Abnormal Exercise Test Research Articles

Relation of coronary artery calcium to exercise testing in healthy subjects

Little is known about the occurrence of coronary artery calcium in apparently healthy volunteers and its relation to exercise testing, the most widely used noninvasive method for identifying subjects at risk. A previous study of this relation used conventional fluoroscopy and focused on men only. 1 Kelley K.J Huang E.K Langou R.A Correlation of fluoroscopically detected coronary artery calcification with exercise stress testing in asymptomatic men. Radiology. 1978; 129: 1-6 Crossref PubMed Scopus (20) Google Scholar , 2 Langou R.A Huang E.K Kelley M.J Cohen L.S Predictive accuracy of coronary artery calcification and abnormal exercise test for coronary artery disease in asymptomatic men. Circulation. 1980; 62: 1196-1203 Crossref PubMed Scopus (82) Google Scholar The present study analyzes the relation between coronary artery calcium, as detected by digital fluoroscopy, and exercise test results in a large cohort of apparently healthy men and women who are at usual cardiovascular risk.

Relation of C-reactive protein to extent and severity of coronary narrowing in patients with stable angina pectoris or abnormal exercise tests

Recent studies have implicated inflammation in the pathogenesis of coronary artery disease and of acute coronary syndromes.1‐3 Systemic markers of inflammation such as C-reactive protein (CRP) are elevated in patients with coronary atherosclerosis, 4 and increase significantly in patients with unstable angina or acute myocardial infarction.5 CRP levels are also powerful predictors of cardiac complications and death in patients with unstable coronary syndromes5 as well as in healthy men and women without a prior cardiac history.6,7 A potential explanation for the high event rate in patients with elevated CRP levels is that a high CRP level is a marker for more severe and extensive coronary artery disease. This study was designed to determine whether CRP correlates with the extent and severity of coronary atherosclerosis as assessed by coronary angiography. ••• This was a prospective trial. Outpatients with stable angina or an abnormal stress test who were referred for diagnostic cardiac catheterization with coronary angiography were screened. Patients with any preexisting condition that may cause CRP elevation were excluded. This included patients with known inflammatory, infectious, or neoplastic diseases, and patients with a history of myocardial infarction or unstable angina or any percutaneous interventional or surgical procedure within 2 weeks. Patients taking corticosteroids, or nonsteroidal anti-inflammatory or immunosuppressive drugs were also excluded, as were patients with a prior history of coronary artery bypass graft surgery. Cardiac catheterization and angiography were performed in the standard fashion. Each coronary angiogram was read by 2 interventional cardiologists who were blinded to CRP results and agreement was reached by consensus. Stenosis severity was determined using calipers. To assess the extent of atherosclerotic involvement, a coronary atherosclerosis score was designed using the following model. The coronary artery tree was divided into 9 segments: the left main coronary artery, the proximal, mid-, and distal left anterior descending artery (the major diagonal branch was considered part of the mid‐left anterior descending artery), the proximal circumflex artery including the first obtuse marginal branch, the circumflex artery distal to the first marginal branch, the proximal and mid‐right coronary artery, and the posterior descending artery. Each of these segments was scored from 0 to 3 depending on the most severe diameter stenosis according to the following system: 0 5 normal, 1 5 stenosis between 1% and 49%, 2 5 stenosis between 50% and 99%, and 3 5 total occlusion. In the case of total occlusion, each of the segments distal to the occlusion was arbitrarily given a score of 1. A coronary atherosclerosis score was generated as the sum of the scores in all segments. In addition, the number of vessels with coronary artery disease in each patient was calculated as the number of vessels with a stenosis $50%. CRP was measured immediately after insertion of

Maximal exercise test as a predictor of risk for mortality from coronary heart disease in asymptomatic men

Exercise testing in asymptomatic persons has been criticized for failing to accurately predict those at risk for coronary heart disease (CHD). Previous studies on asymptomatic subjects, however, may not have been large enough or long enough to provide reliable outcome measures. This study examines the ability of a maximal exercise test to predict death from CHD and death from any cause in a population of asymptomatic men. This is a prospective longitudinal study performed between 1970 and 1989, with an average follow-up of 8.4 years. The subjects are 25,927 healthy men, 20 to 82 years of age at baseline (mean 42.9 years) who were free of cardiovascular disease and who were evaluated in a preventive medicine clinic. The main outcome measures are CHD mortality and all-cause mortality. During follow-up there were 612 deaths from all causes and 158 deaths from CHD. The sensitivity of an abnormal exercise test to predict coronary death was 61%. The age-adjusted relative risk of an abnormal exercise test for CHD death was 21 (6.9 to 63.3) in those with no risk factors, 27 (10.7 to 68.8) in those with 1 risk factor, 54 (21.5 to 133.7) in those with 2 risk factors, and 80 (30.0 to 212.5) in those with ≥3 factors. A maximal exercise test performed in asymptomatic men free of cardiovascular disease does appear to be a worthwhile tool in predicting future risk of CHD death. An abnormal exercise test is a more powerful predictor of risk in those with than without conventional risk factors.

Radionuclide Imaging After Intermediate-Risk Exercise ECG

What are the prognostic implications when radionuclide imaging is normal or near-normal in patients with an abnormal exercise test? This study pools data from 4649 patients who underwent both types of testing at 4 different institutions. All patients …

Factores pronósticos tras el infarto agudo de miocardio tratado con fibrinolíticos

The usefulness of the exercise test in evaluating patients with an acute myocardial infarction treated with fibrinolytics is controversial. On the other hand, the prognostic value of a patent infarct-related artery has not been clearly established. The objectives of this study were to assess the validity of the exercise test and to study the prognostic value of the artery patency after a myocardial infarction. We studied 99 patients with a myocardial infarction treated with fibrinolytics, non-complicated. An exercise test and a cardiac catheterization were performed in the first month. The patients were followed-up for 2 years, recording the major cardiac events (death and reinfarction) and the minor events (angina class (II, left cardiac failure class (II or maintained ventricular tachycardia). On multivariate analysis with Cox regression, a workload < 4 METS at the exercise test was the only independent prognostic factor of major events (RR 5.6; CI 95% 1.68-19). The independent prognostic factors of minor events were: multivessel disease (RR 3.36; CI 95% 1.56-7.24), anterior infarction (RR 3.15; CI 95% 1.3-7.6), abnormal exercise test (RR 2.98; CI 95% 1.46-6.09) and ejection fraction < or = 40% (RR 2.48; CI 95% 1.07-5.74). The patency of the infarct-related artery was not a predictor of events. The exercise test is useful in predicting the prognosis in patients treated with fibrinolytics. An occluded infarct-related artery was not an independent predictor of cardiac events in 2 years of follow-up.

Beneficial Effects of Estrogen in Syndrome X of Postmenopausal Women

Background:There are many reports about the correlation between cardiovascular disorders and estrogen deficiency in postmenopausal women. The purpose of current study is to know that postmenopausal estrogen therapy may affect the lipid metabolism and endogenous fibrinolytic system and exercise tolerance. Method: We investigated the relation of estrogen treatment (srogen 0.625 mg/day to serum lipid levels, angiotensin converting enzyme activity, plasminogen activator inhibitor-1 and parameters of treadmill test in 22 post- menopausal women of normal coronary artery with abnormal exercise test complained with chest pain accompanied by postmenopausal symptoms. Results:Estrogen treatment significantly elevated the serum HDL- cholesterol level (42.8 to 50.1 mg/dl, p<0.05 and reduced the PAI-1 level (16.2 to 10.4 ng/dl, p<0.01 without considerable side effects. During the exercise test, the positivity appearance time and total exercise duration is significantly increased after estrogen treatment. Conclusion:The postmenopausal use of estrogen favorably changed the lipid level, fibrinolytic system and might improve the microcirculation which may protect against the ischemic heart disease risk without significant side effects. (Korean Circulation J 1999;29(3 :298-305

Exercise testing in patients with chest pain to sumatriptan

Objectives: In order to assess whether chest pain attributed to sumatriptan is associated with abnormalities on cardiac exercise testing, we performed a case-control study.Subjects: Cases were selected as consumers of sumatriptan who reported sumatriptan associated chest pain. A reference group was selected randomly from consumers of sumatriptan with the same GP as the case, who reported no chest pain after use of sumatriptan. If possible, controls were matched for age (within 5-year groups) and gender.Outcomes: In a total of 74 cases and 55 controls symptom-limited exercise tests were performed. Besides a small difference in age, there were no differences in basic characteristics between cases and controls. Three cases had ST-depression on ECG during exercise. However, none of the variables measured during exercise testing differed significantly between cases and controls.Conclusions: The prevalence of abnormal exercise tests in patients with sumatriptan-induced chest pain is low, and not statistically different from patients without chest pain after intake of sumatriptan. Routine performance of exercise testing in patients with sumatriptan-associated chest pain is not recommended.

DOES AGE AFFECT THE PREDICTIVE VALUE OF THE MAGNITUDE OF EXERCISE-RELATED ST DEPRESSION FOR THALLIUM RESULTS

1428 The incidence of coronary artery disease is higher in an older population, which by Bayesian analysis would be expected to affect the predictive value of exercise parameters. In this study, the SPECT Th-201 scans of 148 men with≥1mm ST depression (horizontal/downsloping) during symptom-limited exercise(treadmill) thallium testing were reviewed to determine how age affects the usefulness of the magnitude of exercise-related ST depression for predicting thallium results. Patients with baseline ST-T changes or a prior abnormal exercise test as a reason for referral were excluded. The group was stratified based on age (above or below 65 years) and the degree of ST depression (1-2 mm vs >2 mm). The incidence of reversible thallium defects (ThPOS) was then determined for each group. TableTableFor the entire group, 1-2 mm ST depression and >2 mm ST depression showed the same predictive value for ThPOS. Men >65 years had a sig higher%ThPOS than men <65 years (69% vs 48%, P=.01), and the predictive value of 1-2 mm was sig higher in men >65 years than men <65 years(P=.01). However, within each age group there was no sig difference in predictive value for ThPOS between patients with 1-2 mm ST depression and patients with >2 mm ST depression. Conclusion: In men with an abnormal exercise EKG, increased magnitude of ST depression (1-2 mm vs >2 mm) does not result in sig additional predictive value for thallium results. The increased incidence of ThPOS associated with increased age does not affect the relative predictive value of different magnitudes of ST depression for thallium results.

Familial Dilated Cardiomyopathy: Cardiac Abnormalities Are Common in Asymptomatic Relatives and May Represent Early Disease

Objectives. This study sought to determine whether early disease is identifiable in asymptomatic relatives of patients with dilated cardiomyopathy (DCM) by means of noninvasive cardiologic assessment.Background. DCM is diagnosed on the basis of advanced heart failure, where cardiac dilation and impaired contractility are recognized in the absence of a recognized etiology (World Health Organization criteria). However, initial clinical presentation may be with severe complications: thromboembolism, arrhythmia or sudden death. DCM has recently been recognized to be familial, with autosomal dominant inheritance in many cases. Familial disease is present in 9% to 20% of patients with DCM, and the ability to identify early disease in such people may improve patient management and aid in the understanding of pathogenesis.Method. We prospectively assessed 408 asymptomatic relatives (mean [±SD] age 35 ± 15 years, 193 men) of 110 consecutive patients with DCM by means of history and physical examination, two-dimensional echocardiography, 12-lead and signal-averaged electrocardiography and metabolic exercise testing. We hypothesized that signs of lesser cardiac dysfunction in such relatives might indicate early disease.Results. Twenty-nine percent of relatives had abnormal results on the echocardiogram. Twenty percent (n = 45) had left ventricular enlargement (LVE), defined as LV end-diastolic diameter (LVEDD) ≥112% predicted; 6% (n = 13) had depressed fractional shortening (dFS), defined as FS ≤25%; and 3% (n = 7) had frank DCM, defined as LV dilation, impaired contractile performance and LVEDD ≥112% plus FS ≤25%. Other abnormalities of cardiac function were identified in relatives with LVE or dFS: A greater number with LVE had an abnormal metabolic exercise test result than normal relatives (9% vs. 1%, p < 0.05). Relatives with LVE and abnormal maximal oxygen consumption (Vo2max) (defined as Vo2max <80% predicted) had a lower absolute Vo2max than normal relatives (30 ± 8 vs. 43 ± 9 ml/min per kg, p = 0.01). The QRS duration (at the 25-Hz filter) on the signal- averaged electrocardiogram was prolonged in relatives with LVE (103 ± 13 ms) and dFS (102 ± 12 ms) compared with that of normal relatives (97 ± 12 ms, p < 0.05). Over a mean 39-month follow-up period, 12 relatives with LVE (27%) and none with dFS developed symptomatic DCM (p < 0.0001). One relative with LVE died suddenly, and another underwent heart transplantation.Conclusions. Nearly one-third of asymptomatic relatives (29%) have echocardiographic abnormalities, and 27% of such relatives progress to development of overt DCM. Early identification of such people would permit appropriate intervention that might influence the serious complications and mortality of this disease.

Coronary artery calcification in women with syndrome X: usefulness of double-helical CT for detection.

To determine the usefulness of double-helical computed tomography (CT) for detection of diseased coronary arteries in women with anginal pain, positive exercise stress test results, and angiographically normal coronary arteries (syndrome X). Double-helical CT of the coronary arteries was performed in 81 consecutive women who were referred for coronary angiography for evaluation of chest pain. Patients were classified into three groups according to stress test and angiographic results: normal (normal exercise test results and angiographically normal coronary arteries), syndrome X (abnormal exercise test results and angiographically normal coronary arteries), and coronary artery disease (at least one diseased vessel seen at angiography). The prevalence of coronary calcification in the syndrome X group was 63% (10 of 16 patients) compared with 96% (45 of 47 patients) in the coronary artery disease group (P = .002) and 22% (four of 18 patients) in the normal group (P = .02). The lowest total coronary calcification score and logarithmic transformed data were found in the normal group (2.9 +/- 0.7), statistically significantly higher values were found in the syndrome X group (4.3 +/- 1.5), and the highest values were found in the coronary artery disease group (5.1 +/- 2.0; for trend, P = .03). Double-helical CT may be useful in detection of atherosclerosis in women with syndrome X who demonstrate normal coronary arteries at angiography.

Who needs an exercise stress test? Evaluating the new American College of Sports Medicine risk stratification guidelines.

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. Subjects included men and women over 30 years of age, free from known CHD according to the Lipid Research Clinic Follow-up Cohort. Endpoints included an abnormal exercise test result (+/- 1 mm ST, anginal chest pain, or exercise hypotension) and future death of CHD ascertained during an average 12.2 years of follow-up. Data analysis included 2 x 2 contingency tables to compare the test characteristics of the old and new guidelines. Among 4,074 subjects, 219 (5.4%) had abnormal exercise test results and 65 (1.6%) eventually died of CHD. The new guidelines classified 75.7% of individuals as high risk versus 58.7% using the old guidelines. Comparing the new guidelines with the old, test sensitivity was significantly (P = 0.007) higher for patients with an abnormal exercise test result (87% versus 77%) than for patients who died of CHD (100% versus 99%). Test specificity of the new guidelines was significantly (P < 0.001) lower than the old guidelines for individuals with abnormal exercise test results (25% versus 42%) and those who died of CHD (25% versus 42%). The new guidelines also showed significantly lower overall diagnostic accuracy and positive likelihood ratios compared with the old guidelines for both patients with abnormal exercise test results and those who died of CHD. The positive predictive value for the new and old guidelines for both patients with abnormal exercise test results and those who died of CHD were similar. Although the new guidelines are more sensitive in the abnormal exercise test result endpoint, they are less specific and overall less accurate than the old guidelines given the low prevalence of CHD in this asymptomatic population. The current guidelines should be modified to better target high-risk adults.

Cardiovascular function in children following bone marrow transplant: a cross-sectional study.

Sixty-three patients who had undergone a BMT at age < or = 18 years were evaluated cross-sectionally to determine cardiac function as well as the long-term prevalence, types, severity, and risk factors of cardiac abnormalities. Patients were > or = 1 year post-BMT and were evaluated by history, resting ECG, echocardiography (ECHO), exercise treadmill test, chest X-ray, pulmonary function tests and review of past cardiac studies. Patients were assigned a New York Heart Association (NYHA) class based on an activity and cardiac symptoms questionnaire. Pretransplant preparative regimens included high-dose cyclophosphamide (CY) and total body/lymphoid irradiation (n = 38), CY in combination with other chemotherapy (n = 22), and other drug combinations (n = 3). Forty patients (63.5%) had received prior anthracyclines (median 307 mg/m2). Patients' ages ranged from 1.9 to 32 years (median 10.9 years) with median follow-up of 3.3 years (range 1-16.3 years). Twenty-six patients (41.3%) had a cardiac abnormality detected at follow-up. In 21 patients the abnormal finding had not been present at the pre-BMT evaluation. Ten patients (16.4%) had resting ECG abnormalities. Left ventricular ejection fraction (LVEF) by ECHO was mildly decreased to 50-54% in three patients and markedly decreased to 40% in one patient. Only one patient (1.7%) developed a mildly abnormal shortening fraction of 27%. All patients with ECHO abnormalities were asymptomatic. Twenty-three of 31 patients > or = 9 years of age (74%) who underwent a treadmill exercise test had a borderline or abnormal response to exercise. There was no correlation between demographic factors, previous therapy, preparative regimen or length of follow-up with the post-BMT ECG, ECHO and treadmill abnormalities. Overall, eight patients (12.7%) were symptomatic and NYHA class II or III, and all had abnormal exercise tests. The presence of symptoms and NYHA class were predictors for oxygen consumption during exercise (P = 0.03 and 0.02, respectively) and tended to predict overall treadmill results also. Late cardiac abnormalities do occur following BMT in childhood and thus, there is a clear need for continued, serial long-term cardiac evaluation in transplant survivors. Evaluations should include exercise stress testing to detect inadequate cardiac output as well as oxygen consumption during exercise.

Combined rest and exercise electrocardiographic repolarization findings in relation to structural and functional abnormalities in asymptomatic aortic regurgitation

The relationship of combined rest and exercise electrocardiographic (ECG) repolarization abnormalities to left ventricular geometry and function was examined in 48 patients with asymptomatic chronic pure aortic regurgitation and no recent use of digitalis. Echocardiographic and radionuclide cineangiographic findings were compared in groups defined by the presence or absence of the “strain” pattern of repolarization abnormality on the resting ECG and also by the presence or absence of standard positive repolarization changes during upright treadmill exercise (>0.1 mV additional horizontal or downsloping ST depression). These hierarchic groups demonstrated trends toward progressively abnormal left ventricular dimensions, mass, wall stress, and change in ejection fraction with exercise. Although the presence of the strain pattern on the resting ECG alone was most strongly correlated with underlying functional and geometric abnormalities, an abnormal exercise test response was independently associated with abnormal left ventricular systolic dimension. The large group of patients with no symptomes and normal resting repolarization had only 0% to 4% prevalences of markedly increased systolic dimension (>55 mm), reduced ejection fraction at rest (<45%), or reduced ejection fraction during exercise (<40%), whereas the small group of patients with abnormal resting repolarization and a positive exercise test response had 50% to 83% prevalences of these findings. These data suggest a possible role for rest and exercise ECG in the serial evaluation of patients with aortic regurgitation.

Cost-analysis of four diagnostic strategies for Pneumocystis carinii pneumonia in HIV-infected subjects

The aim of this study was to analyse the cost-effectiveness ratio of four diagnostic strategies for Pneumocystis carinii pneumonia (PCP) in patients infected with human immunodeficiency virus (HIV). Two hundred and ten HIV-infected patients with suspected PCP underwent induced-sputum (IS) followed, if negative, by bronchoalveolar lavage (BAL); 85 of these patients were able to undergo an exercise test (ET), prior to induced sputum and BAL. The following strategies were analysed: BAL strategy (BAL whenever PCP is suspected); IS strategy (induced sputum followed by BAL if negative); exercise test (ET) strategy, (ET followed by BAL if the results are abnormal); and the ES (exercise sputum) strategy (i.e. BAL only after abnormal ET and negative IS). The cost of each strategy was calculated by taking into account only direct costs; the conditions in which two given strategies would be cost-equivalent were also evaluated. The prevalence of PCP in this population was 31%; IS had 100% specificity and 71% sensitivity, whilst ET had 100% sensitivity and 77% specificity. The costs of BAL, IS, ET and ES strategies were 210,000, 191,940, 140,700 and 112,700 FF, respectively. The ES strategy is, thus, most suitable for our unit. The most economic strategy depends not only on the cost and characteristics of the procedures, but also on the prevalence of PCP in the test population. In conclusion, we developed a model for use by diagnostic centres in choosing the most suitable strategy, on the basis of the local prevalence of PCP.

Anatomic and physiologic heterogeneity in patients with syndrome X: An intravascular ultrasound study

We used intravascular ultrasound imaging of the epicardial vessels to assess coronary morphology, vasomotor response to exercise and exercise-vasomotion after beta-adrenoceptor blockade in patients with syndrome X. Syndrome X is defined as chest pain, abnormal exercise test results and normal coronary angiographic findings. Because of the limitations of coronary angiography, intravascular ultrasound was used to define coronary pathophysiology. Thirty patients with syndrome X were studied with intravascular ultrasound imaging (30 MHz, 4.3F catheter) of all three major epicardial vessels. Supine arm exercise was performed during coronary imaging. Lumen area was assessed at rest and during peak exercise. The exercise-imaging protocol was repeated after loading with 0.1 mg/kg body weight of intravenous propranolol. Three morphologic groups were identified using intravascular ultrasound: normal coronary arteries (no plaque, intimal thickness < 0.25 mm, n = 12), atheromatous disease (mean [+/- SD] area stenosis 37.9 +/- 7.2%, n = 10) and marked intimal thickening (0.73 +/- 0.11 mm, n = 8). Patients with normal coronary arteries displayed a vasodilatory response to exercise (+16.9% area increase); patients with abnormal coronary arteries displayed a vasoconstrictive response to exercise (-17.4% in the group with plaque; -17.6% in the group with intimal thickening). Propranolol loading attenuated the vasodilatory response in the group with normal coronary arteries (+6.4% area increase) and attenuated the vasoconstrictive response in the two groups with abnormal coronary arteries (-8.0% in the group with plaque; -8.8% in the group with intimal thickening). Most patients with syndrome X have abnormal coronary arteries by intravascular ultrasound. Intravascular ultrasound identifies three distinct morphologic groups: normal coronary arteries, atheromatous plaque and intimal thickening. Exercise-vasomotion is normal in patients with syndrome X who have normal coronary arteries by ultrasound; patients with abnormal arteries (plaque or intimal thickening) have an abnormal (constrictive) response to exercise. Propranolol loading attenuates vasoreactivity in all subgroups, suggesting divergent therapeutic utility.

Effect of precordial electrocardiographic electrode placement on ST-segment measurement during exercise.

Research protocols often utilize serial exercise testing to examine the efficacy of anti-ischemic therapies. These tests, however, are prone to multiple sources of bias. This investigation sought to determine the influence of varying precordial electrocardiographic (ECG) electrode placement on the detection of exercise-induced ST-segment shifts. Fifteen coronary artery disease patients with abnormal exercise tests were studied. Based on the previous exercise test, the precordial electrode position exhibiting the greatest ST-segment shift was selected as the reference electrode. Four additional electrodes were placed around this reference electrode and exercise testing was performed. ECG strips were recorded every minute. The time-to-onset and -offset of ischemic-type ST-segment depression was recorded. ST-segment depression was recorded during exercise from the reference electrode in 12 of 15 patients. Ischemic-type ST-depression was also recorded in each of these 12 patients with the surrounding electrodes; however, the time-to-onset detected by all four surrounding electrodes concurred in only 5 of 12 (42%) patients. The time-to-offset of the ST-segment depression concurred in 9 of 12 (75%) patients. Serial ECGs recorded from similar but not exactly the same precordial ECG electrode position should yield similar results for the detection of ischemia, but time-to-onset or -offset of ischemia may differ by 60 s or more. Small changes in the time-to-onset and -offset of ischemia should not be considered reliable indicators of anti-ischemia efficacy.

1028-66 Clinical and Demographic Findings in Patients with Ischemia and “Normal” Coronary Arteries: An ACIP Ancillary Study

Little information is available on patients (pts) with abnormal exercise tests (ETT) and ischemia on ambulatory ECG (AECG) monitoring who have normal coronary arteries or minimal coronary stenosis (&lt;50% diameter). Accordingly, we characterized the clinical, demographic and angiographic features of 68 pts with asymptomatic cardiac ischemia (ACI) during AECG monitoring, an abnormal ETT but no significant coronary narrowing (Gpl) and compared them to 615 pts enrolled in the Asymptomatic Cardiac Ischemia Pilot (ACIP) study all of whom demonstrated ischemia and significant coronary narrowing (Gp II).Empty CellGP IGp IIPAge, yrs. (mean ± s.d.)58 ± 1062 ± 8&lt;0.001Male(%)58.884.7&lt;0.001History of MI (%)8.540.0&lt;0.001Hypercholesterolemia (%)22.043.4&lt;0.001Diabetes Mellitus (%)3.417.1&lt;0.01Ever Smoked (%)37.265.5&lt;0.001Angina (ETT, AECG, Hx)69.270.90.80AECG Ischemic Episodes/24 hrs (mean ± s.d.)1.7 ± 1.42.6 ± 28&lt;0.01LVH by EKG (%)8.26.30.62Any Coronary Narrowing (≥20% Stenosis) %52.9100-Maximum % Stenosis (mean ± s.d.)l8.8 ± 18789.1 ± 14.0-Complex Plaque (%)4.450.2&lt;0.001Ejection Fraction &lt;55%1.518.6 55-70%37.967.6&lt;0.001 &gt;70%60.613.8 Pts without significant coronary narrowing were younger, had higher ejection fractions, were less often male. less likely to have risk factors, history of MI, complex plaque and had less AECG ischemia. These demographic and clinical differences may help identify pts with an alternative mechanism of ACI.

Acute Myocardial Infarction: Risk Stratification in the Thrombolytic Era

Acute Myocardial Infarction: Risk Stratification in the Thrombolytic Era

Paramyotonia congenita: Abnormal short exercise test, and improvement after mexiletine therapy

The diagnosis of paramyotonia congenita (PC) can be aided by demonstrating a decrease in compound motor action potential amplitude after exercise and a decrement on repetitive stimulation, following cold exposure. We report a patient with PC who presented with complaints of cold-induced hand and jaw stiffening, in the absence of any episodes of weakness. Treatment with mexiletine led to resolution of the abnormalities exhibited during a short exercise test and repetitive stimulation following ice bath immersion. Molecular genetic analysis revealed a missense mutation (cytosine to thymidine) on chromosome 17 in the alpha-subunit of the skeletal muscle sodium channel gene that results in the replacement of threonine with methionine. This case demonstrates that, despite the absence of weakness, the short exercise test following cold exposure can be used to confirm the diagnosis of PC in patients without episodic weakness. Furthermore, improvement of the electrophysiologic abnormalities with mexiletine was documented, corresponding with clinical improvement.

Coronary artery disease is highly prevalent among patients with premature peripheral vascular disease

This study was designed to document the prevalence of coronary artery disease (CAD) and associated cardiac complications among patients with symptoms of premature peripheral vascular disease. We studied the peripheral and coronary arterial circulations of 59 consecutive male military veterans diagnosed with premature peripheral vascular disease (age of onset < or = 45 years) affecting the lower extremity. Patients who had not previously undergone coronary angiography underwent exercise stress testing. Patients unable to perform exercise testing and those with abnormal exercise test results underwent coronary angiography. There was no evidence of CAD in 16 patients (29%) on the basis of normal exercise test results (n = 12) or normal coronary angiography results (n = 4). Forty-three patients (71%) had significant (> or = 50% lesion) CAD by coronary catheterization. Cardiac complications were frequent among the 43 patients. Eleven (65%) of the 17 patients with single-vessel CAD had previously documented myocardial infarctions, as did three (75%) of the four patients with two-vessel CAD and 18 (82%) of the 22 patients with three vessel or greater CAD. Three (18%) patients with one-vessel CAD had undergone coronary artery bypass grafting or percutaneous transluminal coronary angioplasty for symptoms, as had one patient (25%) with two-vessel CAD and 19 patients (86%) with three-vessel or greater CAD. Five patients died during the study period, four of myocardial infarction and one of stroke. Premature peripheral atherosclerosis is associated with a high prevalence of CAD. Detection of CAD is important in this group, because cardiac complications are frequent.