EKG review 1

EKG

electrocardiogram:process of recording the electric activity of the heart

Cardiac cycle:

sequence of electrical and mechanical events during 1 complete heartbeat

polarization:

heart is in a state of rest-electrical charges are balanced

depolarization:

discharge of energy that accompanies the transfer of electrical charges across the cell membrane causing heart muscle to contract ( systole)

repolarization:

return of electrical charges to their original state of rediness-the chambers refill with blood and relaxing ( dystolic)

cardiac output:

volume of blood pumped by one ventricle in one minute

septum:

divides heart into R & L sides

endocardium:

inner smooth layer of the heart

myocardium:

middle muscular layer of the heart

epicardium:

the outer fibrous layer of the heart

Pericardium:

protective membranous sac that surrounds the heart

pericardial fluid:

fluid within the pericardial cavity

tricuspid valve:

separates the R atrium and the R ventricle -prevents backflow

Bicuspid/mitral valve:

separates the L atrium and the L ventricle-prevents backflow

Pulmonary semi-lunar valve:

separates the R ventricle from the pulmonary artery

Aortic semi-lunar valve:

separates the L ventricle from the aorta

coronary arteries:

supply the myocardium with oxygen

coronary sinus:

brings blood back to the right atrium

Aorta:

The aorta is the largest artery in the body.The aorta distributes oxygenated blood to all parts of the body

Vanae Cavae:

largest vein in the body; deoxygenated blood enters the heart through the superior venae canve to the right atrium.

SA Node:

pacemaker (sino-atrial node)

AV Node:

gatekeeper (atrio-ventricular node)

Inherent rate for SA Node:

60-100 BPM

Inherent rate for AV node:

40-60 BPM

Inherent rate for Ventricular cells:

20-40 BPM

Automaticity:

ability of certain myocardial cells to initiate and maintain rhythmic heart activity w/o neurological supply

Excitability:

myocardial cells to respond to an impulse

Conductivity:

myocardial cells to relay an impulse

Contractility:

ability to respond to electrical impulse with pumping action

Wandering baseline:

uneven baseline due to loose electrode

interrupted baseline:

breaks between the complexes due to a lead falling off

AC Interference/ 60 cycle interference:

small fuzzy waves usual due to metal; frayed wires or something else plugged in outlet

somatic tremor:

jagged peaks, unnatural baseline deflections usually due to voluntary or involuntary muscle movement; pt talks , nervous, shivering, coughs

refractory period relative:

cells can be stimulated but you will not get desired effect

refractory period absolute:

cells can not be stimulated

stylus:

writing arm of ekg machine

galvanometer:

changes electrical current to mechanical motion

standard paper speed:

25mm/sec

To slow down complexes:

50mm/sec

Horizontal lines represent:

time

Vertical lines represent :

voltage

Time in one small square:

.04 sec

Time in one big square:

.20 sec

Voltage in one small square:

.1mV

Voltage in one large square:

.5mV

Normal standardization:

10 mm high by 2 mm wide

To decrease the size of the complexes, change sensitivity to:

1/2 or 5mm high

3 methods of calculating heart rate:

count r waves in 6 sec strip and multiply by 10; count the large boxes between r waves and divide into 300 or count little boxes between r waves and divide into 1500

Systole:

phase of contraction

Diastole:

phase of relaxation

parasympathetic nerves:

slows heart rate down

What color is RA lead:

white

What color is LA lead:

Black

What color is RL lead and what is it used for:

green and for grounding

What color is LL lead:

red

What color is V1:

Red

What color is V2:

yellow

What color is V3:

green

What color is V4:

blue

What color is V5:

orange

What color is V6:

purple

What are the standard limb leads:

Lead I, Lead II and Lead III

The standard limb leads are also called:

bipolar leads

What are the augmented leads:

aVR, aVL and aVF

The augmented leads are also called:

unipolar leads

The chest leads are :

V1-V6

The chest leads are also called:

precordial leads

A wave is:

any deflection from the baseline

A complex is:

a group of related waves

A segment is:

distance between 2 waves

A interval is:

a wave plus a segment

P wave represents:

atrial depolarization

QRS complex represents:

ventricular depolarization

T wave represents:

ventricular repolarization

U wave represents:

rarely seen and is repolarization of the purkinje fibers

What is a holter monitor, why used, \# elctrodes and what should pt do and not do?

24 hr ekg to diagnose cardiac arrythimias and conduction abnormalities. 5 leads. Pt should not get wet, handle monitor or electrodes and no electric blankets. Pts need to keep diary entering all activities.

Lead I records electrical activity from:

RA to LA

Lead II records electrical activity from:

RA to LL

Lead III records electrical activity from:

LA to LL

AVR records electrical activity from:

a point between LA & LL to RA

AVL records electrical activity from:

a point between RA & LL to LA

AVF records electrical activity from:

a point between RA & LA to LL

V1 records electrical activity from:

central point to 4th ICS at R sternum

V2 records electrical activity from:

central point to 4 ICS at L sternum

V3 records electrical activity from:

central point to point between V2 & V4

V4 records electrical activity from:

central point and 5 ICS at mid clavicular

V5 records electrical activity from:

central point to 5 ICS at anterior axillary

V6 records electrical activity from:

central point to 5 ICS at mid axillary

Basically irregular:

regular underlying rhythm with beat or two that interrupts

Regularly irregular:

definite pattern to irregularity

Totally irregular:

no pattern to irregularity

How do you place a pt for EKG:

supine position

If they have a head injury how do you place them for EKG:

head raised at 30 degree angle

If the pt has difficulty breathing how do you place for EKG:

head raised at 45 degree angle

Ectopic focus:

site of electrical activity other than SA Node

Escape:

When AV node takes over pacing the heart 40-60 BPM

Irritability:

when another myocardial cell other than SA Node begins pacing the heart for no reason

Bigeminy:

every other beat

Trigeminy:

every 3rd beat

Quadgeminy:

every 4th beat