NHA EKG Technician flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Soap and water hand hygiene

Indicated when hands are visibly soiled and after contact with spore-forming organisms such as Clostridioides difficile, because alcohol-based rubs do not reliably kill spores.

Alcohol-based hand rub

Preferred for routine hand decontamination when hands are not visibly soiled; apply enough product to keep hands wet for at least 20 seconds, then rub until dry.

Two patient identifiers

Verify identity with two independent identifiers, such as full name plus date of birth or medical record number, before acquiring any EKG tracing.

Electrode site preparation

Clean skin with alcohol and let it dry, then abrade lightly if needed; removing oils and dead cells lowers impedance and reduces tracing artifact.

Clipping chest hair

Clip excessive chest hair with scissors or clippers instead of shaving, because shaving creates micro-abrasions that raise infection risk and impair electrode contact.

Equipment grounding

Use three-prong grounded plugs and avoid daisy-chained extension cords; proper grounding prevents macroshock and microshock hazards during EKG recording.

Somatic tremor artifact

High-frequency spiky baseline interference caused by shivering or voluntary muscle movement; warming the patient and supporting the limbs reduces it.

Standard precautions

Applied to every patient regardless of diagnosis; blood and all body fluids are treated as potentially infectious and gloves are worn when contact is likely.

Sinoatrial node firing rate

The primary pacemaker sits at the junction of the superior vena cava and right atrium and fires at an intrinsic rate of 60 to 100 beats per minute.

AV node escape rate

The secondary pacemaker has an intrinsic rate of 40 to 60 beats per minute and delays impulses about 0.1 second before ventricular activation.

Normal PR interval

Measured from the start of the P wave to the start of the QRS; normally 0.12 to 0.20 seconds, or three to five small boxes at 25 mm/s.

Normal QRS duration

Less than 0.12 seconds, or three small boxes; it represents ventricular depolarization and lengthens with bundle branch block or ventricular rhythms.

Bazett QT correction

QTc equals the measured QT interval divided by the square root of the RR interval in seconds, correcting the QT interval for heart rate.

P wave depolarization

Represents atrial depolarization initiated at the SA node; normally upright in lead II and inverted in lead aVR.

Normal electrical axis

Between -30 and +90 degrees; values outside this range indicate left or right axis deviation from conduction disease or chamber enlargement.

Coronary territory lead mapping

Right coronary ischemia appears in leads II, III and aVF; left anterior descending in V1-V4; circumflex in I, aVL, V5 and V6.

V1 electrode placement

Fourth intercostal space at the right sternal border; V2 is placed at the same level on the left sternal border.

V4 electrode placement

Fifth intercostal space at the midclavicular line; V3 is placed halfway between V2 and V4.

Limb lead color codes

In the United States: right arm white, left arm black, left leg red, right leg green; the right leg electrode acts as the ground.

Standard paper speed

At 25 mm/s one small box equals 0.04 second and one large box equals 0.20 second; 30 large boxes equal 6 seconds.

Standard calibration 10 mm/mV

A 1-millivolt signal produces 10 millimeters of deflection, or two large boxes; any change in gain must be noted on the tracing.

Arm lead reversal sign

Right arm and left arm reversal produces a negative P wave and negative QRS in lead I, with an upright P wave in aVR.

60-cycle interference

Thick fuzzy baseline caused by nearby electrical equipment; improving electrode contact, cable routing and grounding reduces this artifact.

Six-second strip method

Count the QRS complexes in a 6-second strip, then multiply by 10 to estimate the ventricular rate per minute.

Sinus rhythm criteria

Regular rhythm at 60 to 100 beats per minute, upright P wave in lead II before every QRS, and a PR interval of 0.12 to 0.20 seconds.

Atrial fibrillation hallmark

Irregularly irregular ventricular rhythm with no identifiable P waves; the baseline shows chaotic fibrillatory activity instead of discrete atrial deflections.

Atrial flutter waves

Sawtooth flutter waves with an atrial rate near 250 to 350 per minute; 2:1 AV conduction yields a ventricular rate near 150.

Premature ventricular complex

Wide bizarre QRS complex longer than 0.12 seconds with no preceding P wave, usually followed by a full compensatory pause.

Ventricular fibrillation

Chaotic undulating waveform with no discernible QRS complexes; the patient is pulseless and needs immediate CPR and defibrillation.

First-degree AV block

PR interval longer than 0.20 seconds that remains constant, with every P wave followed by a QRS complex.

Wenckebach block pattern

Second-degree type I AV block in which the PR interval progressively lengthens until one QRS complex is dropped, then the cycle resets.

STEMI elevation thresholds

New ST elevation of at least 1 mm in two contiguous limb leads, or at least 2 mm in V2-V3 in men and 1.5 mm in women.