Heart failure means that the heart muscle is not an effective pump. This may be due to weakening of the heart muscle or a limitation of relaxation. A weakened heart muscle may not be strong enough to pump an adequate amount of blood out of its chambers. The heart’s pumping inefficiency causes a buildup of blood in the lungs, a condition called pulmonary congestion.
Types of heart failure
- Left-sided Heart Failure – the left ventricle typically pumps out inadequate amounts of oxygenated blood to the rest of the body, and fluid backs up into the lungs.
- Right-sided Heart Failure – the resistance to blood flow through the lungs exceeds the right ventricle’s ability to pump blood into the lungs. Consequently, blood backs up into the liver and other organs. The most common cause of right-sided heart failure is actually left-sided heart failure.
- Systolic Heart Failure – the heart’s pumping function is depressed.
- Diastolic Heart Failure – the heart is unable to fill up with an adequate amount of blood. Diastolic heart failure usually occurs because the muscular heart wall thickens and stiffens. Abnormal thickening of the heart muscle wall, called hypertrophy, has many causes, the most common of which is hypertension. Less commonly, hypertrophic cardiomyopathy may cause heart muscle to thicken.
WHAT ARE THE SYMPTOMS?
The symptoms of heart failure often develop slowly because the body can compensate for early effects of the disease, thus the heart’s function may diminish significantly without noticeable symptoms. Symptoms include:
- Shortness of breath (dyspnea);
- Swelling and weight gain; and
CAUSES AND RISK FACTORS
Heart attacks are the most common cause of heart failure. Other causes include:
- Malfunction of the aortic, mitral, pulmonary or tricuspid valves;
- Uncontrolled or longstanding hypertension;
- Cancer therapies, such as radiation and chemotherapy;
- Certain treatments for AIDS;
- Viral or bacterial infections;
- Complications during pregnancy;
- Chronic alcohol abuse; and
- Idiopathic, meaning the cause is unknown.
Conditions that increase the risk of heart failure include:
- Diabetes mellitus;
- Some diabetes medications, including rosiglitazone (Avandia) and pioglitazone (Actos);
- Sleep apnea;
- Congenital heart defects; and
- Kidney conditions.
Typically, a physician diagnoses congestive heart failure by considering the person’s medical history and performing a physical examination. The diagnosis is typically confirmed with other tests, including blood tests, chest x-rays, and echocardiography.
The physician will also measure the patient’s ejection fraction (the percentage of blood that the heart pumps in each heartbeat) to determine tell how well the heart is working. Tests the physician may use in addition to echocardiography include:
- Left ventriculogram;
- Nuclear imaging;
- Computed tomography (CT) scan; and
- Magnetic resonance imaging (MRI).
The basic strategies for controlling heart failure are to relieve symptoms and to prevent the progressive decrease in the heart’s pumping function. Lifestyle changes and medication are the methods most commonly used to achieve these strategies. In some instances, the cause of heart failure may be reversible through valve repair or replacement surgery, bypass surgery, or angioplasty.
Physicians prescribe several medications to relieve symptoms and to improve the function of the heart, including:
- Angiotensin converting enzyme inhibitors;
- Aldosterone receptor blockers;
- Angiotensin receptor blockers;
- Vasodilators; and
Patients who have persistent severe heart failure despite medical therapy are candidates for prophylactic placement of an implantable cardiac defibrillator to prevent sudden cardiac death. Other treatments for heart failure include cardiac resynchronization therapy, ventricular assist devices, and heart transplantation.
Physicians also recommend that patients:
- Quit smoking;
- Eliminate salt from the diet;
- Lose weight; and
- Limit alcohol intake