Dysrhythmias Flashcards
What is normal sinus rhythm
60-100
What does the vagus nerve do
slows down heart
What can the sympathetic system do to the AV node
let singles passs more often so increases HR
What can the parasympathetic do to the AV node
opposite of symp
Where does Digoxin work on
AV node
What actually matters when looking at an EKG
Heart Rate
1:1 ratio of atrial and ventricular Cx
narrow QRS (less than 0.1-0.12)
What does the time that the PR interval takes represent
how much AV resistance
What is the normal PR interval time
less than 0.12-0.2
On an EKG chart how many secs are the smallest boxs
0.04 secs
On an EKG chart how many secs are the big boxs
0.2
What is the first thing you should do if the EKG chart shows abnormal rhythms
make sure the leads are still connected
If we still have a sinus rhythm but its lower than 60 bpm what is it called
sinus bradycardia
Who gets sinus bradycardia
carotid sinus massage hypothemia increased vagal tone parasympathomimetic drugs Hypothyroidism Increased intracranial pressure Obstructive jaundice Inferior wall MI
What do we give when sinus bradycardia is pathologic
atropine bec it reduces AV node resistance
What causes sinus Tach
Exercise Pain Hypovolemia Myocardial ischemia Heart failure (HF) Fever
What symptoms make sinus brady pathologic
Hypotension Pale, cool skin Weakness Angina Dizziness or syncope Confusion or disorientation Shortness of breath
What symptoms make sinus tach pathologic
Dizziness and hypotension due to decreased CO
Increased myocardial oxygen consumption may lead to angina
How do we treat sinus tach
fix problem like pain or reduce exercise
beta blockers
What ratio are we going to have in atrial flutter
more atrial contractions than vent Cx
How much CO do we lose with A flutter
10-20% of CO
What are A flutter at higher risk for, why, and what might we do about it
clots because our blood is moving slower so we might give them coumadin
Who gets A flutter
CAD Hypertension Mitral valve disorders Pulmonary embolus Chronic lung disease Cardiomyopathy Hyperthyroidism Drugs: Digoxin, quinidine, epinephrine
What are you at risk for with A flutter
High atrial rates (>100) and resultant loss of the atrial “kick” can decrease CO (by 10 to 20%) and precipitate HF, angina
Risk for stroke due to risk of thrombus formation in the atria
What drugs are the usually best for A flutter
beta blockers
then calcium channel blockers
Who gets defibrillation
V fib
A systole
pulseless V tach
Whats the first thing to check with someone with V tach
see if they have a pulse
Difference of cardioversion from defibrillation
much less voltage
the machine reads the ECG and waits to shock until T wave isnt going
What are the manifestations of A fib
same as A flutter
Who gets A fib
Underlying heart disease, such as rheumatic heart disease, CAD Cardiomyopathy HF Pericarditis Thyrotoxicosis Alcohol intoxication Caffeine use Electrolyte disturbance Cardiac surgery
What do we do for patients going in to get cardioversion for A fib and A flutter
put them on coumadine for 3 days prior
How fast is the HR from cells in the middle of the heart
40-60 like AV node (junctional areas of the heart
What is a 1 deg block
PR interval greater than .2
still has 1:1
What is a 2nd deg block
PR interval > .2
every QRS has a P
but not evwery P has QRS
may have QRS’s that goes missing
What is 3rd deg block
QRS and P are unrelated
For example, Atrium pumping at 60-100 and vents pumping at 20-40
What is the progression of AV blocks
they progress into eachother
Who gets 1 AV block
MI CAD Rheumatic fever Hyperthyroidism Vagal stimulation Drugs: Digoxin, -adrenergic blockers, calcium channel blockers, flecainide
What is a unique trait about symptoms of 1 AV block
usu asymptomatic
What is the first thing to check for with 1 AV block for treatment and why
check there meds bec a new drug may be causing it
What causes 2 AV block
Drugs: digoxin, Beta-adrenergic blockers
CAD and other diseases that can slow AV conduction
rheumatic heart disease
Anterior MI
What are some treatments of 2 AV block
atropine
temporary pacemaker
What are we hoping for after giving atropine for 2 AV block
increased Vent rate
What is a common symptoms caused by 2 AV block
hypotension
MI’s
What are the steps for analyzing an ECG
Rates (both atrial and vent) Regularity (do they march out) P wave shape (want it to be sharp) Ratio of P waves to QRS PR interval time QRS time
