Progress in cardiovascular diseases
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Prog Cardiovasc Dis · Nov 2006
ReviewSystolic dysfunction in heart failure with a normal ejection fraction: echo-Doppler measurements.
Heart failure with a normal ejection fraction, also called heart failure with preserved ejection fraction or diastolic heart failure, is thought to be characterized by normal systolic function and disturbed diastolic function only. However, studies using newer Doppler-echocardiographic techniques have shown that ventricular function is not normal particularly in the long axis. Ejection is relatively preserved because of increased radial function. ⋯ The use of ejection fraction, which has a normal distribution, to dichotomize patients with heart failure is not supported on theoretical or experimental grounds, and any cutoff is arbitrary. Patients with heart failure have a mixture of systolic and diastolic abnormalities and variable degrees of remodeling. It is more important to correctly identify these in the individual patient.
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Cardiovascular complications are the major cause of perioperative morbidity and mortality of patients undergoing major vascular surgery. This is related to the frequent presence of an underlying coronary artery disease. This paper reviews the pathology of perioperative cardiac complications and cardiac risk assessment and risk reduction strategies. ⋯ Patients with 1 or 2 cardiac risk factors represent an intermediate-risk group for perioperative cardiac complications. If beta-blockers are prescribed, the probability of cardiac complications is low and there is no need for further noninvasive testing. Patients with 3 or more risk factors are at high risk for cardiac complications and the use of noninvasive testing may help further refine cardiac risk based on the presence and absence of test-induced myocardial ischemia. beta-Blockers should be prescribed to all patients, and coronary revascularization should be reserved for high-risk patients who have a clearly defined need for revascularization independent of the need for major vascular surgery.
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The arterial endothelium is a vital homeostatic cell layer responsible for a variety of functions such as thromboresistance, control of vessel tone, and vessel growth. Recent evidence has indicated that both active and passive cigarette smoking are associated with dysfunction of normal endothelial physiology, in a dose dependent and potentially reversible way. Endothelial abnormalities may predispose to the atherogenic and thrombotic problems associated with cigarette smoking.
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Various forms of smokeless tobacco (mainly snuff and chewing tobacco) cause an immediate increase in heart rate and blood pressure, but regular users of smokeless tobacco do not have permanent changes of heart rate or blood pressure when not exposed to tobacco. Cardiac output during workload and maximal working capacity are unaffected. Users of smokeless tobacco usually do not have the biochemical stigmata that regular smokers have. ⋯ Results on the risk for myocardial infarction have provided conflicting evidence, 2 case-control studies showing the same risks as in non-tobacco users and one cohort study showing an increased risk for cardiovascular death. In all, the use of smokeless tobacco (with snuff being the most studied variant) involves a much lower risk for adverse cardiovascular effects than smoking does. Whether or not the apparent risk reduction is a useful strategy to help inveterate smokers to quit is a matter of debate, as are the public health effects of a high prevalence of snuff use in some populations.