EKG Ch 8

A collection of vocabulary flashcards focusing on key terms and concepts related to the Cardiac Conduction System and EKG tracings.

Cardiac output

The amount of blood the heart pumps each minute, determined by stroke volume and heart rate.

Mechanical function

Relates to the heart muscle, valves, blood supply, and vessels; crucial for effective pumping.

Electrical function

Involves the special cardiac tissue controlling mechanical actions via electrical impulses.

Stroke volume

The amount of blood pumped by the heart with each contraction.

Heart rate

The number of times the heart beats per minute.

Myocardial infarction

Medical term for a heart attack; occurs when blood flow decreases or stops to a part of the heart.

SA node

Sinoatrial node; the primary pacemaker of the heart located in the upper right atrium.

AV node

Atrioventricular node; slows electrical impulses before they reach the ventricles.

Bundle of His

The pathway for electrical impulses from the AV node to the ventricles.

Purkinje fibers

Fibers that relay electrical impulses to the ventricular myocardium, causing contraction.

Normal sinus rhythm (NSR)

A normal heartbeat pattern characterized by regular pacing from the SA node.

Depolarization

The process during which cardiac cells become more positively charged and contract.

Repolarization

The process during which cardiac cells return to a resting negative charge and relax.

Isoelectric line

The baseline of an EKG tracing; a flat portion between waves.

QRS complex

Represents ventricular depolarization; made up of Q, R, and S waves.

P wave

The first positive deflection on an EKG; represents atrial depolarization.

T wave

Represents ventricular repolarization on an EKG.

PR interval

The time from the start of the P wave to the start of the QRS complex.

QRS interval

Duration measured from when the Q or R wave leaves the baseline to when the S wave returns.

R-R interval

The time between two consecutive R waves on an EKG, used to determine heart rate.

ST segment

The interval from the end of the QRS complex to the beginning of the T wave.

U wave

Also known as the U wave; a small, rounded wave that follows the T wave, not always present.

Intrinsic rate

The natural pacing speed of specific parts of the heart's conduction system.

Electrical impulses

Signals that initiate and coordinate heart contractions.

Heart valves

Structures that regulate blood flow through the heart chambers.

Atria

The two upper chambers of the heart that receive blood.

Ventricles

The two lower chambers of the heart responsible for pumping blood to the body.

Electrocardiogram (EKG)

A test that records the electrical activity of the heart.

EKG technician

A healthcare professional who conducts EKG tests and generates tracings.

Heart rhythm

The pattern of electrical impulses causing heartbeats.

Heart rate determination methods

Methods used to calculate heart rate from EKG tracings.

Large block method

A technique to determine heart rate by counting large blocks between R waves.

Small block method

A technique to determine heart rate by counting small blocks between R waves.

6-second method

A technique to determine heart rate by counting QRS complexes in a 6-second window.

Arrhythmia

An abnormal heart rhythm that may indicate a problem with the heart's electrical system.

Atrial rate vs. Ventricular rate

Atrial rate measures P waves, while ventricular rate measures R waves.

Regularity of rhythm

Determining whether the heart rhythm is consistent or shows irregularities.

Calipers

A tool used to measure intervals and segments on an EKG tracing accurately.

P wave abnormalities

Changes in the P wave that can indicate heart issues, such as abnormal shape or absence.

QT interval

The time from the start of the Q wave to the end of the T wave; important in assessing cardiac health.