AMCA ETC key terms

A graphic recording of the heart's electrical activity obtained by placing electrodes on the skin and displaying the voltage differences over time on paper or a monitor screen.

The machine or device that detects, amplifies, and records the electrical signals of the heart to produce an electrocardiogram tracing.

A conductive pad or sensor attached to the skin that picks up the heart's electrical signal and transmits it to the electrocardiograph for recording.

A specific view of the heart's electrical activity created by a particular combination of electrodes; each lead shows the heart from a different angle.

The six frontal-plane leads (I, II, III, aVR, aVL, aVF) formed by electrodes placed on the arms and legs, showing electrical activity from the sides and inferior wall.

The six chest leads (V1 through V6) placed across the front of the thorax that record electrical activity in the horizontal plane, primarily of the ventricles.

Any unwanted electrical or mechanical interference on an ECG tracing that is not produced by the heart, such as muscle tremor, movement, or electrical noise.

A slow, rhythmic up-and-down drift of the entire ECG tracing, usually caused by patient breathing, movement, or poor electrode contact with the skin.

Jagged, irregular high-frequency spikes on the ECG caused by muscle movement or shivering, which can mimic or obscure the true cardiac rhythm.

The normal heart rhythm originating from the sinoatrial node, characterized by regular P waves before every QRS complex at a rate of 60 to 100 beats per minute.

The heart's natural pacemaker located in the upper right atrium, which generates electrical impulses that normally initiate each heartbeat.

A structure at the junction of the atria and ventricles that delays electrical impulses briefly before passing them to the ventricles, allowing the atria to empty.

The first small upward deflection on an ECG, representing electrical activation (depolarization) of the atria.

The large spike on an ECG representing depolarization of the ventricles, which triggers the main pumping contraction of the heart.

The rounded deflection following the QRS complex that represents repolarization (electrical recovery) of the ventricles.

The time from the start of the P wave to the start of the QRS complex, normally 0.12 to 0.20 seconds, reflecting conduction through the atria and AV node.

The time from the start of the QRS complex to the end of the T wave, representing total ventricular depolarization and repolarization; it varies with heart rate.

The electrical activation of cardiac muscle cells as they change from a resting to an excited state, which precedes contraction of the heart chamber.

The process by which cardiac muscle cells return to their resting electrical state after depolarization, preparing them for the next contraction.

One complete sequence of heart contraction and relaxation, including atrial and ventricular filling and emptying, which corresponds to one heartbeat.

The phase of the cardiac cycle when the heart muscle contracts and pumps blood out of the chambers into the circulation.

The phase of the cardiac cycle when the heart muscle relaxes and the chambers fill with blood.

The number of times the heart beats per minute, commonly estimated on an ECG by counting QRS complexes in a time interval or using the large-box method.

A heart rate that is slower than normal, generally defined as fewer than 60 beats per minute in an adult.

A heart rate that is faster than normal, generally defined as more than 100 beats per minute in an adult at rest.

Any abnormality in the rate, regularity, or origin of the heart's electrical rhythm, ranging from harmless to life-threatening.

A chaotic, disorganized electrical activity of the heart in which chambers quiver instead of contracting effectively; ventricular fibrillation is a cardiac emergency.

The absence of electrical activity in the heart, producing a flat line on the ECG; it is a cardiac arrest rhythm requiring immediate emergency response.

Delivery of a controlled electrical shock to the heart to stop a dangerous rhythm such as ventricular fibrillation and allow a normal rhythm to resume.

Emergency technique combining chest compressions and rescue breaths to maintain blood flow and oxygenation when a patient's heart has stopped.

A portable device that analyzes the heart rhythm and delivers a shock if a shockable rhythm is detected, designed for use by trained bystanders and responders.

Infection-control practices applied to all patients, including hand hygiene and use of gloves and other barriers, to prevent transmission of bloodborne and other pathogens.

Barrier items such as gloves, gowns, masks, and eye protection worn by healthcare workers to protect themselves and patients from exposure to infectious materials.

Cleaning the hands with soap and water or alcohol-based sanitizer at appropriate times to reduce the spread of infection between patients and staff.

The ethical and legal duty to protect a patient's private health information from unauthorized disclosure, including test results and personal details.

A patient's voluntary agreement to a procedure after receiving and understanding information about its purpose, risks, benefits, and alternatives.

A portable device worn by a patient for 24 to 48 hours or longer that continuously records the ECG to detect intermittent rhythm abnormalities.

A cardiac test that records the ECG while the patient exercises or receives medication to increase heart rate, evaluating how the heart responds to stress.

Continuous remote observation of a patient's ECG rhythm through a transmitter to a central station, allowing early detection of dangerous rhythm changes.