What is Heart Failure?

There are over five million people in the United States that suffer from congestive heart failure (CHF), a condition that gradually develops over time as the heart muscle weakens and must work harder to pump blood throughout the body.  CHF is a disorder of growth and remodeling in which the heart’s ability to pump oxygen-rich blood to the body becomes progressively inadequate to meet the body’s needs.  Recent results indicate that the abnormal growth and remodeling associated with CHF is due to aberrant cardiac motion.

Causes:

Virtually anyone can develop heart failure, but there are risk factors that can make an individual more susceptible to the disease than others.  These factors include coronary artery disease or atherosclerosis, high blood pressure, and heart attack.  Other factors may include genetics, obesity, high alcohol consumption, and a sedentary life style.

Symptoms:

Since congestive heart failure usually develops slowly, an individual may go years without experiencing symptoms.  This slow onset and progression is a reflection of the heart’s effort to deal with its gradual weakening.  The heart takes measures to compensate for this weakening by enlarging and pumping at a faster pace as a means to circulate more blood throughout the body; ultimately, these efforts render the heart even more inefficient.  Symptoms tend to worsen over time and may include difficulty breathing, fatigue, and coughing.  Heart failure is often not recognized until it has progressed to an advanced stage, with fluid building up in the lungs, feet, legs, and possibly the liver.  The American College of Cardiology and New York Heart Association have each established a classification system for the varying stages of heart failure according to severity.

CHF may be life-threatening and can cause sudden death.  Patients with severe heart failure may require heart transplants or the implantation of a cardiac assist device.  Patient outlook varies and is dependent upon the cause and extent of the disease.  With adequate treatment, symptoms and cardiac functioning will improve for many patients.

Treatment:

Pharmacotherapy is the preferred form of treatment because it is minimally invasive; however, it is often ineffective and will later necessitate surgical intervention.  Heart transplantation is an effective treatment, but the majority of patients seeking a heart will not be placed on the waiting list—there are less than 2,000 hearts available per year, and the demand for donors is far greater.  Moreover, transplant surgery is highly traumatic, invasive, and introduces a risk of infection to the patient.  Complications may also arise with anti-rejection medication.  Another form of treatment known as cardiac resynchronization therapy (CRT) uses a specialized pacemaker to re-coordinate the electrical excitation of the right and left ventricles.  This form of treatment has been shown to reduce symptoms and improve cardiac function, but is only available for a select group of patients--those with asynchrony.

When pharmacotherapy fails, the next common form of treatment is a cardiac assist device.  These devices can be divided into two broad categories: blood contacting and heart contacting.  Blood contacting devices include aortic balloon pumps and axial flow pumps (such as the DeBakey LVAD) and may improve blood flow.  However, there are constant issues with blood cell damage and clotting because these devices make contact with the blood, which can result in serious complications.  Heart contacting devices can be further divided into two groups: surgical/passive devices (stem cells and heart support meshes) and active devices.