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.
The most common symptom of atrial fibrillation is palpitations, an uncomfortable awareness of the rapid and irregular heartbeat. Other symptoms of atrial fibrillation are caused by the diminished delivery of blood to the body. These symptoms include: 1  dizziness, 2  fainting, 3  weakness, 4  fatigue, 5  shortness of breath, and.