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.
What Causes Atrial Tachycardia? The cause of Atrial Tachycardia is similar to any other form of tachycardia in which the underlying mechanism may be a rapid discharge of an abnormal focus or a rapid rhythm as a result of some pathological conditions due to some drug toxicity most commonly digoxin toxicity.