Heart failure is failure of the cardiac pump that is unable to deliver the oxygen and nutrients (blood flow) necessary for the organs to function. It results in breathlessness and fatigue.
This disease is due to an intrinsic defect of the heart muscle or its irrigation by the coronary vessels, alteration of energetic metabolism or heart desynchronization. A desynchronized heart is a heart that has lost the balance of the propagation of electrical impulses and thus the resulting contraction. Thus a wall can contract while another one is at rest with a consequent significant loss of efficiency.