EKG Flashcards
each small square on an EKG is?
1mm on each side
each 5th square on a EGK is…
is a larger darker sq. measuring 5mm
at normal speed one small square passes the stylus every
0.04 seconds
How many seconds is one large square on an EKG?
0.2 seconds
1 second on an EKG equals to?
5 large square passing the stylus (25 mm/ second)
standard speed on an EKG is…
25 mm/ second
standard speed may …
altered per providers request
-slow/fast heartbeat
spread the wave form out over a farther distance
allow interpretation of the tracing
otherwise use standard speed
What is standard amplitude (gain) on an EKG
measure voltage
one millivolt (mv) of electrical activity move the stylus upward 10 mm
2 large squares
EKG machine can…
vary in size & shape but have the same parts
12 leads on EKG’S can record
3,4,6 leads @ a time on one sheet of paper
What channel EKG do you use with Ambulatory care?
uses 3 channel EKG which records 3 leads @ once
What type of EKG machine do hospitals usually use?
use telemetry
single channel EKG records one lead @ a time & produces a running strip
EKG Electrodes
placed on 10 areas of the body
records heart activity from 12 different angles & planes
contains electrolyte gel that serves as conductor
Electrolyte gel
serves as conductor
apply first
expired gel & electrodes can produce artifacts
EKG Machine Calibration
you can adjust sensitivity
1 STD= deflection of the stylus 10 mm (2 Lg Sq)
1/2 STD = deflection of the styylus of 5 mm (1 Lg Sq)
2 STD= deflection of the stylus of 20 mm (4Lg Sq)
Example of EKG Machine Calibration
QRS is so tall the stylus is moving off the paper, change STD to 1/2
if too short change to 2 STD
heart layers
Pericardium
epicardium
myocardium
endocardium
pericardium
double sac encloses the heart and consists of a visceral pericardium and a parietal pericardium
epicardium
outermost layer of heart
inner most layer of pericardium
strong fibrous layers
connects diaphragm & mediastinum protection, stability, & lubrication between heart & organs in chest
myocardium
middle layer
involuntary straited muscle
physical contraction of heart
endocardium
inner most layer
lines chambers of heart & forms surface valves
smooth structure
protects inner surface
falicilites flow of blood through the heart
heart valves
control direction of blood flow through the heart
flaps make up a valve
extremely strong but also floppy require support to ensure tight close of flaps
chordae
special filaments connect the tricuspicl & mitral valves to the papillary muscle along the inside wall of the ventricles`
What are the valves in the heart?
tricuspid
mitral or bicuspid
pulmonary
aortic
tricuspid valve
seperates right artium and right ventricle
mitral valve
seperates left artium from the left ventricle
pulmonary valve
lies between right ventricle and pulmonary artery
aortic valve
lies between the left ventricle and the aorta
atrioventricular vavlves
tricuspid & mitral valves
lies between atrium and ventricles
semilunar valves
synchronized closure prevents blood from flowing backwards
semilunar valves
aortic & pulmonary
synchronized closure prevent backward blood flow
coronary circulation
most important circulation
supplies oxygenated blood to the myocardium (muscle of the heart)
happens during diastole
right & left coronary arteries do what ?
supply the heart blood ( nutrients & oxygen)
diastole
period of relaxation of the heart
systole
period of contraction of the heart
coronary vessels
right & left coronary arteries originate in the root of the aorta
what happens during ventricular systole
semilunar flaps of the aortic valve occlude ( closses off ) THE ARIFICES ( OPENINGS)
pressure inside the ventricles
high causing high pressure on the epicardium
compressing the coronary vessels
coronary vessels on the epicardium during systole become?
during systole
tortuous (bending)
b/c it is contracting
attempting to perfuse is going to be hard
right coronary artery
main artery
(RCA) carries oxygenated blood to right atrium, right ventricle, part of the left atrium & interior wall of left ventricle
perfuses sinoatrial node (SA node)
left main coronary artery
(LMAC) 2nd main artery
carries blood to myocardium
snort & branches into the left cirumflex (LEX) & left anterior decending artery (LAD)
left circumflex artery
carries oxygenated blood to postlateral back side as part of the left ventricle
left anterior decending artery
(LAD) supplies anterior wall of the left ventricle
occlusion of LAD can lead to ventricular dysrhythmia & death
ventricular dysrthyhmia
out of normal sinus rythm
sinoatrial artery
perfuses SA node
branches from RCA (right coronary artery)
occulsion can manifest as sinus bradycardia ( low heart rate) on EKG
atrioventricular node artery
2nd path way
AV node artery perfuses the AV node
arises from RCA in vast majority of people
occulsion = high degree blook on EKG
collateral circulation
alternate or “back up” blood vessels that take over when another artery or vein becomes blocked or damaged
large coronary artires are not interconnected small arteries grow & connect when blood flow decreases
coliateral vessels help give back for decreased o2 supply
AV node
holds electrical signal from SA node for short period to allow ventricles to fill completely with blood following atrial depolarization
PR interval
P wave ends & Q wave begins
0.12- 0.02 seconds
SA node
cluster of cells in right atrial wall
natural pacemaker of heart
deploarization in R utium 1st left
P wave on EKG = atrial deploarzation
P wave on EKG
atrial depolarization
internal pathways
electrical impluses travel from SA Av via intervocal pathways
connect SA/VA node
3 internodal pathways
anterior
medial
posterior
internal pathways
transmit impulses
from SA node to L atrium is?
bachmann’s bundle
complete heart block of AV node means?
AV node is unable to conduct and electrical impulses from SA node
bundle of his
next to AV node
transmits from atria to ventricles
divides into bundle branches on either side of septum between the ventricles
right bundle branch
RBB
carries impulses from bundle of his to purkinje fibers
causes R ventricular deplorazation
RBB recives blood supply from LAD
what is the difference between the right/left bundle branches?
the workload
right ventricle pumps blood = lungs
left ventricle pumps blood= entire body
b/c it has a greater muscular thickness
left bundle branch
LBB
located in intraventricular septum
carries electrical impluses from bundle of his to purkinje fibers of the L ventricle
short divides L anterior & L posterior fascicle
purkinje fibers
network of wide diameter & junctional conduction pathways
depolarizes ventricles
initates myocardial contraction
without the SA/AV nodes stimulation the purkinje fibers fire @ how many BPM?
20-40 BPM
polarization
resting state of the myocarcial wall
no electric activity occurs
flat line on EKG rythm strip
depolarization
electrical system in the heart stimulates myocardial cells
repolrization
reaching a resting state
QRS
grouped together in the QRS complex
Big Wave
P wave
contraction of atria
beginning of cardiac deploriarzation
begins when SA node fires
occurs before QRS complex
positive deflection
one cycle
PQRST complex
PR segment/ interval
return to baseline after atrial contraction
PR internal= time from beginning of atrial contraction depolarization to beginning of ventricular contraction depolrization
P=P internal
time between the P waves
time between atrial depolrization cycles
analyzing rate and rythm
R-R intervals
time between R waves
time between ventricular depolrization cycles
analyzing rate & rhythm
T wave
ventricular repolrization
follows QRS complex
peak towards the end of the wave instead of middle
U wave
not always visible
repolrization of bundle of his and purkinje fibers
small upward curve following T wave
can be cause of electrolyte imbalances
QT interval
time between the beginning of QRS complex through the T wave
ventricles contract and relax
one complete ventricular cycle
What kind of terminology should you use with pediatric patients
Age appropriate
- electrodes are “stickers”
- EKG is a “picture” of the energy or movement of the heart
Are there pediatric electrodes
Yes
Where do you put V6 on a pediatric patient when space is limited
Midaxillary line
Where do you place V3 on a pediatric patient when space is limited
The right side in the same position
- document this as V3R
Where should electrodes go on a patient with extremity amputations
Arm- upper chest
Leg- lower abdomen
Should you be careful when placing electrodes on a patient that has had a mastectomy?
Yes, skin is fragile
Where do you place V1 and V2 on a patient with breast implants
Place higher above implant
If a patient has larger breast where should place the electrodes
Lift the breast up and place under
Where should you never place the electrode on a patient that is pregnant
Never on the abdomen
If your patient is in the later stages of pregnancy, how should you position them for a EKG
Place them slightly turned to left and put a small pillow/rolled towel under their right hip
- helps keep the weight of the uterus off the inferior vena cava
Holter monitor
Portable cardiac monitor that the patient wheres for generally 24 hours, to diagnose problems
- patient carry’s a diary
- avoids high voltage magnets and metal detectors
Telemetry
Constantly monitors the electrical activity of the heart
- 3 or 5 lead
3 lead electrode placement
White - right shoulder
Black- left shoulder
Red - left right abdomen
5 lead electrode placement
White- right shoulder
Black - left shoulder
Red- left Lower abdomen
Green- lower right abdomen
Brown- just to the right of the bottom of the sternum (similar info of the V1 in 12 lead tracing)
