User Manual

GLOSSARY OF TERMS
234 PatientNet Operator’s Manual, v1.04, 10001001-00X, Draft
All information contained herein is subject to the rights and restrictions on the title page.
Learned Reference - the template of the patients “normal” or dominant ECG com-
plex to which every incoming beat is compared. (PN)
Modified Chest Lead MCL1 - the bipolar lead closely resembling lead V1, views the
anteroseptal wall of the heart.
Multifocal - (multiform) PVCs that have different QRS complexes as a result of their
originating in different ectopic ventricular sites.
Noise - extraneous spikes, waves, and complexes in the ECG signal caused by muscle
tremor, 60-cycle AC interference, improperly attached electrodes, and biomedical
telemetry-related events such as out-of-range ECG transmission and weak transceiver
batteries.
Normal Sinus Rhythm - normal rhythm of the heart, originating in the SA node with
a rate of 60 to 100 beats per minute.
Pacemaker, artificial - an electronic device used to stimulate the heart to beat when
the electrical conduction system of the heart malfunctions causing bradycardia or ven-
tricular asystole. An artificial pacemaker consists of an electronic pulse generator, a
battery, and a wire lead that sense the electrical activity of the heart and deliver electri-
cal impulses to the atria, ventricles, or both when the pacemaker senses an absence of
electrical activity.
Pacemaker Filter - a blanking interval set by the system operator. The system presets
it at 25 msec and the operator may adjust it from 5 msec to 80 msec. The appropriate
setting of this interval enables the arrhythmia software to avoid false asystole calls
and/or double counting of QRS complexes. (PN)
Pacemaker Spike - the narrow sharp wave of the ECG caused by the electrical
impulse generated by an artificial pacemaker.
Pacemaker Rhythm - a rhythm that is produced by an artificial pacemaker.
Precordial Leads (unipolar) - the precordial leads record currents moving away from
the anterior and the left surface of the chest. The unipolar chest leads are Leads V1 to
V6.
R-R Interval - the section of the ECG complex between the onset of one QRS com-
plex and the onset of the adjacent QRS.
R-on-T Phenomenon - an ominous type of premature ventricular contraction that
falls on the T wave of the preceding QRS-T complex. It may cause repetitive firing
and result in ventricular tachycardia or ventricular fibrillation.
Rate - term used to quantify the number of heart beats per minute.
Repolarization - the electrical process by which a depolarized cell returns to its polar-
ized, resting state.
Rhythm - term used to describe the regularity or irregularity of the component aspects
of the ECG.
Sense - the term used to describe a pacemaker’s ability to generate a contraction with
every spike.