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.
All of these can be symptoms of paroxysmal atrial fibrillation. Atrial fibrillation (AF or AFib) happens when the atria (upper chambers of the heart) lose their regular rhythm and beat chaotically. When this happens, blood isnât really streaming through the heart and body efficiently. This inefficient flow can cause blood to pool inside the atria, increasing the risk of blood clots.