What happens to the heart?
Systolic heart failure typically affects the left side of the heart. This is the side that pumps blood to the body. The heart's lower chamber, called the left ventricle, cannot pump blood as well.
It's called systolic because your ventricle doesn't squeeze forcefully enough during systole, which is the phase of your heartbeat when your heart pumps blood.
Tests may show a low ejection fraction. This means that your left ventricle isn't working as well as normal. Doctors sometimes call it heart failure with reduced ejection fraction.
What causes it?
There are many different problems that can cause systolic heart failure.
Cause | What is it? | How it causes heart failure |
|---|---|---|
Coronary artery disease or heart attack | Blockages in your coronary arteries that limit blood flow to your heart muscle | It weakens or damages heart muscle and impairs the muscle's ability to pump. |
| Cardiomyopathy | A disease of the heart muscle | The heart muscle is weakened, which affects its ability to pump properly. |
| High blood pressure | Elevated pressure in your arteries | The heart works harder to pump against increased pressure, which weakens the muscle. |
| Aortic stenosis | Opening of aortic valve is narrowed, impairing blood flow | The heart works harder to pump blood through the narrowed valve, weakening the muscle. |
| Mitral regurgitation | Mitral valve doesn't close properly, causing leakage on left side of the heart | Increased blood volume stretches and weakens heart muscle. |
| Viral myocarditis | Viral infection of your heart muscle | Inflammation in the heart muscle affects the heart's ability to pump. |
| Arrhythmia | Irregular heart rhythm | Irregular rhythm reduces the pumping effectiveness of the heart. |
Gradual heart damage
Coronary artery disease causes gradual heart damage over time. Ischemia is the medical term for what happens when your heart muscle doesn't get enough oxygen. Ischemia may happen only once in a while, such as when you are exercising and your heart muscle needs more oxygen than it normally does. Ischemia can also be ongoing (chronic) if your coronary arteries are so narrowed that they limit blood flow to your heart all the time. This chronic lack of oxygen can gradually damage portions of your heart muscle. Your heart can slowly lose its ability to pump blood to your body.