Heart and EKG Overview

Flashcards covering key terms and concepts related to the heart, EKG readings, and cardiac function.

EKG/ECG

Electrocardiogram, a test that records the electrical activity of the heart.

Leads

Wires placed on the body to measure electrical activity in different positions; typically includes right arm, left arm, and left leg.

Depolarization

The process by which the heart muscles contract and pump blood.

Repolarization

The recovery phase of heart muscle cells after depolarization, preparing them for the next contraction.

SA Node

Sinoatrial node; the heart's primary pacemaker that initiates the heartbeat.

AV Node

Atrioventricular node; it transmits impulses from the atria to the ventricles.

Purkinje Fibers

Specialized fibers that propagate electrical impulses throughout the ventricles.

QRS Complex

The part of the EKG that represents the depolarization of the ventricles.

P Wave

The part of the EKG that represents the depolarization of the atria.

Ventricular Fibrillation

A life-threatening condition where the ventricles quiver instead of contracting effectively.

Cardiac Cycle

The sequence of events in one heartbeat, including electrical activity, muscle contractions, and valve movements.

Heart Sound 1

The sound produced by the closing of the AV valves after ventricular contraction.

Heart Sound 2

The sound produced by the closing of the semilunar valves after ventricular repolarization.

T Wave

The part of the EKG that represents the repolarization of the ventricles.

Bipolar Leads

Leads that measure electrical potential between two points on the body.

Threshold Potential

The critical level to which a membrane potential must be depolarized to initiate an action potential.