Arterial dilators

The oxides of nitrogen are somewhat sol in w, reacting with it in the presence of oxygen to form nitric and nitrous acids. This is the action that takes place deep in the respiratory system. The acids formed are irritants, causing congestion of the throat and bronchi, and edema of the lungs. The acids are neutralized by the alkalies present in the tissues, with the formation of nitrates and nitrites. The latter may cause some arterial dilation, fall in blood press, headache and dizziness, and there may be some formation of methemoglobin. However, the nitrite effect is of secondary importance... 

NTG causes venodilation, which lowers preload and myocardial oxygen demand. In addition, arterial vasodilation may lower BP, thereby reducing myocardial oxygen demand. Arterial dilation also relieves coronary artery vasospasm and improves myocardial blood flow and oxygenation. 

Stable angina pectoris Decreased myocardial oxygen consumption -decreased LV end-diastolic dimension -decreased LV filling pressure -decreased LV systolic pressure -decreased PVR Increased coronary blood flow -epicardial coronary artery dilation -stenotic segment dilation -coronary collateral vessel dilation -increased subendocardial perfusion... 

Lp(a) concentration in blood of children with FH and impairment of endothelial-dependent arterial dilation. 

A Swiss physician, Andreas Guentzig, developed the first balloon catheter which was small enough to reach into the coronary arteries. In 1977, he performed the first successful coronary artery dilation treatment. An estimated one million patients per year receive angioplasty as part of their treatment. 

Thus, the nitrates enable myocardial flow resistance to be reduced even in the presence of coronary sclerosis with angina pectoris. In angina due to coronary spasm, arterial dilation overcomes the vasospasm and restores myocardial perfusion to normal. O2 demand falls because of the ensuing decrease in the two variables that determine systolic wall tension (afterload) ventricular filling volume and aortic blood pressure. 

Dotter CT, Rosch J, Anderson JM, et al. Transluninal iliac artery dilatation nonsurgical catheter treatment of atheromatous narrowing. JAMA 1978 230 117. 

Arteries Dilation (via EDRF). Constriction (high-dose direct effect)... 

Walser B., Giordano R. M., and Stebbins C. L. (2006). Supplementation with omega-3 polyunsaturated fatty acids augments brachial artery dilation and blood flow during forearm contraction. Eur. J. Appl. Physiol. 97 347-354. 

In addition, a vasodilator in combination with an angiotensin-converting enzyme inhibitor has been used in congestive heart failure. The vasodilators may be classified as venodilators, arterial dilators, or balanced-type vasodilators. 

Primary angiitis of the CNS causes inflammation particularly in small leptomeningeal vessels, whereas larger vessels can also be affected. Systemic variants of vasculitis and secondary arteritis of the CNS affect mostly small or medium-sized arteries to different degrees, and occasionally the venous system is also afflicted as in Behcet disease. Segmental stenoses are frequently found, often not including bifurcations and alternating with arterial dilatations. This pattern is not definitively specific and can also be seen in atherosclerosis. Even with an optimal MRA technique, DSA still remains necessary for the depiction of tiny vessel lesions (Fig. 5.26). 

In most patients the dural fistula is supplied by a thoracic or lumbar artery. Deep located fistulas of the lumbosacral region are rare and beset with particular diagnostic problems mainly due to the unusual anatomic and hemodynamic conditions. In these cases MRI should be focused on the lumbosacral region. The arterialized dilated vein of the filum can be detected in 3-mm slices after paramagnetic contrast administration even if the flow is very slow. 

In CHF, the impaired contractile function of the heart is exacerbated by compensatory increases in both preload and afterload. Preload is the volume of blood that fills the ventricle during diastole. Elevated preload causes overfilling of the heart, which increases the workload. Afterload is the pressure that must be overcome for the heart to pump blood into the arterial system. Elevated afterload causes the heart to work harder to pump blood into the arterial system. Vasodilators are useful in reducing excessive preload and afterload. Dilation of venous blood vessels leads to a decrease in cardiac preload by increasing venous capacitance arterial dilators reduce systemic arteriolar resistance and decrease afterload. 

At higher doses, further venous pooling occurs. There are also more marked arterial effects, and decreased systemic arteriolar resistance is accompanied by a reduction in systolic and diastolic blood pressure and cardiac output. Activation of compensatory sympathetic reflexes results in tachycardia and peripheral arteriolar vasoconstriction tending to restore systemic vascular resistance. Venodilating and arterial dilating effects are often termed indirect or peripheral effects since they relieve ischemia by reducing myocardial oxygen demand [1,13]. 

Anti-cholesterol drugs help arteries dilate, 20 July 1998 www.healthcentral.com/news... 

An 18-year-old man experienced sudden and severe chest pain while drinking alcohol. He vomited, collapsed, and died. On postmortem examination, thrombosis of the left coronary artery, dilated cardiomyopathy with congestive heart failure, and pulmonary embolism were noted. Blood analysis showed raised cocaine and marijuana concentrations and a trace of alcohol. 

Any reading about polyphenols in the medical journals inevitably leads us back to the health of the endothelium and the role of nitric oxide (NO). Truly, that s where the action is, with good reason, since NO has vital abilities to help arterial dilation, prevent inflammation, limit the formation of blood clots, and, in general, promote arterial health. In that special AJCN supplement, one of the most prominently discussed sources of polyphenols was GSE. That s because GSE has one of the highest concentrations of those potent substances. Just a little bit goes a long way. 

T.B. Ultrasonographic diagnosis of acute alcohohc hepatitis pseudoparallel channel sign of intrahepatic artery dilation. Gastroenterology 1993 105 1477-1488... 

MOA Nitrates cause venous and arterial dilatation. However, venous dilatation is more evident because it increases venous pooling, therefore decreasing preload and reducing myocardial or gen demand, in addition, nitrates dilate epioirdial coronary arteries, consequently decreasing coronary vasospasm. 

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