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.
Print. An atrial ectopic beat is a problem in the electrical system of the heart. It is an extra heartbeat caused by a signal to the upper chambers of the heart (the atria) from an abnormal electrical focus.It is also called an atrial premature beat or a premature atrial contraction.hese premature heartbeats are associated with lung diseases, especially if high blood pressure is present in the arteries that go between the heart and lungs. Stimulants (such as coffee and tea, alcohol or some types of cold, allergy or asthma remedies) will sometimes set off the extra beat.