EKG

what does ekg stand for

electrocardiogram

what is the primary function of an EKG

to record and analyze the electrical activity in the heart

what are some indicators a EKG might be necessary

fast heart rate, heart palpitations, heart attack, chest pain

what is the significance of the p wave

shows the start of the cycle

what does the qrs complex represent in an EKG tracing

represents ventricular depolarization; triggers ventricle contraction

name the main components of the cardiac conduction system

sa node, av node, bundle of his, bundle branches, purkinje fibers

sa node

generates electrical signals, top part of atria, where it starts

av node

slows down electrical signals to allow the atria to contract before the ventricles

bundle of his

carries electrical signal from av node to interventricular septum, top of septum, branch off

bundle branches

2, left and right, bottom(apex) of heart

purkinje fibers

spread electrical signals through ventricular walls causing ventricles to contract, fish hook, loop around sides of heart

what is this

normal sinus(60-100bpm)

what is this

sinus bradycardia(slow, less than 60bpm)

what is this

sinus tachycardia(fast, more than 100bpm)

what is this

asystole(no electrical activity)

an EKG is an(description not what stands for)

electrical visual of the heart

at rest, the cells of the heart are

negatively charged

when the heart depolarizes, it becomes

positively charged

The size of the deflection (or curve) on the ECG reading corresponds to the size or magnitude of the dipole

in the direction (parallel to) of the dipole

In a standard ECG there are ____ electrodes

10

How many limb electrodes are in a standard ECG?

4

Do all leads produce the same ECG tracing/image?

yes