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.
Texas Independence. Texasâs struggle for independence from Mexico and its annexation by the United States led to the Mexican War. From 1846 to 1848, the United States fought Mexico to acquire land stretching from Texas to the Pacific Ocean. By the 1830s, American settlers in Mexicoâs Texas territory outnumbered native Mexicans.