Progress in cardiovascular diseases
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Prog Cardiovasc Dis · Mar 1998
ReviewPerioperative cardiac evaluation for noncardiac surgery noninvasive cardiac testing.
Prognostic risk stratification to identify perioperative and long-term cardiac risk in selected patients undergoing noncardiac surgery is part of good clinical practice. Exercise variables associated with significant increased risk include poor functional capacity (eg, <4 metabolic equivalents), marked exercise-induced ST segment shift or angina at low workloads, and inability to increase or actually decrease systolic blood pressure with progressive exercise. Approximately 40% of patients tested before peripheral vascular surgery will have an abnormal exercise electrocardiogram (ECG). ⋯ Myocardial perfusion variables predictive of increased cardiac events include severity of the perfusion defect, number of reversible defects, extent of fixed and reversible defects, increased lung uptake of thallium-201, and marked ST segment changes associated with angina during the test. The reported sensitivity and specificity of dobutamine-induced echocardiographic wall motion abnormalities in patients with peripheral vascular disease is similar to myocardial perfusion scintigraphy, but the confidence limits are wider due to the smaller sample size in these more recent studies. In conclusion, noninvasive cardiac testing should be used selectively in patients undergoing noncardiac surgery; the results provide useful estimates of short- and long-term risk of cardiac events, and the magnitude of abnormal response on noninvasive testing should be used to formulate decisions regarding the need for coronary angiography and subsequent revascularization.
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Prog Cardiovasc Dis · Mar 1998
ReviewSurgery-specific considerations in the cardiac patient undergoing noncardiac surgery.
Myocardial infarction after noncardiac surgery in patients with coronary artery disease results from the interplay of patient-specific, anesthetic-specific, and surgery-specific factors. Surgery-specific factors include the stress response to injury, both neurohormonal and hemostatic alterations, and clinically-significant operative parameters such as urgency, duration, blood loss, body core temperature, fluid shifts, and location of surgery. ⋯ Overall, the morbidity and mortality of surgery is minimal even in high-risk patients, and the contribution of surgery-specific factors to operative risk is subtle compared with that of patient specific-factors such as severity of coronary disease and other comorbid conditions. Nonetheless, the optimal surgical management of patients with coronary disease requires the collaborative effort of the anesthesiologist, cardiologist, and surgeon.
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The intraoperative management of the high-risk patient has received a great deal of attention and research during the past decade. Based on the available evidence, there appears to be no one best anesthetic technique or agent. ⋯ Perioperative pharmacological treatment with alpha-2 agonists and beta-adrenergic blocking agents are associated with a reduced incidence of perioperative myocardial ischemia and improved long-term survival, respectively. Future research will be required to determine whether prophylactic therapy or early treatment of perioperative myocardial ischemia will lead to improved outcome.
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Prog Cardiovasc Dis · Jan 1998
ReviewRight ventricular function in congenital heart disease: pressure and volume overload lesions.
The right ventricle is often subject to both pressure and volume overload in congenital heart disease. Evaluating right ventricular function in both the native lesion and after surgery in light of these loading conditions, presents a unique challenge for investigators studying these misshapen hearts. The purpose of this article is to briefly delineate what is generally known about right ventricular function in congenital heart disease and to touch on some noninvasive imaging modalities which have helped shed some light on this matter.
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Prog Cardiovasc Dis · Nov 1997
ReviewThrombosis, antithrombotic agents, and the antithrombotic approach in cardiac disease.
To develop a rational approach to antithrombotic therapy, in cardiac disease, a sound understanding is required (1) of the hemostatic processes leading to thrombosis, (2) of the various antithrombotic agents, and (3) of the relative risks of thrombosis and thromboembolism in the various cardiac disease entities. With the understanding of pathogenesis and risk of thrombus formation, a rational approach to the use of antiplatelet and anticoagulant agents can be formulated. ⋯ Patients at low risk of thrombus formation should not receive antithrombotics. Such rational approach to antithrombotic therapy serves as the basis of this article.