Heart failure
Heart failure, also known as congestive heart failure, is a syndrome caused by an impairment in the heart's ability to fill with and pump blood.
Although symptoms vary based on which side of the heart is affected, HF typically presents with shortness of breath, excessive fatigue, and bilateral leg swelling. The severity of the heart failure is mainly decided based on ejection fraction and also measured by the severity of symptoms. Other conditions that have symptoms similar to heart failure include obesity, kidney failure, liver disease, anemia, and thyroid disease.
Common causes of heart failure include coronary artery disease, heart attack, high blood pressure, atrial fibrillation, valvular heart disease, excessive alcohol consumption, infection, and cardiomyopathy. These cause heart failure by altering the structure or the function of the heart or in some cases both. There are different types of heart failure: right-sided heart failure, which affects the right heart, left-sided heart failure, which affects the left heart, and biventricular heart failure, which affects both sides of the heart. Left-sided heart failure may be present with a reduced ejection fraction or with a preserved ejection fraction. Heart failure is not the same as cardiac arrest, in which blood flow stops completely due to the failure of the heart to pump.
Diagnosis is based on symptoms, physical findings, and echocardiography. Blood tests, and a chest X-ray may be useful to determine the underlying cause. Treatment depends on severity and case. For people with chronic, stable, or mild heart failure, treatment usually consists of lifestyle changes, such as not smoking, physical exercise, and dietary changes, as well as medications. In heart failure due to left ventricular dysfunction, angiotensin-converting-enzyme inhibitors, angiotensin II receptor blockers, or angiotensin receptor-neprilysin inhibitors, along with beta blockers, mineralocorticoid receptor antagonists and SGLT2 inhibitors are recommended. Diuretics may also be prescribed to prevent fluid retention and the resulting shortness of breath. Depending on the case, an implanted device such as a pacemaker or implantable cardiac defibrillator may sometimes be recommended. In some moderate or more severe cases, cardiac resynchronization therapy or cardiac contractility modulation may be beneficial. In severe disease that persists despite all other measures, a cardiac assist device ventricular assist device, or, occasionally, heart transplantation may be recommended.
Heart failure is a common, costly, and potentially fatal condition, and is the leading cause of hospitalization and readmission in older adults. Heart failure often leads to more drastic health impairments than the failure of other, similarly complex organs such as the kidneys or liver. In 2015, it affected about 40 million people worldwide. Overall, heart failure affects about 2% of adults, and more than 10% of those over the age of 70. Rates are predicted to increase.
The risk of death in the first year after diagnosis is about 35%, while the risk of death in the second year is less than 10% in those still alive. The risk of death is comparable to that of some cancers. In the United Kingdom, the disease is the reason for 5% of emergency hospital admissions. Heart failure has been known since ancient times in Egypt; it is mentioned in the Ebers Papyrus around 1550 BCE.
Definition
The term 'cardiovascular insufficiency' is sometimes used when the heart does not function effectively as a pump and fails to circulate enough blood through the circulatory system to meet the body's needs. This generally leads to the syndrome of heart failure, a combination of signs and symptoms when the heart functions poorly as a pump. This leads to high filling pressure in the left atrium with fluid accumulation and water retention. Most of the visible signs of heart failure are the result of this fluid accumulation and the adjective congestion is added to the definition of heart failure. Impaired ejection can lead to inadequate blood flow to the body tissues, resulting in ischemia.Signs and symptoms
Congestive heart failure is a pathophysiological condition in which the heart's output is insufficient to meet the needs of the body and lungs. The term "congestive heart failure" is often used because one of the most common symptoms is congestion or fluid accumulation in the tissues and veins of the lungs or other parts of a person's body.Congestion manifests itself particularly in the form of fluid accumulation and swelling, in the form of peripheral edema and pulmonary edema and ascites. Pulse pressure, which is the difference between the systolic and diastolic blood pressures, is often low/narrow in people with heart failure, and this can be an early warning sign.
Symptoms of heart failure are traditionally divided into left-sided and right-sided because the left and right ventricles supply different parts of the circulation. In biventricular heart failure, both sides of the heart are affected. Left-sided heart failure is the more common.
Left-sided failure
The left side of the heart takes oxygen-rich blood from the lungs and pumps it to the rest of the circulatory system in the body. Failure of the left side of the heart causes blood to back up into the lungs, causing breathing difficulties and fatigue due to an insufficient supply of oxygenated blood. Common respiratory signs include increased respiratory rate and labored breathing. Rales or crackles are heard initially in the lung bases and when severe in all lung fields indicate the development of pulmonary edema. Cyanosis, indicates deficiency of oxygen in the blood, is a late sign of extremely severe pulmonary edema.Other signs of left ventricular failure include a laterally displaced apex beat and a gallop rhythm, which may be heard as a sign of increased blood flow or increased intracardiac pressure. Heart murmurs may indicate the presence of valvular heart disease, either as a cause or as a consequence of heart failure.
Reverse insufficiency of the left ventricle causes congestion in the blood vessels of the lungs so that symptoms are predominantly respiratory. Reverse insufficiency can be divided into the failure of the left atrium, the left ventricle, or both within the left circuit. Patients will experience shortness of breath on exertion and, in severe cases, dyspnea at rest. Increasing breathlessness while lying down, called orthopnea, also occurs. It can be measured by the number of pillows required to lie comfortably, with extreme cases of orthopnea forcing the patient to sleep sitting up. Another symptom of heart failure is paroxysmal nocturnal dyspnea: a sudden nocturnal attack of severe shortness of breath, usually occurring several hours after falling asleep. There may be "cardiac asthma" or wheezing. Impaired left ventricular forward function can lead to symptoms of poor systemic perfusion such as dizziness, confusion, and cool extremities at rest. Loss of consciousness may also occur due to loss of blood supply to the brain.
Right-sided failure
Right-sided heart failure is often caused by pulmonary heart disease, which is typically caused by issues with pulmonary circulation such as pulmonary hypertension or pulmonic stenosis. Physical examination may reveal pitting peripheral edema, ascites, liver enlargement, and spleen enlargement. Jugular venous pressure is frequently assessed as a marker of fluid status, which can be accentuated by testing hepatojugular reflux. If the right ventricular pressure is increased, a parasternal heave which causes the compensatory increase in contraction strength may be present.Backward failure of the right ventricle leads to congestion of systemic capillaries. This generates excess fluid accumulation in the body. This causes swelling under the skin and usually affects the dependent parts of the body first, causing foot and ankle swelling in people who are standing up and sacral edema in people who are predominantly lying down. Nocturia may occur when fluid from the legs is returned to the bloodstream while lying down at night. In progressively severe cases, ascites and liver enlargement may develop. Significant liver congestion may result in impaired liver function, jaundice, and coagulopathy.
Biventricular failure
Dullness of the lung fields when percussed and reduced breath sounds at the base of the lungs may suggest the development of a pleural effusion. Though it can occur in isolated left- or right-sided heart failure, it is more common in biventricular failure because pleural veins drain into both the systemic and pulmonary venous systems. When unilateral, effusions are often right-sided.If a person with a failure of one ventricle lives long enough, it will tend to progress to failure of both ventricles. For example, left ventricular failure allows pulmonary edema and pulmonary hypertension to occur, which increases stress on the right ventricle. Though still harmful, right ventricular failure is not as deleterious to the left side.
Causes
Since heart failure is a syndrome and not a disease, establishing the underlying cause is vital to diagnosis and treatment. In heart failure, the structure or the function of the heart or in some cases both are altered. Heart failure is the potential end stage of all heart diseases.Common causes of heart failure include coronary artery disease – including a previous myocardial infarction, high blood pressure, atrial fibrillation, and valvular heart disease – excessive alcohol use, infection, and cardiomyopathy of an unknown cause. In addition, viral infection and subsequent myocarditis – inflammation of the heart's myocardial tissue – can similarly contribute to the development of heart failure. Genetic predisposition plays an important role. If more than one cause is present, progression is more likely and prognosis is worse.
Heart damage can predispose a person to develop heart failure later in life and has many causes including systemic viral infections, chemotherapeutic agents such as daunorubicin, cyclophosphamide, trastuzumab and substance use disorders of substances such as alcohol, cocaine, and methamphetamine. An uncommon cause is exposure to certain toxins such as lead and cobalt. Additionally, infiltrative disorders such as amyloidosis and connective tissue diseases such as systemic lupus erythematosus have similar consequences. Obstructive sleep apnea is regarded as an independent cause of heart failure. Recent reports from clinical trials have also linked variation in blood pressure to heart failure and cardiac changes that may give rise to heart failure.