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According to Huether & McCance, 2018, the pathophysiology of heart failure is defined as “the pathophysiologic condition in which the heart is unable to generate an adequate cardiac output for tissues." Ischemic heart disease and hypertension are the most prevalent predisposing risk factors with many of those cases occurring in hypertensive patients (Huether & McCance, 2018). Micro-level (cellular)At the micro level of the pathophysiology of heart failure, the myocardial cells are damaged from lack of oxygen, infarcts, high blood pressure, infection or disease. With a loss to the quantity of functional myocardial cells, a reduction in the efficiency of the heart muscle occurs, creating a cascade of problems in the body. Without blood to carry essential components to sustain life to the organs, they, in turn, begin to malfunction or function at less than the body requires to run at its best.Because the heart is weakened at the cellular level, the ability to pump blood as mentioned above is reduced. Initially, the heart tries to compensate for the loss of cardiac output by developing more muscle mass, enlarging, and pumping at a faster rate. The body begins to adjust to the lower cardiac output by compensating in several ways. The blood vessels may
THE CAUSES AND CARE4narrow to increase the blood pressure and blood may be diverted from organs and less vital tissues such as the kidneys. The heart muscle stiffens further reducing its ability to pump blood efficiently (Mayo Clinic, n.d.). As the heart struggles to keep up with the body’s demand for oxygen and blood, the signs and symptoms of heart failure begin to appear.Macro (body system)At the macro-level of the pathophysiology of heart failure, the coronary arteries supply the heart with oxygen, nutrients, and blood. If these arteries become diseased or damaged a decrease in necessary oxygen, nutrients, and blood occur. They can be damaged by cholesterol-containing deposits known as plaque. Plaque builds up and narrows the coronary arteries that carry the necessary blood to keep the heart supplied with oxygen and nutrients (Mayo Clinic, n.d.). If the necessities that sustain the heart are not reaching the organs, they become congested, and edema begins to occur in the body tissues (Garcia & Wright, 2010). There are two main types of heart failure left and right sided. These two break down into subtypes of failure: heart failure with reduced ejection fraction, heart failure with preserved ejection fraction, and high-output failure.Left-sided heart failure is also known as congestive heart failure. It is categorized as heart failure with reduced ejection fraction (systolic heart failure) or preserved ejection fraction (diastolic heart failure). Systolic heart failure occurs when the hearts ejection fraction is less than forty percent, and the heart cannot perfuse vital tissues because of the inadequate ejection fraction. The primary cause of decreased contractility is myocardial infarction. Injuries such as infarctions can cause a change in one or more of the four chambers of the heart because of extracellular structure changes and dilation of the myocardium (heart muscle). Due to the changes in the chambers of the heart, other areas can become distended and “remodeled.”