Left-sided heart failure
The heart's pumping action moves oxygen-rich blood as it travels from the lungs to the left atrium, then on to the left ventricle, which pumps it to the rest of the body. The left ventricle supplies most of the heart's pumping power, so it's larger than the other chambers and essential for normal function. In left-sided or left ventricular (LV) heart failure, the left side of the heart must work harder to pump the same amount of blood.
There are two types of left-sided heart failure. Drug treatments are different for the two types.
- Systolic failure: The left ventricle loses its ability to contract normally. The heart can't pump with enough force to push enough blood into circulation.
- Diastolic failure (also called diastolic dysfunction): The left ventricle loses its ability to relax normally (because the muscle has become stiff). The heart can't properly fill with blood during the resting period between each beat.
Right-sided heart failure
The heart's pumping action moves "used" blood that returns to the heart through the veins through the right atrium into the right ventricle. The right ventricle then pumps the blood back out of the heart into the lungs to be replenished with oxygen.
Right-sided or right ventricular (RV) heart failure usually occurs as a result of left-sided failure. When the left ventricle fails, increased fluid pressure is, in effect, transferred back through the lungs, ultimately damaging the heart's right side. When the right side loses pumping power, blood backs up in the body's veins. This usually causes swelling or congestion in the legs, ankles and swelling within the abdomen such as the GI tract and liver (causing ascites).
Congestive heart failure
Congestive heart failure (CHF) is a type of heart failure which requires seeking timely medical attention, although sometimes the two terms are used interchangeably.
As blood flow out of the heart slows, blood returning to the heart through the veins backs up, causing congestion in the body's tissues. Often swelling (edema) results. Most often there's swelling in the legs and ankles, but it can happen in other parts of the body, too.
Sometimes fluid collects in the lungs and interferes with breathing, causing shortness of breath, especially when a person is lying down. This is called pulmonary edema and if left untreated can cause respiratory distress.
Heart failure also affects the kidneys' ability to dispose of sodium and water. This retained water also increases swelling in the body's tissues (edema).
This content was last reviewed April 2015.