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Systolic Heart Failure - Topic Overview

Systolic heart failure happens when the left side of your heart doesn't pump blood out to the body as well as normal.

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.

What causes it?

There are many different problems that can cause systolic heart failure.

Causes of systolic heart failure


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 muscleIt weakens or damages heart muscle and impairs the muscle's ability to pump.
CardiomyopathyA disease of the heart muscle The heart muscle is weakened, which affects its ability to pump properly.
High blood pressureElevated pressure in your arteries The heart works harder to pump against increased pressure, which weakens the muscle.
Aortic stenosisOpening of aortic valve is narrowed, impairing blood flowThe heart works harder to pump blood through the narrowed valve, weakening the muscle.
Mitral regurgitationMitral valve doesn't close properly, causing leakage on left side of the heartIncreased blood volume stretches and weakens heart muscle.
Viral myocarditisViral infection of your heart muscleInflammation in the heart muscle affects the heart's ability to pump.
ArrhythmiaIrregular heart rhythmIrregular 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.

Chronic ischemia can allow your heart muscle to get just enough oxygen to stay alive but not enough oxygen to work normally. Ongoing poor blood flow to the heart muscle reduces the heart's ability to contract and causes it to pump less blood during each beat. The less blood your heart pumps out to your body, the less blood it is actually pumping back to itself through the coronary arteries. The end result is that heart failure makes ischemia worse, which in turn makes heart failure worse.


WebMD Medical Reference from Healthwise

Last Updated: April 26, 2012
This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.
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