NURS 225 Chapter Notes - Chapter 34: Systemic Venous System, Diastolic Heart Failure, Ejection Fraction
Document Summary
There is interaction between the actin and myosin filaments during cardiac muscle contraction. It is a decrease in myocardial contractibility, characterized by an ejection fraction of less than 40% In systolic heart failure, the ejection fraction declines progressively with increasing degrees of myocardial dysfunction. Sometimes the ef can drop to single digits. With a decrease in ej, there is a resultant increase in end-diastolic volume, ventricular dilation, and ventricular wall tension and a rise in ventricular end-diastolic pressure. Diastolic dysfunction refers to when the diastole part of this action is abnormal. The ventricles do not properly relax and become stiff meaning they cannot fill with blood properly. This causes blood to dam up in other parts of the body. Pressure in the ventricles then increases as blood from the next heartbeat tries to enter. Impairs the ability to move deoxygenated blood from the systemic circulation into the pulmonary circulation. Accumulation or congestion of blood into the systemic venous system.
