2. A vessel approaching a blind bend in a river can sound one prolonged blast on the ships' whistle to alert any other vessels to its presence, if another vessel is nearby then they will respond with one prolonged blast on the ships' whistle.
Atrial fibrillation, known as AF or Afib, is an irregular and often very fast heart rate. This may cause symptoms like heart palpitations, fatigue, and shortness of breath. Treating atrial fibrillation is important because it may cause a stroke and negatively impact your quality of life.
Atrial fibrillation (AFib) is a medical disorder that affects the upper chambers, known as atria, of the heart. People with AFib experience irregular heartbeats caused by abnormal electrical signals in the atria. The electrical impulses erroneously circulate through the atria, causing the atria to contract with an irregular rhythm and fast rate.