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.
There are a number of temporary (acute) that can cause atrial fibrillation (AFib). For the most part, when the temporary condition ceases or is treated, AFib usually is resolved. Many of the acute conditions listed can cause chemical imbalances that may lead to electrical imbalances in your heart, triggering AFib.