Female black bears may give birth to 1 to 6 cubs (twins are most common) in January or February. Black bear cubs may be 1/250th the size of the mother bear, and are the smallest newborns, compared to their mothers, of any placental mammal.
A left ventricular assist device, or LVAD, is a mechanical pump that is implanted inside a person's chest to help a weakened heart pump blood. Unlike a total artificial heart, the LVAD doesn't replace the heart. It just helps it do its job. This can mean the difference between life and death for a person whose heart needs a rest after open-heart surgery or for people waiting for a heart transplant.
But more importantly, the MUGA scan gives an accurate and reproducible means of measuring and monitoring the âejection fractionâ of the cardiac ventricles. The left ventricular ejection fraction (LVEF) is an excellent, and the most commonly used, measure of overall cardiac function. The ejection fraction is simply the proportion of blood that is expelled from the ventricle with each heart beat. So, for instance, if the left ventricle ejects 60% of its blood volume with each beat, the LVEF is 0.6.