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.
Uterine Fibroids: Symptoms and Causes Uterine fibroids: symptoms and causes Often, fibroids do not show any symptoms and are only discovered during routine check-ups. But around one in every three women with fibroids will experience some symptoms which will interfere with daily life.