The pacemaker may have one to three leads, depending on the type of pacemaker needed to treat your heart problem. There are different types of pacemakers: Single-chamber pacemakers use one lead in the upper chamber (atria) or lower chamber (ventricles) of the right side of the heart.
The MexicanâAmerican War, also known as the Mexican War, the U.S.âMexican War or the Invasion of Mexico, was an armed conflict between the United States of America and the United Mexican States from 1846 to 1848.
The people of the United States will know of the Mexican-American War, but even they may not know the causes so today we will talk about the causes of the Mexican-American War. Causes of the Mexican-American War. Texas. Between 1835 and 1836 the Texas Revolution occurred. This revolution was because Texas, being a part of Mexico at this time, was not happy about the Mexican government.