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.
An early complex that breaks the regularity of the underlying rhythm and that is characterized by a narrow QRS complex and an upright P wave that differs in shape and size from the P waves of the other complexes MOST accurately describes a(n): premature atrial complex.