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.
Problems with this electrical conduction system can cause an arrhythmia. Arrhythmias can cause the heart to pump less effectively because the coordination of the heart muscle becomes uncoordinated. Certain arrhythmias increase your risk of other medical problems like stroke or blood clots. In an arrhythmia, abnormal electrical signals through the heart muscle may cause the heart to beat too fast, too slow, or in an irregular manner. In any of these situations, the heart may not be able to pump an adequate amount of blood to the body with each beat.