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 is often referred to as sick sinus syndrome because the sinoatrial (sinus) node in the right atrium controls the electrical impulses. The cause of atrial fibrillation is not always known. Conditions that can cause damage to the heart and lead to atrial fibrillation include: 1  high blood pressure.  congestive heart failure.
Symptoms of fibromyalgia include: 1  Widespread pain. The pain associated with fibromyalgia often is described as a constant dull ache that has lasted for at least three months. To be considered widespread, the pain must occur on both sides of your body and above and below your waist. 2  Fatigue.