Types of Heart Failure
Normally 50-75% of the blood in the heart is pumped into the body with each
heartbeat. This is called the left ventricular ejection fraction (LVEF) and
indicates the percent of blood that is ejected with each heartbeat.
Systolic heart failure or systolic dysfunction
occurs when the heart muscle becomes weakened isn't able to empty at least 50%
of the blood with each heartbeat. Heart function can be mildly, moderately, or
severely reduced. Symptoms of heart failure don't usually occur until the
ejection fraction is less than 40%. People with severely reduced heart function
may eject less than 20% of the blood from the heart with each heartbeat.
Diastolic heart failure or diastolic
dysfunction occurs when the heart muscle becomes stiff and can't relax and fill
properly with blood. When the heart can't fill properly, there is a reduced
amount of blood in the heart to be ejected with each heartbeat. At least 30% of
the people in the US with heart failure have diastolic dysfunction.
The end result of both of these types of heart failure is that the left side
of the heart fails to pump enough blood to nourish the body.
Right-sided heart failure prevents blood from
flowing normally from the body, to the right side of the heart, into the lungs
to receive oxygen, and then into the left side of the heart to be pumped out to
the body. This reduces the amount of blood that fills the left side of the
heart and the amount ejected may fail to meet the needs of the body.