STUDY OBJECTIVES: To determine the safety and utility of immediate exercise testing in the evaluation of low-risk patients presenting to the emergency department with chest pain and its applicability to a heterogeneous population of men and women. METHODS: We conducted a prospective study of the safety and utility of immediate ...

There is an evident need for a quantitative laboratory marker for ascertaining disease activity and treatment effects in multiple sclerosis (MS) patients. Activity of the disease process in MS is accompanied by myelin breakdown and appearance of myelin basic protein (MBP) in cerebrospinal fluid (CSF). In this paper MBP in ...

This study was performed to determine whether nitroglycerin can increase blood flow to collateral-dependent myocardium during exercise. Intermittent repetitive occlusions of the left circumflex coronary artery (LCX) were used to stimulate growth of coronary collateral vessels in seven adult mongrel dogs. Coronary pressure distal to the occluder was measured with ...

BACKGROUND: The diagnostic information from an ECG taken while at rest and an exercise test is considered less reliable in women than in men, mostly due to a high percentage of false-positive tests. This can be explained by a lower pre-test likelihood of coronary heart disease. AIMS: To evaluate the ...

Twenty-nine patients with documented coronary artery disease underwent cardiopulmonary exercise tests before and following a percutaneous transluminal coronary angioplasty (PTCA). The patients medication regimen and exercise protocols remained the same in both cases. Following PTCA, significant improvement (p < 0.001-0.0001) was noted in oxygen consumption (1,526.8 +/- 470.0 vs. 1,686.2 ...

The purpose of this study was to test whether the systolic myocardial wall motion abnormalities at the early stages of ischemia are applicable to the diagnosis of coronary artery disease. Forty-four patients with suspected coronary artery disease were studied with the use of low-level exercise echocardiography. Exercise was stopped at ...

In this prospective study, we examined the diagnostic accuracy of exercise-induced left QRS axis deviation as a marker of LAD coronary artery stenosis. The mean frontal QRS axis of 66 consecutive patients with chest pain and exercise-induced ST segment depression referred for diagnostic coronary angiography was analyzed and related to ...

AIMS: To study the impact of smoking on the change in exercise capacity in patients treated with coronary angioplasty. METHODS: Three hundred and sixty-eight men below 70 years of age eligible for percutaneous transluminal coronary angioplasty without previous coronary interventions were consecutively enrolled. Of the 334 patients (90.8%) who completed ...

BACKGROUND: It has been shown that exercise-induced coronary vasodilation of angiographically normal coronary vessels is reduced in hypercholesterolemic patients. The purpose of this study was to evaluate the effect of calcium channel blockers on coronary vasomotion of angiographically smooth coronary arteries in hypercholesterolemic patients. METHODS AND RESULTS: A total of ...

Exercise-induced myocardial ischemia is difficult to detect with ST-T changes in patients with right bundle branch block (RBBB). We sought to predict exercise-induced myocardial ischemia with QT interval behavior during exercise in patients with RBBB. Twenty-two patients with angiographically proven coronary artery disease and RBBB and 9 healthy volunteers underwent ...

Exercise echocardiography has experienced a rapid rise in clinical acceptance because of its recognized ability to detect coronary artery disease in addition to attractive features such as portability, versatility and relatively low cost. To achieve and maintain accuracy and diagnostic yield, adequate training of the sonographer and the cardiologist is ...

Aerobic exercise training induces an increase in coronary blood flow capacity that is associated with altered control of coronary vascular resistance and, therefore, coronary blood flow. The relative importance of metabolic, myogenic, endothelium-mediated, and neurohumoral control systems varies throughout the coronary arterial tree, and these control systems contribute in parallel ...

We previously reported that combined blockade of adenosine receptors and ATP-sensitive K+ channels (K+(ATP) channels) blunted but did not abolish the response of coronary blood flow to exercise. This study tested the hypothesis that the residual increase in coronary flow in response to exercise after adenosine receptor and K+(ATP) channel ...

PURPOSE: Although nitrates are known to improve indices of exercise capacity in patients with coronary artery disease, their effects on oxygen uptake kinetics during the onset of exercise have not been clarified. We evaluated the acute effects of isosorbide dinitrate on the kinetics of oxygen uptake during the onset of ...

BACKGROUND: Clinical symptoms have been found to correlate only poorly with the severity of the culprit lesion in coronary artery disease. The purpose of the present study was to evaluate the influence of the culprit lesion and its change during exercise on clinical symptoms in patients with this condition. METHODS: ...

Physical exercise has become universally accepted as an important component in the primary prevention of coronary disease and in the management of subjects with established coronary artery disease. Exercise should be utilized appropriately for each individual's needs and done in concert with aggressive modification of other risk factors such as ...

As we learn more about the origins of coronary artery disease, research has begun to focus on its prevention. The purpose of this study was to determine if exercise stress testing of the offspring of our cardiac rehabilitation patients would be a useful adjunct to their general cardiac risk factor ...

Children who underwent arterial switch operation for simple transposition of the great arteries in the neonatal period are now reaching an age when exercise testing becomes feasible. This study was conducted to assess exercise tolerance and electrocardiographic response to exercise stress in 50 asymptomatic children, aged 4 to 9 years, ...

BACKGROUND: Activated clotting time (ACT) values during percutaneous transluminal coronary angioplasty (PTCA) after the initial 10,000 U heparin bolus are often below target values of 350 or 400 s (Hemochron) and have to be supplemented with additional heparin. This study evaluated the initial 10 min post-heparin bolus clotting time value ...

Exercise is effective in both preventing and treating coronary artery disease (CAD). Exercise improves cardiovascular efficiency and, in combination with other measures such as medication use, diet changes, and smoking cessation, may arrest or reverse atherosclerosis. Exercise prescriptions will vary according to disease level or risk, but the basic principle ...

Mitral valve prolapse is sometimes associated with chest pain, but this symptom may also be caused by coexisting coronary disease. The accuracy of exercise echocardiography in diagnosing coronary disease in these patients and the most cost-efficient diagnostic approach are unclear. We studied 96 patients (aged 59 +/- 12 years; 70 ...

Atherosclerosis and inflammatory arterial diseases are rare in young people. Since the early 1980s, an increasing incidence of iliac arterial stenosis in competition cyclists has been reported. Histological findings in these individuals are specific, with fibrosis of the intimal wall on histology and no atherosclerotic or inflammatory lesions. Clinical consequences ...

To assess the peripheral vascular effects of estrogen in women without coronary disease, normal postmenopausal women (mean age 56 +/- 8 years) participated in a randomized, crossover trial using treadmill exercise echocardiography, and received oral conjugated estrogen, 0.625 mg/day or underwent a drug-free period. There was no significant effect on ...

We report on a case of significant exertional symptoms secondary to occlusion of a nondominant right coronary artery proximal to the sino-atrial branch, with associated exercise-induced sinus node dysfunction. Successful angioplasty of the occluded right coronary artery restored a normal functional capacity and sinus tachycardia response to exercise.

PURPOSE: To examine the long-term association of leisure time physical activity (LTPA) and risk of death from coronary heart disease (CHD) and all-causes. METHODS: Data are from a prospective study of 12,138 middle-aged men at high risk for CHD participating in the MRFIT. Men were classified into deciles based on ...

PURPOSE: The American College of Sports Medicine recently published new guidelines to classify individuals at increased risk for coronary heart disease (CHD) before starting a vigorous (> 60% maximum oxygen consumption) exercise program. We compared the prognostic value of the new guidelines to the earlier guidelines. METHODS: Subjects included men ...

The endothelium-derived peptide endothelin-1 (ET-1) was evaluated in 14 male patients [mean age 52.74 years (SEM 1.10)] affected by coronary artery disease during a bicycle electrocardiographic stress test and dipyridamole echocardiogram. Both tests were performed before and after coronary revascularization. Fourteen healthy male subjects served as controls [mean age 53.21 ...

The effects of exercise training on the coronary vasodilation following activation of the Bezold-Jarisch reflex were examined in conscious dogs. Mongrel dogs were chronically instrumented using sterile techniques for measurements of systemic hemodynamics and left circumflex coronary blood flow (CBF). With the heart rate controlled (150 bpm), veratrine (0.5 to ...

OBJECTIVES: This study sought to 1) assess in vivo release of platelet-derived growth factor (PDGF) and basic fibroblast growth factor (bFGF) into the coronary circulation after vascular injury in human subjects; and 2) evaluate mitogenic effects of PDGF and bFGF on the patient's own vascular smooth muscle cells (VSMCs). BACKGROUND: ...

Exercise testing is an effective method for evaluating patients with chest pain, for diagnosing and managing coronary artery disease, for determining prognosis in patients with known coronary disease, for determining exercise capacity, for evaluating exercise-induced arrhythmias, for verifying the safety of exercise, and for customizing an exercise prescription. With proper ...

Exercise-induced left bundle branch block is a relatively rare finding during exercise tolerance testing. A 36-year-old female with intermittent exercise-induced left bundle branch block, a MIBI study suggesting anterior ischemia and normal coronary arteries is reported. A review of the English and French language literature published from January 1985 to ...

In recent years, it has been established in humans that progression of atherosclerosis can be slowed, and in some cases, regressed. This differs from previous decades in which such observations were only considered possible in animals. The emergence of more effective lipid-lowering agents along with aggressive dietary and other lifestyle ...

Multivariable analysis of clinical and exercise test variables has the potential to become both a useful tool for assisting in the diagnosis of coronary artery disease and reducing the cost of evaluating patients with suspected coronary disease. Managed care and capitation require that tests such as the exercise test or ...

In hypertension, several factors disturb coronary circulation and the metabolic reserve of the heart. This study was undertaken to test whether in hypertensive patients global and regional left ventricular (LV) function is related during exercise to the presence of significant coronary stenosis and whether lowering of coronary perfusion pressure through ...

BACKGROUND: Coronary flow reserve (CFR) is reduced in a majority of patients after heart transplantation (HTx). Pharmacological interventions, however, provide only limited information on CFR under physiological conditions. Thus, CFR during exercise was evaluated in the present study. METHODS AND RESULTS: Coronary angiography was performed at rest and during supine ...

Previously, we observed that alpha 1-but not alpha 2-adrenergic vasoconstriction restricted blood flow distal to a coronary artery stenosis that resulted in myocardial hypoperfusion during exercise. This study was performed to test the hypothesis that vascular smooth muscle alpha 2-adrenergic vasoconstriction during exercise does exert a flow-limiting effect distal to ...

The purpose of this study was to delineate among the usually gathered parameters in an electrocardiographic exercise test the determinants of its positive outcome (delta ST decreases > or = 1 mm measured at 80 msec from the J point). The authors studied 832 patients investigated with Bruce's exercise testing ...

Coronary blood flow velocity was measured during handgrip exercise using breath-hold velocity encoded cine magnetic resonance imaging. Peak diastolic coronary flow velocity in the left anterior descending artery was 20.6 +/- 9.3 cm/s (mean +/- SD) at baseline and increased significantly to 31.1 +/- 16.4 cm/s after exercise (50.7 +/- ...

To evaluate the accuracy of exercise echocardiography for the recognition of coronary artery disease in the presence of left ventricular hypertrophy 70 patients were studied. Significant coronary artery disease was present in 25 patients and left ventricular hypertrophy had 29 patients. All patients underwent an exercise ECG and echocardiographic test ...

Exercise echocardiography is a sensitive, specific, and highly accurate method for detecting coronary restenosis and progressive compromise of untreated arterial segments in patients who have undergone percutaneous transluminal coronary angioplasty. It is far more reliable in predicting the status of the coronary anatomy in such patients than exercise electrocardiography or ...

BACKGROUND: Abnormal coronary vasomotor responses have been described in transplant patients. The aim of this study was to evaluate the graft epicardial vasomotor responses to different stimuli that increase coronary blood flow. METHODS AND RESULTS: Twelve heart transplant recipients with angiographically normal epicardial coronary arteries were compared 2.7 +/- 1.2 ...

Coronary plaque morphology (simple or complex) has a recognized clinical, pathophysiologic, and prognostic importance, but its routine use is hampered by the subjective and qualitative nature of the assessment. The aim of this study was to assess the feasibility and accuracy of mathematical, objective, operator-independent assessment of plaque morphology, by ...

BACKGROUND: The diagnostic value and incremental contribution of different noninvasive tests to the identification of coronary artery disease in 128 patients from a general population with intermediate pretest likelihood (48.0%) were determined by ordered logistic regression analysis and receiver-operating characteristic (ROC) curves. METHODS AND RESULTS: Patients referred for suspicion of ...

Estimating left ventricular wall stress has recognized applications, but formulae for global stress cannot be applied to ischemic ventricles. A mathematic method for estimating regional stress in infarcted ventricles has been described. The hypothesis tested was that exercise-induced ischemia increases end-systolic wall stress. Subcostal four-chamber echocardiograms were recorded at rest ...

This study determined the changes in NO production from the coronary circulation of the conscious dog during exercise. The role of endogenous NO as it relates to coronary flow, myocardial work, and metabolism was also studied. Mongrel dogs were chronically instrumented for measurements of coronary blood flow (CBF), ventricular and ...

Among 23,059 patients who underwent exercise myocardial tomography between 1985 and 1994 at our institution, there were 817 (3.5%) with a strongly positive exercise electrocardiogram and normal myocardial tomograms. Among these, 52 patients had no conditions known to be associated with a false-positive exercise electrocardiogram and no previous coronary revascularization, ...

Sustained inhibition of NO synthesis (N omega-nitro-L-arginine [L-NNA], 20 mg.kg-1.d-1, 7 days) was investigated at rest and during exercise in conscious dogs. At rest, L-NNA did not alter mean arterial blood pressure but markedly increased total peripheral resistance (+73 +/- 14%, P < .01). Exaggerated hypertension was observed during exercise ...

The exercise capacity of 155 hospital-based patients (125 males and 30 females) who underwent treadmill testing and coronary angiography for investigation of chest pain was used to derive regression equations for exercise capacity (METS) against age. A regression equation [18 - 0.16 x (age)] for males and [11 - 0.84 ...

Platelet activation induced by shear forces occurring in a stenosed coronary artery is one of the mechanisms of coronary thrombosis. We evaluated the shear-induced platelet aggregation (SIPA) dynamics in patients with effort angina during treadmill exercise. SIPA was measured by a rotational cone-plate aggregometer. SIPA was markedly increased by exercise ...

PURPOSE: To assess the efficacy of informed consent in subjects differing in disease severity, ranging from those with immediately life-threatening disease to healthy volunteers. SUBJECTS AND METHODS: A total of 127 subjects, enrolled in four types of clinical research protocols, were tested. Subjects completed questionnaires before entry into the protocol, ...