Search Results
Results 201 - 250 of 726
< 1 2 3 4 5 6 7 8 9 10 >
Antzelevitch C - - 2001
The mechanisms responsible for active cardiac arrhythmias are generally divided into two major categories: (1) enhanced or abnormal impulse formation and (2) reentry. Reentry can be subdivided into three subcategories: (1) circus movement, (2) reflection, and (3) Phase 2 reentry. Reentry occurs when a propagating impulse fails to die out ...
Mettauer B - - 2001
PURPOSE: The mechanisms of the training-induced improvements in left ventricular assist (LVAD) patients are unknown. METHODS: We measured the hemodynamic, gas exchange, and metabolic and hormonal effects of 6-wk exercise training in a cardiogenic shock patient who was assisted by an LVAD. RESULTS: After training, the peak power and VO2 ...
Rozanski A - - 2001
The variety of noninvasive imaging modalities now available permits assessment of different aspects of left ventricular function in the postexercise state. Some of these modalities, such as first-pass radionuclide ventriculography, permit a nearly instantaneous assessment of left ventricular function in the early postexercise state. These modalities indicate that most exercise-induced ...
Kelsch T - - 2001
The survival rate of patients undergoing cardiopulmonary resuscitation is 5 to 15%. New cardiopulmonary resuscitation treatment approaches under investigation include the use of vasopressin as a vasopressor, amiodarone for the treatment of ventricular tachyarrhythmias, and adenosine antagonists (i.e., theophylline) for bradyasystolic rhythms. More innovative approaches include the use of thyroid ...
Krittayaphong R - - 2000
Ventricular arrhythmia (VA) from right ventricular outflow tract (RVOT) is a common problem. Symptomatic patients are usually treated with beta-blockers. There is little data on the systematic evaluation of the drug efficacy. The objectives of this study were 1) To determine proportion of exercise induced ventricular arrhythmia among patients with ...
Omvik P - - 2000
BACKGROUND: Losartan reduces blood pressure in patients with essential hypertension, but the long-term central hemodynamic effects at rest and during exercise are not known. METHODS AND RESULTS: After 8 months of losartan treatment (50 to 100 mg daily, mean 82 mg), intra-arterial pressure was reduced from 165/102 mm Hg to ...
Konar D - - 2000
Sarvangasana (SVGN) is a head-down-body-up postural exercise in a 'negative g' condition. Though highly recommended as one of the three best of all the asanas it has not yet been studied for its very obvious effects on the cardiovascular (CV) functions. This paper reports the results of the first systematic ...
Pokan R - - 2000
PURPOSE: The aim of this study was to evaluate differences in the left atrial (LAD), total ventricular end-diastolic (TEDD), end-systolic diameters (TESD), and left ventricular shortening fraction (SF) compared with heart rate (HR) and systolic blood pressure (SBP) during exercise and recovery. METHODS: Healthy young male (N = 15) and ...
Jouven X - - 2000
BACKGROUND: Exercise testing is widely used in the diagnosis of coronary artery disease, but the long-term outcome for asymptomatic persons with exercise-induced premature ventricular depolarizations remains unclear. We used data from the Paris Prospective Study I to assess the long-term outcome for such persons. METHODS: A total of 6101 asymptomatic ...
Petrella R J - - 2000
We investigated anaerobic threshold (< theta(L)) gas exchange kinetics and maximal oxygen uptake (VO2,max) among older men with reduced left ventricular end-diastolic filling (LVDF). Ten men (mean age, 73 years) with LVDF impairment and low fitness, but without other cardiovascular dysfunction were studied. Treatments compared to control included: 5 days, ...
Okeie K - - 2000
OBJECTIVES: We sought to characterize stress-induced left ventricular systolic dysfunction in patients with hypertrophic cardiomyopathy (HCM). BACKGROUND: Myocardial ischemia and diastolic dysfunction occur in patients with HCM. We hypothesized that, in the setting of transient myocardial ischemia, left ventricular systolic dysfunction occurs during exercise and dobutamine stress. METHODS: We studied ...
Mady C - - 2000
BACKGROUND: Chagas' disease is a known dilated form of cardiomyopathy. However, a great number of patients, although showing electrocardiographic (ECG) well-recognized changes, maintain normal ventricular chamber dimensions and are asymptomatic. The aim of the present study was to objectively characterize functional capacity in asymptomatic patients with Chagas' disease and normal ...
Yoshikawa M - - 2000
At least 25-30% of patients with a permanent implantable left ventricular assist device (LVAD) experience right ventricular failure; therefore, an implantable biventricular assist system (BiVAS) with small centrifugal pumps is being developed. Many institutions are focusing and developing a control system for a left ventricular assist system (LVAS) with rotary ...
Webb-Peploe K M - - 2000
We looked at the benefits and complications of a home-based exercise programme in patients with ischaemic and idiopathic dilated cardiomyopathy. Twenty-four patients with left ventricular end-diastolic dimension >6.5 cm and fractional shortening <25% entered a cross-over trial of 8 weeks training versus 8 weeks rest. Echocardiography, electrocardiogram and cardiopulmonary exercise ...
Yan L - - 2000
We tested the hypothesis that lowering the level of cyclic GMP would have positive functional effects on isolated rabbit ventricular myocytes regardless of the basal cyclic GMP level. Cell shortening data were collected with a video detector; O(2) consumption data were obtained with a Clark electrode; intracellular cyclic GMP levels ...
Patwardhan A J - - 2000
OBJECTIVE: This study focuses on variation in brain morphology associated with supernumerary X chromosome and Klinefelter syndrome (KS). Using an unselected birth cohort of KS subjects and high-resolution MRI, the authors investigated the neuroanatomic consequences of the 47,XXY karyotype in the presence and absence of exogenous testosterone supplementation. METHODS: Regional ...
Ajisaka R - - 2000
The aim of the present investigation was to compare the hemodynamic and thermal responses to a 30-min aerobic exercise between middle- or old-aged patients with normal left ventricular function and those with left ventricular dysfunction. Constant-load sitting ergometer exercise of approximately 90% of the subject's oxygen uptake (VO2) at the ...
Mahon N G - - 2000
BACKGROUND: Left ventricular enlargement with normal systolic function is common in asymptomatic relatives of patients with familial dilated cardiomyopathy, many of whom progress to overt dilated cardiomyopathy at follow up. OBJECTIVE: To examine maximal and submaximal gas exchange variables of cardiopulmonary exercise testing in asymptomatic relatives with left ventricular enlargement. ...
Manto M U - - 2000
We describe a patient presenting clinical features of corticobasal degeneration (CBD), including reflex myoclonus in the left upper limb. This patient complained of a marked worsening of involuntary movements in the left upper limb after exercise. We analysed the electrophysiological characteristics of myoclonus in the basal state and after a ...
Barnes E - - 2000
OBJECTIVE: To determine whether pharmacological stress leads to prolonged but reversible left ventricular dysfunction in patients with coronary artery disease, similar to that seen after exercise. DESIGN: A randomised crossover study of recovery time of systolic and diastolic left ventricular function after exercise and dobutamine induced ischaemia. SUBJECTS: 10 patients ...
Zeitz C J - - 2000
The effects of inotropically active agents on the left ventricular force-interval relation are a potential determinant of their clinical utility and safety. However, little information is available concerning the effects of noncatecholamine positive inotropic agents on this relation. Therefore this study compared the short-term effects of digoxin and milrinone on ...
Caulkett N A - - 2000
Three mule deer and 4 mule deer/white-tailed deer hybrids were immobilized in a crossover study with carfentanil (10 microg/kg) + xylazine (0.3 mg/kg) (CX), and medetomidine (100 microg/kg) + ketamine (2.5 mg/kg) (MK). The deer were maintained in left lateral recumbency for 1 h with each combination. Deer were immobilized ...
Claessens P - - 2000
"Sudden cardiac death" in seemingly healthy, active, and asymptomatic people has always been a tragic fact and is now occurring more frequently. Thus, the preventive detection of "subjects at risk" becomes a priority. A traditional resting electrocardiogram can sometimes give useful indications. Fifty-two competitive triathletes were compared with 22 control ...
Kose, Noriyuki
A 15-year-old girl, who was previously in good health, suddenly collapsed while jogging. Immediate cardiopulmonary resuscitation (CPR) was initiated, and she arrived at our hospital 13 minutes later. The ventricular fibrillation (VF) on admission was reverted to sinus rhythm 18 minutes after collapse by the second cardioversion. The echocardiogram revealed ...
Libonati J R - - 1999
There are several important links between aerobic exercise performance and the diastolic phase of the cardiac cycle. During acute exercise, diastolic function must be augmented in order for left ventricular filling to match increased left ventricular output, i.e., cardiac output. This challenges the myocardium because the shortened duration of diastole ...
Fisher J D - - 1999
OBJECTIVES: We sought to determine whether objective tests of antiarrhythmic drug efficacy could produce favorable short- and long-term outcomes in a family with idiopathic malignant ventricular arrhythmias. BACKGROUND: In 1973 a family presented with a history of several generations of syncopal spells and sudden death. Some individuals had nonspecific electrocardiographic ...
Lucía A - - 1999
OBJECTIVES: To determine whether the heart rate (HR) response to exercise in 21 highly trained cyclists (mean (SD) age 25 (3) years) was related to their heart dimensions. METHODS: Before performing an incremental exercise test involving a ramp protocol with workload increases of 25 W/min, each subject underwent echocardiographic evaluation ...
Sato A - - 1999
BACKGROUND: Measuring the transmitral flow velocity with Doppler echocardiography is a useful method for evaluating left ventricular diastolic function. However, there are few data regarding the effect of posture during exercise on transmitral flow velocity. METHODS: The transmitral flow velocity with pulsed-wave Doppler echocardiography was measured during supine and upright ...
Willenheimer R - - 1999
To assess the effects of 6 months intervention with +ramipril on resting and post exercise left ventricular function in patients with stable ischaemic heart disease and preserved left ventricular systolic function. METHODS and Patients (n=98, age 65+/-9 years, 37% women) were randomized to double-blind treatment with ramipril 5 mg. day(-1)(n=32), ...
Kapoor R K - - 1999
OBJECTIVE: To study subclinical left ventricular dysfunction in anemic children. SETTING: Hospital. SUBJECTS: The study population consisted of 52 cases of anemia (16 mild, 14 moderate, 22 severe) and 20 normal age and height matched children aged between 7-12 years. METHODS: These children were subjected to Echocardiography on Ascuson XP ...
Whyte G P - - 1999
PURPOSE: The purpose of the present investigation was to examine differences that may exist in maximal and submaximal exercise gas exchange parameters and their use in differentiating pathological and physiological left ventricular hypertrophy. METHODS: Exercise gas exchange responses were measured on-line during a maximal ramping cycle-ergometer exercise test in 10 ...
Woolf-May K - - 1999
In this study we compared the efficacy of Doppler and atrioventricular plane motion echocardiography in detecting the changes in left ventricular function caused by moderate-intensity training. Fifty-nine healthy men and women (aged 40-68 years) were divided into either a group of walkers (n = 32) or controls (n = 27). ...
Squires R W - - 1999
PURPOSE: In the current era of efficient use of personnel and cost containment, the use of non-physicians in selected roles previously occupied exclusively by physicians has become increasingly prevalent. Traditionally, physicians have directly supervised graded exercise testing of patients with chronic heart failure. The purpose of this prospective pilot investigation ...
Chen C H - - 1999
OBJECTIVES: We tested the hypothesis that acute intravenous verapamil acutely enhances aerobic exercise performance in healthy older individuals in association with a combined reduction of ventricular systolic and arterial vascular stiffnesses. BACKGROUND: Age-related vascular stiffening coupled with systolic ventricular stiffening may limit cardiovascular reserve and, thus, exercise performance in aged ...
van der Velden J - - 1999
To investigate whether during cardiac hypertrophy changes occur in contractile protein composition and in mechanical and energetic properties of the myocardium, contractile protein composition, isometric force and adenosine triphosphate (ATP) consumption were studied in control and hypertrophied guinea-pig hearts. Cardiac hypertrophy was induced by adding minoxidil (120 or 200 mg/l) ...
Kumita S - - 1999
99Tcm-labelled myocardial perfusion tracers allow simultaneous assessment of myocardial perfusion and left ventricular function using ECG-gated SPET. The aim of this study was to evaluate left ventricular performance during exercise by means of ECG-gated myocardial perfusion SPET. After the administration of 99Tcm-tetrofosmin (555-740 MBq), eight healthy volunteers aged 27-49 years ...
Kim J J - - 1999
Transcoronary alcohol ablation (TAA) therapy of septal hypertrophy was recently proposed as a therapeutic modality for obstructive hypertrophic cardiomyopathy (HC). However, questions remain about the effect of TAA on exercise performance. We performed a time-course analysis of exercise capacity and exercise hemodynamics in 20 patients with symptomatic obstructive HC after ...
Burke A P - - 1999
Arrhythmogenic right ventricular cardiomyopathy is emerging as a relatively common cause of exercise-induced sudden death in the young. The diagnostic criteria at autopsy are, however, not fully established, leading to both over- and underdiagnosis. We report a young man and a young woman dying suddenly of right ventricular dysplasia during ...
Millane T - - 1999
A 3-year-old girl presented with a febrile illness complicated by right ventricular outflow tract tachycardia, which persisted after resolution of the presumed viral infection. The tachycardia was intermittent, but was significantly exacerbated by exercise. Radiofrequency ablation (RFA) of the ectopic focus was successfully performed and the child remains free of ...
Takakura Masahiro - - 1999
We tested the ability of cycle ergometer exercise echocardiography to detect cases of occult cor pulmonale among 25 patients with chronic obstructive pulmonary disease (COPD). The M-mode echocardiographic ventricular septal motion, left ventricular shape determined by short-axis two-dimensional (2-D) echocardiography, and right and left ventricular pressure curves were recorded at ...
Schoonderwoerd B A - - 1999
We present a patient with exercise-induced paroxysmal atrial fibrillation who was eventually scheduled for a Cox-maze operation due to persistence of his complaints of fatigue, impaired exercise tolerance, and predominantly exercise-related irregular palpitations despite treatment with several antiarrhythmic drugs. A preoperative exercise stress test without antiarrhythmic or negative chronotropic drugs, ...
Olivotto I - - 1999
BACKGROUND: Exercise testing has long been employed in patients with hypertrophic cardiomyopathy (HCM), although concerns have constantly been expressed regarding its safety. This study reviews a large number of exercise tests performed in a community-based population with HCM, in terms of safety and clinical utility. METHODS: We analyzed a total ...
Walsh J T - - 1999
OBJECTIVE: To examine the relation between patterns of ventricular remodelling and haemodynamic and neurohormonal variables, at rest and during symptom limited exercise, in the year following acute myocardial infarction in patients not receiving angiotensin converting enzyme (ACE) inhibitors. DESIGN: A prospective observational study. Patients: 65 patients recruited following hospital admission ...
Andrén B - - 1999
BACKGROUND: The present study was designed to assess the impact of left ventricular hypertrophy (LVH) independent of hypertension on the presence of silent myocardial ischemia and arrhythmia, as well as on systolic and diastolic function in otherwise healthy elderly men. METHODS AND RESULTS: Twenty apparently healthy normotensive subjects with LVH ...
Trikas A - - 1998
OBJECTIVES: The objective of this study was to examine the association between exercise capacity and echocardiographic indexes of atrial and ventricular function and size in patients with beta-thalassemia major. BACKGROUND: In patients with beta-thalassemia major, the assessment of cardiac function with echocardiography alone does not always correspond to their functional ...
Goosey V L - - 1998
The purpose of this study was to establish whether bilateral symmetry exists during wheelchair propulsion in the elbow movement pattern of trained wheelchair racers. Seven endurance-trained wheelchair racers volunteered to participate in the study. Each subject was recorded by two-dimensional video analysis while pushing on a single-roller wheelchair ergometer at ...
Alexiou K - - 1998
OBJECTIVES: We investigated whether endogenous pulmonary big endothelin has arrhythmogenic properties under normal conditions and in heritable hyperlipidemia. BACKGROUND: Endothelin (ET), one of the most potent vasoconstrictors, is known to induce ventricular arrhythmias. It is unclear, however, whether its precursor, big endothelin, released from the lung, contributes to arrhythmogenesis. METHODS: ...
Nieuwland W - - 1998
AIMS: Most studies in chronic heart failure have only included patients with marked left ventricular systolic dysfunction (i.e. ejection fraction < or =0.35), and patients with mild left ventricular dysfunction are usually excluded. Further, exercise capacity strongly depends on age, but age-adjustment is usually not applied in these studies. Therefore, ...
Foster C - - 1998
Measures of left ventricular function during exercise provide information that is more accurate than the exercise ECG in the diagnosis of coronary artery disease, supportive of the data provided by myocardial perfusion studies, and of great prognostic significance. We review basic methods for evaluating left ventricular function during exercise and ...
Maki S - - 1998
Patients with hypertrophic cardiomyopathy (HC) die suddenly. Proposed risk factors for sudden cardiac death (SCD) in HC are youth, a family history of SCD, syncope, and ventricular tachycardia. Hemodynamic variables have not convincingly proved to be risk factors for SCD. Therefore, this study was designed to examine predictors of SCD ...
< 1 2 3 4 5 6 7 8 9 10 >