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.
Sinus tachycardia is a normal increase in the heart rate. How it happens. The sinoatrial (SA) node --- the heart's natural pacemaker-sends out electrical signals faster than usual. The heart rate is fast, but the heart beats properly.inus tachycardia is a normal increase in the heart rate. How it happens. The sinoatrial (SA) node --- the heart's natural pacemaker-sends out electrical signals faster than usual. The heart rate is fast, but the heart beats properly.
Exercise, stress or fear can cause. the heart to beat faster, but this is a normal. response. With tachycardia, the heart beats at. more than 100 beats per minute and can beat. as fast as 400 beats per minute for no specific. reason.