heart is unable to pump sufficiently to maintain blood flow
Two types of left heart failure
the ability of the left ventricle to contract, or to relax, is affected
Heart failure with reduced ejection fraction (HFrEF), also called 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.
Heart failure with preserved ejection fraction (HFpEF), also called diastolic failure (or diastolic dysfunction): The left ventricle loses its ability to relax normally (because the muscle has become stiff).
Failure of the left side of the heart causes blood to back up (be congested) into the lung
Right-sided heart failure is often caused by pulmonary heart disease
Heart failure is the potential end stage of all diseases of the heart
Heart failure is caused by any condition that reduces the efficiency of the heart muscle, through damage or overloading.
The heart of a person with heart failure may have a reduced force of contraction due to overloading of the ventricle
normal heart, increased filling of the ventricle results in increased contraction force by the Frank–Starling law of the heart, and thus a rise in cardiac output
No diagnostic criteria have been agreed on as the gold standard for heart failure
mixed presentations are common and left heart failure is a common cause of right heart failure.
There is no single diagnostic test for heart failure
BNP measures severity of heart failure
Heart failure is not the same as heart attack (in which part of the heart muscle dies) or cardiac arrest (in which blood flow stops altogether)
The term "congestive heart failure" is often used, as one of the common symptoms is congestion, or build-up of fluid in a person's tissues and veins in the lungs or other parts of the body.
Specifically, congestion takes the form of water retention and swelling (edema), both as peripheral edema (causing swollen limbs and feet) and as pulmonary edema (causing breathing difficulty), as well as ascites (swollen abdomen)