First of all, heartbeats are caused by electrical impulses that happen in the atria. Cells called sino-atrial nodes (SA nodes) generate the first pulse. The signal travels to another node called the AV node that causes the heart to contract and make a heartbeat. These electrical impulses stimulates the atria, contracts the muscles and allow blood to be pumped. Irregular heartbeats are called arrythmia. Tachycardia is an irregularly fast heartbeat. Ventricular fibrilation occurs when the heart doesnt beat properly. Instead of sending out thr electrical impulses, the heart just jiggles in place, doing nothing. This is caused by disordered electrical impulses. Although the heart moves, there isn't enough impulse to move blood through the heart, failing to circulate blood throughout the body. Symptoms include rapid heartbeats, chest pain, nausea, and dizziness. Medicine can be used to control the heart, and if it gets serious, an external defibrillator can be used to change the heartbeat back to its normal rhythm.
Links:
http://www.medicalnewstoday.com/articles/188837.php
http://www.nlm.nih.gov/medlineplus/ency/article/007200.htm
Good post Josh - interesting stuff. I like that you posted links and included a you tube video. Lots of good information in one spot. Nice!
ReplyDeleteNext time, try embed the links so that you can click on them instead of cut and paste... it's on the top navigation bar by the movie/picture icon... think it says "link".