Case 3: Insulin-dependent diabetes mellitus.

Dyslipidemia secondary to insulin-dependent diabetes mellitus is common among patients whose plasma glucose levels are poorly controlled. Because of the high mortality associated with diabetes, prompt intervention to correct the dyslipidemia is warranted.

Case 4: A patient with systemic hypertension and congestive heart failure.

Hypertension in the setting of symptomatic congestive heart failure requires aggressive treatment. The optimal antihypertensive agent in such patients is one that effectively controls blood pressure without compromising the failing heart.

Case 3: A patient with systemic hypertension and left ventricular hypertrophy.

Hypertension is often referred to as the "silent killer" because most hypertensive patients are asymptomatic until cardiovascular sequelae such as stroke, myocardial infarction, heart failure, or renal failure occur. LVH is a common finding in patients with hypertension, especially African-Americans. Data from the Framingham Heart Study indicate that LVH is an independent risk factor for major cardiovascular events. In the Amlodipine Cardiovascular Community Trial, 37% of 124 hypertensive patients screened by means of echocardiography had LVH at baseline. Although there was no difference in the prevalence of LVH by gender or age, African-American patients were nearly twice as likely to have LVH than white patients (64% vs. 34%, p<0.05). Hence, aggressive therapy to reach target goals outlined in the Sixth Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC VI) is especially important in this group of patients. Even lifestyle modifications such as weight reduction and limitation of salt intake, if sufficiently aggressive, can lead to regression of LVH, as demonstrated by results of the Treatment of Mild Hypertension Study (TOMHS). Most classes of antihypertensive drugs are effective in causing regression of LVH. Vasodilators, such as minoxidil and hydralazine, do not have an effect on regression, possibly because reflex tachycardia and stimulation of catecholamines and the renin-angiotensin system associated with these agents may negate the benefit of reduced afterload. There is some controversy regarding the ability of the angiotensin receptor blockers to reduce LVH. In some studies, these agents were associated with regression, whereas in others they were not. Whether targeting LVH as the primary treatment goal in hypertensive patients will have long-term benefits on outcome above and beyond simply reducing blood pressure is not clear.

Sudden cardiac death associated with exercise: the risk-benefit issue.

Although there is an overall increased risk of sudden cardiac death associated with physical exertion, the risk is small. Yet it warrants consideration by physicians and their adult patients who pursue exercise because, in any individual patient, the risk may be high. To advise patients properly on the risks and benefits of exercise, physicians should have an understanding of the risks of exercise, a strategy for patient evaluation that effectively identifies patients at risk, and a knowledge of appropriate exercise procedures that minimize risk. Patients should also know proper exercise procedures, be aware that there is some degree of risk in exercise, know their exercise tolerance, understand self-monitoring procedures, and be sensitive to prodromal symptoms. The essential feature of prudent exercise is a gradual progression during which an individual remains well within the limits of his/her exercise tolerance.

Case 1: isolated systolic hypertension.

Despite the prevalence of isolated systolic hypertension (ISH) in the elderly, many physicians are reluctant to treat the disorder. Recently identified as one of the major health challenges of the new millennium, ISH is the focus of this month's CME-accredited case study in hypertension, featured at www.CardiovascularEd. com.

Case 6: Renovascular hypertension.

Renovascular hypertension is a progressive disorder that can result in serious complications without adequate treatment. Unfortunately, identification of patients with the condition is often difficult, and the optimal approach to management continues to be debated.

Case 2: a patient with low levels of high-density lipoprotein cholesterol.

Approximately 11% of all American men >20 years of age have low levels of high-density lipoprotein cholesterol (<35 mg/dl) in isolation, with an even higher prevalence in high-risk populations. One feature of the 1993 National Cholesterol Education Program guidelines-and the focus of this month's CME-accredited case study-is an increased emphasis on high-density lipoprotein cholesterol levels as an important aspect of risk stratification for coronary heart disease.

Case 2: a patient with an intermittent racing heartbeat.

Most clinicians currently rely on patient history and specific electrocardiographic criteria to establish the diagnosis of arrhythmias. However, as illustrated by this case, the physical examination-especially auscultation of the first heart sound-can also provide useful diagnostic clues.

Relation of blood pressure during exercise to anaerobic metabolism.

To determine the effects of anaerobic metabolism on blood pressure (BP), 25 subjects were studied for BP response to graded and continuous leg-crank ergometry under both aerobic and anaerobic conditions. Measurements obtained during exercise also included ventilatory equivalents for oxygen and carbon dioxide to determine anaerobic threshold. Systolic and diastolic BP responses to exercise before anaerobic threshold were compared with responses after anaerobic threshold by linear regression analyses. The systolic BP response to graded exercise was significantly accelerated (p less than 0.01) after anaerobic threshold, demonstrating a nonlinear response to proportionately graded exercise demand. Comparison of the slopes or rates of change in diastolic BP before and after anaerobic threshold also indicated a significant difference (p less than 0.01) under these 2 different metabolic conditions. It is concluded that in contrast to the linear response of BP under conditions of aerobic metabolism, BP responds nonlinearly during anaerobic metabolism.

Case 4: a patient with symptomatic bradycardia.

Both the clinical and electrocardiographic presentations of sick sinus syndrome are highly variable. As illustrated by this month's case of Interactive Grand Rounds, the initial challenge to the clinician is to establish the correct diagnosis in the patient who has symptomatic bradyarrhythmias.

The use of two-dimensional echocardiography for diagnostic screening: an evaluation of screening capabilities and feasibility of use in remote areas.

This is a two-phase study. The first phase assesses the use of portable 2D echocardiography for diagnostic studies in remote areas. The second phase examines the diagnostic capabilities of 2D "only" versus 2D echocardiography combined with M-mode.

Maximal-stress, multiple-lead exercise testing: the significance of ST-segment changes in the detection of coronary arterial occlusive disease.

Recognition of the value of objective parameters in the diagnostic evaluation for coronary arterial occlusive disease had led to increased application of maximal-stress multiple-lead electrocardiography. Changes in the ST-segment during and immediately following exercise are the most significant electrocardiographic indicators of myocardial ischemia. When such causes of ischemia as congenital anomalies, embolism, and arteritis have been excluded, exercise testing is a sensitive and specific means of detecting coronary arterial occlusion. The sensitivity and specificity of this parameter are evaluated in terms of long-term morbidity and mortality and, more recently, through correlation of electrocardiographic results with angiographic evidence. In our series of 308 patients undergoing both exercise testing and coronary arteriography, the sensitivity factor for 80 negative stress tests approached 95 per cent, with only four false-negative resting and exercise electrocardiograms. For 129 patients with ST-segment changes indicative of myocardial ischemia, angiography demonstrated significant coronary stenosis in 84 per cent of the cases. Of the twenty patients with false-positive stress electrocardiograms twelve were females, wich correlates with the generally higher rate of false-negative stress-electrocardiographic response among women.