Recent research examining the effects of mental stress on left ventricular wall motion and/or ejection fraction has used four techniques to measure contractile function: radionuclide ventriculography, a stationary nuclear probe, two-dimensional echocardiography, and an ambulatory radionuclide left ventricular function monitor. This research has consistently revealed that mental stress-induced myocardial ischemia occurs frequently during laboratory stress testing, particularly among patients with exercise-induced ischemia. This ischemia is usually silent, occurs at low heart rate elevations but with significant blood pressure increases compared with exercise-induced ischemia, and is frequently not detected when electrocardiographic markers are used alone. Exploration of factors underlying differences between mental stress- and exercise-induced ischemia has provided a means for studying the complex pathophysiology of myocardial ischemia.

Exercise is a ubiquitous, biologically and clinically significant behavior. Although the somatomotor responses are generally regarded as "behavior," the cardiovascular adjustments that accompany these responses are generally considered to be reflexes that are elicited by neurally mediated stimuli and metabolites arising from working muscles. We report experimental evidence that monkeys can be trained to exercise, to slow heart rate, and to combine these two skills. Furthermore, some animals will emit more physical work at slower heart rates (at comparable levels of cardiac output) and lower left ventricular work during the combined condition relative to an exercise-only condition. Thus, these findings show that the cardiovascular and somatomotor responses of exercise can be dissociated and that both sets of responses should be considered behaviors. Also included are results that show these animals can perform these behaviors during sympathetic or vagal blockade. These findings are further evidence that the cardiovascular adjustments to exercise are, in part, learned behaviors because they show that the behavior--attenuation of the tachycardia of exercise--is not a reflex that is specifically tied to any neuroeffector system; rather, this behavior is emitted to achieve a contingent reward, and the nervous system will use whatever mechanisms are available to attain that consequence.

The hot tip laser system for atheroablation has been used since mid-1984 as a device for broadening the indications for and extending the applicability of angioplasty in the management of lower-extremity atherosclerosis. It has been a controversial device. Although the system demonstrates that it can occasionally be useful for the management of occlusive as opposed to stenotic disease of the infrainguinal arteries, a close examination of the published data fails to demonstrate a consistent improvement in either the primary success or long-term patency rates for thermal energy applied to atheroma for recanalization of the lower extremity arteries.

A variety of surgical procedures are available for the treatment of occlusive disease involving the aorta and iliac arteries. Use of the most appropriate operation in each patient, determined principally by disease location and patient risk, can provide highly effective relief of disabling claudication or limb-threatening ischemia with low morbidity and mortality rates. The excellent, durable results of current surgical practice should serve as the standard with which newer treatment modalities must be compared.

Continuing controversy over the role of carotid endarterectomy in stroke prevention is based largely on reports in which high perioperative morbidity and mortality rates obviate possible long-term benefit from the procedure. The purpose of this review is to examine optimal results of carotid surgery in order to describe the potential for the procedure in stroke prevention. Optimal surgical results are compared with optimal medical results in the therapy of symptomatic patients and with optimal nonsurgical results in the therapy of asymptomatic patients. Factors common to series with excellent results, such as patient selection and operative technique, are examined, and problems such as recurrent carotid stenosis and coexisting coronary disease, which continue to plague even the best surgical series, are discussed.

A number of diagnostic tools have been developed over the past decade that facilitate the noninvasive evaluation of cerebral ischemia. From duplex Doppler ultrasound to xenon computed tomography and magnetic resonance angiography, a greater trend toward combining both anatomic and function information is anticipated. The methodology, limitations, and current clinical applications of these three diverse techniques, with emphasis on xenon computed tomography and magnetic resonance angiography, are discussed. Both xenon computed tomography and magnetic resonance angiography can be performed on current systems with minimal hardware and software modifications. As a result, standard anatomic and structural imaging can be supplemented with diverse information such as quantitative brain perfusion without and with flow challenging as well as flow mapping and velocity imaging, which approximates conventional x-ray angiography.

Renovascular hypertension is caused by two distinct conditions with different causes, fibromuscular dysplasia and atheroma. Diagnosis of the former is both simpler and more rewarding, whereas atheromatous lesions of the renal artery may be secondary to essential hypertension. It is therefore important to establish existence of functional renal ischemia as well as an anatomical lesion. Universal screening of all hypertensive patients is not recommended because of the relatively low prevalence of the disease and insufficient accuracy of available screening tests. When renovascular hypertension is clinically suspected, an oral captopril test is the most reliable office screening test. After this, digital subtraction angiography with renal vein renins or captopril renography are appropriate steps. However, the latter procedure, while promising, requires further evaluation. Duplex scanning of the renal arteries also comes into this category. Arteriography is done last, so that if renal ischemia is indicated, angioplasty can be attempted at the same time as arteriography.

The two major types of intravascular stents are balloon expandable and self-expanding. Many animal and, more recently, clinical studies have begun to delineate the real and potential roles of stents. Although the ideal intravascular stent does not exist, it is possible to identify characteristics of the hypothetical ideal stent. Iliac and femoropopliteal arterial applications of metallic stents are reviewed. Stents have proved useful in postangioplasty elastic recoil, in some cases of postangioplasty restenosis, and in angioplasty-induced dissection. Their role in primary angioplasty procedures is still uncertain, although in iliac angioplasty the immediate hemodynamic effects of angioplasty plus stenting are superior to those of angioplasty alone. It is clear that metallic stents have not solved the problem of postangioplasty restenosis, as restenosis still occurs in a significant number of cases. This problem is particularly evident in the femoropopliteal stent procedures, in which angiographic restenosis (more than 50% single diameter stenosis) at 6 months after treatment has occurred in approximately 30% of cases. The existence of poststenting restenosis, which often involves the stented segment, underscores the need for better drug regimens in angioplasty and for better understanding of the intimal fibrocellular proliferative response of the vessel wall to injury. Although potentially very useful, biodegradable stents are still a dream whose realization will demand the development of better materials.

The durability and the eventual complication rate of endovascular therapy (percutaneous transluminal angioplasty, laser-assisted angioplasty, and atherectomy) are not yet entirely clear, especially with respect to the treatment of atherosclerotic lesions in the femoropopliteal or distal arterial segments. Therefore, the indications for its use have not been firmly established and must take into consideration the natural history of the occlusive disease itself. Although some type of procedural intervention clearly is warranted in the presence of ischemic rest pain or tissue necrosis, intermittent claudication is the only complaint in approximately 70% of patients who present with either aortoiliac or femoropopliteal involvement. Most nondiabetic patients experience substantial symptomatic improvement with a daily exercise program, and their long-term risks for either abrupt deterioration (20-25%) or amputation (less than 10%) are relatively low. In comparison, the 5-year mortality rate ranges from 20-40% even in claudicants, and as many as 40% of those with clinical indications of associated coronary artery disease have been shown angiographically to be candidates for myocardial revascularization. These observations suggest that traditional indications for surgical treatment (truly disabling claudication and/or limb salvage) also should be applied to endovascular therapy until its success is confirmed beyond speculation, and that incidental coronary disease deserves particular attention in patients with lower extremity ischemia.

Noninvasive techniques have assumed an increasingly important role in the management of patients with vascular disease. Both ultrasonic and plethysmographic instruments allow objective evaluation of vascular disorders by the measurement of segmental limb blood pressures, analysis of blood velocity disturbances, recording of digit or limb pulse waveforms, or imaging of vascular disease, with or without Doppler flow analysis or color-flow mapping. These techniques have been applied for screening asymptomatic individuals, diagnosis of symptomatic patients, monitoring of interventional or surgical procedures, and follow-up of the natural history or the efficacy of medical, interventional, or surgical therapy of vascular disease. This article reviews the clinical application of these modalities to patients with peripheral arterial disease and briefly discusses cost-effectiveness and potential abuses of noninvasive technology.

Treatment of complex cerebrovascular disorders, including intracranial aneurysms, carotid cavernous sinus fistulas, vertebral fistulas, arteriovenous malformations, atherosclerosis of brachiocephalic vessels, and arterial vasospasm, is being performed in selected cases by interventional neurovascular techniques. Recent advances in microballoon technology, permanent solidifying polymers, newer embolic agents, high-resolution digital subtraction angiography with road-mapping technique, and steerable micro-guide wires and catheters have greatly improved access in the distal intracranial circulation and markedly reduced the morbidity associated with these procedures. Interventional neuroradiology is emerging as an important adjunct to neurosurgery for selected cerebrovascular disorders.

The role of surgical revascularization in the management of patients with renal artery disease has changed in recent years. This has occurred due to the advent of percutaneous transluminal angioplasty as an effective method of treatment for certain patients, improved results of surgical revascularization in older patients with atherosclerosis, an enhanced appreciation of advanced atherosclerotic renal artery disease as a correctable cause of renal failure, and the development of more effective surgical techniques for patients with severe aortic atherosclerosis and branch renal artery disease. Surgical revascularization is currently the treatment of choice for patients with branch renal artery disease, ostial atherosclerotic renal artery disease, a renal artery aneurysm, and patients in whom renal percutaneous transluminal angioplasty has been unsuccessful. Excellent clinical results continue to be achieved with surgical revascularization in properly selected patients.

Nonoperative therapy includes conservative noninterventional modalities and the endovascular interventional modalities of percutaneous transluminal angioplasty and a variety of laser systems and atherectomy devices. The role and impact of all nonoperative treatments are considered in the perspectives of the natural history of lower-extremity arteriosclerosis and its present surgical (operative) treatment. Nonoperative treatments may replace and/or facilitate surgical treatment in operative candidates. Nonoperative methods may also justify treatment in patients who cannot or should not be subjected to surgery. Facts and opinions relating to these uses of nonoperative treatments are presented, and the qualifications and credentialing of individuals who should be treating patients with lower-extremity ischemia resulting from peripheral arteriosclerosis are discussed.

The evidence that ETS increases risk of death from heart disease is similar to that which existed in 1986 when the US Surgeon General concluded that ETS caused lung cancer in healthy nonsmokers. There are 10 epidemiological studies, conducted in a variety of locations, that reflect about a 30% increase in risk of death from ischemic heart disease or myocardial infarction among nonsmokers living with smokers. The larger studies also demonstrate a significant dose-response effect, with greater exposure to ETS associated with greater risk of death from heart disease. These epidemiological studies are complemented by a variety of physiological and biochemical data that show that ETS adversely affects platelet function and damages arterial endothelium in a way that increases the risk of heart disease. Moreover, ETS, in realistic exposures, also exerts significant adverse effects on exercise capability of both healthy people and those with heart disease by reducing the body's ability to deliver and utilize oxygen. In animal experiments, ETS also depresses cellular respiration at the level of mitochondria. The polycyclic aromatic hydrocarbons in ETS also accelerate, and may initiate, the development of atherosclerotic plaque. Of note, the cardiovascular effects of ETS appear to be different in nonsmokers and smokers. Nonsmokers appear to be more sensitive to ETS than do smokers, perhaps because some of the affected physiological systems are sensitive to low doses of the compounds in ETS, then saturate, and also perhaps because of physiological adaptions smokers undergo as a result of long-term exposure to the toxins in cigarette smoke. In any event, these findings indicate that, for cardiovascular disease, it is incorrect to compute "cigarette equivalents" for passive exposure to ETS and then to extrapolate the effects of this exposure on nonsmokers from the effects of direct smoking on smokers. These results suggest that heart disease is an important consequence of exposure to ETS. The combination of epidemiological studies with demonstration of physiological changes with exposure to ETS, together with biochemical evidence that elements of ETS have significant adverse effects on the cardiovascular system, leads to the conclusion that ETS causes heart disease. This increase in risk translates into about 10 times as many deaths from ETS-induced heart disease as lung cancer; these deaths contribute greatly to the estimated 53,000 deaths annually from passive smoking. This toll makes passive smoking the third leading preventable cause of death in the United States today, behind active smoking and alcohol.