Types of heart failure

Heart failure can be classified as follows:

• Heart failure with reduced pumping ability (heart failure with reduced ejection fraction, also called systolic failure): The heart muscle has become weaker, and can no longer pump enough blood through the body. As a result, the organs in the body don’t get enough oxygen. Doctors sometimes also distinguish between mildly and severely reduced ejection fraction (EF).
• Heart failure with preserved pumping ability (heart failure with preserved ejection fraction, also called diastolic failure): Although the heart muscle is still strong, the tissue is stiffer than in a healthy heart. As a result it can no longer expand enough to fill with enough blood after the muscle contracts (squeezes). Then not enough blood flows through the body, especially during physical exertion.

Classification of heart failure by pumping ability is important for being able to select suitable medication.

Heart failure can develop suddenly, for instance after a severe heart attack or due to certain heart rhythm problems. This is known as acute heart failure and is a medical emergency.

But it usually develops gradually as a result of a different medical problem, such as constant high blood pressure. This is known as chronic heart failure.

Heart failure often affects either the left or the right side of the heart, but sometimes both halves are involved (biventricular heart failure):

• Left-sided heart failure: The left ventricle of the heart no longer pumps enough blood around the body. As a result, blood builds up in the blood vessels that carry blood away from the lungs. This causes shortness of breath, trouble breathing or coughing – especially during physical exertion. Left-sided heart failure is the most common type of heart failure. It is usually caused by coronary artery disease (CAD), a heart attack or long-term high blood pressure.
• Right-sided heart failure: Here the right ventricle of the heart is too weak to pump enough blood to the lungs. This causes blood to build up in the veins (the blood vessels that carry blood from the organs and tissue back to the heart). The increased pressure inside the veins can push fluid out of the veins into surrounding tissue. This leads to a build-up of fluid in the legs, or less commonly in the genital area, organs or the abdomen (belly). Right-sided heart failure may develop as a result of advanced left-sided heart failure, and is then treated in the same way. It is sometimes caused by high blood pressure in the lungs, an embolism in the lungs (pulmonary embolism), or certain lung diseases such as COPD.
• Biventricular heart failure: In biventricular heart failure, both sides of the heart are affected. This can cause the same symptoms as both left-sided and right-sided heart failure, such as shortness of breath and a build-up of fluid.