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Results 451 - 500 of 729
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Uematsu T - - 1989
The performance of the Bayesian feedback method for predicting lignocaine dosage developed by Vozeh et al. was evaluated in 53 Japanese patients, treated for either suppression or prophylaxis of ventricular arrhythmias, with respect to accuracy, precision, efficiency, and safety. The lignocaine serum concentrations at 12 h (C12) and 24 h ...
Rugh K S - - 1989
Myocardial and haemodynamic responses to strenuous treadmill exercise were monitored with chronically implanted instrumentation in seven physically untrained ponies. In two other ponies, haemodynamics were monitored using a conventional catheter technique. During exercise (mean +/- sem heart rate = 203 +/- 3 beats/min), left ventricular peak systolic ahd end-diastolic blood ...
Billman G E - - 1988
Mongrel dogs with healed myocardial infarctions were given a 2 min coronary occlusion during an exercise test. The exercise plus ischemia test induced ventricular fibrillation in nine animals. One week later, the test was repeated after pretreatment with magnesium sulfate (100 mg/kg i.v.). Magnesium prevented ventricular fibrillation in seven of ...
Imai K - - 1988
To investigate the relationship between left ventricular function and electrical changes during myocardial ischemia, ambulatory left ventricular function monitoring and ECG recording were made during the ergometer exercise test in 14 patients with coronary artery disease. An ambulatory ventricular function monitor consists of a small cadmium telluride (CdTe) radionuclide probe ...
Schneider W - - 1988
1. To compare different methods of cardiac stress testing that are clinically applied in the management of coronary heart disease, 2 groups of dogs each were chronically instrumented and subjected to treadmill exercise or isoprenaline infusion in the presence of coronary stenosis. 2. It was of interest to determine differences ...
Morady F - - 1988
The purpose of this study was to determine the maximum shortening of ventricular refractoriness that occurs following an increase in rate and to quantitate the duration of ventricular pacing required to obtain this maximum shortening of refractoriness. The subjects of the study consisted of 41 patients who underwent a clinically ...
Billman G E - - 1988
There is increasing evidence that the use of cocaine can trigger lethal cardiac events, including ventricular fibrillation. The mechanism responsible for these lethal cardiac arrhythmias remains to be determined. Therefore, 13 mongrel dogs were instrumented so that heart rate, left ventricular pressure (LVP), and d(LVP)/dt could be measured. After a ...
Horowitz S F - - 1988
Ingested cobalt has previously been associated with the development of a congestive cardiomyopathy. Despite occasional reports of cardiomyopathy after industrial exposure to cobalt, this association remains controversial. In a study of 30 cemented tungsten carbide workers with a mean duration of exposure to cobalt of 9.9 +/- 5.3 years radionuclide ...
Podrid P J - - 1988
Exercise testing has been widely applied for the evaluation of patients with coronary artery disease. The principles underlying its use for this indication make it a useful adjunctive technique, when combined with ambulatory monitoring, to diagnose arrhythmias and monitor antiarrhythmic drug therapy. During exercise, there is a withdrawal of vagal ...
Wong K Y - - 1988
An earlier study of 25 patients who were investigated by radionuclide angiography after a Mustard procedure showed that they had had evidence of right and left ventricular dysfunction at rest and with exercise. Twenty one (mean age 17.0 years (range 13.7-20.6) 11 female patients) of the original 25 patients were ...
Fleck S J - - 1988
The cross-sectional and longitudinal data available indicate that the following conclusions are warranted concerning the effects of resistance training on the cardiovascular system. Resistance training causes increased absolute left ventricular wall thickness and left ventricular mass. These increases are not as evident when expressed relative to body surface area or ...
Allen B J - - 1988
The results of exercise treadmill stress testing were analyzed in 64 consecutive patients presenting with either ventricular fibrillation (42%) or hemodynamically significant ventricular tachycardia (58%). Underlying diseases included coronary artery disease (55%), dilated cardiomyopathy (16%), and miscellaneous disorders (29%). Patients were additionally studied with ambulatory electrocardiographic monitoring and programmed stimulation. ...
- - 1988
Electrophysiologic studies (EPS) are often useful in managing patients with cardiac arrhythmias, while transcatheter ablation, an investigational technology, holds promise as a cure for many of these disorders. Hospitals seeking to establish themselves as centers for arrhythmia treatment must offer EPS; it is important, however, that they exercise caution before ...
Strader J R - - 1988
During submaximal exercise, an alpha adrenergic vasoconstriction that opposes metabolic dilation exists in the coronary circulation. Fifteen dogs were given i.c. injections of prazosin (0.5 mg) or yohimbine (0.7 mg) to determine the participation of alpha 1 and alpha 2 adrenoceptors in the vasoconstriction during exercise. All dogs were chronically ...
Dapoigny M - - 1988
The tip of an intraluminal probe was positioned in the cecum, and before and after a standard meal (greater than 800 kcal), the rapid myoelectrical activity of the right, the left, and the rectosigmoid colon in six healthy subjects was recorded. In each colonic site, we recorded two different patterns ...
Rubin S A - - 1988
This report describes the inadvertent induction of non-sustained atrial and ventricular arrhythmias due to the malfunction of a programmable cardiac stimulator. The malfunction occurred when line power resumed after a brief municipal power outage ("blackout") during an invasive electrophysiological study. The stimulator spontaneously delivered very high frequency pulses through the ...
Hess O M - - 1988
Myocardial structure of left ventricular segments with recurrent myocardial ischemia was evaluated by morphometry and compared with that of segments with normal blood supply in 15 patients with exercise-induced myocardial ischemia. Left ventricular high-fidelity pressure measurements and simultaneous biplane angiocardiography were performed in patients at rest and during supine bicycle ...
Wenger N K - - 1988
There is lack of consistent correlation between left ventricular function at rest, haemodynamic measurements at rest, symptomatic status and exercise tolerance. Haemodynamic data appear comparable in patients whose exercise tolerance is limited clinically by fatigue and by breathlessness. Selected patients with left ventricular dysfunction and compensated congestive heart failure can ...
Podrid P J - - 1988
Indecainide, a new class 1C agent, was administered to 16 patients with a history of ventricular fibrillation or ventricular tachycardia. Evaluation of drug effect consisted of acute testing with 125 mg followed by a period of maintenance therapy. Efficacy, as evaluated with both ambulatory monitoring and exercise testing, was defined ...
Kellermann J J - - 1988
Exercise performance in patients with impaired ventricular function does not correlate well with the severity of dysfunction. Patients with ventricular dysfunction can achieve a fairly high work capacity, and the physiological variables respond in a similar way, regardless of whether or not the patients do or do not have impaired ...
Opasich C - - 1988
The anaerobic threshold (AT) has been proposed as an index to assess the functional status of patients with chronic heart failure. The focus of this report was to evaluate in post-myocardial infarction patients the utility of the AT for (a) assessing the severity of exercise-induced left ventricular impairment, (b) determining ...
Imai N - - 1988
To determine whether endogenous opiates have a role in circulatory regulation during mild to moderate exercise, 11 chronically instrumented dogs were exercised on a treadmill up a 6% incline at 2.5 and 5.0 mph, each for 20 min, after treatment with either the opiate receptor antagonist naloxone (1 mg/kg bolus ...
Blomström-Lundqvist C - - 1988
Temporal signal averaging of the surface QRS (V1 + V3 + V5) was performed in 16 patients with arrhythmogenic right ventricular dysplasia and in 16 normal subjects. The differences between ARVD patients and normals were large for the filtered QRS duration (FQRSd) (146.2 +/- 18.9 ms vs. 91.8 +/- 4.1 ...
Schneider W - - 1988
The effects of the Ca++-antagonist verapamil on hemodynamic and regional myocardial functional parameters were studied in a canine model of exercise-induced myocardial dysfunction which mimics exercise-induced angina pectoris. Six dogs, trained to submit to five treadmill exercise cycles, each consisting of 4 min of running and 11 min of recovery, ...
Mühlberger V - - 1988
Clinical, angiographic and hemodynamic parameters were assessed preoperatively and 12-20 weeks (mean +/- SD: 14 +/- 2) after left ventricular anterior aneurysmectomy in 31 consecutive patients. In 18 patients, associated coronary artery bypass surgery was necessary (1.4 grafts/patient). One patient with mitral valve insufficiency postoperatively required mitral valve replacement. No ...
Henze E - - 1988
This study was undertaken to evaluate the effect of flecainie (Fle) and propafenone (Pro) on rest and exercise myocardial contractility after prolonged oral administration. Standardized, fully automated, gated radionuclide angiograms at rest and during maximum exercise were performed single blinded and prospectively in 19 patients before and after oral treatment ...
Valdes R R - - 1988
Digoxin-like immunoreactive factors (DLIFs) in serum may represent endogenous cardiotropic agents. We determined if blood levels of these endogenous factors changed during prolonged strenuous exercise. Total and loosely protein-bound (LPB) DLIF were measured by radioimmunoassay in the serum of nine healthy subjects during prolonged exercise to exhaustion. Mean total and ...
Kondoh C - - 1988
Left ventricular function during supine bicycle exercise was studied using multigated blood pool imaging in ten patients with tricuspid atresia after Fontan's operation and in 13 children and adults (control group). The mean age of the patients was 16 years and the mean interval between operation and study was 5 ...
Timmis A D - - 1987
The effects of captopril versus placebo on oxygen consumption in the exercising leg have been examined using Doppler measurements of femoral flow and arteriovenous oxygen difference. Twenty patients with heart failure were randomized to captopril 25 mg (N = 10) or placebo (N = 10). Maximal supine exercise of one ...
Weir I - - 1987
A slow growing encapsulated haemangioma of the left atrium was diagnosed by means of cross sectional echocardiography. The heterogeneous nature of the tumour was reflected in a central area of relative echolucency. After successful surgical removal of the tumour, the patient's symptoms of lethargy and limited exercise capacity improved considerably.
Douglas P S - - 1987
To determine the effects of prolonged exercise on systolic and diastolic left ventricular function, we studied 21 athletes before, at the finish (within 11 +/- 5 min), and during recovery (28 +/- 9 hr) after the Hawaii Ironman Triathlon (2.4 mile swim, 112 mile bike, 26.2 mile run). Two-dimensionally guided ...
Stevenson W G - - 1987
To determine if electrical stimulation during the basic ventricular drive train introduces local effects that influence ventricular refractoriness during endocardial stimulation in humans, 10 patients were studied. With a hexapolar catheter with 3 mm interelectrode distances positioned at the right ventricular apex, the ventricular functional and effective refractory periods were ...
Raberger G - - 1987
Alinidine and ULFS 49, two specific bradycardic agents were comparatively investigated with propranolol in a model of exercise-induced regional myocardial contractile dysfunction in dogs. Standardized treadmill exercise resulted in a marked decrease in regional function in the myocardium supplied by the critically stenosed circumflex branch of the left coronary artery. ...
Choong C Y - - 1987
In 14 patients during exercise, intravenous nitroglycerin improved anginal threshold and increased workload compared with control subjects. At similar workloads, the decreased left ventricular volumes suggested decreased myocardial oxygen consumption due to peripheral unloading. At maximal exercise with nitroglycerin (50 +/- 17 to 79 +/- 15 watts), rate-pressure product and ...
Takei F - - 1987
The influence of the rate of ventricular enlargement on the morphology of hydrocephalic white matter was studied and correlated with previous studies of water content. Different rates of ventricular enlargement were obtained in two groups of cats by opening either the calvaria or the calvaria and the dura mater before ...
Seaberg D - - 1987
To determine the effects of dynamic exercise on ductal left to right shunting and skeletal and myocardial blood flow distribution, a persistent ductus arteriosus was created by balloon catheters in neonatal piglets. At 8-10 weeks of age, aortic, pulmonary artery, and left atrial catheters were placed and radiolabelled microspheres injected ...
Hoffmann A - - 1987
Exercise performance in 41 men with impaired left ventricular function following an acute myocardial infarction was studied. Twenty (intervention group) subsequently underwent a 4-month supervised exercise training programme in an outpatient capacity, with three sessions per week. On completion, exercise performance was compared to the 21 control patients who received ...
Gülker H - - 1987
In this study prophylactic antiarrhythmic effects of verapamil on exercise-induced ventricular arrhythmias are evaluated. Investigations were carried out on a total of 22 patients. All patients showed frequent and/or complex ventricular arrhythmias during repeated exercise tests under control conditions. After two control exercise tests all patients were treated with verapamil ...
Lombardi F - - 1987
In a selected group of 10 apparently healthy subjects and 22 patients with organic heart disease, all with frequent ventricular ectopic beats on Holter monitoring, we assessed the influence of sympathetic activation by comparing the arrhythmogenic effects of a symptom-limited bicycle exercise stress test and 90 degree head up tilt. ...
Rämö P - - 1987
The effects of six week, high-dose anabolic steroid treatment (methandienone, 1.5 mg/kg/day) on the changes in left ventricular function induced in dogs by endurance training were studied by a catheterization technique under anaesthesia. Pacing, isoproterenol and dextran infusions were used as loading tests (respectively). Dogs were randomized into an exercise ...
Schneider W - - 1987
1 Because controversy exists regarding the effects of dihydroergotamine (DHE) on the performance of underperfused myocardium, the effects of DHE were investigated in a model of exercise-induced regional myocardial dysfunction in conscious dogs. 2 We also investigated a possible functional antagonism between DHE and nitroglycerin that might reduce the latter ...
Wolfe A J - - 1987
The kinetics of Bacillus subtilis macrofiber helix hand inversion was examined. Inversion was induced by transfer of structures produced in one medium to another medium. When cultured at 20 degrees C in either medium, the doubling time was approximately 100 min. To establish a baseline, the macrofiber twist state produced ...
Sung R J - - 1987
Sixty-four patients with reproducible exercise-induced ventricular arrhythmias were enrolled in an open-label, multicenter study to assess the efficacy and safety of oral nadolol therapy. There were 53 men and 11 women ranging in age from 19 to 75 years (mean 53.9). The severity of arrhythmias varied from frequent ventricular premature ...
Cleland J G - - 1987
In a group of 62 patients with chronic heart failure 29% developed ventricular tachycardia during exercise testing. The two-year survival of this group was only 22%, compared to 55% in those not demonstrating ventricular tachycardia (P less than 0.01). In a double-blind cross-over study against placebo, with three-month treatment periods, ...
Coumel P - - 1987
The arrhythmogenic effects of exercise tests are often unpredictable, sometimes paradoxical, and usually poorly reproducible. This explains why they are rather neglected by rhythmologists in studying the mechanisms of arrhythmias and the effects of antiarrhythmic drugs and why their prognostic value is a matter of controversy. At the same time ...
Rowland T W - - 1987
Echocardiography offers many advantages for non-invasively assessing cardiac function during exercise, but the use of this technique is hampered by interference created by respirations and body motion. The persistence of alterations in ventricular dimensions in the immediate post-recovery period, however, provides an artifact-free opportunity for evaluating recovery from the inotropic ...
Cokkinos D V - - 1987
We studied the efficacy of propafenone in 16 patients (pts) with exercise-induced ventricular arrhythmias (VA). Propafenone was given in doses of 450 mg (13 pts) to 900 mg (3 pts) per day and was compared with placebo. An arrhythmic index was calculated by dividing the frequency and severity of VA ...
Diamantopoulos E J - - 1987
The prevalence and type of arrhythmias has been studied in a representative sample of 2000 Athenians, aged 18-81 years, who underwent exercise testing on a treadmill according to the Bruce protocol. It was found that 121 persons (mean age 55.7 +/- 14.9 years, 31% greater than 65 years), exhibited arrhythmias ...
Willens H J - - 1987
Thirty patients with ischemic (n = 14) or idiopathic dilated (n = 16) cardiomyopathy were followed long-term to determine the prognostic value of measuring entry exercise capacity. At the time of referral for management of symptomatic heart failure, studies included radionuclide angiography, M-mode echocardiography, 24-hour Holter and graded exercise testing ...
Roe B B - - 1987
Although fortunately rare, the serious and potentially fatal complication of air embolism continues to occur following open-heart surgery. Its reliable prevention is dependent on the avoidance of specific procedural hazards and the exercise of various maneuvers to evacuate residual air from the heart before it is allowed to eject. Specifically, ...
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