Generality
Heart failure is the heart's inability to supply an adequate amount of blood for the body's normal needs. For a number of reasons, the heart muscle can weaken and generate less contractile force.
The most common causes of heart failure include serious health conditions that damage the heart, including myocardial infarction and other forms of ischemic heart disease, hypertension, valvulopathy and cardiomyopathy. Heart failure can involve the left, right side of the heart. or both. Typically, the onset of the condition affects the left side (specifically, the left ventricle), but the effects can also affect the other side.
The condition is diagnosed by physical examination of the patient, supported by blood tests and confirmed by echocardiography.
Often, it is not possible to reverse the conditions that induce heart failure, but this can be treated with good results. Depending on the etiology and severity of the clinical picture, the disorder can be managed with drug therapy, pacemaker implants, devices ventricular assistance or, in severe cases, with a heart transplant. The best way to prevent heart failure is to control the risk factors and conditions that contribute to its onset, such as hypertension, high cholesterol, diabetes and obesity.
Causes
In most cases, heart failure is not a consequence of a single cause, but develops from the overlap of multiple predisposing conditions. In the presence of these disorders, the heart muscle can become progressively too weak to function properly, until to lose its ability to pump blood at the right pressure and efficiently through the body. In such circumstances, heart failure is due to the chronic alteration of ventricular contractility (the ability to generate a force from a given diastolic volume). Even a dysfunction of an atrioventricular valve can induce a slowing of the ventricular filling, therefore the reduction in stroke volume during diastole. In addition, any of the following conditions can damage or weaken the heart and contribute to heart failure:
- High blood pressure (hypertension): If blood pressure is high, the heart muscle has to increase its activity to circulate blood throughout the body. Over time, hypertension can induce a compensatory increase in the thickness of the myocardium (hypertrophy). As a result, the heart muscle can reduce its ability to stretch during alternating contractions and relaxation, and decrease the amount of blood housed in its cavities (the walls of which become thicker). Hypertension can therefore interfere with the capacity of the heart to maintain proper cardiac output and, over time, cause heart failure;
- Coronary heart disease: The arteries that supply blood to the heart muscle can shrink their lumen due to the progressive accumulation of fatty deposits and scar tissue (a process called coronary arteriosclerosis). As a result, the blood slowly moves through the arteries, leaving some areas of the heart muscle weak and chronically devoid of oxygen-rich blood. This imbalance contributes to the onset of angina or other heart ailments;
- Ischemic heart disease: A blood clot in one of the coronary arteries can cause irreversible damage and injury to the heart muscle, usually during an acute heart attack. However, the obstruction of blood flow can also occur gradually, progressively weakening the ability to maintain adequate cardiac output: this is the case of atherosclerosis. For this, it is important to detect this phenomenon, as a therapeutic intervention on blocked blood vessels can lead to an improvement in heart function.
- Cardiomyopathy: it is recognized as one of the most involved causes of "heart failure. The etiology is often unclear, but can include genetic factors, infections, alcohol abuse and the toxic effect of drugs (such as cocaine) or certain drugs used." for chemotherapy;
- Heart rhythm abnormalities (cardiac arrhythmias): can worsen heart failure or contribute to causing the condition. An irregular heart rhythm (atrial fibrillation is the most common irregularity) increases the risk of developing a blood clot (thrombosis). which can cause a stroke. In some people, this alteration can also cause heart failure, particularly in the case of tachycardia (if the HR is greater than 140 beats per minute).If the heart beats too fast, it may not have enough time to fill and empty properly, and over time, the heart muscle may weaken. In these cases, treating the heart rhythm disorder can reverse the condition. Even a very slow heartbeat (less than 40 beats per minute) can reduce the efficiency of the heart and lead to symptoms of heart failure;
- Heart valve disorders: The heart contains four one-way valves to ensure that blood flows are moving in the right direction. A damaged valve, due to a heart defect, coronary artery disease or local infection, forces the heart to increase its activity to maintain the proper blood supply to the body. Gradually, this extra work can weaken the heart. Defective heart valves, if found in time, can be effectively treated by repair or replacement.
- Myocarditis: consists of "inflammation of the heart muscle. Usually, myocarditis is caused by a" viral infection and can induce heart failure.
- Congenital heart conditions: Some people with heart failure have structural heart defects from birth. Some babies, for example, are born with an "abnormal connection between the left and right sides of the heart (Botallo's oval hole), which allows blood to flow from one side to the other (usually, from left to right).
- Other diseases: chronic diseases such as diabetes, severe anemia, hyperthyroidism, hypothyroidism, pulmonary emphysema, systemic lupus erythematosus and an accumulation of iron (hemochromatosis), proteins € ‹(amyloidosis) or inflammatory cells ( sarcoidosis) can help increase the risk of developing heart failure. Causes of acute heart failure include myocardial infarction, infections that attack the heart muscle, allergic reactions, and the use of certain medications (chemotherapy or diabetes management).
Symptoms
For further information: Heart Failure Symptoms and Heart Failure Symptoms
The main symptoms of heart failure are wheezing, extreme fatigue and swollen ankles, which can extend to the legs. However, these symptoms can also be caused by other conditions and, for this reason, the doctor may suggest some investigations to ascertain "heart failure" or to rule it out as the cause of the symptoms.
Other symptoms that are associated with heart failure include:
- Persistent cough;
- Loss of appetite or nausea
- Weight loss;
- Tachycardia (rapid heartbeat).
Symptoms of heart failure can come on rapidly (acute heart failure), while in other cases they can develop gradually over the long term (chronic heart failure).
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