NHA EKG Technician key terms

Infection-control steps taken with every patient because any blood or body fluid may carry disease; includes hand hygiene, gloves and other barriers, clean equipment, and careful handling of sharps and spills.

Cleaning the hands with soap and water or an alcohol-based rub before and after patient contact and after removing gloves; the most effective single action for preventing infection spread in health care.

Barriers such as gloves, gown, mask, and eye protection worn to keep blood, body fluids, and droplets off the skin and mucous membranes; the items chosen depend on the task and the patient's precautions.

Extra transmission-based precautions, contact, droplet, or airborne, used for patients with known or suspected contagious illness; they may require a mask, gown, dedicated equipment, or a private room.

Confirming who the patient is using two independent facts, typically full name and date of birth, before any procedure; required before placing leads or attaching a monitor to the wrong person.

A patient's voluntary agreement to a procedure after being told what will be done, why, and what risks exist; the technician confirms consent was given and stays within their scope when answering questions.

Clean technique that reduces the number and spread of microorganisms, using disinfected equipment, clean gloves, and hand hygiene; it is not the same as surgical asepsis, which aims for sterility.

Steps that reduce the chance a patient will faint during a recording, such as having them lie down, staying at their side, and noticing pale skin, sweating, or complaints of dizziness early.

The heart's natural pacemaker, a small group of cells in the upper right atrium that fires about 60 to 100 times a minute and normally starts the impulse for each heartbeat.

A structure between the atria and ventricles that slows the electrical impulse briefly so the atria can empty before the ventricles contract, and that limits how many fast atrial impulses get through.

Specialized conducting fibers that carry the impulse quickly through the ventricular walls so the ventricles contract together, normally from the apex toward the base of the heart.

The electrical change in which a heart cell's inside becomes positive as ions cross its membrane; in the atria it produces the P wave, and in the ventricles it produces the QRS complex.

The return of a heart cell's charge to its resting state after depolarization; ventricular repolarization appears on the EKG as the T wave and falls within the QT interval.

The ability of certain heart cells, especially those in the SA node and other pacemaker sites, to create an electrical impulse on their own without a signal from nerves.

The brief time after a heart cell fires when it cannot be excited again; this protects the heart from excessively rapid re-excitation and sets a limit on how fast a rhythm can go.

The amount of blood the heart pumps each minute, equal to heart rate multiplied by stroke volume; it shows whether the heart is delivering enough blood for the body's needs.

Vessels on the heart's outer surface that supply the heart muscle with oxygen and nutrients; when narrowed or blocked they cause ischemia, which shows up as ST-segment and T-wave changes.

A conductive pad, usually adhesive and gel-backed, attached to the skin to pick up the heart's electrical signal and send it through a cable to the EKG machine.

The view of the heart's electrical activity produced by a specific pair or combination of electrodes; a 12-lead EKG records twelve of these views at the same time.

A recording made with ten electrodes that produces twelve different views of the heart, including six limb leads and six chest leads; used to look for rhythm problems, ischemia, and chamber enlargement.

Leads I, II, III, aVR, aVL, and aVF, which are derived from electrodes placed on the arms and legs and view the heart in the frontal plane.

The six chest leads, V1 through V6, placed across the front of the chest; they view the heart in the horizontal plane and help detect changes in specific regions of the ventricles.

Cleaning the electrode sites, clipping excess hair if needed, and lightly rubbing the skin to remove oils and dead cells so the pads stick well and artifact from poor contact is reduced.

Any signal on the tracing that does not come from the heart, such as movement, loose electrodes, or electrical interference; it can mimic or hide a real rhythm and should be corrected before interpreting.

Jagged, irregular artifact caused by the patient's muscles trembling, shivering, or moving; it blurs the baseline and can imitate atrial fibrillation or fine ventricular activity.

A slow, drifting up-and-down movement of the tracing caused by poor electrode contact, sweating, breathing, or patient motion; it makes measuring amplitudes and ST segments unreliable.

The rectangular calibration mark placed at the start of a tracing; at standard settings it is 10 mm tall and shows that the machine is recording voltage and paper speed correctly.

How fast the recording paper moves, usually 25 mm per second; at that speed one small box equals 0.04 second and one large box equals 0.20 second, which is used for measuring intervals.

The first small upward deflection of a normal complex, representing atrial depolarization; its presence, shape, and relation to the QRS help identify sinus rhythms and atrial enlargement.

The time from the start of the P wave to the start of the QRS complex, normally 0.12 to 0.20 second; a longer interval suggests a conduction delay between the atria and ventricles.

The deflection representing ventricular depolarization, normally narrow and under 0.12 second; a wide QRS suggests the impulse is traveling through the ventricles abnormally or from a ventricular source.

The flat section between the end of the QRS complex and the start of the T wave; elevation or depression here can signal myocardial injury or ischemia and is a key finding to report.

The time from the start of the QRS complex to the end of the T wave, covering ventricular depolarization and repolarization; it varies with heart rate, and a prolonged QT raises the risk of dangerous rhythms.

A normal rhythm that starts in the SA node, with a P wave before every QRS, a steady rate between 60 and 100, and consistent intervals; it is the reference pattern other rhythms are compared to.

A sinus rhythm with a rate slower than 60 beats per minute; it may be normal in athletes or during sleep, but can also cause dizziness or low blood pressure and should be reported.

A sinus rhythm faster than 100 beats per minute, often caused by exercise, fever, pain, anxiety, or blood loss; P waves are present but may be hidden in the preceding T wave at very fast rates.

An irregular rhythm with no clear P waves, a wavy baseline, and an irregularly irregular ventricular rate; the atria quiver instead of contracting, so clots can form and the pulse must be checked carefully.

An early beat that starts in the ventricles, producing a wide, odd-looking QRS with no preceding P wave and usually a pause afterward; frequent or grouped PVCs are reported to the provider.

A flat line with no electrical activity, meaning the heart is not generating any impulse; it is a cardiac arrest rhythm, so check leads and the patient, then call for emergency help immediately.