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Biomedical subjects

R S Gibson

Publications and source records attributed to R S Gibson.

At least 73 records · Page 4Linked to original sources
PubMed1993

Growth and body composition of periurban Guatemalan children in relation to zinc status: a longitudinal zinc intervention trial.

Changes in growth, body composition, and zinc indexes were evaluated after 25 wk in a double-blind zinc-supplementation study of 162 periurban Guatemalan children aged 81.5 +/- 7.0 mo (mean +/- SD). Children receiving the zinc supplement (10 mg Zn/d as amino acid chelate) for 90.1 +/- 9.2 d had higher mean fasting plasma zinc (16.2 +/- 2.9 vs 14.9 +/- 2.1 mumol/L, P < 0.01), a greater increase in median triceps skinfold Z score (0.50 vs 0.38, P < 0.05), and a smaller deficit in median midarm circumference (MAC) Z score (-0.03 vs -0.20, P < 0.05) compared with the placebo group. Initial hair zinc classified as < 1.68 and > 1.68 mumol/g was the only laboratory variable that explained some of the variance in final Z scores of midarm-muscle area (P < 0.05) and MAC (P < 0.01). Children responded to the zinc supplement with changes in indexes of body composition rather than growth.

Anthropometry↗
PubMed1993

The zinc nutriture of preschool children living in two African countries.

The zinc nutrition of rural Malawian children (24 females, 33 males; age 62 +/- 10 mo) consuming cereal-based diets was compared with that of rural Ghanaian children (43 females, 33 males; age 59 +/- 10 mo) consuming cereals or starchy staples, using hair zinc concentrations, growth and body composition indices, and dietary intakes. Intakes of energy, protein, Ca, Zn, dietary fiber and phytate at two seasons of the year were estimated from 3-d weighed food records, using analyzed and literature food composition values. The mean annual intakes of energy (5419 +/- 1081 vs. 4698 +/- 885 kJ), protein (31.8 +/- 7.0 vs. 24.1 +/- 6.8 g), Zn (7.4 +/- 1.9 vs. 5.1 +/- 1.1 mg) and phytate (1899 +/- 590 vs. 604 +/- 151 mg), and the mean molar ratios of [phytate]/[Zn] and [Ca] x [phytate]/[Zn] mmol per MJ (25 +/- 4 vs. 12 +/- 2 and 44 +/- 13 vs 20 +/- 8 mmol/MJ), were higher for Malawian than for Ghanaian children. More Malawian than Ghanaian children had [phytate]/[Zn] > or = 15 (72% vs. 0%) and were severely stunted (57 vs. 28%). Ninety-four percent of children in Malawi and 83% in the Ghanaian village of Slepor had low hair Zn concentrations (< 1.68 mumol/g) compared with 39% in Gidantuba, Ghana. In Gidantuba, children with low hair Zn concentrations had low upper-arm-muscle-area-for-age and upper-arm-muscle-area-for-height Z-scores. The high intakes of phytic acid relative to zinc in Malawi suggest that these children were at greater risk for inadequate zinc nutriture than their Ghanaian counterparts.

Analysis of Variance↗
PubMed1993

A multi-element isotopic tracer assessment of true fractional absorption of minerals from formula with additives of calcium, phosphorus, zinc, copper and iron in young piglets.

True fractional absorption of minerals was measured to determine the bioavailability of Zn, Fe, Mn and Se from liquid formulas fortified with stepwise additions of Ca and P (as Ca glycerophosphate and carbonate, Ca*P), and Zn, Cu and Fe (as sulfate salts). Growth, deposition of tracers in organs and bone mineral content of femurs as assessed by single photon absorptiometry were measured. Four-day-old piglets (n = 36) were randomly assigned to groups fed a basal diet or additions of Ca*P (Ca = 25, P = 18 g/kg dry diet), Ca*P+Zn (Zn = 0.04 g/kg), Ca*P+Zn+Cu (Cu = 0.007 g/kg) or Ca*P+Zn+Cu+Fe (Fe = 0.008 g/kg). Oral and intravenous administration of extrinsic isotopes of 59Fe, 54Mn, 65Zn, 75Se and 47Ca was followed by fecal monitoring for 15 d and true absorption calculated after accounting for endogenous excretion. Addition of Ca*P+Zn reduced Zn absorption (P < 0.05) and Ca*P+Zn+Cu reduced Fe absorption (P < 0.01), but Mn and Se absorptions were not altered. Uptake of only Zn tracer into heart was significantly different (P < 0.05) among diet groups. Weight gain and linear growth were similar in all groups. Addition of Ca*P produced higher bone mineral density, but its effect on Zn absorption warrants further investigation.

Absorptiometry, Photon↗
PubMed1993

Subsets of ambulatory myocardial ischemia based on heart rate activity. Circadian distribution and response to anti-ischemic medication. The Angina and Silent Ischemia Study Group (ASIS)

BACKGROUND: Identification of whether episodes of ambulatory ischemia are caused by increases in myocardial oxygen demand or to episodic coronary vasoconstriction in patients with stable coronary disease may be important to guide selection of optimal anti-ischemic therapy and to gain insight into mechanisms responsible for adverse cardiac events. METHODS AND RESULTS: Mean minute heart rate activity during ambulatory ECG (AECG) monitoring was determined for 50 patients treated with propranolol, diltiazem, nifedipine, or placebo in a randomized, double-blind, crossover trial. Periods of heart rate increases of various magnitudes and durations and starting at various baseline heart rates on each therapy were identified throughout each 48-hour AECG recording, and the proportion of these periods associated with an ischemic episode was determined. The circadian variation of ischemic episodes categorized by the presence or absence of an increase in heart rate was analyzed. Eighty-one percent of ischemic episodes were preceded by an increase in heart rate > or = 5 beats per minute. The likelihood of developing ischemia associated with a heart rate increase was proportional to the magnitude and duration of the heart rate increase and the baseline heart rate before the increases in heart rate: likelihood ranged from 4% when the heart rate increased 5-9 beats per minute and lasted < 10 minutes to 60% when the heart rate increased > or = 20 beats per minute and lasted > or = 40 minutes. The likelihoods of developing ischemia based on changes in the heart rate variables were similar for each of the therapies. Propranolol therapy significantly reduced the magnitude and duration of heart rate increase and the baseline heart rate compared with therapy with placebo, diltiazem, or nifedipine (P < .001). Ischemic episodes associated with a heart rate increase displayed a daytime peak, whereas ischemia occurring without a heart rate increase occurred evenly throughout the day. Propranolol reduced the proportion of heart rate-related ischemic episodes and increased the proportion of non-heart rate-related episodes compared with placebo (P < .02), and nifedipine exerted the opposite effect (P = .005). Multivariate analysis indicated that the probability of developing ischemia was strongly associated with heart rate variables and was unaffected by time of day. CONCLUSIONS: Most episodes of ambulatory ischemia are associated with a preceding period of increased heart rate. The likelihood of developing ischemia is predicted by heart rate variables and unaffected by time of day. Anti-ischemic efficacy is generally a result of the medication's efficacy in reducing heart rate variables. A minority of ischemic episodes are not associated with preceding periods of increased heart rate, may be caused by episodic coronary vasoconstriction, and are more effectively reduced by nifedipine than propranolol.

Circadian Rhythm↗
PubMed1992

Indices of iron and copper status during experimentally induced, marginal zinc deficiency in humans.

This study examined the effect of diet-induced, marginal zinc deficiency for 7 wks in 15 men (aged 25.3 +/- 3.3 yrs; mean +/- SD) on selected indices of iron and copper status. The regimen involved low-zinc diets based on egg albumin and soy protein with added phytate and calcium such that mean [phytate]/[Zn] and [phytate] X [Ca]/[Zn] molar ratios were 209 and 4116, respectively, for 1 wk, followed by 70 and 2000, respectively, for 6 wks. Subjects were then repleted with 30 mg Zn/d for 2 wks. Plasma copper, Cu,Zn-superoxide dismutase (Cu,Zn-SOD) activity in plasma and red blood cells (RBC), hemoglobin, hematocrit, and serum ferritin were determined weekly on fasting blood samples. Significant reductions (p less than 0.05) after 7 wks in RBC Cu,Zn-superoxide dismutase (49.5 +/- 7.2 vs 33.6 +/- 6.3 U/mg Hb) and serum ferritin (69.2 +/- 38.7 vs 53.8 +/- 33.7 micrograms/L) occurred; no comparable decline was noted for plasma Cu, hemoglobin, or hematocrit. Significant (p less than 0.05) but less consistent changes were also observed in plasma superoxide dismutase activity. None of the changes were associated with the decreases in plasma, urinary and hair zinc concentrations, and alkaline phosphatase activity in RBC membranes. Results indicate that the biochemical iron and copper status of the subjects was marginally impaired, probably from the dietary regimen that induced marginal zinc deficiency.

Adult↗
PubMed1992

The relationship between 1-year mortality and infarct location in patients with non-Q wave myocardial infarction.

The association between 1-year mortality and infarct location was evaluated in 544 patients with acute non-Q wave myocardial infarction. Infarcts were anterior (alone or including other locations) in 51.1% (n = 278) of cases, localizable but not anterior 29.6% (n = 161) of the time, and nonlocalizable in 19.3% (n = 105) of patients. One-year actuarial mortality (73 deaths) was 16.9% in the anterior group, 13.3% in the nonanterior group, and 6.8% in nonlocalizable patients (p = 0.037). Anterior and localizable nonanterior mortality were similar (p = 0.367). However, there were differences when mixed location infarcts were excluded. Mortality in the inferior infarction only group (2.8%, n = 36) was less than in the lateral infarction only group (16.8%, n = 79, p = 0.041) and almost significantly less than in the anterior only group (15.1%, n = 62, p = 0.064). The positive prognosis in the inferior infarction only group may be associated with the low rate of ST depression among these patients compared with those with other infarct locations (p less than 0.0001). Mortality among localizable infarcts (15.5%) was greater than among those that were nonlocalizable (6.8%, p = 0.021). Despite the low overall risk of the nonlocalizable infarcts, 41.9% (n = 44) of these patients developed at least one important risk factor while in hospital.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1992

Erythrocytes, erythrocyte membranes, neutrophils and platelets as biopsy materials for the assessment of zinc status in humans.

During a controlled zinc depletion-repletion study, fifteen men aged 25.3 (SD 3.3) years were fed on a low-Zn diet with high phytate:Zn and phytate x calcium:Zn molar ratios for 7 weeks, followed by a 2 week repletion period when 30 mg supplemental Zn/d was given. Changes in plasma, urine, and hair Zn concentrations, taste acuity, and cellular immune response confirmed the development of mild Zn deficiency. Zn concentrations in neutrophils, platelets, erythrocytes and erythrocyte membranes, mean platelet volume, and activities of alkaline phosphatase (EC 3.1.3.1) and alpha-D-mannosidase (EC 3.2.1.24) in neutrophils did not respond to changes in Zn status. In contrast, alkaline phosphatase activity in erythrocyte membranes showed a significant decline which was consistent in all subjects (nmol product formed/min per mg protein; baseline v. 7-week Zn depletion, 0.656 (SD 0.279) v. 0.506 (SD 0.230), at 7 weeks; P < 0.05); neutral phosphatase activity remained unchanged. Alkaline phosphatase activity in erythrocyte membranes may be a potential index of Zn status in humans.

Adult↗
PubMed1992

Selenium intakes of children from Malawi and Papua New Guinea consuming plant-based diets.

Dietary selenium intakes were determined over three seasons for 66 children aged 4-6 y in rural Malawi, and at one season for 67 children aged 6-10 y in rural Papua New Guinea. The selenium content of the foods consumed was assessed using instrumental neutron activation analysis. Median intakes of selenium for the Malawian children were 20 micrograms per day, 21 micrograms per day, and 15 micrograms per day at harvest, postharvest, and preharvest seasons, respectively. More than 43% of the Malawian intakes were below the U.S. Recommended Dietary Allowances for 4-6 y olds (20 micrograms per day). Median intake of Se for the Papua New Guinean children was 20 micrograms per day, with 87% of the intakes below the recommended level for 7-10 y olds (30 micrograms per day). Statistical comparisons of selenium intakes over three seasons for the 51 children present in all survey periods revealed that mean intakes were not significantly different in survey periods one and two, but decreased significantly in survey period three, when expressed per day (p less than 0.002), per MJ (p less than 0.003), or per kg (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Child↗
PubMed1991

The prognostic and economic implications of a strategy to detect and treat asymptomatic ischemia: the Atenolol Silent Ischemia Trial (ASIST) protocol.

Although silent ischemia may be linked to increases in cardiovascular morbidity and mortality, the long-term effects of a strategy aimed at the detection and treatment of this asymptomatic condition have not been fully explored. We therefore have developed the Atenolol Silent Ischemia Trial (ASIST), the first multicenter, randomized, prospective study of the prognostic implications of silent ischemia in asymptomatic and minimally symptomatic patients with coronary artery disease. Inclusion criteria for study patients were documented coronary artery disease, evidenced angiographically or by previous myocardial infarction, and transient ischemia, evidenced by abnormalities of regional wall motion, stress thallium-201, or exercise electrocardiogram. The main objective of ASIST is to assess the influence of frequency and duration of symptomatic and asymptomatic ischemic episodes on the occurrence of fatal and nonfatal cardiac events. Atenolol, a beta 1-selective adrenergic blocker, was chosen as the therapeutic intervention because of its potential benefits in treating both symptomatic and asymptomatic ischemia. Ambulatory electrocardiographic monitoring will be used to measure the frequency and duration of ischemic episodes during daily life. The predictive ability of short-term (4-week) effects on long-term (52-week) response to atenolol treatment is also being assessed, along with the economic impact of this diagnostic and therapeutic strategy. Given the current emphasis on reducing morbidity and mortality associated with coronary artery disease, ASIST results should shed light onto the long-term management and prognostic implications of this otherwise asymptomatic condition.

Atenolol↗
PubMed1991

Dietary phytate x calcium/zinc millimolar ratios and zinc nutriture in some Ontario preschool children.

Millimolar ratios of phytate/Zn, Ca x phytate/Zn, and Ca x phytate/Zn per 4.2 MJ were calculated from 3-d weighed-food records collected from 62 male (M) (mean age: 58 +/- 7 mo [mean +/- SD]) and 44 female (F) (mean age: 58 +/- 6 mo) preschool children from Southern Ontario. Food-composition values for phytate were based on laboratory analysis and the literature. No gender differences existed for median millimolar ratios of phytate/Zn (median: M, 5.3; F, 5.3), and Ca x phytate/Zn per 4.2 MJ (M, 68.1; F, 59.5), but median intakes of phytate (M, 399; F, 333 mg/d) and median millimolar ratios of Ca x phytate/Zn (median: M, 102.1; F, 72.3; p less than 0.01) were higher for boys than for girls. Of the children, only two (1M, 1F) and 22 (17 M, 5F) had millimolar ratios of phytate/Zn and Ca x phytate/Zn per 4.2 MJ, respectively, that were above critical values. Millimolar ratios of Ca x phytate/Zn (p = 0.06) and Ca x phytate/Zn per 4.2 MJ (p = 0.05) were higher in boys with hair zinc less than 1.07 mumol/g v greater than or equal to 1.07 mumol/g. Analysis of variance showed that height was influenced by an interaction between millimolar ratios of Ca x phytate/Zn per 4.2 MJ and sex (p = 0.0007), when age and midparent height were treated as covariates. Results suggest that dietary Ca x phytate/Zn millimolar ratios, when expressed per 4.2 MJ, influenced the zinc nutriture of these Southern Ontario boys.

Calcium, Dietary↗
PubMed1991

Weight is not an accurate criterion for adult cardiac transplant size matching.

Owing to the limited availability of donor hearts, standard donor criteria for heart size matching need to be reexamined. The current practice at most centers is to match the donor's body weight to within +/- 20% of the recipient's. Our hypothesis was that minimal differences exist in heart sizes of the adult donor population, and therefore, the donor pool could be expanded for any given patient. M-mode echocardiographic measurements of left and right ventricular internal dimensions, left ventricular mass, and percent fractional shortening were reviewed in 235 normal adult subjects (101 men, 134 women). Low correlation coefficients and a high degree of variance were consistently observed between cardiac parameters and body size. There were no significant differences in left ventricular internal dimension when women weighing 40 to 109 kg were compared with men statistically different among men weighing 50 to 99 kg. No difference was noted in right ventricular size among men and women. Echocardiography is a simple and accurate technique to assess cardiac dimensions. Body weight does not correlate well with adult cardiac size and should not be used as an exclusion criterion for a donor heart.

Body Height↗
PubMed1991

Growth in children from the Wosera subdistrict, Papua New Guinea, in relation to energy and protein intakes and zinc status.

In a cross-sectional study of 123 children aged 24-120 mo from the Wosera subdistrict of Papua New Guinea, height, weight, hematocrit, hemoglobin, hair zinc, and presence of malaria were measured. Two 24-h recalls were undertaken in 67 of the children aged 72-120 mo; 52%, 73%, and 76% had energy, protein, and zinc intakes, respectively, less than two-thirds of the FAO/WHO/UNU recommendations. Stunting was prevalent (29%); 16% were moderately wasted. The prevalence of stunting and hair zinc concentrations less than 1.68 mumol/g was gender related; 38% of males vs 20% of females had Z scores for height-for-age (HAZ scores) less than -2 (P = 0.04); 26% of males vs 11% of females had hair zinc less than 1.68 mumol/g (P less than 0.05). Analysis of variance showed that age, sex, hemoglobin, and log hair zinc influenced HAZ scores, depending on the age group; both sex and the log of the hair zinc values were significant factors in the older children. Stunting in Worsera children was related to chronic deficits in energy and protein and was excerbated in the older male children by suboptimal zinc status.

Age Factors↗
PubMed1991

Development of a dietary model for the study of mild zinc deficiency in humans and evaluation of some biochemical and functional indices of zinc status.

After a 1-wk baseline period, a dietary regimen was developed to induce mild zinc deficiency in 15 males (aged 25.3 +/- 3.3 y, mean +/- SD). The regimen consisted of 1 wk on a liquid diet containing 0.6 mg Zn/d and molar ratios of phytate to zinc (phy:Zn) and of phytate X calcium to zinc [(phy X Ca): Zn] of 209 and 4116, respectively, followed by 6 wk on a diet based on soy protein and egg albumin containing 4 mg Zn/d and with phy:Zn and (Ca X phy):Zn of 70 and 2000, respectively. Subjects were then repleted with 30 mg Zn/d for 2 wk. Fasting blood and urine samples were taken weekly. Changes were observed in mean plasma (mumol/L) and urinary zinc (mumol/d): baseline 97.0 +/- 10.9 and 8.0 +/- 2.7, depletion 80.1 +/- 13.4 and 4.3 +/- 2.3, and repletion 100.8 +/- 13.6 and 8.2 +/- 3.1, respectively (P less than 0.05); taste acuity (0.05 less than P less than 0.10); and cellular immune responses (P less than 0.05). Activities of plasma angiotensin-1-converting enzyme and acidic alpha-D-mannosidase were unchanged. Mild zinc deficiency was induced by the dietary regimen.

Adult↗
PubMed1991

The diagnostic and prognostic value of exercise electrocardiography in asymptomatic subjects and stable symptomatic patients.

In asymptomatic patients, the use of exercise ECG testing for the detection of subclinical coronary artery disease has considerable theoretical appeal, but its practical application is severely hampered by the constraints of Bayes' theorem. Serial exercise ECGs do not appear to offer significant improvement in this regard. Thallium-201 perfusion scintigraphy performed in conjunction with an exercise ECG can greatly improve the predictive value of such testing, although at considerable cost. Screening strategies with promise are those that reserve exercise testing for individuals at greater-than-average risk for subclinical coronary artery disease (eg, patients with multiple coronary risk factors) or that prescribe sequential testing, where only those with an abnormal exercise ECG are subjected to thallium-201 scintigraphy. At present, the optimal method of identifying asymptomatic individuals at high risk of a major cardiac event remains undefined. The use of maximal-effort stress testing has stood the test of time in the evaluation of patients with stable symptoms suggestive of coronary artery disease. This is particularly true when variables other than the ECG response to exercise are considered. The independent contribution of exercise angina remains controversial; however, recent studies indicate that it correlates with a more severe symptom pattern and more extensive coronary artery disease. Prognostic stratification in these studies was improved by considering both subjective and objective manifestations of ischemia. Although exercise ECG testing has been shown to have important prognostic value after acute myocardial infarction, exercise thallium-201 scintigraphy offers several potential advantages for asymptomatic post-myocardial infarction patients, several of which this paper reviews. The more optimal prognostic efficiency of thallium-201 scintigraphy is due in part to the fact that the error rate in falsely classifying patients at low risk is substantially smaller with scintigraphy than with stress electrocardiography. Because of this, there appears to be adequate rationale for recommending exercise perfusion imaging, rather than exercise ECG testing alone, as the preferred method for evaluating mortality and morbidity risks after acute myocardial infarction.

Coronary Disease↗
PubMed1991

Management of acute non-Q-wave myocardial infarction. The role of prophylactic diltiazem therapy and indications for predischarge coronary arteriography.

Non-Q-wave myocardial infarction (MI) differs from Q-wave MI in 3 important respects: a smaller infarct size, possibly due to early reperfusion resulting from spontaneous thrombolysis, relief of spasm, or both; more frequency patency of the infarct-related artery; and a larger residual mass of viable but jeopardized myocardium within the perfusion zone of the infarct-related vessel. Left ventricular function is generally better unless impaired by previous MI. After the acute phase, the prognosis is worse when residual ischaemia is present, and reinfarction rates during hospitalisation and in the subsequent year of follow-up are higher. As myocardial ischaemia is potentially reversible, its presence should be actively sought in all patients with recognised non-Q-wave MI. On the basis of current knowledge and available data, the following guidelines for the management of non-Q-wave MI patients can be recommended: (1) diltiazem and aspirin should be administered to all patients as soon as the diagnosis is established, unless contraindications exist; (2) patients who develop early recurrent ischaemia on therapy (i.e. angina with associated ST-T-wave changes) should undergo prompt cardiac catheterisation and myocardial revascularisation; and (3) patients with entirely uncomplicated hospital histories who are asymptomatic should undergo exercise stress testing, preferably in conjunction with 201Tl perfusion scintigraphy, before hospital discharge. Only those patients with evidence of significant residual ischaemia need cardiac catheterisation and myocardial revascularisation.

Adrenergic beta-Antagonists↗
PubMed1991

Value of planar 201Tl imaging in risk stratification of patients recovering from acute myocardial infarction.

Although exercise ECG testing has been shown to have important prognostic value after acute myocardial infarction, exercise 201Tl scintigraphy offers several potential advantages, including: 1) increased sensitivity for detecting residual myocardial ischemia; 2) the ability to localize ischemia to a specific area or areas subtended by a specific coronary artery; 3) the ability to identify exercise-induced left ventricular dysfunction, which is manifested by increased lung uptake or transient left ventricular dilation; and 4) more reliable risk stratification of individual patients. The more optimal prognostic efficiency of 201Tl scintigraphy partially results from the fact that the error rate in falsely classifying patients as low risk is significantly smaller with 201Tl scintigraphy than with stress ECG. Because of these substantial advantages, there seems to be adequate rationale for recommending exercise perfusion imaging rather than exercise ECG alone as the preferred method for evaluating mortality and morbidity risks after acute myocardial infarction.

Angiography↗
PubMed1990

Clinical relevance of exercise-induced ventricular arrhythmias in suspected coronary artery disease.

Because there is controversy regarding the clinical relevance of exercise-induced ventricular arrhythmias, we analyzed their significance in 383 patients who had undergone both exercise thallium-201 stress-testing and cardiac catheterization. Two-hundred twenty-one patients (58%) had no exercise-induced ventricular arrhythmias while 162 (42%) did. There was no difference between patients with and without exercise-induced ventricular arrhythmias in terms of previous myocardial infarction (p = 0.61), incidence of fixed thallium-201 defects (0.06), number of diseased vessels (p = 0.09) and resting left ventricular ejection fraction (p = 0.06). In contrast, evidence of provocable ischemia (redistribution on thallium-201 and ST-segment depression on the electrocardiogram) were more likely (p less than 0.02) to be seen in patients with exercise-induced ventricular arrhythmias. Discriminant function analysis revealed that these 2 variables best separated patients with and without exercise-induced ventricular arrhythmias. In a 4- to 8-year follow-up, 89 patients had adverse cardiac events. Of these 89, there were 41 deaths, 9 nonfatal myocardial infarctions and 39 coronary revascularization procedures performed later than 3 months after catheterization. Patients with exercise-induced ventricular arrhythmias were more likely (p = 0.01) to have these events than those without these arrhythmias. Moreover, these arrhythmias provided independent prognostic information beyond that provided by the thallium-201 stress test and coronary angiography. We conclude that exercise-induced ventricular arrhythmias are associated with exercise-induced ischemia and provide prognostic information which adds marginally to that provided by other noninvasive and invasive parameters in ambulatory patients being evaluated for chest pain.

Arrhythmias, Cardiac↗