Lecture 11/1: EKG interpretations Flashcards
End test 4
What is an arrhythmia?
A problem with the conduction system or APs going through muscle of the heart
What are some causes of arrhythmias?
- Abnormal firing of pacemaker (faster or slower)
- Shift of pacemaker from sinus node
- Blocks at different points of transmission
- Abnormal pathway transmission
- Spontaneous generation of abnormal impulses
T/F: increasing Vrm closer to threshold potential, especially in pacemaker cells, increases the likelihood of firing a spontaneous AP from etopic pacemakers and cauing an arrhythmia.
T
______ K+ will decrease the concentration gradient. This will _______ the Vrm, which will increase HR.
Increasing
Increase
T/F: Things that increase Vrm prevent the heart from reseting/repolaring correctly
T
Keep looking at this card
When will the AP fire if the Vrm is raised?
Early
This will cause an arrhythmia
T/F: in a healthy heart, the ventricles generates the AP
F
SA node does
What increases the likelihood of in arrhythmia?
Increasing Vrm
What are 2 things that can cause an increase in Vrm?
- Ischemia/Infarct
- Increase K+
Sinus Tachycardia: where does it originate?
SA node
Sinus Tachycardia: what is a characterized by?
Fast HR
P waves at a rate of greater than 100 bpm
Sinus Tachycardia: Causes:
- Increased body temp
- sympathetic stimulation
- loss of vagal stimulation of PNS
- Toxic conditions in heart
How does increased body temperature cause increase HR?
Increased body temp –> increase metabolic demands –> increased HR
Why does blood loss initially increase HR?
BP will drop –> info in fed to CNS –> ANS will tell heart to beat faster.
What compensatory mechanism do some arrhythmias have? What medication can you give to combat this?
Reflex activation of the SA node resulting in reflex sinus tachycardia
Beta blocker (-olol)
Sinus Tachycardia: describe the P & QRS complexes
RR intervals
There is a P for every QRS complex
Short RR intervals
What are toxic conditions in the heart that can increase Vrm?
Nicotine
Alcohol
Increased K+
Acidosis
NAKA
(create toxic conditions at SA node)
Sinus Bradycardia: where does it originate?
SA node
Sinus Bradycardia: what is a characterized
Slow HR
P waves at a rate of less than 60 bpm
Describe why Sinus Bradycardia is normal in athletes
D/t training, physiologically, they have a larger heart. Because of this, their SV is larger as well causing them to have a larger CO. The CNS senses this and the ANS slows down the heart rate so the body can have the proper CO needed (and not more than needed)
T/F: if you are healthy and have a lower resting heart rate, this is a problem
F
This is a good thing, unless dangerously low.
If your resting heart rate is _____, this is bad.
high
What are some common problems associated with high resting heart rate?
Hyperthyroidism
Valve problem
Sinus Bradycardia: Causes:
- Vagal stimulation (PNS)
- Decreases SNS tone
- Neural reflex to drugs (Ex. Lots of phenephrine –> vasoconstriction –> ANS decreases HR to decrease CO)
Sinus Bradycardia: describe the P & QRS complexes
RR intervals
There is a P for every QRS complex
Long RR intervals
What is another name for paroxysmal atrial tachycardia?
Supraventricular Tachycardia
What is a normal RR interval?
0.83 seconds
Atrial Tachycardia (SVT): Describe
SA node firing in an irregular way
RR intervals are regular then irregular
Atrial Tachycardia (SVT): Causes
Temporary decrease in vagal tone
When it stops, rhythm should go back to normal
Atrial Tachycardia (SVT): describe the P & T waves
May overlap and cant distingish them
Atrial Tachycardia (SVT): Treatments
Vagaling down
Beta blocker
SA node block: Causes:
Severe dysfunction
Ischemia
This causes the SA node to not be able to reset any VG L-type Ca++ channels
SA node block: what happens to the P wave?
May be inverted
may not have one
SA node block: where is the new pacemaker
- AV node
- then purkinje fibers
SA node block: describe how the p wave will look and why?
- No p wave: deep within the AV node or within the purkinje fibers (takes awhile to travel backwards through AV node, QRS is happening. P wave hidden within QRS)
- inverted p wave: at the beginning/front of AV node
Describe what happens in the heart when you move the pacemaker or have ectopic pacemakers (specifically SA node blocks)
Ventricles depolarizes early causing early closure of AV valves. Atria is contracting, while AV valves are closed –> pushing blood against close valves = blood turbulence –> damage the heart valves; generates blood clots; moves blood clots that are already there; calcified heart valves
What medication should you be on if you have a fib or a flutter? Why?
Anticoagulant
Syncytiums are not having coordinated contractions causing blood turbulence against heart valves causing increase risk of blood clots and calcified valves
What is the purpose of the delay at the AV node?
Coordinated contractions between syncytiums
To filter unwanted electrical activity