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1.
Ann Noninvasive Electrocardiol ; 20(6): 554-60, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25640186

RESUMO

BACKGROUND: The Diagonal Line Rule (DLR) is an educational pattern recognition tool for the classification of 12-lead electrocardiograms (ECGs) as normal or abnormal. OBJECTIVE: To develop a score using the DLR for the risk stratification of abnormal ECGs. METHODS: Patients at the Palo Alto, VA, referred for a routine resting ECG between 1987 and 1999 were retrospectively considered. The initial ECGs of 43,798 patients were scored according to the DLR. The main outcome variable was cardiovascular mortality with 8 years of follow-up. RESULTS: ECG abnormalities identified by the DLR were combined with age, gender, and ST depression to develop an additive score. The score was validated and shown to stratify levels of cardiac risk with a 0.78 area under the receiver operating characteristic (ROC) curve for identifying those who had a cardiovascular death. CONCLUSION: The score effectively stratifies ECGs for prediction of risk of cardiovascular death.


Assuntos
Doenças Cardiovasculares/mortalidade , Eletrocardiografia , Indicadores Básicos de Saúde , Adulto , Idoso , Doenças Cardiovasculares/diagnóstico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Retrospectivos , Medição de Risco
2.
Ann Noninvasive Electrocardiol ; 18(6): 519-29, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24147772

RESUMO

BACKGROUND: There is limited data describing ST segment amplitude in apparently healthy, asymptomatic populations. We analyzed ST amplitude in the standard resting electrocardiogram (ECG) in a large, multiethnic, stable, clinical population. METHODS: We evaluated computerized ST amplitude measurements from the resting ECGs of 29,281 ambulatory outpatients collected between 1987 and 1999 at the Palo Alto, VA. With the PR interval as the isoelectric line, both elevation criteria (≥0.1 mV, ≥0.15 mV, and ≥0.2 mV) and depression criteria (≤-0.05 mV or ≤-0.1 mV), were applied. Cox-Hazard survival analysis techniques were used to demonstrate in which leads ST amplitude displacement was associated with cardiovascular (CV) death. To create a cohort without ECG patterns clearly associated with disease, we excluded ECGs with inverted T waves, wide QRS, or diagnostic Q waves and coded the remaining "normal" ECGs for ST elevation and depression to determine a normal range. RESULTS: The only ST amplitudes that were significantly and independently associated with time to CV death when adjusted for age, gender, and ethnicity were ST depression in all of the lateral leads (I, V4 -V6 ). When isolated to the inferior leads, (II and AVF), no ST amplitude criteria were associated with CV death. Among the "normal ECG" subgroup the precordial leads exhibited the greatest median ST amplitudes and the most significant differences between the leads, genders and ethnicities. CONCLUSIONS: Significant differences in ST amplitude were present in the precordial leads according to gender and ethnicity. This was particularly apparent when amplitude threshold were set for comparisons. Our findings provide the normal range for ST amplitude that when exceeded, should raise clinical concern.


Assuntos
Eletrocardiografia/métodos , Eletrocardiografia/estatística & dados numéricos , Infarto do Miocárdio/diagnóstico , Descanso , California/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/epidemiologia , Prognóstico , Modelos de Riscos Proporcionais , Valores de Referência , Estudos Retrospectivos , Veteranos
3.
Br J Sports Med ; 43(9): 696-701, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19734505

RESUMO

The exercise electrocardiogram (ECG) is widely considered the best available test for screening asymptomatic adults without known cardiovascular (CV) disease prior to initiating a vigorous exercise programme due to its prognostic value, widespread availability and low cost. Observational studies have demonstrated an increased relative risk of CV events with positive screening exercise ECG tests in men with diabetes, advanced age, or multiple cardiac risk factors. Recent observational studies have not demonstrated similar prognostic value for exercise ECG testing in asymptomatic healthy women. Despite the predictive ability of exercise ECG testing in several groups, there have been no studies demonstrating a significant impact of screening on morbidity and mortality in completely asymptomatic patients, leading to significant discordance in consensus guidelines on screening. One prospective observational study is ongoing in Italy that may for the first time demonstrate the ability to decrease incident CV events using preparticipation screening exercise ECG testing in adult athletes with targeted exclusion from athletics. Until more conclusive data is available the authors currently recommend screening exercise ECG testing in asymptomatic men with diabetes and asymptomatic men over age 45 with two or more CV risk factors prior to initiating a vigorous exercise programme. Consideration should also be given to screening asymptomatic patients younger than 45 with particularly strong risk factor exposure or elderly patients with fewer than two risk factors.


Assuntos
Envelhecimento/fisiologia , Doenças Cardiovasculares/diagnóstico , Eletrocardiografia , Teste de Esforço/economia , Tolerância ao Exercício/fisiologia , Exercício Físico/fisiologia , Fatores Etários , Idoso , Doenças Cardiovasculares/complicações , Doenças Cardiovasculares/fisiopatologia , Análise Custo-Benefício , Eletrocardiografia/economia , Teste de Esforço/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Sensibilidade e Especificidade
4.
Clin Cardiol ; 30(4): 189-94, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17443659

RESUMO

BACKGROUND: The prevalence and prognostic values of electrocardiogram (ECG) abnormalities in Hispanics have not been compared to other ethnicities in a large population. Despite a worse cardiovascular risk profile, the prevalence of cardiovascular disease is lower in Hispanics compared to non-Hispanics. HYPOTHESIS: We hypothesized that ECG abnormalities were less common in Hispanics and were not as strongly associated with cardiovascular mortality. METHODS: 45,563 ECGs ordered for usual clinical indications in a Veteran's hospital were available for analysis. 1,392 patients who died within one week of the ECG were excluded. Demographic characteristics were recorded and the population was followed for an average of 7.5 years using the California Death Index. The presence of baseline ECG characteristics were recorded and analyzed using the GE/Marquette computerized ECG system. Age, sex and heart rate adjusted Cox hazard ratio analyses were performed. RESULTS: Being Hispanic was associated with lower cardiovascular death, with a hazard ratio (HR) of 0.76 (95% CI 0.65-0.89). Findings such as atrial fibrillation, presence of Q-waves, left ventricular hypertrophy (LVH), upright T-waves in aortic valve replacement (aVR) and cardiac Infarction Injury Scores > 6 were significantly less prevalent in Hispanics than in non-Hispanics. These findings were similarly associated with increased cardiovascular mortality in both groups, each with a HR of approximately 2. CONCLUSION: The lower prevalence of ECG characteristics associated with coronary heart disease, atrial fibrillation and left ventricular hypertrophy support prior observations that cardiovascular disease is less prevalent in the Hispanic population. These findings, however, are similarly associated with increased mortality compared to non-Hispanics.


Assuntos
Doenças Cardiovasculares/diagnóstico , Doenças Cardiovasculares/etnologia , Eletrocardiografia , Hispânico ou Latino , Processamento de Sinais Assistido por Computador , Adulto , Fatores Etários , Idoso , California/epidemiologia , Doenças Cardiovasculares/mortalidade , Doenças Cardiovasculares/fisiopatologia , Feminino , Seguimentos , Frequência Cardíaca , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Prognóstico , Modelos de Riscos Proporcionais , Projetos de Pesquisa , Estudos Retrospectivos , Medição de Risco , Análise de Sobrevida
5.
Spinal Cord ; 44(8): 474-9, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16331308

RESUMO

STUDY DESIGN: Cross-sectional analysis of a convenience sample of locally recruited participants, including both patients and volunteers. OBJECTIVES: To determine whether there is an association between plasma homocysteine and hypertension in persons with spinal cord injury (SCI). SETTING: Spinal Cord Injury Service of the Veterans Affairs Palo Alto Medical Center (California, United States of America). METHODS: The incidence of hypertension, dyslipidemia, insulin resistance, and the presence of metabolic syndrome were determined in 168 individuals with SCI (mean age 50.2 +/- 12.8 years). Fasting lipids, insulin, glucose, plasma homocysteine, and anthropometric data was gathered for each subject. RESULTS: Blood pressure values (P < 0.001) and mean arterial pressure (P < 0.05) increased with higher plasma homocysteine levels. Homocysteine values were also significantly greater among individuals with hypertension compared with those who were normotensive or prehypertensive (P < 0.0001). There was an inverse relationship between plasma homocysteine levels and glomerular filtration rate and effective renal plasma flow (P < 0.05). CONCLUSIONS: Plasma homocysteine levels are elevated in persons with SCI who have hypertension and inversely related to renal function, which suggests that renal dysfunction may be a link between homocysteine and hypertension in persons with SCI. SPONSORSHIP: Funded by the VA Rehabilitation Research and Development Service, Merit Review Grant #B2549R.


Assuntos
Homocisteína/sangue , Hipertensão/sangue , Hipertensão/epidemiologia , Nefropatias/sangue , Nefropatias/epidemiologia , Traumatismos da Medula Espinal/sangue , Traumatismos da Medula Espinal/epidemiologia , Distribuição por Idade , California/epidemiologia , Feminino , Humanos , Incidência , Masculino , Medição de Risco/métodos , Fatores de Risco , Veteranos/estatística & dados numéricos
6.
J Am Coll Cardiol ; 38(7): 1980-7, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11738304

RESUMO

OBJECTIVES: The goal of this study was to validate the prognostic value of the drop in heart rate (HR) after exercise, compare it to other test responses, evaluate its diagnostic value and clarify some of the methodologic issues surrounding its use. BACKGROUND: Studies have highlighted the value of a new prognostic feature of the treadmill test-rate of recovery of HR after exercise. These studies have had differing as well as controversial results and did not consider diagnostic test characteristics. METHODS: All patients were referred for evaluation of chest pain at two university-affiliated Veterans Affairs Medical Centers who underwent treadmill tests and coronary angiography between 1987 and 1999 as predicted after a mean seven years of follow-up. All-cause mortality was the end point for follow-up, and coronary angiography was the diagnostic gold standard. RESULTS: There were 2,193 male patients who had treadmill tests and coronary angiography. Heart rate recovery at 2 min after exercise outperformed other time points in prediction of death; a decrease of <22 beats/min had a hazard ratio of 2.6 (2.4 to 2.8 95% confidence interval). This new measurement was ranked similarly to traditional variables including age and metabolic equivalents but failed to have diagnostic power for discriminating those who had angiographic disease. CONCLUSIONS: Heart rate at 1 or 2 min of recovery has been validated as a prognostic measurement and should be recorded as part of all treadmill tests. This new measurement does not replace, but is supplemental to, established scores.


Assuntos
Angina Pectoris/diagnóstico , Eletrocardiografia , Teste de Esforço , Frequência Cardíaca/fisiologia , Adulto , Idoso , Angina Pectoris/mortalidade , Angina Pectoris/fisiopatologia , Pressão Sanguínea/fisiologia , Causas de Morte , Angiografia Coronária , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Taxa de Sobrevida
7.
Am Heart J ; 142(6): 1041-6, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11717610

RESUMO

BACKGROUND: Physical activity and symptom questionnaires have been used as surrogates for exercise testing to estimate a patient's functional capacity and to individualize an exercise testing protocol in accordance with exercise testing guidelines. To validate these approaches, they must be compared with measured oxygen uptake (peak VO (2)). METHODS: Before exercise testing was performed, a brief, self-administered questionnaire (Veterans Specific Activity Questionnaire [VSAQ]) was given to 337 patients referred for exercise testing for clinical reasons. The VSAQ was used to estimate exercise tolerance on the basis of symptoms during daily activities to individualize ramp rates on the treadmill so that the test duration would be approximately 10 minutes. Clinical and demographic variables were added to the VSAQ responses in a stepwise regression model to determine their ability to predict both directly measured peak VO (2) and peak metabolic equivalents (METs) predicted from the treadmill workload. RESULTS: The mean exercise time was 9.6 +/- 3 minutes. Responses to the VSAQ and age were the strongest predictors of both measured and predicted exercise capacity. Small but significant contributions to the explanation of variance in both measured and estimated METs were made by resting heart rate, forced expiratory volume in 1 second expressed as a percentage of normal, exercise capacity predicted for age, and body mass index. The multiple R values from the regression equations for measured and estimated METs were 0.58 and 0.72, respectively. CONCLUSIONS: Estimating a patient's symptoms associated with daily activities along with age are the strongest predictors of a patient's exercise tolerance. The VSAQ, combined with pretest clinical data, predicts the estimated MET value from treadmill speed and grade better than directly measured METs do. When used for estimating a patient's symptom limits to individualize ramp rates on a treadmill, this approach yields an appropriate test duration in accordance with recent exercise testing guidelines.


Assuntos
Teste de Esforço/normas , Tolerância ao Exercício/fisiologia , Consumo de Oxigênio , Inquéritos e Questionários , Atividades Cotidianas , Exercício Físico/fisiologia , Feminino , Volume Expiratório Forçado , Humanos , Masculino , Pessoa de Meia-Idade , Modelos Estatísticos , Análise Multivariada , Prognóstico
8.
Arch Intern Med ; 161(18): 2239-44, 2001 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-11575981

RESUMO

BACKGROUND: The recent American College of Cardiology/American Heart Association exercise testing guidelines provided equations to calculate treadmill scores and recommended their use to improve the predictive accuracy of the standard exercise test. However, if physicians can estimate the probability of coronary artery disease as well as the scores can, there would be no reason to add this complexity to test interpretation. To compare the exercise test scores with physician's estimation of disease probability, we used clinical, exercise test, and coronary angiographic data to compute the recommended scores and print patient summaries and treadmill reports. OBJECTIVE: To determine whether exercise test scores can be as effective as expert cardiologists in diagnosing coronary disease. METHODS: Five hundred ninety-nine consecutive male patients without previous myocardial infarction with a mean +/- SD age of 59 +/- 11 years were considered for this analysis. With angiographic disease defined as any coronary lumen occlusion of 50% or more, 58% had disease. The clinical/treadmill test reports were sent to expert cardiologists and to 2 other groups, including randomly selected cardiologists and internists, who classified the patients as having high, low, or intermediate probability of disease and estimated a numerical probability from 0% to 100%. RESULTS: Forty-five expert cardiologists returned estimates on 336 patients, 37 randomly chosen practicing cardiologists returned estimates on 129 patients, 29 randomly chosen practicing internists returned estimates on 106 patients, 13 academic cardiologists returned estimates on 102 patients, and 27 academic internists returned estimates on 174 patients. When probability estimates were compared, the scores were superior to all physician groups (0.76 area under the receiver operating characteristic curve to 0.70 for experts [P=.046], 0.73 to 0.58 for cardiologists [P=.003], and 0.76 to 0.61 for internists [P=.006]). Using a probability cut point of greater than 70% for abnormal, predictive accuracy was 69% for scores compared with 64% for experts, 63% to 62% for cardiologists, and 70% to 57% for internists. CONCLUSION: Although most similar to the disease estimates of the presence of clinically significant angiographic coronary artery disease provided by the expert cardiologists, the scores outperformed the nonexpert physicians.


Assuntos
Doença das Coronárias/diagnóstico , Teste de Esforço , Exame Físico , Adulto , Idoso , Idoso de 80 Anos ou mais , Angiografia Coronária , Doença das Coronárias/etiologia , Suscetibilidade a Doenças/diagnóstico , Suscetibilidade a Doenças/etiologia , Eletrocardiografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Equipe de Assistência ao Paciente , Probabilidade
10.
Prog Cardiovasc Dis ; 44(1): 55-67, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11533927

RESUMO

Given renewed interest in the primary prevention of cardiovascular disease, we comprehensively reviewed the utility of the electrocardiogram (ECG) for screening considering the seminal epidemiologic studies. It appears that conventional risk factors relate to long-term risk, while ECG abnormalities are better predictors of short-term risk. For individual ECG abnormalities as well as for pooled categories of ECG abnormalities, the sensitivity of the ECG for future events was too low for it to be practical as a screening tool. This almost certainly relates to the low prevalence of these abnormalities. However, all ECG abnormalities increase with age and pre-test risk. Also screening with the ECG is of minimal cost and likely to decrease further as stand-alone machines are replaced by integration into personal computers (PC). Another potential impact on performing screening ECGs would be distribution and availability of digitized ECG data via the World Wide Web. For clinical utility of ECG data, comparison with previous ECGs can be critical but is currently limited. PC based ECG systems could very easily replace many of the ECG machines in use that only have paper output. PC-ECG systems would also permit interaction with computerized medical information systems, facilitate emailing and faxing of ECGs as well as storage at a centralized web-server. Web-enabled ECG recorders similar to the new generation of home appliances could follow this quick PC solution. A serious goal for the medical industry should be to end the morass of proprietary ECG digital formats and follow a standardized format. This could lead to a network of web-servers from which every patient's ECGs would be available. Such a situation could have a dramatic effect on the advisability of performing screening ECGs.


Assuntos
Eletrocardiografia , Cardiopatias/diagnóstico , Programas de Rastreamento/métodos , Bloqueio de Ramo/diagnóstico , Medicina Baseada em Evidências , Sistema de Condução Cardíaco/fisiopatologia , Humanos , Hipertrofia Ventricular Esquerda/diagnóstico , Hipertrofia Ventricular Esquerda/epidemiologia , Infarto do Miocárdio/diagnóstico , Prevalência , Estudos Retrospectivos , Fatores de Risco , Sensibilidade e Especificidade
11.
Chest ; 120(3): 1003-13, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11555539

RESUMO

OBJECTIVE: To report the prevalence of abnormal treadmill test responses and their association with mortality in a large consecutive series of patients referred for standard exercise tests, with testing performed and reported in a standardized fashion. BACKGROUND: Exercise testing is widely performed, but few databases exist of large numbers of consecutive tests performed on patients referred for routine clinical purposes using standardized methods. Even fewer of the available databases have information regarding all-cause mortality as an outcome. METHODS: All patients referred for evaluation at two university-affiliated Veterans Affairs medical centers who underwent exercise treadmill testing for clinical indications between 1987 and 2000 were determined to be dead or alive using the Social Security death index after a mean 6.2 years (median, 7 years) of follow-up. Clinical and exercise test variables were collected prospectively according to standard definitions; testing and data management were performed in a standardized fashion using a computer-assisted protocol. All-cause mortality was utilized as the end point for follow-up. Standard survival analysis was performed, including Kaplan-Meier curves and a Cox hazard model. RESULTS: There were 6,213 male patients (mean +/- SD age, 59 +/- 11 years) who underwent standard exercise ECG treadmill testing over the study period with a mean follow-up duration of 6.2 +/- 3.7 years. There were no complications of testing in this clinically referred population, 78% of whom were referred for chest pain, or risk factors or signs or symptoms of ischemic heart disease. Overlapping thirds had typical angina or history of myocardial infarction (MI). Five hundred seventy-nine patients had prior coronary artery bypass surgery, and 522 patients had a history of congestive heart failure (CHF). Indications for testing were in accordance with published guidelines. Twenty percent died over the follow-up period, for an average annual mortality rate of 2.6%. Cox hazard function chose the following variables in rank order as independently and significantly associated with time to death: exercise capacity (metabolic equivalents < 5, age > 65 years, history of CHF, and history of MI. A score based on these variables (summing up the four variables [if yes = 1 point]) classified patients into low-risk, medium-risk, and high-risk groups. The high-risk group (score > or = 3) has a hazard ratio of 5.0 (95% confidence interval, 4.7 to 5.3) and a 5-year mortality rate of 31%. CONCLUSION: This comprehensive analysis provides rates of various abnormal responses that can be expected in patients referred for exercise testing at a typical medical center. Four simple variables combined as a score powerfully stratified patients according to prognosis.


Assuntos
Doença das Coronárias/mortalidade , Teste de Esforço , Idoso , Angina Pectoris/mortalidade , Arritmias Cardíacas/mortalidade , Doença das Coronárias/fisiopatologia , Hemodinâmica , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Prognóstico , Modelos de Riscos Proporcionais , Fatores de Risco
12.
Sports Med ; 31(6): 387-408, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11394560

RESUMO

Multivariable analysis of clinical and exercise test data has the potential to become a useful tool for assisting in the diagnosis of coronary artery disease, assessing prognosis, and reducing the cost of evaluating patients with suspected coronary disease. Since general practitioners are functioning as gatekeepers and decide which patients must be referred to the cardiologist, they need to use the basic tools they have available (i.e. history, physical examination and the exercise test), in an optimal fashion. Scores derived from multivariable statistical techniques considering clinical and exercise data have demonstrated superior discriminating power compared with simple classification of the ST response. In addition, by stratifying patients as to probability of disease and prognosis, they provide a management strategy. While computers, as part of information management systems, can run complicated equations and derive these scores, physicians are reluctant to trust them. Thus, these scores have been represented as nomograms or simple additive tables so physicians are comfortable with their application. Their results have also been compared with physician judgment and found to estimate the presence of coronary disease and prognosis as well as expert cardiologists and often better than nonspecialists. However, the discriminating power of specific variables from the medical history and exercise test remains unclear because of inadequate study design and differences in study populations. Should expired gases be substituted for estimated metabolic equivalents (METs)? Should ST/heart rate (HR) index be used instead of putting these measurements separately into the models? Should right-sided chest leads and HR in recovery be considered? There is a need for further evaluation of these routinely obtained variables to improve the accuracy of prediction algorithms especially in women. The portability and reliability of these equations must be demonstrated since access to specialised care must be safe-guarded. Hopefully, sequential assessment of the clinical and exercise test data and application of the newer generation of multivariable equations can empower the clinician to assure the cardiac patient access to appropriate and cost-effective cardiological care.


Assuntos
Doença das Coronárias/diagnóstico , Teste de Esforço , Adulto , Fatores Etários , Idoso , Doença das Coronárias/epidemiologia , Eletrocardiografia , Teste de Esforço/estatística & dados numéricos , Feminino , Insuficiência Cardíaca/diagnóstico , Frequência Cardíaca , Humanos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Exame Físico , Prognóstico , Fatores Sexuais
13.
Chest ; 119(6): 1933-40, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11399726

RESUMO

OBJECTIVE: Our aim was to derive and validate a simplified treadmill score for predicting the probability of angiographically confirmed coronary artery disease (CAD). BACKGROUND: The American College of Cardiology/American Heart Association guidelines for exercise testing recommend the use of multivariable equations to enhance the diagnostic characteristics of the standard treadmill test. Most of these equations use complicated statistical techniques to provide diagnostic estimates of CAD. Simplified scores derived from such equations that require physicians only to add points have been developed for pretest estimates of disease and for prognosis. However, no simplified score has been developed specifically for the diagnosis of CAD using exercise test results. METHODS: Consecutive patients referred for evaluation of chest pain who underwent standard treadmill testing followed by coronary angiography were studied. A logistic regression model was used to predict clinically significant (> or = 50% stenosis) CAD and then the variables and coefficients were used to derive a simplified score. The simplified score was calculated as follows: (6 x maximal heart rate code) + (5 x ST-segment depression code) + (4 x age code) + angina pectoris code + hypercholesterolemia code + diabetes code + treadmill angina index code. The simplified score had a range from 6 to 95, with < 40 designated as low probability, between 40 and 60 was intermediate probability, and > 60 was high probability for CAD. RESULTS: A total of 1,282 male patients without a prior myocardial infarction underwent exercise treadmill testing and coronary angiography in the derivation group, and there were 476 male patients in the validation group from another institution. The area under the receiver operating characteristic curve (+/- SE) for the ST-segment response alone was 0.67 as compared to 0.79 +/- 0.01 for the diagnostic score (p > 0.001). The prevalence of significant disease for the men was 27% in the low-probability group, 62% in the intermediate-probability group, and 92% in the high-probability group, which was similar to the prevalence in the validation group, with 22%, 58%, and 92% in low-, intermediate-, and high-probability groups, respectively. The low-probability group had < 4% prevalence of severe disease. In both populations, 7 more patients out of 100 were correctly classified than with the use of ST-segment criteria. When used as a clinical management strategy, the score has a sensitivity of 88% and a specificity of 96%. CONCLUSION: This simplified exercise score that estimates the probability of CAD can be easily applied without a calculator and is a useful and valid tool that can help physicians manage patients presenting with chest pain.


Assuntos
Doença das Coronárias/diagnóstico , Teste de Esforço/métodos , Angiografia Coronária , Humanos , Masculino , Pessoa de Meia-Idade , Sensibilidade e Especificidade
15.
Am Heart J ; 142(1): 127-35, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11431668

RESUMO

OBJECTIVE: Our purpose was to report the prevalence of abnormal treadmill test responses and their association with mortality in a large consecutive series of patients referred for standard diagnostic exercise tests, with testing performed and reported in a standardized fashion. BACKGROUND: Exercise testing is widely performed, but an analysis of responses has not been presented for a large number of consecutive tests performed on patients referred for diagnosis of cardiac disease. METHODS: All patients referred for evaluation at 2 university-affiliated Veterans Affairs Medical Centers who underwent exercise treadmill tests for clinical indications between 1987 and 2000 were determined to be dead or alive according to the Social Security Death Index after a mean 5.9-year follow-up. Patients with established heart disease (ie, prior coronary bypass surgery, myocardial infarction, or congestive heart failure) were excluded from analyses. Clinical and exercise test variables were collected prospectively according to standard definitions; testing and data management were performed in a standardized fashion with a computer-assisted protocol. All-cause mortality was used as the end point for follow-up. Standard survival analysis was performed, including Kaplan-Meier curves and a Cox hazard model. RESULTS: After the exclusions, 3974 men (mean age 57.5 +/- 11 years) had standard diagnostic exercise testing over the study period with a mean of 5.9 (+/-3.7) years of follow-up (64% of all tested). There were no complications of testing in this clinically referred population, 82% of whom were referred for chest pain, risk factors, or signs and symptoms of ischemic heart disease. Five hundred forty-nine (14%) had a history of typical angina. Indications for testing were in accordance with published guidelines. A total of 545 died, yielding an annual mortality rate of 1.8%. The Cox hazard model chose the following variables in rank order as independently associated with time to death: change in rate pressure product, age greater than 65 years, METs less than 5, and electrocardiographic left ventricular hypertrophy. A score based on these variables classified patients into low-, medium-, and high-risk groups. The high-risk group with a score greater than 3 has a hazard ratio of 4 (95% confidence interval 3.82-4.27) and an annual mortality rate of 4%. CONCLUSION: This comprehensive analysis provides rates of various abnormal responses that can be expected in men referred for diagnostic exercise testing at typical Veterans Administration Medical Centers. Four simple variables combined as a score predict all-cause mortality after clinical decisions for therapy are prescribed.


Assuntos
Teste de Esforço/normas , Cardiopatias/diagnóstico , Idoso , Distribuição de Qui-Quadrado , Coleta de Dados/normas , Cardiopatias/mortalidade , Humanos , Masculino , Pessoa de Meia-Idade , Guias de Prática Clínica como Assunto , Prevalência , Modelos de Riscos Proporcionais , Estudos Prospectivos , Análise de Sobrevida , Veteranos
16.
Am Heart J ; 142(1): 136-41, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11431669

RESUMO

OBJECTIVE: Our purpose was to assess the diagnostic characteristics of the exercise test in patients who fail to reach conventional target heart rates and in patients on beta-blockers. BACKGROUND: Exercise test results are often considered "inadequate" or "nondiagnostic" in patients taking beta-blockers and in patients who do not achieve 85% of their age-predicted maximal heart rate. METHODS: The results of exercise tests and coronary angiography performed to evaluate chest pain in 1282 male patients without a prior history of myocardial infarction, coronary revascularization, diagnostic Q wave on the baseline electrocardiogram, or previous cardiac catheterization were analyzed with respect to beta-blocker exposure and failure to reach 85% age-predicted maximal heart rate. Sensitivity, specificity, and predictive accuracy of exercise testing, as well as area under the curve for the receiver operating characteristic plots were calculated for these subgroups with use of coronary angiography as the reference. The angiographic criterion for significant coronary artery disease was 50% narrowing or greater in one or more major coronary arteries. RESULTS: The population was divided into 4 exclusive groups on the basis of whether they reached their target heart rates and whether they were receiving beta-blockers. Sixty to 40 percent of this clinical population failed to reach target heart rate, of which 24% (n = 303) were receiving beta-blockers and 40% (n = 518) were not. The group of patients who reached target heart rate and were not taking beta-blockers was taken as the reference group (n = 409). The group of patients supposedly beta-blocked but who reached the target heart rate (n = 52) had hemodynamic and test characteristics similar to those of the reference group and most likely were not taking their beta-blockers or were not adequately dosed. The prevalence of angiographic coronary disease was significantly higher in the 2 groups failing to reach target heart rate, both in the presence and absence of beta-blockers, compared with the reference group (68% and 64%, respectively, vs 49%, P <.01). Although the areas under the curve of the receiver operating characteristic curves for ST depression of the groups failing to reach target heart rate were not significantly different from the reference group, the predictive accuracy and sensitivity were significantly lower for 1 mm of ST depression in the beta-blocked group who did not reach target heart rate (predictive accuracy of 56% vs 67%, sensitivity of 44% vs 58%, P <.01). The only way to maintain sensitivity with the standard exercise test in the beta-blocker group who failed to reach target heart rate was to use a treadmill score or 0.5-mm ST depression as the criteria for abnormal. CONCLUSION: Sensitivity and predictive accuracy of standard ST criteria for exercise-induced ST depression are significantly decreased in male patients who are taking beta-blockers and do not reach target heart rate. In those who fail to reach target heart rate and are not beta-blocked, sensitivity and predictive accuracy are maintained.


Assuntos
Antagonistas Adrenérgicos beta/administração & dosagem , Doença das Coronárias/diagnóstico , Doença das Coronárias/tratamento farmacológico , Teste de Esforço , Frequência Cardíaca/fisiologia , Fatores Etários , Distribuição de Qui-Quadrado , Fenômenos Cronobiológicos , Angiografia Coronária , Doença das Coronárias/fisiopatologia , Eletrocardiografia , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Curva ROC , Sensibilidade e Especificidade
17.
Chest ; 119(5): 1576-81, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11348969

RESUMO

OBJECTIVE: The purpose of this study was to determine the characteristics of exercise treadmill testing in diabetic patients presenting with chest pain. BACKGROUND: The diagnosis of coronary artery disease (CAD) in diabetic patients is confounded by different manifestations of coronary disease than are seen in the general population. Because of the association of diabetes with accelerated CAD, it is critical to assess the diagnostic utility of the standard exercise test in diabetic patients with chest pain. METHODS: This study was a retrospective analysis of standard exercise test results in 1,282 male patients without prior myocardial infarction who had undergone coronary angiography and were being evaluated for possible CAD at two Veterans' Administration institutions. RESULTS: In patients with diabetes, 38% had an abnormal exercise test result, and the prevalence of angiographic CAD was 69%; the sensitivity of the exercise test was 47% (95% confidence interval [CI], 41 to 58), and specificity was 81% (95% CI, 68 to 89). In patients without diabetes, 38% had an abnormal exercise test result, and the prevalence of angiographic CAD was 58%; the sensitivity of the exercise test was 52% (95% CI, 48 to 56), and specificity was 80% (95% CI, 76 to 83). The receiver operating characteristic curves were also similar in both diabetic and nondiabetic patients (0.67 and 0.68, respectively). CONCLUSION: These data demonstrate that the standard exercise test has similar diagnostic characteristics in diabetic as in nondiabetic patients.


Assuntos
Dor no Peito/etiologia , Doença das Coronárias/complicações , Doença das Coronárias/diagnóstico , Complicações do Diabetes , Eletrocardiografia , Teste de Esforço , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Reprodutibilidade dos Testes , Estudos Retrospectivos , Sensibilidade e Especificidade
18.
Prim Care ; 28(1): 1-4 ,v, 2001 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11346495

RESUMO

In the changing economic times, internists and family physicians are becoming the main performers of the standard exercise test. The education of those noncardiologists who wish to perform exercise testing is quite important. In the new millennium, the American College of Cardiology/American Heart Association evidence-based guidelines on exercise testing continue to have a large impact. Used for diagnosis or prognosis, exercise scores such as the Duke exercise score will be applied to each test. Increased computerization and the internet will bring inexpensive web-enabled devices for sophisticated exercise testing into the doctor's office and allow remote over-reading services.


Assuntos
Doenças Cardiovasculares/diagnóstico , Teste de Esforço/tendências , Atenção Primária à Saúde , Previsões , Guias como Assunto , Humanos
19.
Prim Care ; 28(1): 219-32 ,ix, 2001 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11346507

RESUMO

This article reviews the role of exercise testing in the assessment of patients with suspected coronary disease. To accomplish this, four major topics are considered: the general concept of risk stratification; the estimation of outcomes using data from the initial evaluation of the patient; diagnostic assessment with the exercise test; and prognostic assessment with the exercise test. This review focuses on the standard treadmill exercise test.


Assuntos
Teste de Esforço/efeitos adversos , Segurança , Arritmias Cardíacas/etiologia , Bloqueio de Ramo/etiologia , Humanos , Hipotensão/etiologia , Síncope/etiologia
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