Cardiovascular physiology refers to the different functions of the heart and circulatory system and the study of the factors that affect them. The human heart is responsible for circulating nutrient-rich blood to all of the body's organs and tissues, hence making it possible to maintain life. Ejection fraction refers to the relative amount of blood that is pumped out of both the right and left ventricles with each contraction of the heart. There are a number of ways to increase ejection fraction, with regular exercise and a heart-healthy diet being the safest and most effective.
Like any machine, there are times when the heart is functioning efficiently and healthily. Other times, different factors may cause the heart to function improperly. Genetics, diet, exercise, and weight all contribute to how well this biological machine operates, and although there are certain aspects of heart health outside of a person's control, there are also many things a person may do to improve functionality, such as taking action to increase ejection fraction.
The ejection fraction is characterized by the formula E = SV / EDV, where "E" represents the ejection fraction, "SV" stands for stroke volume, and "EDV" is the end diastolic volume. Stroke volume alludes to the volume of blood ejected out of the heart, whereas end diastolic volume is the amount of blood left in the ventricular chambers after the heart has contracted. Stroke volume is the numerator, and end diastolic volume is the denominator, so in order to increase ejection fraction, one must either increase stroke volume or decrease end diastolic volume.
Due to the inverse relation between SV and EDV, the increase of one leads to a decrease in the other; therefore, in order to increase ejection fraction, the focus should be on improving the quantity of blood moved out of the ventricles. The best way to do this is to increase the size of the ventricles and the contractility, or force with which they contract. The heart is a muscle, so it responds to exercise by strengthening over time. Generally speaking, physical stress causes the rebuilding of muscle fibers, in turn, making the stressed muscle more powerful.
When the heart is stressed, for example, through repetitive cardiovascular exercise, it becomes stronger and is able to pump a greater amount of blood from each chamber. Additionally, the chambers themselves grow larger as more fibers are created. All of these factors contribute to help increase ejection fraction through the improved stroke volume that is experienced as a result of exercise.
Other ways to improve one's ejection fraction also exist. When heart damage occurs, through a heart attack or other dysfunction, extreme measures may be needed. Heart transplants are sometimes conducted in dire circumstances to give a person a new heart that has superior functionality and ejection fraction to the previous one. There is contradictory evidence regarding certain drug therapies and ejection fraction increases; however, ongoing research is being conducted to address these discrepancies.