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.
1 A rising heart rate does not cause your blood pressure to increase at the same rate. 2  Even though your heart is beating more times a minute, healthy blood vessels dilate (get larger) to allow more blood to flow through more easily.3  When you exercise, your heart speeds up so the blood can reach your muscles. For people with high blood pressure, there's no substitute for measuring blood pressure. 2  A rising heart rate does not cause your blood pressure to increase at the same rate. 3  Even though your heart is beating more times a minute, healthy blood vessels dilate (get larger) to allow more blood to flow through more easily.