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.
In many patients, the symptoms are related to a faster heart beat. However, some patients have symptoms, even if the heart rate is not fast. In some patients, if the heart beats too slowly during atrial fibrillation, this can also cause symptoms. An irregular pulse (usually detected by listening to the heart with stethoscope) is the most common sign of atrial fibrillation at physical examination. Table 1. Common signs and symptoms of atrial fibrillation.