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.
Ventricular premature complexes. Bigeminy: alternating patterns of VPCs and normal impulses. Cardiac impulses originate in the AV node or below. - Causes: poor tissue perfusion, and pulse defects. - On ECG: wide and bizzare QRS complexes with no associated P wave, VPC is followed by a pause.