Assessment of risk for developing coronary heart disease in asymptomatic individuals.

The assessment of risk for developing coronary heart disease (CHD) in asymptomatic individuals continues to be an important challenge for clinicians. We suggest that the Framingham risk score provides a pragmatic basis for assessing global 10-year CHD risk in this population. The Framingham risk score should be supplemented with additional information pertaining to diabetes, metabolic syndrome, family history, and peripheral arterial disease before a final decision is made with respect to individual risk. In terms of additional investigations, it is suggested that measurement of the ankle brachial index and a stress test that focuses on functional capacity be incorporated into the evaluation of asymptomatic subjects for CHD. The role of emerging risk factors remains unresolved as is the value of attempting to routinely diagnose subclinical disease with measurements such as the coronary calcium score.

Effects of red wine, alcohol, and quercetin on coronary resistance and conductance arteries.

Moderate consumption of alcoholic beverages is associated with a reduced risk of coronary heart disease (CHD). Some evidence suggests that red wine is particularly beneficial in this regard and may account in part for the French paradox, although the mechanism of this effect is unknown. We assessed the effects of red wine, ethanol, and quercetin, a major flavonoid constituent of red wine, in coronary resistance vessels (80-150 microm, i.d.) and conductance vessels (300-525 microm, i.d.) of the rabbit. Vessel wall tension was measured in isolated segments maintained in a wire-type myograph (37 degrees C) and preconstricted with 30 mM K+. At an alcohol concentration (14 mM) equivalent to moderate consumption, red wine evoked a small, transient constrictor effect in resistance and conductance vessels (9+/-4%, n = 5; 8+/-1%, n = 7, respectively; p < 0.05). Ethanol alone at this concentration was without effect. Quercetin (5.6, 8, and 30 microM) significantly relaxed resistance (-32+/-4%, n = 10; -47+/-2%, n = 7; -82+/-6%, n = 8, respectively) and conductance (-20+/-3%, n = 8; -32+/-4%, n = 8; -72+/-7%, n = 8, respectively) coronary arteries. Vasorelaxation by quercetin was endothelium-independent and was significantly greater in resistance than in conductance vessels. These data suggest that red wine and ethanol do not evoke relaxation in small coronary arteries at concentrations associated with moderate consumption. Quercetin elicits marked coronary vasorelaxation that is endothelium-independent. However, the concentrations of quercetin necessary to achieve this action are not attained with moderate red wine consumption.

Effects of Hatha Yoga Practice on the Health-Related Aspects of Physical Fitness.

Ten healthy, untrained volunteers (nine females and one male), ranging in age from 18-27 years, were studied to determine the effects of hatha yoga practice on the health-related aspects of physical fitness, including muscular strength and endurance, flexibility, cardiorespiratory fitness, body composition, and pulmonary function. Subjects were required to attend a minimum of two yoga classes per week for a total of 8 weeks. Each yoga session consisted of 10 minutes of pranayamas (breath-control exercises), 15 minutes of dynamic warm-up exercises, 50 minutes of asanas (yoga postures), and 10 minutes of supine relaxation in savasana (corpse pose). The subjects were evaluated before and after the 8-week training program. Isokinetic muscular strength for elbow extension, elbow flexion, and knee extension increased by 31%, 19%, and 28% (p<0.05), respectively, whereas isometric muscular endurance for knee flexion increased 57% (p<0.01). Ankle flexibility, shoulder elevation, trunk extension, and trunk flexion increased by 13% (p<0.01), 155% (p<0.001), 188% (p<0.001), and 14% (p<0.05), respectively. Absolute and relative maximal oxygen uptake increased by 7% and 6%, respectively (p<0.01). These findings indicate that regular hatha yoga practice can elicit improvements in the health-related aspects of physical fitness. (c)2001 CHF, Inc.

Evaluation of chest pain suspicious for acute coronary syndrome: use of an accelerated diagnostic protocol in a chest pain evaluation unit.

Management of patients presenting to the emergency department with chest pain suggestive of acute myocardial infarction (AMI) remains a continuing challenge. A low threshold for admission has been traditional because of concern for patient welfare and the litigation potential associated with the inadvertent discharge of patients with ischemic events. Because of this approach, < 30% of patients admitted for chest pain ultimately are found to have an acute coronary syndrome. To reduce unnecessary admissions, maintain patient safety, and enhance cost-effectiveness, innovative strategies have been applied to the management of patients with chest pain. It is now recognized that a low-risk group can be identified by the clinical presentation and initial electrocardiogram. Chest-pain centers have been developed to provide further risk stratification and systematic management of these patients. We employ an accelerated diagnostic protocol based on immediate exercise treadmill testing to evaluate low-risk patients. Moderate-risk patients are assessed over a 6-hour observation period with serial electrocardiograms and evaluation of cardiac-injury markers. Patients with positive evaluations are admitted. Those with negative results undergo either exercise echocardiography or rest myocardial perfusion imaging utilizing technetium-99m sestamibi. Patients with positive functional tests are admitted. Those with negative studies are discharged with outpatient follow-up. These strategies have provided a safe and accurate means of patient disposition from the emergency department with the potential for vital cost savings.

Interobserver agreement in the electrocardiographic diagnosis of acute myocardial infarction in patients with left bundle branch block.

STUDY OBJECTIVE: To determine the interobserver agreement between cardiologists and emergency physicians in the ECG diagnosis of acute myocardial infarction (AMI) in patients with left bundle branch block (LBBB) using the ECG algorithm previously described by Sgarbossa et al. METHODS: Using the Sgarbossa ECG algorithm, 4 cardiologists and 4 emergency physicians independently interpreted a test set of 224 ECGs with LBBB, of which 100 ECGs were from patients with an evolving AMI. A subset of 25 ECGs was reinterpreted by each reader to test intraobserver agreement for AMI as well as interobserver agreement for the degree of ST-segment deviation. Agreement rates for AMI were estimated using the kappa statistic. In addition, the sensitivity and specificity for diagnosing AMI were determined for each reader, using the Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries (GUSTO I) enzyme criteria for AMI as the gold standard. The study was conducted at 3 university-affiliated medical centers. The test set contained ECGs from 100 patients enrolled in the GUSTO I trial with LBBB on their initial ECG and an evolving AMI confirmed by serum cardiac enzyme changes, and 124 control patients from the Duke Databank for Cardiovascular Disease who had stable, angiographically documented coronary artery disease and LBBB. RESULTS: There was excellent interobserver agreement (kappa=0.81, 95% confidence interval [CI] 0.80 to 0.83) between cardiologists and emergency physicians for diagnosing AMI. Intraobserver agreement kappa values for AMI diagnosis by cardiologists and emergency physicians were 0.81 (95% CI 0.67 to 0.94) and 0.71 (95% CI 0.54 to 0.89). The median sensitivity for diagnosing AMI by cardiologists and emergency physicians was 73% (range 66% to 80%) versus 67% (range 61% to 75%); median specificity was 98% (range 97% to 99%) versus 99% (range 98% to 99%). Spearman rank correlation coefficients for the degree of ST-segment deviation in all 12 leads was 0.86 (95% CI 0.85 to 0.87) among all readers. CONCLUSION: There is excellent interobserver agreement between cardiologists and emergency physicians for diagnosing AMI when applying the Sgarbossa ECG algorithm to patients with LBBB. Emergency physicians should be able to reliably use this algorithm when evaluating patients.

Interpretation of immediate exercise treadmill test: interreader reliability between cardiologist and noncardiologist in a chest pain evaluation unit.

STUDY OBJECTIVE: To determine whether attending physicians in a chest pain evaluation unit (CPEU) can perform and interpret exercise testing with the same accuracy as cardiologists. METHODS: Between January 1996 and November 1998, immediate exercise tests were performed and interpreted by internists with additional training in exercise testing who serve as attending physicians in a CPEU at a large university medical center. For quality assurance, all tests were overread by a cardiologist. Test results were compared for each reader, and all tests with discrepant readings were reinterpreted by an independent cardiologist who was blinded to the previous results. Patients' clinical course was monitored for at least 30 days after exercise testing. RESULTS: The study group consisted of 645 patients (347 men, 298 women). Discrepant interpretations were found in 11 (1. 7%) patients. The agreement was 98.4% (kappa value 0.9618). The majority of discrepancies were insignificant and were based on subtle differences in the definition of a nondiagnostic test or the degree of ST-segment shift. Of the 11 discordant readings, the blinded cardiologist concurred with 5 (45%) of the CPEU interpretations and 4 (36%) of the cardiologist interpretations. In 2 cases, there was disagreement by all 3 interpreters. There was no cardiac morbidity or mortality of any patient with a discrepant reading. CONCLUSION: Our results suggest that noncardiologists serving as attending physicians in a CPEU can accurately interpret exercise tests and overreading by cardiologists for quality assurance is unnecessary.

Prevention of coronary heart disease. Part II. Secondary prevention, detection of subclinical disease, and emerging risk factors.

The prevention of CHD should be a major priority among primary care physicians and subspecialists who have any dealing with the cardiovascular system. There is ample evidence from epidemiologic studies for the impact of specific risk factors on CHD events. There is also ample evidence from observational studies and clinical trials that interventions of lifestyle and pharmacologic therapy can decrease morbidity and mortality from CHD before or after the first event. It behooves the physician who wishes to practice good medicine to understand the pathophysiologic roles of the risk factors and the evidence from epidemiologic studies and clinical trials for their association with cardiovascular disease. It is important to determine the efficacy of interventions, both lifestyle and pharmacologic, in modifying CHD risk. To be effective in doing so, the practicing physician has to have the motivation to determine target goals for risk factor modification in each patient, to understand the patient's own motivations in modifying risk factors, and to define clearly with the patient the expectations of such interventions. Although there are guidelines for risk factor modification in modification of cholesterol and in hypertension, the periodic renewal of these guidelines reflects the changing concepts of risk and its modification. A cardiovascular risk factor intervention categorization is presented in Table 12. The physician must be convinced that such intervention is beneficial to the patient, cost-effective, and thus fulfills the expectations of medical practice. The practice of medicine in the evaluation and treatment of coronary heart disease has always been challenging and stimulating. The prevention of CAD disease should ultimately provide the greatest accomplishment.

Chest pain emergency units.

Each year in the United States, more than 2 million patients are hospitalized with chest pain suggestive of myocardial ischemia, with fewer than 20% of these patients having an acute coronary event. Chest pain emergency units have been created to facilitate urgent therapy for patients with a serious cardiovascular event and to triage lower risk patients to less intensive, more cost-effective inpatient care or discharge to home. The clinical history, physical examination, and initial electrocardiogram are key to initial stratification of patients for further management, but additional methods are necessary to clearly distinguish patients with inconclusive findings at presentation as high- and low-risk. Innovative electrocardiographic methods have increased sensitivity for detecting myocardial ischemia. Accelerated diagnostic protocols with new cardiac serum markers can detect myocardial ischemia or infarction with increasing accuracy. Early echocardiographic, scintigraphic, and treadmill stress protocols can further evaluate patients who have nondiagnostic electrocardiograms and negative serum markers. This review presents the current status of chest pain emergency units and the evolving management strategies they encompass.