Increasing systemic blood pressure or ventricular dilation would increase wall tension and oxygen demand, whereas ventricular hypertrophy would tend to minimize increasing MVO 2.Chronic stable angina should be managed initially with -blockers because they provide better symptomatic control at least as well as nitrates or calcium channel blockers and decrease the risk of recurrent myocardial infarction (MI) and CAD mortality.
With improvements in stent technology, more patients are eligible for this approach compared with CABG. Coronary artery vasospasm (variant or Prinzmetals angina) produces similar symptoms but is not due to atherosclerosis. Microvascular angina that is myocardial ischemia without occlusive CHD is seen more commonly in women than in men. Other manifestations of atherosclerosis include heart failure, arrhythmias, cerebrovascular disease (stroke), and peripheral vascular disease. The American Heart Association (AHA), the American College of Cardiology, and the European Society of Cardiology have published management guidelines for stable and unstable angina. In 2009, the death rates from CVD were 387 (per 100,000) for black males, 281.4 for white males, 269.9 for black females, and 190.4 for white females. The disparity in mortality from IHD between men and women decreases with aging, being about four to five times more common in men from the age of the mid-30s to a preponderance of female deaths in the very elderly. Sap new license key crackEstimates of the incidence and prevalence of angina are not entirely accurate due to waxing and waning of symptoms; angina may disappear in up to 30 of patients with angina that is less severe and of recent onset. Countries such as Japan and France are on the low end of the spectrum, whereas Finland, Northern Ireland, Scotland, and South Africa have very high rates of IHD. The Specific Activity Scale developed by Goldman et al. New York Heart Association (NYHA) or Canadian Cardiovascular Society functional classifications for reproducibility and provides better agreement with exercise treadmill testing. Twelve-year survival from the Coronary Artery Surgery Study (CASS) for patients with zero-, one-, two-, and three-vessel disease was 88, 74, 59, and 40, respectively. Other factors that increase the risk of death in medically managed patients include the presence of heart failure (or markers such as poor ventricular wall motion and low ejection fraction), smoking, left main or left main equivalent coronary artery disease (CAD), diabetes, or prior MI. Twelve-year survival for patients with at least one diseased vessel and ejection fractions in the ranges of 50 (0.50), 35 to 49 (0.35 to 0.49), and 0 to 34 (0 to 0.34) is 73, 54, and 21, respectively. Of particular note, patients with left main CAD (or left main equivalent) are at extremely high risk and constitute a unique group for therapeutic consideration. In the CASS, at 15 years of follow-up, 37 of the surgery group and 27 of the medical group are surviving; median survival is 13.3 years versus 6.7 years, respectively ( P 11 Indeed, current guidelines provide similar recommendations for PCI and CABG in certain patients. If systolic function was normal, then median survival and percent surviving were not different between the surgery and medical groups (median survival of about 15 years). Patients screened but not randomized to CASS had similar survival rates, suggesting that results from randomized patients may be applicable to more generalized populations as a measure of external reliability. An understanding of the determinants of myocardial oxygen demand (MVO 2 ), regulation of coronary blood flow, the effects of ischemia on the mechanical and metabolic function of the myocardium, and how ischemia is recognized is important to understand the rationale for the selection and use of pharmacotherapy for IHD. In contrast, anoxia, defined as the absence of oxygen to the myocardium, results in continued perfusion with washout of acid by-products of glycolysis, thereby preserving the mechanical and metabolic status of the heart to a greater extent than does ischemia for short periods of time. Overall, intramyocardial wall tension is thought to be the most important among these three factors. As the consequences of IHD are a result of increased demand in the face of a fixed supply of oxygen in most situations, alterations in MVO 2 are critically important in producing ischemia and for interventions intended to alleviate ischemia. MVO 2 cannot be directly measured in patients; however, an indirect assessment that correlates reasonably well with MVO 2 as determined in experimental animal models is the tensiontime index (TTI). This is a measure of the area under the curve of the left ventricular (LV) pressure curve. Tension in the ventricle wall is a function of the radius of the LV and intraventricular pressure. These factors are related through Laplaces law, which states that wall stress is related directly to the product of intraventricular pressure and internal radius and inversely to wall thickness multiplied by a factor of two.
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