PURPOSE: Our purposes were to compare the responses to exercise testing in elderly (> or =65 years of age) and younger men, and to investigate whether exercise testing has similar prognostic value in the two age groups. METHODS: We included all elderly (n = 1185) and younger (n = 2789) ...

In humans, pulmonary oxygen uptake (.V(O2)) kinetics may be speeded by prior exercise in the heavy domain. This "speeding" arises potentially as the result of an increased muscle O(2) delivery (.Q(O2)) and/or a more rapid elevation of oxidative phosphorylation. We adapted phosphorescence quenching techniques to determine the.Q(O2)-to-O(2) utilization (.Q(O2)/.V(O2)) characteristics ...

Statistical tools can be used to create scores for assisting in the diagnosis of coronary artery disease and assessing prognosis. General practitioners and internists frequently function as gatekeepers, deciding which patients must be referred to the cardiologist. Therefore, they need to use the basic tools they have available (ie, history, ...

BACKGROUND: More than 500,000 men play "gentlemen's" recreational hockey in Canada, but the safety of this exercise has not been studied. Exercising at extremes of intensity has been associated with an increased risk of cardiac events. Our objective was therefore to determine baseline cardiac risk factors among adult recreational hockey ...

BACKGROUND: New treatment indications and improved technique modifications have made ambulatory phlebectomy increasingly popular in the management of intermediate and large truncal varicosities. OBJECTIVE: To describe a new technique of ambulatory phlebectomy that combines a multifocal incisional and endovascular cannulation approach. This study compares this newly described technique to the ...

PURPOSE: To determine the severity and extent of emphysema in heavy smokers by high-resolution CT (HRCT) and to correlate the findings with spirometric tests (STs) and symptomatology. MATERIAL AND METHODS: Fifty adult smokers with a mean age of 53 years with a smoking history of more than 30 pack years ...

PURPOSE: The purpose of this investigation was 1) to evaluate the time course of the rating of perceived exertion (RPE; 6-20 Borg scale) during short-term, high-intensity, constant-load running (ST); and 2) to determine the reproducibility of RPE during ST. METHODS: Fifteen well-trained males (VO2max = 58.0 +/- 4.6 mL x ...

OBJECTIVES: We investigated whether augmentation of bradykinin (BK) bioavailability with angiotensin-converting enzyme (ACE) inhibition is associated with reduced exercise-induced myocardial ischemia in hypertension. BACKGROUND: Bradykinin responses are depressed in hypertension, and endothelial dysfunction contributes to myocardial ischemia by promoting abnormal coronary vasomotion during stress. METHODS: Fourteen hypertensive (HT) and 17 ...

BACKGROUND: Quantitative heart rate adjusted exercise ST criteria like microV/beats per minute (bpm) improve the diagnostic accuracy of the exercise ECG. However, there are few quantitative HR adjusted postexercise variables available. The aim of the present exercise study was to evaluate a new such variable from computerized averaging of the ...

An inhibitory effect of steviol, metabolite of the natural sweetener stevioside, on transepithelial transport of p-aminohippurate (J(PAH)) was observed in isolated S(2) segments of rabbit renal proximal tubules using in vitro microperfusion. Addition of steviol (0.01--0.25 mM) to the bathing medium significantly depressed J(PAH) (approximately 50--90%). This inhibitory effect was ...

OBJECTIVE: To examine the modality and morbidity of asymptomatic ST segment elevation in leads V1 to V3 with right bundle branch block (Brugada-type ST shift). METHODS: 8612 Japanese subjects (5987 men and 2625 women, mean age 49.2 years) who underwent a health check up in 1997 were investigated. Those with ...

Pulmonary artery hypoplasia, either congenital or acquired, is a rare abnormality seen in adults. We reported the first case of adult, isolated, left pulmonary artery hypoplasia, with exertional angina and prominent ST depression in exercise stress test, that seemed to be caused by exertional hypoxemia. Several vasodilators, including nitroglycerin, prostaglandin ...

Simultaneous ST segment elevation and depression recorded during an exercise treadmill test and its correlation with coronary angiogram is a new finding that does not find a place in medical literature. We conclude that in the presence of simultaneous ST segment elevation and ST segment depression during exercise treadmill test ...

BACKGROUND: Exercise-induced ST-segment elevation in Q-wave leads has been traditionally associated with passive stretching of the infarct wall, perinecrotic ischemia and, according to recent scintigraphic studies, with myocardial viability. At present, however, no definitive conclusions are available. We evaluated the potential role of a time-domain analysis of exercise-induced ST-segment elevation ...

In 12-lead electrocardiography (ECG), detection of myocardial ischemia is based on ST-segment changes in exercise testing. Magnetocardiography (MCG) is a complementary method to the ECG for a noninvasive study of the electric activity of the heart. In the MCG, ST-segment changes due to stress have also been found in healthy ...

BACKGROUND: Occupational noise-induced hearing loss remains epidemic in the U.S. Air Force (USAF) and aircrew members continue to be affected. This study examines noise-induced hearing loss (NIHL) observed among USAF cryptolinguists that is attributable to radio noise and attempts to determine whether the current USAF Hearing Conservation Program (HCP) adequately ...

AIM: Our purpose was to describe symptoms and electrocardiographic findings at a bicycle exercise test 4 weeks after hospitalization for a suspected or confirmed acute ischemic event but either no or only minor myocardial necrosis and its relationship to long-term prognosis and subsequent revascularization. METHODS: In all patients a symptom-limited ...

BACKGROUND: The clinical significance of stress-induced ST elevation early after acute myocardial infarction and its relation to functional recovery remain controversial. The aims of this study were (1) to determine the incidence of ST elevation during dobutamine and exercise tests and (2) to assess the relative accuracy of exercise and ...

To assess the relation between silent ischemia and objective markers of ischemia we compared ambulatory electrocardiographic (AECG) monitoring, exercise stress testing, and technetium-99m methoxyisobutyl isonitrile single-photon emission computed tomography (SPECT) in 68 patients with coronary artery disease. ST-segment depression at AECG monitoring occurred in 40%, exercise testing was positive in ...

Multichannel magnetocardiography (MCG) during exercise testing has been shown to detect myocardial ischaemia in patients with coronary artery disease. Previous studies on exercise MCG have focused on one or few time intervals during the recovery period and only a fragment of the data available has been utilized. We present a ...

The QUO VADIS study was designed to explore whether 1 year of angiotensin-converting enzyme inhibition with quinapril (40 mg/day) would decrease ischemia in patients who underwent coronary artery bypass grafting (CABG). Patients (n = 149) scheduled for CABG were randomized 4 weeks before surgery. Study medication was used from randomization ...

Eighty-nine high school seniors were administered a questionnaire that gathered information on their exercise habits (ranging from rarely to daily), relationships with parents and peers, depressive tendencies, sports involvement, drug use, and academic performance. Students with a high level of exercise had better relationships with their parents (including greater intimacy ...

Several recent studies suggest that QT dispersion on a standard 12-lead electrocardiogram is a clinically useful indicator of significant coronary stenosis. In this study, we compared the diagnostic accuracy of QT dispersion immediately after exercise as an indicator of coronary stenosis in men and women, and in the presence or ...

OBJECTIVES: We sought to determine the relationship between exercise duration and cardiovascular outcomes in patients with profound (> or =2 mm) ST segment depression during exercise treadmill testing (ETT). BACKGROUND: Patients with stable symptoms but profound ST segment depression during ETT are often referred for a coronary intervention on the ...

OBJECTIVE: Regional defects in ventricle repolarization are extremely sensitive to ischaemia which can be measured as QT dispersion (QTd). We investigated the role of QTd calculated at the time of peak exercise during treadmill studies. METHODS AND RESULTS: Thirty-three women and eighty men, whose treadmill test results and coronary angiography ...

OBJECTIVES: The 'hyperdense MCA sign' refers to an appearance of increased attenuation of the proximal middle cerebral artery (MCA) that is often associated with thrombosis of the M1 MCA segment and may be the only diagnostic feature on computed tomography early after ischaemic stroke. False positives are recognized, and correct ...

OBJECTIVES: To study the safety and efficacy (with reference to exercise ECG testing) of oral L-carnitine in chronic stable angina. METHODS: Forty-seven patients, 30 men and 17 women, aged 56 +/- 8 years, were randomized to receive L-carnitine (n = 28) or placebo (n = 19) in the dose of ...

OBJECTIVES: The study systematically compared different measures of ST segment depression from the treadmill exercise test. BACKGROUND: The value of the treadmill exercise test for objectively measuring treatment effects is limited by random error in the measurement of ST depression and may be biased by regression to the mean or ...

The analysis of exercise electrocardiogram (ECG) is based on the alteration of the measured variables in the detection of coronary artery disease (CAD). In its existing form the analysis of the exercise ECG is laborious and requires much time. The temporal analysis of the ECG variable and the comparison between ...

AIMS: A delayed myocardial protection extends between 24 and 96 h after ischemic preconditioning in animals. To test for this phenomenon in humans, subjects with stable angina were subjected to exercise test-induced myocardial ischemia and the effect of this "preconditioning" ischemic insult on the exercise-induced myocardial ischemia with the re-exercise ...

This study compared the contractile characteristics of myometrium taken from upper and lower uterine segments. Biopsies were obtained from women undergoing classical caesarean section. Myometrial strips were dissected and mounted in an organ bath, and the contractions were recorded. The cross sectional area of the contractile elements within the strips ...

Na(+)-Ca(2+) exchanger (NCX) gene expression is increased in the failing human heart. We investigated the hypothesis that upregulation of NCX can induce depressed contractile performance. Overexpression of NCX was achieved in isolated rabbit ventricular myocytes through adenoviral gene transfer (Ad-NCX). After 48 hours, immunoblots revealed a virus dose-dependent increase in ...

We assessed the effects of L-arginine (an endogenous precursor of nitric oxide) on the magnitude of exercise-induced QT dispersion in patients with coronary artery disease. The study had a randomized double-blind cross-over design. Twenty-five patients with stable coronary artery disease underwent two separate exercise tests: after oral administration of L-arginine ...

We evaluated the effects of replacing the standard St. Thomas Hospital (ST) cardioplegic fluid with Bretschneider (BR) fluid during coronary-aortal bypass graft operation (CABG) in patients with coronary disease. BR fluid contains enormous concentration of histidine (approximately 0.2 mole L-1): thus increased levels of histamine or other metabolites might exert ...

BACKGROUND: Neurohormones may influence vascular tone both during and after exercise. Neuropeptide Y (NPY), which is costored and released with norepinephrine (NE) during sympathetic activity, is a potent vasoconstrictor with a relatively long half-life. We therefore examined its possible association with the ischemic response to exercise in patients with coronary ...

BACKGROUND: ST-segment depression is common in patients with hypertrophic cardiomyopathy (HCM). However, it is not clear whether exercise-induced ST-segment depression in patients with HCM and patent coronary arteries is associated with changes in left ventricular function. METHODS: Left ventricular function was continuously evaluated in 53 patients with nonobstructive HCM during ...

BACKGROUND: Proposed mechanisms for "warm-up" after angina on first exercise include ischemic preconditioning and collateral recruitment. The aim of this study was to determine whether patients with ischemic heart disease and well-developed coronary collateral vessels have a greater warm-up response than those with no visible collateral vessels. METHODS AND RESULTS: ...

BACKGROUND: Warm-up phenomenon, one of the clinical models of ischemic preconditioning, refers to an increased tolerance to myocardial ischemia during the second of two consecutive exercise tests. HYPOTHESIS: Blockers of K(ATP) channels, such as the sulfonylurea drugs, can induce loss of ischemic preconditioning. This study aimed to investigate the effects ...

The transient U wave inversion during exercise is specific for detecting left anterior descending coronary artery (LAD) disease. In a homogeneous patient group restricted to LAD disease, however, the significance of the electrocardiographic finding has not yet been clarified. Thus, clinical characteristics in patients with angiographically documented one-vessel disease of ...

BACKGROUND: Recent studies have indicated that heparin administration might decrease endothelial nitric oxide production. The aim of this study was to investigate the effect of heparin on ischemic threshold. METHODS: Eighteen patients with a positive exercise test and proven coronary artery disease were submitted to a randomized, placebo-controlled trial using ...

False-positive exercise testing in patients with an accessory pathway has been described only in patients with manifest preexcitation during exercise. We describe a patient in whom marked ST-segment changes were seen during an exercise test in the absence of any preexcitation of the QRS complexes. The role of the accessory ...

OBJECTIVE: We prospectively studied the course of exercise induced positive U-wave before and after percutaneous transluminal coronary angioplasty (angioplasty). BACKGROUND: Negative U-wave in ECG is known to be associated with the myocardial ischemia in the territory of the left anterior descending artery. Positive U-wave needs further evaluation to prove its ...

AIMS: The association between stress-induced ST elevation and functional recovery following revascularization after myocardial infarction remains unclear. We assessed the relative accuracy of dobutamine- and exercise-induced ST elevation in Q wave leads in predicting functional recovery following revascularization, and we investigated the relationship of ST elevation to different wall motion ...

It has recently been reported that increased QT dispersion seen on standard 12-lead electrocardiograms (ECGs) reflects transient myocardial ischemia. The present study investigates whether increased QT dispersion induced by exercise is a useful indicator for detecting significant coronary stenosis in patients who do not have chest pain or significant ST-segment ...

OBJECTIVES: The aim of this study is to demonstrate the effect of resting ST segment depression on the diagnostic characteristics of the exercise treadmill test. BACKGROUND: Previous studies evaluating the effect of resting ST segment depression on the diagnostic characteristics of exercise treadmill test have been conducted on relatively small ...

Our aim is to evaluate serial changes in normal full-term fetal cerebral circulation according to the behavioral states. Flow velocity waveforms in the middle cerebral artery and fetal heart rate (FHR) were well recorded in ten of 19 cases by pulsed Doppler ultrasonography and actocardiography over 45 min, respectively. Behavioral ...

Research on microembolic signals (MES) using the dual-gate technique has shown promising results, when the time difference (Deltat) of a MES in two sample volumes (SVs) placed serially has been measured manually. On the other hand, the computerized discrimination of MES and artefacts has been reported not to be superior ...

Whole-body impedance cardiography (ICGWB) has been proposed as a feasible means of measuring cardiac output (CO). However, the source distribution of heart-related impedance variations in the whole body is not known. To establish how much of a signal originates in each segment of the body and what the contribution of ...

OBJECTIVE: ST-segment depression is believed as a common electrocardiographic sign of myocardial ischemia during exercise testing. Ischemia is generally defined as oxygen deprivation due to reduced perfusion. However, the exact relationship of the ischemic definition to ST-segment depression remains unclear. This study was conducted to evaluate the correlation between myocardial ...

OBJECTIVES: To evaluate the long-term predictive value of exercise testing performed early after acute myocardial infarction (AMI) in patients receiving thrombolytic therapy. DESIGN: Nonblinded prospective follow-up study. SETTING: Cardiac rehabilitation unit in a 900-bed university hospital. SUBJECTS: Four hundred forty-three patients allowed to perform exercise testing 3 weeks after AMI ...