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.
Causes of premature contractions. 1  Usually no cause can be found. 2  Occasionally premature beats may be caused by disease or injury to the heart. 3  Your doctor may recommend more tests to make sure your heart is OK.