Search Results
Results 351 - 400 of 728
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Berntsen R F - - 1993
The role of myocardial revascularization in the treatment of malignant ventricular arrhythmias is not well defined. Our hypothesis was that in patients with ventricular tachycardia or fibrillation exposed by exercise-induced ischaemia, the acute transient ischaemia plays a principal causal role, and that in these patients surgical myocardial revascularization alone might ...
Van Gelder I C - - 1993
This study prospectively assessed the time course, magnitude and mechanism of the hemodynamic changes after restoration of sinus rhythm in patients with chronic atrial fibrillation (AF) unassociated with valvular disease. Severe cardiac dysfunction may occur after chronic supraventricular tachycardia in patients with and without underlying cardiac disease. Improvement may follow ...
Tischler M D - - 1993
OBJECTIVES: The aim of this study was to identify dynamic predictors of exercise duration in patients with systolic left ventricular dysfunction and to test the hypothesis that left ventricular shape is an independent determinant of exercise duration in these patients. BACKGROUND: Measurements of left ventricular volumes and ejection fraction at ...
Tuininga Y S - - 1993
The initiating mechanisms of exercise-induced ventricular tachycardia were studied in a population of 5842 patients who performed 9064 bicycle exercise tests. Sixty (1%) patients had 194 episodes of ventricular tachycardia during the test. Forty-two percent of these occurred during exercise and 58% during recovery. Two different initiating electrocardiographic patterns were ...
Liang M T - - 1993
This study examined the effects of anabolic steroids and exhaustive endurance exercise, and the combination of both treatments on in vitro cardiac contractile function. Fifty-two male Sprague-Dawley rats were randomly assigned, in groups of 13, to one of the four groups: sedentary control (C), steroid-treated (ST), exercise-trained (E), and exercise ...
Bauman R P - - 1993
Global and regional atrial blood flow was measured with radioisotope-labeled microspheres in eight dogs during rest and two levels of exercise. Both mean right and left atrial blood flow increased significantly (P < 0.05) to a similar degree with each level of exercise (right atria: 0.27 +/- 0.04, 0.89 +/- ...
Suda K - - 1993
Only limited information is available concerning left ventricular (LV) response to exercise after an external conduit operation for cyanotic congenital heart disease. Sixteen patients who had undergone external conduit repair (EC group) were studied with multi-gated cardiac pool imaging using a supine bicycle ergometer on 20 occasions. Six patients with ...
Casella G - - 1993
BACKGROUND: Controversy exists about the clinical and prognostic significance of exercise-induced ventricular arrhythmias late after myocardial infarction. The aim of the study was to identify the main clinical and prognostic features of exercise-induced ventricular arrhythmias in out-patients with healed Q-wave myocardial infarction. METHODS: The study population was 777 consecutive patients ...
Brutsaert D L - - 1993
Primary diastolic dysfunction or failure is a distinct pathophysiologic entity. It results from increased resistance to ventricular filling, which leads to an inappropriate upward shift of the diastolic pressure-volume relation, particularly during exercise (exercise intolerance). The causes of diastolic failure are inappropriate tachycardia, decreased diastolic compliance and impaired systolic relaxation. ...
Spes C H - - 1993
Orthotopic heart transplantation results in altered atrial anatomy and denervation of the donor heart. To assess the impact of these sequelae on left ventricular filling and systolic performance, 16 heart transplant recipients and 10 normal controls were evaluated by Doppler echocardiography at rest and during graded bicycle exercise. Global and ...
van Rugge F P - - 1993
Magnetic resonance imaging (MRI) provides high-resolution images of the heart. However, physical exercise during MRI is difficult due to space restriction and motion artefacts. To evaluate the feasibility of MRI during stress conditions, dobutamine was used as an alternative to exercise. Haemodynamics, ventricular volumes and wall thickening were measured at ...
Cannon C E - - 1993
Concentric left ventricular hypertrophy (LVH) frequently occurs in subjects with normal resting systolic and diastolic pressures (SP and DP, respectively). LVH in this normotensive-hypertrophic group (NH) may be due to an abnormally exaggerated pressure response to exercise. The SP and DP responses to exercise were studied in 130 subjects free ...
Gosselink A T - - 1993
Digitalis intoxication is one of the most common adverse drug reactions. Although some arrhythmias are seen more frequently than others, virtually any rhythm disturbance, including ventricular tachycardia, may occur. However, to our knowledge, exercise-induced ventricular tachycardia as a complication of digitalis therapy has never been described before. This case presents ...
Nordrehaug J E - - 1993
We studied 14 patients who had exercise-induced ventricular arrhythmias after a previous Q-wave myocardial infarction. All had symptomatic mild heart failure in New York Heart Association class II and a maximal oxygen consumption between 16 and 20 ml/kg/min. They were treated with the angiotensin converting enzyme inhibitor benazepril (20 mg) ...
Tendera M - - 1993
We studied the correlation between changes in left ventricular filling dynamics induced by acute intravenous administration of verapamil and the changes in exercise tolerance induced by oral administration of the agent in 30 patients with hypertrophic cardiomyopathy. Diastolic cardiac function was measured by means of a nuclear stethoscope before and ...
Bartel T - - 1993
OBJECTIVES: A novel non-invasive procedure which evaluates left-right ventricular interaction is introduced. This procedure is suitable for the classification of congestive heart failure. METHODS: In 48 patients showing mild, moderate or advanced stage congestive heart failure (NYHA I-III) Doppler echocardiography was performed at rest, during and after submaximal bicycle exercise. ...
Dahms T E - - 1993
OBJECTIVE: This study was designed to determine whether carbon monoxide has proarrhythmic effects at rest and during upright exercise in patients with myocardial ischemia and moderate baseline ectopic activity. BACKGROUND: Exposure of patients with documented myocardial ischemia to low levels of carboxyhemoglobin (COHb) alters the myocardial response to exercise. Anecdotal ...
Haddad F - - 1993
The primary objective of this study was to ascertain if various degrees of marked chronic food restriction (FR) as well as the combination of FR and exercise training of moderate intensity induce changes in the functional properties of the heart that are consistent with previously reported findings indicative of downregulation ...
Gratama, Jan Willem Christiaan
In a previous study, it was demonstrated that resting myocardial blood flow and oxygen consumption are increased in lambs with a left-to-right shunt due to the augmented cardiac work. This finding forms the basis for the studies in the present thesis. Zie: Summary
Finkelhor R S - - 1993
The exercise-induced changes in left ventricular filling in patients with coronary artery disease are poorly understood. Therefore these changes were studied in relation to a noninvasive indicator of exercise pulmonary venous congestion, the lung-to-heart (L:H) ratio on symptom-limited thallium stress testing. Fifty-six patients undergoing diagnostic treadmill testing were studied; 50 ...
Smith D H - - 1993
Cardiovascular risk factors associated with hypertension include alterations in arterial compliance and an increased tendency to thrombosis. In this study we examined the relationship between arterial compliance and endothelial derived components of the hemostatic system: von Willebrand factor (vWF) and tissue plasminogen activator (t-PA). Ten males (4 normal and 6 ...
Tendera M - - 1993
The effect of sotalol on exercise tolerance and incidence of arrhythmias was studied in 30 patients with hypertrophic cardiomyopathy (HCM). In this short-term, double-blind, cross-over study, exercise time on sotalol (320 mg/day) was significantly longer than on placebo (10.6 +/- 4.0 vs. 9.4 +/- 3.6 min; p < 0.01). Sotalol ...
Tarumi N - - 1993
Left ventricular diastolic filling properties during isometric handgrip exercise were measured by pulsed Doppler echocardiography in 33 noninsulin-dependent diabetic patients with a normal ejection fraction and 15 control subjects. Diabetic patients were subdivided into two groups according to their resting left ventricular filling pattern (A/E): 18 patients were in group ...
Ben-Ari E - - 1993
Global and segmental left ventricular dynamics during strenuous large-muscle isometric exercise were compared between endurance and static type professional athletes and sedentary men. Using a trunk dynamometer and supine echocardiography, only the weight lifters manifested increased (p < 0.01) wall thickness during both diastole and systole, resulting in decreased left ...
Dart A M - - 1992
1. The effect of 4 weeks of moderate exercise training on cardiac left ventricular structure and function was examined by repeated echocardiographic/Doppler examination in 10 previously sedentary volunteers participating in a single blind, sedentary phase controlled, cross-over study. 2. Left ventricular internal diastolic diameter increased after 4 weeks of training ...
Hilleman D E - - 1992
It has been suggested that H2-antagonists may adversely affect left ventricular systolic function. To assess the effects of cimetidine, famotidine, and ranitidine on exercise capacity and left ventricular systolic function, the authors conducted a randomized, double-blind, four-way crossover study in 15 healthy male volunteers with placebo control. Each subject underwent ...
Dritsas A - - 1992
To examine whether QTc and QTc dispersion across the leads of a surface electrocardiogram (ECG) are different in patients with hypertrophic cardiomyopathy (HCM) compared with normal subjects, we measured QT and calculated QTc in all 12 leads of a surface ECG in 24 patients with HCM and in 20 age- ...
Nazari J - - 1992
Moricizine has been touted as having a low incidence of proarrhythmic effects. We present a case of proarrhythmia from moricizine, which presented as exercise induced ventricular tachycardia, and review the literature suggesting that this antiarrhythmic drug shares the proarrhythmic profile of other agents with predominant type Ic action. We conclude ...
Paulus W J - - 1992
BACKGROUND: The exercise-induced rise in left ventricular filling pressures after cardiac transplantation is considered to be the result of a blunted heart rate response, of elevated venous return, and of unfavorable passive late-diastolic properties of the cardiac allograft. In contrast to passive late-diastolic left ventricular properties, the effect of left ...
Iwasaka T - - 1992
To evaluate whether the response of left ventricular pump function during low-level exercise in the early postinfarction period can anticipate its change during the first year after acute myocardial infarction (MI), global and regional ejection fractions (EF) were investigated using radionuclide angiography in 52 consecutive patients with negative predischarge exercise ...
Maehara K - - 1992
OBJECTIVE: The aim was to elucidate the alterations of left ventricular diastolic properties, taking into account changes in unstressed length during exercise stimuli with and without coronary stenosis. METHODS: Left ventricular end diastolic pressure-length strain relations using segment length normalised to Lagrangian strain, and the rate of relaxation, were studied ...
Cigarroa C G - - 1992
BACKGROUND: Chronic cocaine abuse has been associated with a high prevalence of left ventricular hypertrophy (LVH) in normotensive individuals at rest. This study was conducted to determine whether chronic cocaine abusers with LVH would manifest an exaggerated pressor response to treadmill exercise. METHODS AND RESULTS: Forty-nine normotensive chronic cocaine abusers ...
Takemoto K A - - 1992
To determine whether exercise training has an effect on left ventricular diastolic dysfunction associated with the normal aging process, we studied a group of 20 normal healthy adult distance runners (mean miles currently run per week was 45 for an average of 15 years) and 20 normal healthy sedentary individuals ...
Cabanes L - - 1992
BACKGROUND: Bronchial hyperresponsiveness to cholinergic stimuli such as the inhalation of methacholine is common in patients with impaired left ventricular function. Such hyperresponsiveness is best explained by cholinergic vasodilation of blood vessels in the small airways, with extravasation of plasma due to high left ventricular filling pressure. Because this vasodilation ...
Ehsani A A - - 1992
Endurance trained athletes have a larger left ventricular end-diastolic diameter and volume and left ventricular mass than sedentary subjects. The left ventricular wall thickness-to-radius ratio is within the normal range in these athletes, suggestive of volume overload hypertrophy. These morphologic changes are the result of the training stimulus rather than ...
Quyyumi A A - - 1992
The prognostic value of radionuclide measures of left ventricular function at rest and exercise is well established. Some studies have suggested that the frequency and duration of silent ischemia during ambulatory monitoring provide similar prognostic information; however, studies comparing these two techniques have not been performed. This study examines the ...
Dattilo G L - - 1992
The effect of theophylline on atrioventricular conduction in atrial fibrillation was investigated by determining ventricular response rates at rest and during exercise treadmill tests in eight patients (mean [+/- SEM] age, 64.2 +/- 2.0 years) with chronic atrial fibrillation. Tests were performed before and after 7 days of oral theophylline ...
Chikamori T - - 1992
To assess the relation of exercise capacity to indexes of systolic and diastolic function in hypertrophic cardiomyopathy, 81 patients underwent two-dimensional echocardiography, technetium-99m equilibrium radionuclide angiography acquired in list mode and maximal, symptom-limited, treadmill exercise testing with measurement of maximal oxygen consumption (VO2 max). VO2 max for the group was ...
Klues H G - - 1992
To define alterations in the magnitude of the left ventricular outflow tract gradient during supine exercise, 10 patients with hypertrophic obstructive cardiomyopathy were studied under basal conditions and during exercise and recovery with simultaneous invasive hemodynamic measurements, particularly of the peak to peak systolic pressure gradient across the left ventricular ...
Brantberg K - - 1992
Test-retest variability of values for directional asymmetry in primary and secondary horizontal optokinetic after-nystagmus (OKAN I and OKAN II, respectively) was studied in 16 apparently healthy subjects. OKAN was induced by 60 s of whole-field optokinetic stimulation at speeds of 60 degrees/s and 90 degrees/s in either direction (left and ...
Shahi M - - 1992
OBJECTIVE: To assess cardiac structure and function in patients with treated hypopituitarism and to determine their relation to the degree of growth hormone deficiency and body composition pattern. DESIGN: 26 patients with treated hypopituitarism were studied by cross sectional and Doppler echocardiography and by exercise testing. The results were analysed ...
Manier G - - 1991
To determine the effect of strenuous prolonged exercise on systolic and diastolic left ventricular function, 11 non-elite marathon runners aged 37 +/- 7 years (mean +/- SD) were studied before and during early recovery from a marathon race. Cavity dimensions, wall thickness, and fractional shortening were computed from two-dimensionally guided ...
Cohen T J - - 1991
A 31-year-old man who received an automatic cardioverter defibrillator subsequently underwent exercise testing. During exercise, a sinus tachycardia resulted above his device detect rate prompting two shocks, the second of which produced an unstable polymorphous ventricular tachycardia. In this article, we review the literature on automatic cardioverter defibrillator-induced ventricular tachyarrhythmias ...
Camerini F - - 1991
Many studies on the natural history of dilated cardiomyopathy show high probability of death or of cardiac transplantation in a large percentage of patients. These studies have several methodological limitations. Our prospective study, carried out from 1971, and which evaluated 120 patients, showed improved survival in more recent years. Survival ...
Fatkin D - - 1991
A 23-year-old man presented with recurrent exercise-induced ventricular tachycardia (VT), complicated by systemic embolisation. Catecholamine--sensitive VT was reproduced on exercise testing and programmed electrical stimulation, displaying features suggestive of enhanced automaticity as well as re-entry. Both 2D-echocardiography and gated heart pool scan showed localised dyskinetic bulging in the right ventricle. ...
Presti C F - - 1991
Previous studies using Doppler echocardiography to evaluate left ventricular diastolic filling have shown that myocardial ischemia induced by coronary balloon angioplasty or atrial pacing results in a decrease in the left ventricular inflow peak early (E) to peak atrial (A) velocity ratio. To investigate the effects of exercise-induced ischemia on ...
Tsuji H - - 1991
The relationship between myocardial ischemia detected by exercise thallium-201 scintigraphy and repetitive ventricular premature beats (VPBs) during ambulatory monitoring was evaluated in 57 patients with recent myocardial infarction. Multivariate analysis was performed to obtain the relatively important factor related to repetitive VPBs with the use of the following variables: age, ...
Feld H - - 1991
Sustained ventricular tachycardia induced by exercise is uncommon. This is a report of a patient who has a positive exercise test at a high level of exercise. The electrocardiogram has classic ischemic ST depressions. Following the appearance of these ST depressions, the patient developed ventricular tachycardia at a rapid rate. ...
Paridon S M - - 1991
To better understand the role of chronotropic impairment on exercise performance after the atrial switch (Mustard) operation, 20 patients who had undergone this operation for uncomplicated d-transposition of the great arteries exercised to maximal volition using a 1 min incremental treadmill protocol. Heart rate, oxygen consumption, carbon dioxide production and ...
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 ...
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