under contract means there is an offer on it already and the buyer and seller are negotiating back and forth to come to an agreement. if ya need any more help just e-mail me. Lori lspalletta Â· 1 decade ago
Premature atrial complexes are caused by abnormal electrical impulses transmitted by the atria (either of the upper chambers of the heart). The abnormal electrical impulses cause contractions of the upper chamber of the heart earlier than expected. Such premature beats are generally harmless. slide 1 of 7.
When a premature beat occurs in the upper chambers of your heart, itâs known as an atrial complex or contraction. Premature beats can also occur in the lower chambers of your heart. These are known as ventricular complexes or contractions. Causes and symptoms of both types of premature beats are similar.