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.
On the ECG you will see a single premature atrial contraction with an early P wave and a short PR interval followed by a delay in the next contraction. Causes include smoking, lack of sleep, excess caffeine, alcohol and drugs. A-V bundle premature contraction, effect on ECG, and causes.