To determine if patterns of ST depression or elevation during exercise testing provide reliable information about the location of an underlying coronary lesion, we studied 452 consecutive patients with one-vessel disease who underwent treadmill testing. Exercise ST changes were classified as elevation or depression and by lead groups involved. The ...

To investigate the mechanism of action of nitrovasodilators in exercise-induced angina, 15 patients with chronic stable angina underwent a symptom-limited supine exercise test (exercise 1). After recovery, in 10 patients (group I) a coronary vasodilator, SIN-1 (the active metabolite of molsidomine) was injected into the most diseased coronary artery (80 ...

The exercise response to a single oral dose (25 mg) of a new beta-blocking agent that also has potent vasodilating properties, carvedilol, was assessed in 15 patients with stable exertional angina, positive exercise tests (greater than or equal to 1 mm ST depression) and coronary artery disease. A placebo-controlled, randomized, ...

Nineteen patients with syndrome X (typical exertional angina, positive exercise test response [at least 0.1 mV of ST-segment depression], no evidence of coronary spasm and angiographically normal coronary arteries) underwent continuous 48-hour electrocardiographic (ECG) monitoring during unrestricted daily life. Fifty-eight ischemic episodes of at least 0.1 mV of ST-segment depression ...

In this study, we tested the hypothesis that myocardial ischemia induced by exercise in patients is associated with diminished metabolism and/or delayed clearance of an intravenously injected fatty acid, iodine 123-labeled phenylpentadecanoic acid (IPPA). Fifteen normal volunteers and 18 patients with significant coronary heart disease (CHD) received IPPA during exercise. ...

A patient with significant left anterior descending coronary disease is presented who developed significant ST segment elevation and depression at different times under similar testing conditions. Currently proposed explanations for exercise-induced ST segment elevation are discussed. This patient likely represents a case of spasm superimposed on significant obstructive disease, so-called ...

Exercise tests with sublingual nitroglycerin were performed on 7 patients with true positive and 8 patients with false positive exercise test results. Four of 7 patients with true positive changes and 8 patients with false positive changes underwent exercise cardiac scintigraphy. Scintigrams showed perfusion defects in 4 patients with true ...

A new treadmill exercise protocol, modified from the standard Bruce method, was designed to improve ST segment/heart rate slope accuracy and applicability by reducing heart rate increments between exercise stages. In 150 patients exercised according to the new protocol and in 150 patients exercised according to the Bruce protocol, similar ...

Isosorbide 5-mononitrate (IS 5-MN) is an active metabolite of isosorbide dinitrate and is widely used as an antianginal agent. The acute and subacute (2 weeks) effects of IS 5-MN, 40 mg twice daily, were evaluated in 18 patients with stable angina pectoris using computerized exercise testing and a placebo-controlled, double-blind, ...

Exercise testing is contraindicated during active pericarditis because of the possibility of myocarditis. In a patient suspected of having ischemic heart disease, a pericardial rub appeared for the first time following a maximal exercise test, during which the elevated J-points descended to baseline. In two normal volunteer subjects with early ...

Analysis of the rate-related change in exercise-induced ST segment depression, the ST/HR slope, has been shown to significantly improve the accuracy of the exercise ECG for the identification of patients with coronary artery disease and for the recognition of patients with stable angina pectoris who have anatomically or functionally severe ...

During exercise by patients with coronary artery disease (CAD), electrocardiographic evidence of myocardial ischemia may precede the onset of angina or may be unassociated with angina, even at peak levels of stress. However, neither the precise incidence of silent versus symptomatic ischemic episodes nor their interrelation in this setting has ...

The objective of this investigation was to determine whether extended low-frequency response is required to record ischemic ST-segment abnormalities in humans. Bipolar electrocardiograms (ECGs) were recorded in 5 men with coronary artery disease using a high-fidelity instrumentation amplifier and FM tape recorder before, during and after erect bicycle exercise. In ...

A 12 lead electrocardiogram was recorded during treadmill exercise in 57 patients with variant angina in whom coronary angiography was performed. Thirty six patients performed exercise tests with and without calcium antagonists, and 21 performed them only with calcium antagonists. In 55 patients calcium antagonists had prevented spontaneous attacks of ...

Seventy three patients (63 males and 10 females) aged 41-75 years with established stable exertional angina pectoris were studied in a double-blind fashion to confirm the efficacy of 80 mg propranolol administered three times daily and also to examine its effect on ST-segment changes in the electrocardiogram by ambulatory ST-segment ...

To determine whether dipyridamole infusion can be used as an alternative method to physical exercise, 87 lead body surface mapping was performed to compare the distribution patterns of ST-segment depression after 0.568 mg/kg/4 min dipyridamole infusion (D) and after submaximal treadmill exercise (T) in 21 patients with coronary artery disease. ...

The aerobic and anaerobic thresholds determined from venous lactate (AerTLa and AnTLa) or from ventilation and gas exchange (AerTr and AnTr) in relation to muscle fiber composition were compared. Twelve subjects were studied in double exercise tests carried out until voluntary exhaustion. They were divided into two groups according to ...

Exercise testing performed earlier than six weeks post-MI is accepted as "standard" medical practice. Although both heart rate-limited and symptom-limited exercise protocols are used with nearly equal frequency, the latter appears more valuable because the prognostic yield is greater without sacrificing patient safety. Treadmill or cycle ergometers are the preferred ...

This study was performed in order to determine whether exercise-induced myocardial ischemia demonstrated by thallium-201 imaging could be detected by ST segment shifts in patients with abnormal Q waves at rest. Fifty-four patients with coronary artery disease and exercise-induced thallium-201 defects were compared to 22 patients with similar Q wave ...

Cigarette smoking is strongly associated with ischemic heart disease and acute coronary events. The effect of smoking a single cigarette on regional myocardial perfusion was studied in 13 chronic smokers with typical stable angina pectoris using positron emission tomography and rubidium-82 (82Rb). Findings were compared with the effects of physical ...

Exercise may induce ventricular arrhythmias (VA) in patients with coronary artery disease. Exercise-induced VA can identify a subset of patients at higher risk of cardiac sudden death. The role of myocardial ischaemia and/or left ventricular disease in the appearance of VA during exercise is not completely understood. The incidence of ...

The value of an early symptom-limited maximal exercise test in predicting coronary anatomy, left ventricular ejection fraction and hemodynamics was assessed prospectively in 64 patients after an acute non-Q-wave myocardial infarction (MI). Exercise tests and cardiac catheterization were performed at a median of 6 and 7 days, respectively, after non-Q ...

The hypothesis was tested that regional myocardial contractile dysfunction can detect subtle regional coronary blood flow maldistribution induced by exercise. In seven dogs, left ventricular pressure (micromanometer), regional systolic wall thickening (WTh, sonomicrometry), and myocardial blood flow (MBF, microspheres) were measured when mild degrees of coronary artery stenosis were produced ...

To elucidate a mechanism and clinical implications of chest pain and ST segment depression during exercise in patients with hypertrophic cardiomyopathy (HCM), we investigated myocardial lactate metabolism during atrial pacing in 18 patients with HCM and 7 control subjects with normal coronary arteriograms. At an average peak pacing rate of ...

The effect of digoxin on the electrocardiogram at rest and during and after exercise was studied in 11 healthy subjects. Exercise was performed on a heart rate-controlled bicycle ergometer with stepwise increased loads up to a heart rate of 170 beats/min. The subjects were studied after peroral intake of digoxin ...

The rate of depression of the ST segment with increasing heart rate (HR) during exercise has been claimed to predict the extent of coronary artery disease (CAD). To determine whether the maximal ST/HR slope is better than the Bruce treadmill exercise test for predicting the presence of CAD, the maximal ...

Using sonomicrometry, we measured the in vivo tidal shortening and velocity of shortening of the costal and crural segments of the diaphragm in the anesthetized dog in the supine, upright, tailup, prone, and lateral decubitus postures. When compared with the supine position, end-expiratory diaphragmatic length varied by less than 11% ...

To provide more insight into the role of alpha-adrenergic coronary tone in exercise-induced angina, 9 patients with chronic stable angina underwent after coronary angiography a symptom-limited supine exercise test on a cyclo-ergometer. After recovery, phentolamine was directly injected into the most diseased vessel (2 mg in 5 minutes), and immediately ...

Twenty-five healthy adults underwent subcostal-view, four-chamber two-dimensional echocardiographic examination while upright at rest and at the peak of maximal bicycle exercise. The purpose of the study was to determine whether the variability in regional left ventricular endocardial motion, previously demonstrated to be present at rest, persisted at peak exercise. The ...

Electrocardiographic (ECG) changes were studied in 82 adult patients with a mean age of 49 years undergoing microlaryngoscopy. The patients were pretreated with practolol 0.15 mg/kg i.v. 5 min before induction of anaesthesia with thiopental. Anaesthesia was maintained with nitrous oxide in oxygen, fentanyl and suxamethonium-infusion. ECG changes occurred in ...

To determine whether regional myocardial dysfunction occurring after exercise-induced ischemic might be caused by continued abnormalities of myocardial blood flow in the post-exercise period, nine dogs were instrumented with ultrasonic microcrystals for determination of circumferential segment shortening, circumflex artery electromagnetic flow probes, and hydraulic coronary artery occluders. Dogs performed treadmill ...

Nine patients with coronary insufficiency were investigated using an exercise test coupled with quantitative myocardial tomoscintigraphy with thallium-201 before and after 48 hours' treatment with captopril. After captopril treatment, an improvement in ST segment depression was noted during exercise. The quantitative tomoscintigraphy showed a reduction in the ischaemic zone with ...

The treadmill exercise test with the Bruce protocol was performed in three patients with post-myocarditic myocardial hypertrophy (PMH) and ten patients with cardiomyopathy, including three with dilated cardiomyopathy (DCM), five with hypertrophic obstructive cardiomyopathy (HOCM), and two with hypertrophic and nonobstructive cardiomyopathy (HCM). The endurance time was below the normal ...

A double-blind crossover study, with placebo periods preceding each active treatment, was carried out in 29 patients with ischaemic heart disease to compare the clinical efficacy of isosorbide 5-mononitrate 40 mg twice daily and the same regimen of sustained-release isosorbide dinitrate. Assessment was by bicycle ergometry, symptomatology and blood nitrate ...

Short exercise duration is not necessarily ominous in an older patient unless other significant abnormalities, such as ST-segment depression or arrhythmias, are associated. Problems peculiar to the elderly during exercise testing--appearance of fatigue and lightheadedness due to muscle weakness and deconditioning, vasoregulatory insufficiency, and a tendency to unsteadiness of gait--may ...

Exercise electrocardiographic stress testing was performed in 81% of the 780 patients randomized in the Coronary Artery Surgery Study at entry. The cumulative survival at the end of 7 year follow-up was 90% for those assigned to surgical treatment and 88% for those assigned to medical therapy (p = NS). ...

Simultaneous photoplethysmographic (PPG) and strain gauge plethysmographic (SPG) recordings were obtained in normal subjects and patients with venous insufficiency. In PPG tracings, a so called "negative segment," which represented a further fall below the baseline after exercising, was often observed. This negative segment is produced by blood flow from the ...

Both in vivo superficial loop segment microperfusion and in vitro perfusion of isolated medullary thick ascending limb segments were used to assess the effect of vasopressin on loop of Henle chloride absorption in the Brattleboro rat. Superficial loop segments were perfused between the latest proximal and earliest distal tubule in ...

Regional myocardial blood flow during exercise was determined using the thermodilution technique in 2 patients suffering from both spontaneous and exertional chest pain. In both cases we observed that effort-related anginal attacks were due to coronary spasm with sudden reduction of regional left ventricular blood flow. In 1 patient the ...

To investigate the sites of exercise-induced ST segment changes on the body surface in effort angina pectoris without myocardial infarction, we performed 87-lead ECG mapping in 61 patients before and 1.5 and 5 minutes after treadmill exercise. ST segment depression most often occurred in the left anterior chest leads and ...

To investigate the spectrum of change in multiple-lead exercise electrocardiograms, 120-lead body surface potential maps (BSPM) in normal adult subjects during upright, graded, submaximal exercise testing were recorded. Results showed that in the normal group, exercise was associated with substantial electrocardiographic changes on the body surface, many of which persisted ...

A system of 21-lead electrocardiography was used to assess 21 patients with severe angina during and after exercise using on-line computerised ST segment analysis. A direct comparison was made between the results obtained from 18 unipolar precordial leads and those from bipolar leads CM5 and CC5. Treadmill exercise was performed ...

Alaryngeal voice is usually accompanied by esophageal speech; however, about 40% of laryngectomy patients are unable to achieve adequate esophageal speech and must rely on mechanical devices for communication. A technique was developed for performing double-contrast studies of the hypopharynx, cervical esophagus, and pharyngo-esophageal segment using thick barium and the ...

The prognostic value of ST-segment depression during maximal exercise test performed in the third to fourth week after acute myocardial infarction (AMI), was studied in 126 consecutive patients with no evidence of previous myocardial infarction, unstable angina pectoris or severe heart failure. All patients on average increased their pressure-rate product ...

To investigate the mechanism of exercise-induced ST elevation in previous anterior myocardial infarction, exercise body surface mapping was performed on 22 patients with anterior myocardial infarction. ST elevation was compared with the findings of exercise radionuclide ventriculography and exercise thallium-201 myocardial perfusion imaging. ST-segment was quantified by the integral of ...

Male subjects were placed into one of three intoxication conditions (no ethanol, low dose, high dose) and were exposed to humorous segments from television programs. During manifest intoxication or the corresponding period in the no-intoxication control condition, they were exposed, in a balanced order, to a segment containing blunt (i.e., ...

The exercise response to a single oral dose (25 mg) of a new beta-blocking agent that also has potent vasodilating properties, carvedilol (BM 14,190), was assessed in 15 patients with stable exertional angina, positive exercise test responses (greater than or equal to 1 mm of ST depression) and coronary artery ...

Exercise tolerance before and after sublingual isosorbide dinitrate (ISDN), 10 mg, was assessed in 217 consecutive patients with stable angina, positive exercise test, and angiographically proved coronary artery disease. In 65 patients (30%), ISDN prevented exercise-induced ST segment depression and/or increased exercise time to 1 mm ST segment depression (greater ...

In 36 patients with effort angina pectoris without myocardial infarction, the sites of exercise-induced ST changes (depression and elevation) on the body surface were investigated. Exercise-induced ST depression was most often seen in left anterior chest leads. The body surface distribution of ST depression failed to identify the obstructed coronary ...

Does 2 mm of ST depression induced by exercise have the same clinical significance in a patient with a 30-mm R wave as a patient with a 10-mm R wave in the same monitored lead? To answer this question the exercise responses of 85 patients were compared by 2 quantitative ...