Peripheral artery

DHPs are potent arterial vasodilators. They act on resistance vessels and therefore reduce peripheral vascular resistance, lower arterial blood pressure, and antagonize vasospasms in coronary or peripheral arteries. By reducing afterload, DHPs also reduce cardiac oxygen demand. Together with their vascular spasmolytic effect, this explains most of the beneficial actions of DHPs in angina pectoris. Most DHPs are only licensed for the therapy of hypertension, some of them also for the treatment of angina pectoris and vasospastic (Prinzmetal) angina. 

DHPs are also used to treat vasospasms of peripheral arteries (e.g., Raynaud s phenomenon) and pulmonary hypertension. 

Systemic and coronary arteries are influenced by movement of calcium across cell membranes of vascular smooth muscle. The contractions of cardiac and vascular smooth muscle depend on movement of extracellular calcium ions into these walls through specific ion channels. Calcium channel blockers, such as amlodipine (Norvasc), diltiazem (Cardizem), nicardipine (Cardene), nifedipine (Procardia), and verapamil (Calan), inhibit die movement of calcium ions across cell membranes. This results in less calcium available for the transmission of nerve impulses (Fig. 41-1). This drug action of the calcium channel blockers (also known as slow channel blockers) has several effects on die heart, including an effect on die smooth muscle of arteries and arterioles. These drug dilate coronary arteries and arterioles, which in turn deliver more oxygen to cardiac muscle. Dilation of peripheral arteries reduces die workload of die heart. The end effect of these drug is the same as that of die nitrates. 

Adverse reactions associated with these drugs are variable Some of tire more common adverse reactions are listed in tire Summary Drag Table Peripheral Vasodilators and Miscellaneous Vasodilating Drags. Because these drugs dilate peripheral arteries, some degree of hypotension may be associated with their... 

Q Pain related to narrowing ot peripheral arteries, decreased blood supply to the extremities... 

Prevention and treatment of venous thrombosis, PE, peripheral arterial embolism ... 

Many serious health problems result from abnormally located blood clots heart attacks (clots in coronary arteries), pulmonary embolism (clots in the lungs), and peripheral arterial occlusion and deep vein thrombosis (clots in the limbs). Each year heart attacks alone afflict over a million people in the United States, and almost half of them die as a result. 

Direct Fibrinolytics Alfimeprase is a recombinant tmncated form of fibrolase, a fibrinolytic zinc metalloproteinase isolated from the venom of the Southern copperhead snake. It degrades fibrin directly and achieves thrombolysis independent of plasmin formation. This may result in faster recanalization and a decreased risk of hemorrhagic conversion. The initial data on the safety and efficacy of alfimeprase in peripheral arterial occlusion disease appeared very promising, but recent communication from the sponsor revealed that the phase III trials of the drug in peripheral arterial disease and catheter obstruction (NAPA-2 and SONOMA-2) failed to meet their primary and key secondary endpoints of revascularization. A trial for I AT in acute stroke (CARNEROS-1) is planned to begin soon. 

The CAPRIE trial found that compared to aspirin (325 mg daily), clopidogrel (75 mg daily) was associated with RRR of 8.7% p = 0.043) for the composite endpoint of ischemic stroke, Ml, or vascular death among 19,185 subjects with stroke, MI, or peripheral arterial disease, but no significant reduction in the composite endpoint in the subgroup with stroke (RRR 7.3%, p = 0.26). No comparison of clopidogrel with aspirin in the acute stroke period was performed. Furthermore, stroke as an endoint was not significantly reduced in the stroke patients entered in this trial (RRR 8.0%, p = NS). 

Lagiou, P. et al., Flavonoid classes and risk of peripheral arterial occlusive disease a case-control study in Greece, Eur. J. Clin. Nutr., 60, 214, 2006. 

Prior to myocardial infarction, coronary artery bypass graft (CABG), peripheral artery disease, cerebrovascular accident, or aspirin use... 

Elevated peripheral arterial resistance is a hallmark of primary hypertension. The increase in peripheral resistance typically observed may be due to a reduction in the arterial lumen size as a result of vascular remodeling. This remodeling, or change in vascular tone, may be modulated by various endothelium-derived vasoactive substances, growth factors, and cytokines. This increase in arterial stiffness or reduced compliance results in the observed increase in systolic blood pressure.9... 

Peripheral arterial disease (claudication or ankle-brachial index less than 0.9)... 

MN is a 48-year-old man with a history of hypertension and smoking who presents to the clinic for evaluation of his cholesterol. He denies having chest pain or history of myocardial infarction, stroke, or peripheral artery disease. He has no siblings and both parents are alive with no history of CHD. MN says that he smokes about 1 pack of cigarettes per day. He does not exercise on a regular basis. He has been fasting for approximately 11 hours. 

Hung HC, Merchant A, Willett W, Ascherio A, Rosner BA, RimmEand JoshipuraKJ. 2003. The association between fruit and vegetable consumption and peripheral arterial disease. Epidemiology 14(6) 659— 665. 

The response-to-injury hypothesis states that risk factors such as oxidized LDL, mechanical injury to the endothelium, excessive homocysteine, immunologic attack, or infection-induced changes in endothelial and intimal function lead to endothelial dysfunction and a series of cellular interactions that culminate in atherosclerosis. The eventual clinical outcomes may include angina, myocardial infarction, arrhythmias, stroke, peripheral arterial disease, abdominal aortic aneurysm, and sudden death. 

The goals of treatment are to lower total and LDL cholesterol in order to reduce the risk of first or recurrent events such as myocardial infarction, angina, heart failure, ischemic stroke, or other forms of peripheral arterial disease such as carotid stenosis or abdominal aortic aneurysm. 

Goal BP values are <140/90 for most patients, but <130/80 for patients with diabetes mellitus, significant chronic kidney disease, known coronary artery disease (myocardial infarction [MI], angina), noncoronary atherosclerotic vascular disease (ischemic stroke, transient ischemic attack, peripheral arterial disease [PAD], abdominal aortic aneurysm), or a 10% or greater Framingham 10-year risk of fatal coronary heart disease or nonfatal MI. Patients with LV dysfunction have a BP goal of <120/80 mm Hg. 

In addition to coronary sclerosis, evidence is accumulating that high Lp(a) levels may be important in the development of cerebrovascular and peripheral arterial disease, as well (J6, T8, U2). Lp(a) levels not only correlated well with clinical endpoints such as transient ischemic attack and cerebral infarction, but also were associated with the extent and severity of carotid atherosclerosis, as assessed by bidirectional Doppler ultrasound (K23, M33, Z2). 

A marker substance is injected into a central vein. A peripheral arterial line is used to measure the amount of the substance in the arterial system. A graph of concentration versus time is produced and patented algorithms based on the Stewart-Hamilton equation (below) are used to calculate the cardiac output. 

Ramipril (Altace) Angiotensin converting enzyme (ACE) inhibitor Inhibits ACE, decreases peripheral arterial resistance... 

Schneider B. (1992). [Ginkgo biloba extract in peripheral arterial diseases. Meta-analysis of controlled clinical studies]. Arzneimittelforschung. 42(4) 428-36. 

It is well-established that an elevated level of cholesterol, particnlarly that carried largely in the form of LDLs, is an independent risk factor for the development of atherosclerosis and its sequelae, including coronary artery disease (leading to heart attacks), strokes, and peripheral arterial disease. 

During the flow phase there is a marked increase in energy expenditure and oxygen consumption. To satisfy this, the cardiac output is increased, from a resting value of about 5 litres per minute, by two fold during mild trauma, or as much as threefold in severe trauma or sepsis. Resistance to blood flow in peripheral arteries decreases, which can lead to... 

Nifedipine is a calcium-channel blocker of the dihydropyridine group. It relaxes smooth muscle and dilates both coronary and peripheral arteries by interfering with the inward displacement of calcium-channel ions through the active cell membrane. Unlike verapamil, nifedipine can be given with beta-blockers. Long-acting formulations of nifedipine are preferred in the long-term treatment of hypertension. 

Therapeutic applications. PG derivatives are used to induce labor or to interrupt gestation (p. 126) in the therapy of peptic ulcer (p. 168). and in peripheral arterial disease. 

Nifedipine causes relaxation of smooth musculature of vessels, dilates coronary and peripheral arteries, and reduces peripheral resistance, arterial pressure, and the oxygen supply to the heart. 

Verapamil possesses antiarrhythmic, antianginal, and hypotensive activity. It reduces the myocardial need for oxygen by reducing contractility of the myocardium and slowing the frequency of cardiac contractions. It causes dilation of coronary arteries and increased coronary blood flow. It reduces tonicity of smooth musculature, peripheral arteries, and overall peripheral vascular resistance. It provides antiarrhythmic action in supraventricular arrhythmia. 

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