlet oxygen and superoxide) has been shown to lead to the rapid development of electrocardiographic abnormalities and arrhythmias. With rose bengal concentrations of 1,000, 500, ...
Airaksinen K E - - 1989
Left ventricular filling pattern was assessed by pulsed Doppler echocardiography at rest and during handgrip exercise in 33 healthy middle-aged subjects. The peak mitral flow-velocities during the early rapid filling phase (E) and during late (atrial) filling (A) were measured and the ratio of these peak flow-velocities (E:A ratio) was ...
Hasegawa T - - 1989
To evaluate DT during a low-level exercise test, the relation between DT and heart rate was studied by ear densitography in the late phase of hospitalization for acute MI. None of the patients had an ischemic electrocardiographic response. The patients were divided into two groups: group 1 was comprised of ...
Inoue K - - 1989
To evaluate left ventricular systolic and diastolic function in patients with pulmonary hypertension secondary to chronic pulmonary diseases, 86 patients were studied using equilibrium radionuclide angiography with forward and reverse gating from the R wave. At rest left ventricular function, both in systolic and diastolic properties, in patients with pulmonary ...
Fagard R - - 1989
To assess left ventricular structure and function at rest and during exercise in endurance athletes, 10 elite marathon runners, aged 28 to 37 years, and 10 matched nonathletes were studied by echocardiography and supine bicycle ergometry. Each athlete's best marathon time was less than 2 h 16 min. Echocardiography was ...
Ranger S - - 1989
Proarrhythmic effects of flecainide acetate have been reported during exercise, but the mechanism for the arrhythmogenic interaction between flecainide and exercise is unknown. We hypothesized that the sinus tachycardia of exercise may enhance flecainide-induced conduction slowing by increasing use-dependent sodium channel blockade, thereby facilitating the occurrence of ventricular reentry. To ...
Alexopoulos D - - 1989
Impaired diastolic function has been described in healthy elderly subjects. Pulmonary blood volume (PBV) changes with exercise have been associated with left ventricular dysfunction, but not directly related to diastolic abnormalities. Exercise-induced relative changes in PBV were measured using gated blood pool imaging with count density comparisons over the lung ...
Billman G E - - 1989
The effects of calcium channel antagonists and an agonist on susceptibility to ventricular fibrillation were investigated using chronically instrumented dogs with a healed anterior wall myocardial infarction. Three to 4 weeks after the infarction, a 2-min coronary occlusion was initiated during the last minute of exercise and continued for 1 ...
Fukushige J - - 1989
Treadmill exercise electrocardiography (TE) was recorded in 50 patients to evaluate the incidence of exercise-induced ventricular arrhythmias (VAs) in a group of patients who underwent corrective surgery of tetralogy of Fallot (TF) more than four years previously. The results of rhythm evaluation were correlated with cardiac catheterization data as well ...
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