Ventricular pacemaker cells discharge at a slower rate than the SA or AV node. While the SA node typically initiates a rate of 70 beats per minute (BPM), the atrioventricular node (AV node) is usually only capable of generating a rhythm at 40-60 BPM or less. Ventricular contraction rate is thus reduced by 15-40 beats per minute.
Littleton, CO Population and Races. As of 2010-2014, the total population of Littleton is 43,710, which is 8.35% more than it was in 2000. The population growth rate is much lower than the state average rate of 20.84% and is lower than the national average rate of 11.61%.
In 1928 the town became the northern terminus of the Fort Worth and Denver South Plains Railway from Lubbock. Silverton was subsequently incorporated, and it grew. Natural gas was introduced in 1929 by the West Texas Gas Company. By 1940 Silverton had thirty-five businesses and a population of 684. Throughout its history Silverton has suffered from prairie fires, grasshoppers, dust storms, and cyclones. Its worst disaster occurred on the night of May 15, 1957, when a tornado killed twenty-one people and did over $1 million worth of damage.