Video: The Great Migration: Definition & Causes. The economic conditions of World War I led to a massive movement of African Americans from the South to the North, known as the Great Migration. Examine the causes and effects of this phenomenon.
Physicians may want to look closer at WBC levels when obtaining the tests for other reasons, Manson notes. However, infections can cause a high white blood cell count that may make it appear that a patient is at high risk for heart disease when she is not. Therefore, routinely giving everyone the test to screen for heart disease is premature. More research needs to be done..
How Other Factors Affect Heart Rate. 1  Air temperature: When temperatures (and the humidity) soar, the heart pumps a little more blood, so your pulse rate may increase, but usually no more than five to 10 beats a minute. Air temperature: When temperatures (and the humidity) soar, the heart pumps a little more blood, so your pulse rate may increase, but usually no more than five to 10 beats a minute. 2  Body position: Resting, sitting or standing, your pulse is usually the same.