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.
The root cause of Paroxysmal Atrial Tachycardia is when there is an abnormality in the electrical signals in the atria resulting in the atria to beat faster than normal. Due to this signal abnormality, there is an irregularity in signals sent to the heart by the SA node which is also termed as the natural pacemaker of the heart.