You have been told you have atrial fibrillation.
Atrial fibrillation can cause fast heart rates.
Heart disease, lung disease, smoking and excessive alcohol and caffeine intake are among the causes of atrial fibrillation. Your heart has an electrical system which causes it to contract and relax. Normally, each heart beat begins as an impulse from a group of cells, called the SA node, located in the upper right chamber of the heart. The electrical impulse travels across both upper chambers, or the atria. The atria then contract.