ECG Arrhythmia Dictionary
Aberrant – Abnormal or unusual
Accessory Pathway – Located outside of the normal conduction system, myocardial tissue forms a connection between the atria and the ventricles
Acute – Sharp, sudden, intense for a short period of time
Algorithm – Finite number of steps a computer uses in making decisions
Angina – Severe chest pain resulting when the myocardium is deprived of sufficient oxygen
Anterior – Front or ventral; opposite of posterior or dorsal
Arrhythmia – Abnormality in a normal rhythmic pattern (heart beat)
Artifact – Distortion of an ECG tracing by electrical activity that is noncardiac in origin
Atria – Two upper chambers of the heart that receive blood
AV Node – Cells located in the lower portion of the right atrium that allow atria to contract and fill by delaying electrical impulse
Baseline – Line serving as a basis for measurement, calibration or location
Biphasic – Waveform that is positive and negative
Bradycardia – Heart rate slower than 60 beats per min
Bundle Branch Block (BBB) – Irregular conduction of electrical impulses through the right or left bundle branches
Cardiac Cycle – Period from the beginning of one hear beat to the next one
Chronic – Lasting over a long period of time
Compensatory – A normal beat after a PAC follows when expected
Dysrhythmia – Abnormality in a rhythmic pattern
Ectopic Beat – Impulse that does not originate in the sinoatrial node
Escape Beat – An electrical impulse that is spontaneously produced by a lower pacemaker site after the sinus node fails to initiate depolarization
Fascicle – Small bundle on nerve fiber
Focus – Site at which an electrical impulse originates
Fusion Beat – A beat that occurs due to the simultaneous activation of one chamber by two sites
Hook-Up – Skin preparation and lead placement
Idioventricular Rhythm – Three or more sequential ventricular escape beats that occur at a rate of 20-40 beats per minute
Inherent – Natural, intrinsic
Interval – Measure of a waveform and segment
Intermittent – Starting and stopping
Interpolated – PVC that occurs between two normal QRS complexes and that does not interrupt the underlying rhythm
Inverted – Turn upside down or reverse the position of
Ischemia – Decreased supply of oxygenated blood to the heart muscle
Isoelectric Line – When electrical activity is not detected, a straight line is recorded
J point – Place where QRS complex and ST segment meet
LBBB – Left Bundle Branch Block
Lead – Electrical connection attached to the body to record electrical activity
Myocardial Infarction (MI) – Death of injured myocardial cells
Multifocal – Indicates more than one ectopic focus, causing them to look different
Nodal – Term used for junctional beats or rhythms
Non-Compensatory – Normal beat following the premature complex that occurs before expected
Non-sustained – 3-10 beats
Notched – V-shaped
Offset – The end of
Onset – The beginning of
Oversensing – Inappropriate sensing of extraneous electrical signal
Pathological – Nature of disease and cause
Pause – Two seconds or longer before a beat
Posterior – Situated in the back, behind
Premature – Early in occurrence
RBBB – Right Bundle Branch Block
Rate – Number of times a heart beats per minute
Retrograde – Moving backwards
Rhythm – Indicates the site of origin of the electrical impulse, as well as the regularity or irregularity
Segment – Waveform measurement
Sensing – Ability of a pacemaker to recognize and respond to intrinsical electrical activity
Sick Sinus Syndrome (SSS) – Sinus node dysfunction that may be manifested through sinus bradycardia, sinus arrest, or sinus block
Silent ischemia – Episodes in which chest pain is not felt
Sinoatrial Node – Normal pacemaker of the heart with a rhythmic rate of 60-100 beat per minute
Supra – Above
Sustained – More than 10 beats
Symptomatic – Of, relating to, or based on symptoms
Tachycardia – Heart rate greater than 100 beats per min (150-300 BPM)
