Fluke Biomedical ProSim 4 - Manual (Page 45)

Glossary
Introduction
A
A-5
Premature Ventricular Contractions
Six PVC-type selections of focus and timing:
• a left-focus premature ventricular beat with standard timing, 20 % premature;
• a left-focus premature ventricular beat with early timing, 33 % premature;
• a left-focus premature ventricular beat with very early timing, 65 %
premature, which starts during the T wave of the previous beat;
• a right-focus premature ventricular beat with standard timing, 20 %
premature;
• a right-focus premature ventricular beat with early timing, 33 % premature; or
• a right-focus premature ventricular beat with very early timing, 65 %
premature, which starts during the T wave of the previous beat.
A premature ventricular contraction or PVC is an extra beat consisting of an
abnormally wide and unusual QRS complex originating in an ectopic pacemaker
in the ventricles. Early ventricular PVCs occur close to the preceding beat.
Moreover, R-on-T PVCs, which are characterized by a beat that falls on the T
wave of the preceding QRS-T complex, are especially inauspicious because of
their potential to cause ventricular tachycardia or ventricular fibrillation.
Pulse
The rhythmical throbbing of arteries produced by regular contractions of the
heart.
Purkinje Network
The dense collection of Purkinje fibers, which are dispersed throughout the
myocardium and which represent the terminal portion of the heart's electrical
conduction system.
PVCS
Premature ventricular contractions.
QRS Complex
The part of the P-QRS-T wave that records ventricular depolarization and
contraction.
R-Value
The non-pulsating components of tissue, specifically the tissue bed, the venous
blood, the capillary blood, and nonpulsatile arterial blood. Also referred to as the
DC component.
Resistance
The opposition to electric current that is characteristic of a medium, substance, or
circuit element.
SA Node
The dominant pacemaker site in the heart, responsible for setting the heart rate.
Positioned in the right atrium near the inlet of the superior vena cava.
Serial Port
An asynchronous COMmunication port/address to which a peripheral—such as a
printer or a mouse—is connected to a computer or other device. SEE RS-232.