Dysrhythmias 1, 2, and 3 Flashcards
(129 cards)
How to differ a sinus arrhythmia from AFIB
Breathing in will increase the HR
Breathing out will decrease the HR
What is considered sinus bradycardia?
<60 BPM
really only worried if it is <45 BPM though
What can lead to sinus bradycardia?
Normal in healthy individuals
Should go up if they exert themselves
What if sinus bradycardia does not increase with exertion?
Sick sinus bradycardia
What drug can cause bradycardia?
Clonidine - lowers BP but decreases HR
lithium
methyldopa
Why can a stroke lead to bradycardia?
To compensate for increased ICP, the heart will pump softer
Scan the HEAD!
Why can an inferior wall MI cause bradycardia?
Problems of right coronary artery, which supplies the SA node, leads to a decreased HR
What is the treatment for obstructive sleep apnea bradycardia?
Treat the OSA!
CPAP
Don’t treat the bradycardia - it is just a result of the underlying cause, which is the OSA
How to diagnose sinus bradycardia sick sinus syndrome?
Put on treadmill and DO NOT see something close to predicted value (220 - age)
How to treat sick sinus syndrome?
Remove medications to see if this is the underlying cause of their bradycardia (do not remove amiodarone though). Otherwise:
Pacemaker - there HR will fluctuate like crazy, so you can more easily decrease an elevated HR
When do you treat sinus bradycardia?
If they are symptomatic
What shortens in sinus tach?
The T wave to the next Q wave
What underlying things can lead to sinus tachy?
hyperthyroidism, fever, sepsis, pain, anemia, volume depletion, pheochromocytoma, hypoxia, PE, heart failure, acute coronary ischemia, alcohol/alcohol withdrawal, stimulants
How do you treat sinus tachy?
RARELY
If they are in sinus tach, they are there for a reason
What can you do to try to slow down sinus tach?
Vagal maneuvers
even deep breathing
If no fluctuation, it is not sinus!!!
When is sinus tach a concern?
If there is an underlying heart problem
Where do we make up time for sinus tach?
Diastolic shortens, so we get less filling.
We still have the same systolic pump, but filling/relaxation may be compromised
When is sinus tach concerning?
If it is symptomatic and they have an underlying heart problem
What leads to inappropriate sinus tach?
Occurs in absence of heart disease or secondary causes
_ resting HR and/or exaggerated HR response to exercise
Exact cause unknown; possible exaggerated autonomic control
Difference between inappropriate sinus tachy and POTS
POTS is based on change in position while inappropriate sinus tach is based on things that would normally lead to increased HR, but it is an exaggerated response (may increase 2x compared to a normal, healthy patient).
Three different heart blocks
1st degree = PR interval greater than 0.2 seconds
2nd degree = sometimes it goes through
3rd degree = complete heart block; complete A-V dissociation, in which no supraventricular impulses are conducted to the ventricles
What causes first-degree heart block and Mobitz type 1?
May occur in normal individuals with heightened vagal tone
Drug effect - especially digitalis, calcium channel blockers, beta-blockers, or other sympatholytic agents
Electrolyte abnormalities
Organic disease - ischemia, infarction, inflammatory processes (including Lyme disease), fibrosis, calcification, or infiltration
May be transient or chronic
What can lead to a mobitz type II and third degree heartblock?
Almost always due to organic disease involving the infranodal conduction system
May be transient or permanent
What can be a normal heart block? What is not normal?
The first two heart blocks can be normal:
1st degree heart block and Mobitz type 1
The last 2 are almost ALWAYS pathologic:
Mobitz type 2 and type 3 heart block