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: Heart Symptoms, Diagnosis & Treatment for AFib. Atrial fibrillation(AFib) is the most common type of abnormal heart rhythm. Atrial fibrillation or AF can lead to serious heart complications like stroke. Risks associated with AFib are related to heart rhythm changes. Treating atrial fibrillation addresses these changes in heartbeat.