Thursday, 29 May 2014

Free post 3


Heart Failure
Today I will talk about at heart failure, its pathophysiology and some drugs used to treat it.
The reason I tell you about this disease is because the main cause of death in Chile are heart disease (heart failure mainly) inclusive more than cancer (first cause of death in developed country). Cancer is the second cause of death in Chile. Women are less prone to these diseases only until menopause, because the progesterone hormone that protects your cardiovascular system (protective function for the pregnancy). However it is only until menopause, after this incident, the chances are equal both men and women.
Heart DiagramHeart Diagram









The human heart is located within the thoracic cage in the middle of the lungs, shifted to the left. The heart is composed of many specialized tissues such as nerve tissue, whose failure also produces arrhythmias or muscle tissue, which results in heart failure.





The heart consists of four chambers, two upper called atria (right and left) and two lower chambers called ventricles (right and left). The atria and ventricles are separated by a septum, therefore there is no contact between the left and right blood from the heart. The atria and ventricles are separated by atrioventricular valves that open when the pressures are equalized between the chambers. The heart is the main organ of the cardiovascular system, where two types of circulation, pulmonary circulation where oxygen-poor blood from the heart is oxygenated, and systemic circulation which carries oxygenated blood to all tissues through the arteries. But there is a third circulation, the coronary circulation. Coronary circulation is responsible for oxygenating the tissues that form the heart. There is a right coronary artery and a left which bifurcates into two arteries, the circumflex artery and left descending coronary artery. When there is a demand on cardiac either for sport or any thrombus in blood vessels, normal heart becomes enlarged, what is known as cardiac hypertrophy. But there are two types, the physiological and pathological. Physiological hypertrophy is common in high-performance athletes and is completely reversible, the hypertrophic heart returns to a normal heart. Pathological hypertrophy is irreversible and is caused by a remodeling of the muscular wall of the left ventricle which mainly is what makes all pressure to the systemic circulation. After this remodeled heart if the demand continues to increase, the muscular walls are changed by fibrinogen, tissue is cardiac impulse insulation and is also very rigid, resulting in heart failure. Can also result in cardiac hypertrophy due to cardiac ischemia. Ischemia is a lack of oxygen in the cells which results in cell death. Cardiac ischemia is caused by the accumulation of cholesterol plaques in blood vessels called atheroma plaques. These plaques cause atherosclerosis. In the heart, at the bifurcation of the left coronary artery, high blood turbulence occurs which leads to increased accumulation of atheroma plaques, leading to ischemia in the left ventricle. Because of this ischemia, cell death occurs, which generates a hypertrophied heart which eventually will be heart failure. The most important risk factors of this disease are: salt, since it produces hypertension, a diet high in fat and cholesterol, due to the formation of atheroma plaques, a sedentary lifestyle, due to the accumulation of fat, stress, and that produces a constant pressure rise, family heritage, since this disease easily in a few generations . Pharmacological treatment for a person with heart failure is chronic use of antiplatelet drugs to prevent thrombus formation (aspirin), cholesterol lowering by hypocholesterolemic drugs (statins), antihypertensive drugs use to reduce peripheral vascular resistance to the blood pressure (nifedipine) and coronary vasodilators drugs in preventing cardiac ischemia (nitrates and nitrites).

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