EKG and Irregular Atrial Rhythms Flashcards
What does the EKG measure?
The electrical activity of a heart beat
- each beat sends an electrical wave through the heart tissue
What does an EKG determine?
heart rate and rhythm
needs interpretation
Phase 0 of EKG
Depolarization and rapid entry of Na+
Phase 1 of electrophysiological principles
Early depolarization
K+ slowly enters
Phase 2 of electrophysiological principles
Plateu continues
slower entry of Ca++
Phase 3 of electrophysiological principles
K+ moves out of the cell
Phase 4 of electrophysiological principles
Resting phase
What ability is indicated with automaticity?
Pacemaker ability
What does rhythmicity indicate?
systematic pattern
What does conductivity indicate?
spreads impulses
What does contractility indicate?
the contraction ability
What are the 4 electrophysiological principles?
Automaticity
Rhythmicity
Conductivity
Contractility
What is activated with the SA node?
the atria
What is the intrinsic rate of the SA node?
60-100 bpm
What is activated with the AV node?
ventricles
What is the intrinsic rate of the AV node?
40-60 bpm
What is the intrinsic rate of the bundle of HIS and purkinje fibers?
30-40 bpm
What happens during the P wave?
atrial depolarization
- impulses spread to the left atrium via the bachmann bundle
What happens during the P-R interval?
depolarization reaches the AV node causing that slight delay
What happens during the QRS complex?
Ventricular depolarization
- the electric impulse reaches the purkinje fibers
How many seconds in an EKG strip?
6 second intervals
How many seconds are in a small square?
0.04 seconds
How many seconds in a large square?
0.20
How many leads are there?
6
Where is V1 and V2 placed?
Near the sternal border
Where is V3 placed?
Midway between V2 and V4
Where is V4 placed?
5th intercostal space @ L midclavicular line
Where is V5 placed?
Left anterior axillary line at V4 level
Where is V6 placed?
Left mid axillary line at V4/V5 level
How do you count the HR on an EKG?
count the QRS in a 6-second intervals then x10 which gives the HR for 1 minute
When does the PR interval start and end?
start of P wave to start of R wave
What does the P-R interval measure?
the time beween the start of atrial depolarization and ventricular depolarization
What is normal PR interval?
3-5 small squares
or
0.12-0.20 seconds
When does the QRS start and end?
starts of Q wave to end of S wave
Describe the QRS complex in an EKG strip
Q - first downward deflection
R - first upward deflection
S - second downward deflection
The QRS complex measures what?
the depolarization of ventricles
What is normal QRS complex interval?
0.06-0.10 seconds (1 1/2 - 3 small boxes)
What is an abnormal QRS complex interval?
> 0.12 seconds
What is the systematic approach of an EKG?
- P wave
- PR interval
- QRS complex
- QRS interval
- T wave
- Look at the R to R wave
- How is the HR
- Observe the pt and sx
What are the causes for PAC?
- when isolated = benign finding (non-lethal)
- associated with underlying cardiac conditions (early sign of CVD)
- HTN, caffeine
- Pregnant
- COPD, asthma
- Metabolic - hyperthyroid disease
- stress or extreme fatigue
- medications for asthma or hayfever
What are the symptoms of PAC?
Skipped beat
fatigue or SOB
Exercise intolerance
Chest pain (advanced PAC)
How do you decrease PAC symptoms?
reduce intensity
monitor vitals
report to a team
What is atrial tachycardia (supraventricular)?
Atrial depolarization is happening so fast
P wave isnt seen and hidden in the QRS/ventricular activity
What are the causes of atrial tachycardia?
- stretching of the atria via HTN and cardiomyopathy
- MI hx
- excessive alchohol or stimulants
- irritable focus
Sometimes idiopathic
What is irritable focus?
cell outside the sinus node starts generating an electical impulse automatically on their own
What are the sx of atrial tachycardia?
palpitations
fainting
chest pain
SOB
fatigue
exercise intolerance
How do you reduce atrial tachycardia?
Reduce intensity
monitor vitals
alert the team
What is the characteristic of atrial fibrillation?
A very common arrhythmias
- Has no waves before QRS and very irregular HR
- jagged baseline
What is the characteristics of atrial flutter?
“saw-tooth” appearance that represents multiple P waves for each QRS complex
What causes a-fib and a-flutter?
- interferance of electrical conductivity
- age
- heart diseases
- alchohol
- endocrine disorders
- neurologic disorders
- hemodynamic stress
- sleep apnea
- inflammation
What are the sx of a-fib and flutter?
- tachycardia
- SOB
- dizziness
- syncope
- fatigue
- exercise intolerance
- chest pain
- anxiety
- night sweats or waking up with palpitations
How do you decrease sx of a-fib and flutter?
- stopping activity then calling the team to monitor patient
- Use RPE for beta blockers
- Deep breathing to slow down HR
What happens with the electrical impulses of atrial impulses?
The impulses don’t travel in a straight line
- move in a circle inside the atria = regular tachycardia
How is the speed of an electrical signals in a-fib?
travel through the atria - fast and disorderly = heart quivers instead of squeezing strongly
= tachycardia in an irregular rhythm and reduced atrial kick
Why is a-fib more dangerous?
Irregular atrial contractions in fib = increasing the risk of clot formation
higher risk of CVA
