Pressures are measured and blood samples are taken from within the heart and its major blood vessels. Aorta The largest artery in the body, which carries blood from the left side of the heart to every part of the body. Array A lead consisting of three electronically common elements joined at a yoke. The SQ array is used as part of an AICD system. Arrest The stopping of a function.
Cardiac arrest is the stopping of the heartbeat and the heart's function.
Arrhythmia An abnormal rhythm of the heart beat. Asynchrony A condition in which the heart fails to maintain a normal time sequence between atrial and ventricular contractions. Atherectomy A minimally invasive CAD intervention procedure which involves the excision and removal of blockages by catheters with miniature cutting systems. Atria The upper chambers of the heart, specifically the right atrium and left atrium. This part of the heart's electrical pathway helps carry signals from the atria to the ventricles.