According to research, heart failure causes substantial burden in healthcare settings which leads to increase in mortality, morbidity and the cost of healthcare. Heart failure is one of the leading cause of deaths, killing approximately 610 000 people in the United States annually. Globally, the disease kills about 26 million per year. There are four types of heart failure; systolic, diastolic, right-sided and congestive heart failure. In the systolic failure, the left ventricle loses its capability of contracting normally and thus the blood pumping pressure from the heart reduces. Therefore, the heart fails to pump enough blood for circulation. On the other hand, in diastolic failure, the left ventricle loses its ability of relaxing normally. As a result, the heart fails to be filled with enough blood during the rest period which occurs between two consecutive beats.
The right-sided heart failure, also known as right ventricular (RV) health failure arises from failure of proper functioning of the left ventricle. The failure of the left ventricle leads to transfer of increased fluid pressure back to the lungs and this finally leads to damage of the right side of the heart. The injury of the right ventricle results in loss of its pumping power forcing blood to flow back to the veins. The disorder leads to swelling of legs, ankles and abdomen like liver and GI tract.
Congestive heart failure (CHF) is caused by slowing of the blood flowing out of the heart, forcing the blood returning to the heart via the veins back up, leading to congestion in body tissues. CHF leads to swelling (edema), mostly common in the legs and ankles but can also be seen in other parts of the body. Sometimes there is collecting of fluid in the lungs which inhibits proper breathing hence resulting in shortness of breath. This is known as pulmonary edema and can lead to respiratory distress if left untreated. Moreover, heart failure hinders the capability of kidney to dispose water and sodium out of the body. The retained water also elevates the swelling of body organs (edema). Study shows that the risk of developing congestive heart failure (CHF) is about 20% for both men and women.
The heart failure kills millions of people each year and thus it is essential to understand the risk factors and characteristics of the disorder. Risk factors are categorized into two classes; namely modifiable risks and non-modifiable risks. Modifiable risk factors can be controlled and includes things such as obesity, high intake of fats and smoking. In contrast, non-modifiable risk factors consists of things which we have no control of them and these are gender, age and heredity. According to studies, heart disease results from injuries which occur to the inner layers and linings of the arteries. The damage of these arteries leading to build up of plaques especially in areas where the damage has occurred. Factors contributing to heart injuries include smoking, sugar elevation in the blood arising from diabetes or insulin resistance, inflammation of blood vessels, increased quantities of cholesterol in the blood, and high blood pressure. The purpose of this paper is to conduct an in-depth research of heart failure based on the setting for the pathopharmacological foundation for advanced practice nurse.
There are various disease processes causing heart failure. Some of these include diastolic, systolic, right ventricular and congestive heart failure. Both systolic and diastolic lead to failure of the left ventricle. A person suffers from systolic heart failure when the heart muscles losses its capability of contracting normally. It is important for the heart to undergo contraction to pump oxygenated blood out to the body. However, the weakening and enlarging of the heart results in this condition which in turn leads to inability of the heart to pump enough blood for circulation. According to research, this condition is more common in men than women. Conversely, diastolic heart failure, also known diastolic dysfunction, takes place when the muscles of the heart become stiffer than usual. The stiffness inhibits the filling of heart with blood which leads to lack of proper supply of blood to the rest of the body organs. Studies show that the diastolic dysfunction is more common in women than men.
The right ventricular heart failure occurs when the right side of the heart fails to execute its functions properly. Research shows that this condition is usually triggered by the failure of the left side of the heart. Blood accumulation in the lungs as a result of left-sided heart failure forces right ventricular to work harder in unfavorable conditions. Consequently, the right side of the heart strains leading to right ventricular heart failure. Research also points that right ventricular heart failure may arise from other conditions like lung disease. Mayo clinic shows that right ventricular heart failure is marked by swelling which occurs in lower extremities. The swelling arises from fluid backup in the feet, legs and abdomen.
Congestive heart failure interferes with the pumping power of the heart muscles. The condition mostly refers to the stage in which there is building up of fluids around the heart which inhibits proper pumping of blood from the heart to the other body organs. Science proves beyond doubt that CHF occurs when the ventricles fails to pump sufficient volumes of blood to the body tissues. If left untreated, the end result is backing of blood in the liver, lungs, abdomen and lower body which can lead to death. Therefore, it is advisable for anyone suspecting to have this condition to seek immediate medical assistance before the disorder grows to life threatening stage.
Heart failure manifests itself in clinical settings when the heart fails to supply sufficient quantities of blood for maintaining metabolic requirements for systemic venous return. The disorder results from various mechanisms like salt and water retention disorders, pump function disorders, and neuro-hormonal activation disorders (Palazzuoli, 2010). The disease establishes itself in the body when the cardiac muscles function abnormally causing the heart not to pump the required volumes of blood. There are numerous factors which lead to injury of the heart which include smoking, blood vessel inflammation, high blood pressure and increased quantities of cholesterol in human blood.
Research shows that in a period of one year, the heart experiences four million beats. These beats are enough to pump enough blood which can fill an oil tanker during the lifetime of human beings. The heart consist of striated cardiac muscles and receives the supply of oxygen and nutrients from the coronary arteries. The damage of cardiac muscles takes place with time in some people leading to weakening of the ability of the heart to pump blood. The inadequate pumping of blood forces a fluid build-up in the liver, lungs, legs and other vital body organs.
There are other disorders which lead to heart failure. Some of these include anemia, diabetes, obstructive sleep apnea, obesity, cardiac muscle disease and cardiomyopathy. Furthermore, heart valve disorders can also cause heart failure. Valves which are leaking or even damaged forces the heart to pump blood harder than normal. The primary pathologies of heart failure include lowered output of cardiac muscles which cause an increase in the heart rate, reduced reserve of cardiac muscles, blood overloading of the ventricle during diastole, hypertrophy and decrease of stroke volume as the ventricle rises at the end of systole.
A2. Standard of Practice
The Clinical Practice Guidelines which have been published by National Guideline Clearinghouse (NGC) drives the national standard of practice for the heart failure. The NGC offers recommendation guidelines on current evidence based practices which assists healthcare professionals in providing safe and effective care to individuals suffering from heart failure. The evidence based practice guidelines are potentially useful in maximizing patient outcomes.
The American College of Cardiology recommends that any patient suspected to suffer from heart failure should undergo thorough history and physical examination which should be conducted by a physician. The diagnosis will help in identification of any cardiac or non-cardiac disorders and any potential behaviors which may lead to the progression of the disorder in human body. Additionally, the American College of Cardiology provides that physicians should assess volume status and other essential signs as well as the weight of the patient, presence of peripheral edema and Orthopnea, and jugular venous pressure because they account for some of fluid retention symptoms. Besides, the healthcare professionals should record risk scores upon patient assessment as this aids in estimating the risk of mortality in patients living with the heart disease.
Patients showing signs and symptoms of heart failure should undergo initial laboratory tests such as complete blood count, serum creatinine, serum electrolytes, glucose, liver function tests, troponin, urinalysis, bun, fasting lipid profile, and thyroid stimulating hormone tests. Research is still in progress to improve the outcomes of the therapies already proposed since heart failure is associated with high mortality rates, increased rate of hospitalization and decrease in the quality of life. The effect of therapies may not be easily noticeable because heart failure is a chronic condition.
A2a. Pharmacological Treatments
There are various drugs used in the treatment of heart failure. Some of these include cardiac glycosides, diuretics, aldosterone receptor antagonists, beta-adrenoceptor antagonists, angiotensin-converting enzyme inhibitors (ACE), angiotensin II receptor blockers, and anti-thrombotic agents. Some of these medications are discussed below.
These drugs are manufactured from the foxglove plant (Digitalis purpurea). William Withering was the first one to describe the therapeutic benefits of digitalis in 1875. The drugs were originally used to treat dropsy, which is another name for edema. Scientific research has established that digitalis is most useful for treatment edema arising from a weakened heart. These medications function by inhibiting Na+/K+-ATPase which moves sodium ions inside the cell and potassium ions outside the cell. Cardiac glycosides lead to increase in sodium concentration since they inhibit Na+/K+-ATPase. The process leads to intracellular calcium accumulation via the Na+-Ca+ exchange system. Increased intracellular calcium in the heart results in more release of sarcoplasmic reticulum. As a consequence, more calcium is available to bid to troponin-C hence increasing contractility (inotropy). Na+/K+-ATPase inhibition in the vascular smooth muscles increases depolarization resulting in smooth contraction of muscles and vasoconstriction.
Diuretics have been popular for many centuries, and research shows that they were the first therapeutic interventions for CHF. Mercurial-based diuretics were in use for the treatment of edema in as early as 1600s. In the 20th century, the carbonic anhydrase inhibitor was invented, followed closely by thiazide diuretics and finally loop diuretics. Research shows that diuretics are the most commonly prescribed drug for treating heart failure in the United States. They are integral components in treating chronic heart failure. Furosemide, bumetanide, ethacrynic and torsemide are most common loop diuretics. The diuretics work by inhibiting Na-K-2Cl cotransporter in the loop of Henle’s thick ascending limb. In the act of hindering the reabsorption of sodium, these drugs also reduce reabsorption of water.
Aldosterone Receptor Antagonists
Aldosterone is a hormone which is secreted by the zona glomerulosa found in the adrenal glands. The hormone was initially isolated by Simpson and Tait about 150 years ago. Studies have established that the hormone enhances reabsorption of potassium and sodium in the kidney. Therefore, it is classified as a mineralocorticoid hormone. Decrease in renal perfusion through angiotensin II, adrenocorticorticotropic hormone, and hyperkalemia stimulates the release of aldosterone. Aldosterone receptor antagonists function by binding of mineralocorticoid in the renal epithelial cells. According to research, aldosterone increases coronary inflammation, myocardial fibrosis, ischemic, cardiac hypertrophy, ventricular arrhythmias and necrotic lesions. Spironolactone and eplerenone are two main aldosterone antagonists which are commercially available. The difference between the two forms of drugs comes in the fact that spironolactone is non selective whereas the eplerenone is selective to the aldosterone receptor. Studies show that the two drugs improves the mortality and morbidity of patients with advanced heart failure.