Title What is baseballâs âmodern eraâ? The start of the 20th century might not seem particularly modernâafter all, there were only 45 states in the Union, hardly anyone owned a car (the Model T didnât debut until 1908) and William McKinley, a Civil War vet, occupied the White House.
Causes. Exercise is a common cause of rapid heart rate. Your heart rate should elevate during exercise, but it may be a problem if your heart rate remains elevated for more than 10 minutes after you finish your workout. Dehydration can also cause a faster heart rate.xercise is a common cause of rapid heart rate. Your heart rate should elevate during exercise, but it may be a problem if your heart rate remains elevated for more than 10 minutes after you finish your workout.
If the heart beats more rapidly than normal, this arrhythmia is called tachycardia. An unpleasant sensation in the heart, whether rapid or slow, regular or irregular, and of which one is consciously aware, is called a palpitation. Physical Causes of Rapid or Irregular Heart Rate. 1  arrhythmia.  postmyocardial infarction.