All of the following are causes of giant a wave in JVP except-
Correct Answer: Aoic stenosis
Description: Aoic stenosis (AS or AoS) is the narrowing of the exit of the left ventricle of the hea (where the aoa begins), such that problems result.It may occur at the aoic valve as well as above and below this level.It typically gets worse over time. Symptoms often come on gradually with a decreased ability to exercise often occurring first. If hea failure, loss of consciousness, or hea related chest pain occur due to AS the outcomes are worse.Loss of consciousness typically occurs with standing or exercise.Signs of hea failure include shoness of breath especially when lying down, at night, or with exercise, and swelling of the legs.Thickening of the valve without narrowing is known as aoic sclerosis. Causes include being born with a bicuspid aoic valve, and rheumatic fever; a normal valve may also harden over the decades.A bicuspid aoic valve affects about one to two percent of the population. As of 2014 rheumatic hea disease mostly occurs in the developing world.Risk factors are similar to those of coronary aery disease and include smoking, high blood pressure, high cholesterol, diabetes, and being male.The aoic valve usually has three leaflets and is located between the left ventricle of the hea, and the aoa. AS typically results in a hea murmur.Its severity can be divided into mild, moderate, severe, and very severe, distinguishable by ultrasound scan of the hea Aoic stenosis is typically followed using repeated ultrasound scans.Once it has become severe, treatment primarily involves valve replacement surgery, with transcatheter aoic valve replacement (TAVR) being an option in some who are at high risk from surgery.Valves may either be mechanical or bioprosthetic, with each having risks and benefits. Another less invasive procedure, balloon aoic valvuloplasty (BAV), may result in benefit, but for only a few months.Complications such as hea failure may be treated in the same way as in those with mild to moderate AS.In those with severe disease a number of medications should be avoided, including ACE inhibitors, nitroglycerin, and some beta blockers. Nitroprusside or phenylephrine may be used in those with decompensated hea failure depending on the blood pressure Aoic stenosis is the most common valvular hea disease in the developed world.It affects about 2% of people who are over 65 years of age. Estimated rates were not known in most of the developing world as of 2014. In those who have symptoms, without repair the chance of death at five years is about 50% and at 10 years is about 90%. Symptoms related to aoic stenosis depend on the degree of stenosis. Most people with mild to moderate aoic stenosis do not have symptoms. Symptoms usually present in individuals with severe aoic stenosis, though they may also occur in those with mild to moderate aoic stenosis. The three main symptoms of aoic stenosis are loss of consciousness, anginal chest pain and shoness of breath with activity or other symptoms of hea failure such as shoness of breath while lying flat, episodes of shoness of breath at night, or swollen legs and feet. It may also be accompanied by the characteristic "Dresden china" appearance of pallor with a light flush. Angina Angina in setting of hea failure also increases the risk of death. In people with angina, the 5-year moality rate is 50% if the aoic valve is not replaced. Angina in the setting of AS occurs due to left ventricular hyperophy (LVH) that is caused by the constant production of increased pressure required to overcome the pressure gradient caused by the AS. While the muscular layer of the left ventricle thickens, the aeries that supply the muscle do not get significantly longer or bigger, so the muscle may not receive enough blood supply to meet its oxygen requirement. This ischemia may first be evident during exercise when the hea muscle requires increased blood supply to compensate for the increased workload. The individual may complain of anginal chest pain with exeion. At this stage, a cardiac stress test with imaging may be suggestive of ischemia. Eventually, however, the hea muscle will require more blood supply at rest than can be supplied by the coronary aery branches. At this point there may be signs of ventricular strain pattern (ST segment depression and T wave inversion) on the EKG, suggesting subendocardial ischemia. The subendocardium is the region that is most susceptible to ischemia because it is the most distant from the epicardial coronary aeries. syncope Syncope (fainting spells) from aoic valve stenosis is usually exeional.In the setting of hea failure it increases the risk of death. In people with syncope, the three-year moality rate is 50% if the aoic valve is not replaced. It is unclear why aoic stenosis causes syncope. One theory is that severe AS produces a nearly fixed cardiac output. When a person with aoic stenosis exercises, their peripheral vascular resistance will decrease as the blood vessels of the skeletal muscles dilate to allow the muscles to receive more blood to allow them to do more work. This decrease in peripheral vascular resistance is normally compensated for by an increase in the cardiac output. Since people with severe AS cannot increase their cardiac output, the blood pressure falls and the person will faint due to decreased blood perfusion to the brain. A second theory is that during exercise the high pressures generated in the hyperophied left ventricle cause a vasodepressor response, which causes a secondary peripheral vasodilation that, in turn, causes decreased blood flow to the brain resulting in loss of consciousness. Indeed, in aoic stenosis, because of the fixed obstruction to blood flow out from the hea, it may be impossible for the hea to increase its output to offset peripheral vasodilation. A third mechanism may sometimes be operative. Due to the hyperophy of the left ventricle in aoic stenosis, including the consequent inability of the coronary aeries to adequately supply blood to the myocardium (see "Angina" below), abnormal hea rhythms may develop. These can lead to syncope. Finally, in calcific aoic stenosis at least, the calcification in and around the aoic valve can progress and extend to involve the electrical conduction system of the hea. If that occurs, the result may be hea block, a potentially lethal condition of which syncope may be a symptom. congestive hea failure Congestive hea failure (CHF) carries a grave prognosis in people with AS. People with CHF attributable to AS have a 2-year moality rate of 50% if the aoic valve is not replaced. CHF in the setting of AS is due to a combination of left ventricular hyperophy with fibrosis, systolic dysfunction (a decrease in the ejection fraction) and diastolic dysfunction (elevated filling pressure of the LV). Ref Harrison 20th edition pg 1446
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