What is heart failure?

The heart is a powerful muscle, approximately the size of your fist, that pumps blood throughout the body. The left side of the heart receives blood from the lungs that is full of oxygen and then pumps it out to the body, including all your organs, brain, limbs, and other body parts. After the body uses up the oxygen in the blood, the blood is returned back to the right side of the heart, where it is pumped to the lungs to receive more oxygen. The cycle then repeats itself.

Your heart consists of four chambers that hold the blood as it moves through the heart. The upper chambers are called atria. The lower chambers are called ventricles, and they do the main work of the heart, pumping blood out of the heart. There are four valves in the heart that act like one-way doors, separating the blood as it moves forward. Healthy valves open to let blood through and then close to keep blood from moving backward (Figure 12).

Heart failure means that your heart cannot supply enough blood and oxygen to your body to keep up with your body’s demands. Sometimes heart failure is called “congestive heart failure” because it is often associated with fluid buildup, swelling, and difficulty breathing.

Heart failure is not a heart attack, which is when a sudden blockage occurs in one of the arteries that feeds the heart (known as the coronary arteries). This is usually associated with significant chest pain and can be a life-threatening emergency. In contrast, heart failure is often a chronic condition that can be present for a very long time. Patients with heart failure typically experience fluctuations and variations in the severity of their symptoms over time.

Heart failure is often classified into two categories: systolic dysfunction and diastolic dysfunction. Systolic dysfunction is when the heart muscle becomes enlarged and weakened. The weakened heart muscle doesn’t pump enough blood forward when the ventricles contract. Diastolic dysfunction is when the heart muscle is not weakened but rather has become stiff. The stiff muscle can’t relax between contractions, which prevents the heart chambers (known as ventricles) from adequately filling with enough blood. In either case the heart is not working efficiently.

The term “heart failure” refers to the various symptoms that patients may experience but does not explain the cause of their heart problem. Most patients who have heart failure do have some type of abnormality of their heart function.

The symptoms of heart failure are

• Fatigue or tiredness with little effort

• Shortness of breath with exertion, becoming easily breathless

• Loss of appetite or nausea

• Swelling in ankles or legs

• Abdominal bloating or fullness

• Rapid weight gain

• Problems breathing when lying flat, or needing to sit up or use extra pillows to sleep

• Waking up at night coughing or short of breath

• Increased nighttime urination

• A racing or skipping heartbeat