EKG Terminology Flashcards
Depolarization
When heart muscle contract
-on EKG tracing
—P wave represents: atrial depolarization
—QRS waves represent: ventricular depolarization
Repolarization
When heart muscle relaxes
-on EKG tracing
—atria relaxing, ventricles contracting
—occurs on QRS wave
Stylus
Heated instrument on EKG machine burns recording on to heat-sensitive paper
- if too thick or dark: heat can be reduced
- if too light: heat can be increased
Electrodes
Device attached to arm, legs and chest sense electrical impulses
- electrolyte conduction material impregnated in pads
- have a connection: metal plate or suction bulb. Electrolyte gel added as conductor
Leads
Wires transmit signal for EKG recording from various electrode location
Standard
Mark appears beginning or end of EKG tracing, universal signal of speed, sensitivity of tracing
-standard: 10 mm high, 5 mm wide
Unipolar
Electrical conduction comes from one specific location
Bipolar
Electrical conduction occur between two poles
-first three leads (I, II, III)
Augmented
Enhanced to produce clear tracing.
-used in arm and leg leads with aVR (augmented vector right), aVL (augmented vector left), aVF (augmented vector foot)
Artifacts
Unwanted disturbance interfere with accurate interpretation of EKG tracing
- machine malfunction
- body movement
- electrical interference
- poor contact of electrodes
Somatic tremor
Body movement
- shivering
- coughing
- talking
- movement
- uncontrolled movement due to disease
Alternating current interference
- Cause by improper grounding
- machine not equipped to filter out extraneous electrical currents
- thick appearance with relatively even sharp spikes
Wandering line
- Poor lead contact with skin
- baseline wander up and down
- possible source: lotions, powder, oil, ointments, nylon stockings
