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.
Mexican War of Independence. The Mexican War of Independence (Spanish: Guerra de Independencia de MÃ©xico) was an armed conflict, and the culmination of a political and social process which ended the rule of Spain in 1821 in the territory of New Spain.