What are the causes for Cardiomyopathy?

The heart is an electrically-innervated, muscular pump that pushes blood throughout the body through blood vessels. A specialized group of cells located in the upper chamber (atrium) of the heart, acts as a pacemaker that generates an electrical impulse. This impulse begins a sequential electrical stimulation of heart muscle that then contracts in a coordinated way. Accordingly, first the upper chamber of the heart is stimulated to contract and send blood into the lower chambers (ventricles) of the heart. There is a slight delay in the electrical signal that allows the ventricles to fill. Then the ventricles contract pumping blood throughout the body. Another slight delay then occurs, allowing blood to return to the upper chambers of the heart, refilling the heart for the next cycle. Cardiac output is a measurement of heart function that measures the amount of blood that the heart pumps in a specific period of time.
  • The stroke volume is the amount of blood that the heart pumps with one contraction.
  • The stroke volume multiplied by the number of heart beats per minute is the cardiac output.
  • Normally, the adult heart pumps about 5 liters of blood through the blood vessels of the body every minute.
The ejection fraction is a measurement of the heart's effectiveness in pumping blood. It is the percentage of blood in a filled ventricle that is pumped out of the heart with each contraction. A normal heart will have an ejection fraction of 60%-70%. This number can decrease if the heart muscle cannot squeeze or contract adequately.

Source: http://www.emedicinehealth.com