Ventricular Dysrhythmias Flashcards
What are ventricular dysrhythmias?
Slow, abnormal, non-simultaneous depolarization of ventricles at a rapid rate
What does the QRS of a ventricular dysrhythmia look like?
Large, wide QRS
Where is the p wave in a ventricular dysrhythmia?
Usually hidden in the QRS
What are the 3 H’s (causes) of ventricular dysrhythmias?
Heart disease
Hypoxia
Hypokalemia
What does a decreased CO lead to a loss of?
Atrial kick
What are the 12 reversible causes of ventricular dysrhythmias called?
Hs and Ts
What are the Hs of the Hs&Ts?
Hypovolemia
Hypoxia
Hydrogen ion excess (acidosis)
Hypoglycemia
Hypokalemia
Hyperkalemia
Hypothermia
What are the Ts of the Hs and Ts?
Tension pneumothorax
Tamponade (cardiac)
Toxins
Thrombosis (PE)
Thrombosis (MI)
What does the QRS look like during a PVC?
Wide
What are types of PVCs?
unifocal, multifocal, bigeminy, trigeminy
List 4 types of ventricular dysrhythmias
PVCs
V tach
V fib
Torsades de Pointes
What is the definition of a PVC?
Ectopic impulses that originate in the ventricle that discharge before the next sinus is due
There is no __ wave associated with PVCs
P wave
How long in seconds is the qrs of a PVC?
> 0.12 seconds
What does the HR look like in someone having PVCs?
Regular except for when premature beat interrupts
What is the r to r interval for a PVC?
It’s equal
What are unifocal PVCs?
All originate from the same ventricular location, so their configuration looks identifcal
List 5 types of PVCs
Unifocal
Couplets
Multifocal
Bigeminy or bigeminal
Trigeminy or trigeminal
What is a couplet PVC?
Two PVCs originating from the same ventricular location that occurs togethers
What is a multifocal PVC?
A PVC that originates at two or more ventricular locations and therefore have different configurations
What is a bigeminy PVC?
Repeated pattern of one normal SA node-initiated beat followed by one PVC
Bigeminy PVCs occur at…
every other beat
Trigeminy PVCs occur at…
every two beats
What is a trigeminy PVC?
Repeated pattern of two normal beats followed by one PVC
If the PVCs look the same they are…
unifocal
If the PVCs look the same they are…
unifocal
PVCs that look uniform =
unifocal
What type of dysrhythmia is this?
Unifocal PVC
What type of dysrhythmia is this?
Couplet PVC
Two PVCs that occur together are called…
Couplet
What type of dysrhythmia is this?
Multifocal PVC
Multifocal PVCs can have many forms such as…
One flipped on positive axis
One flipped on negative axis
Which is worse, multi, couplet or unifocal PVCs?
Multifocal PVCs because multiple places in the ventricle are firing
What type of dysrhythmia is this?
Bigeminy PVC
What type of PVC occurs every other beat?
Bigeminy
How frequent to bigeminy PVCs occur?
Every 2nd beat
What PVC can be characterized as having “bunny ears”?
Bigeminy PVC
How can you differentiate between a bigeminy PVC and a couplet PVC?
Bigeminy PVCs occur at every other beat
What type of dysrhythmia is this?
Trigeminy PVC
Is it normal to occasionally have a PVC?
Yes, many people will occasionally have a pVC
What are common causes of a PVC?
Hypokalemia
Hypomagesemia
Hypoxia/hypoxemia
Caffeine
Tobacco
Stress
Reperfusion after lysis of a clot (Acute MI)
How do you treat PVCs?
Treat the cause!
If someone is having a PVC, what amount is criteria for a concern?
More than 6 per minute or three in a row
What types of PVCs are a cause for concern?
Couplet PVCs
More than 3 ina row
Multifocal
PVC occurring in R on T
What does a multifocal PVC indicate?
Ventricular irritability
What does a PVC occurring in R on T mean?
Down stroke of the t-wave during relative refractory or vulnerable period
What type of dysrhythmia is this?
PVC occurring in R on T
What causes a R-on-T phenomenon?
a ventricular depolarization superimposing on the previous beat’s repolarization
What is the danger of a R-on-T phenomenon?
It can cause someone to go into cardiac arrest
What type of dysrhythmia is this?
Ventricular tachycardia
Where are the p-waves in ventricular tachycardia?
You cannot see them, usually absent
What is the R-R interval like in ventricular tachycardia?
Usually regular
What does the QRS look like in ventricular tachycardia?
Wide and bizarre
What the the heart rate of someone experiencing ventricular tachycardia?
100-250 bmp
What are common causes of ventricular tachycardia?
Poor oxygenation/decreased CO
Increase in catecholamines
Electrolyte imbalances
MI/ischemia
Acute heart failure
Drugs
Etc
What two catecholamines are a potential cause of ventricular tachycardia?
Epinephrine
Norepinephrine
What two electrolyte imbalances are potential causes of ventricular tachycardia?
Potassium and/or magnesium
What is a slow ventricular tachycardia?
Heart rate of 100-150
What is a fast ventricular tachycardia?
Heart rate greater than 150
If someone is experiencing ventricular tachycardia, what two things must you always check?
LOC and pulse
What is important concerning pulse checks and ventricular tachycardia?
You can have pulse and pulseless ventricular tachycardia
If someone is experiencing a SLOW ventricular tachycardia, initially the may…
Have compensated CO but will deteriorate quickly
Does someone with fast ventricular tachycardia have CO compensation?
No, there is not enough filling time and the patient will decompensate quickly
What is the main function of amiodarone?
Antiarrhythmic
How does amiodarone work?
Blocks potassium channels thereby delaying repolarization and prolonging refractory period
Also affects sodium and calcium with alpha and beta blocking properties
What is another name for the refractory period on an EKG?
QT interval
Amiodarone works by prolonging…
QT interval
Amiodarone works by delaying…
repolarization
Amiodarone is used as a first line agent for which dysrhythmias?
Ventricular tachycardia
Ventricular fibrillation
Uncontrolled atrial fibrillation
What is the IV loading dose of amiodarone?
150mg over the first 10 minutes
How is the IV loading dose of amiodarone diluted?
Dilute 150 mg in 100 ml of D5W
After the IV loading dose of amiodarone, what is the next dose?
After 10 minutes, 360mg over the next 6 hours (1mg/min)
After the IV loading dose of amiodarone, and the next maintenance dose, what is the remaining dose for amiodarone?
540mg over next 18 hrs (0.5mg/min)
After a patient is stabilized, how is amiodarone given?
PO to bridge the gap after IV is tapered off
What are the side effects of amiodarone?
Headache
Dizziness
Hypotension
Bradycardia
Blue-gray skin color
What are symptoms that a patient is not tolerating amiodarone well?
Hypotension and bradycardia
What are two types of defibrillators?
Monophasic
Biphasic
What is a monophasic defibrillator?
Energy goes in one direction, requires more energy
What type of current does a monophasic Lifepak defibrillator have?
Fixed current to deliver 200-360 joules
What type of defibrillator is a biphasic zoll?
Delivers energy in two different directions, uses less energy
What type of current is the biphasic zoll?
Can manually or automatically adjust strength of current to deliver 120-200 joules
What is the advantage of a biphasic zoll over a monophasic lifepak?
Less tissue damage due to less current
What can an elective cardioversion cause?
It can cause an R-to-T phenomenon which can put patient into a life threatening dysrhythmia
What is an elective cardioversion?
Form of shock that delivers an electrical current that is synchronized with the patient’s heart rhythm
When is an elective cardioversion typically used?
For SVT, Afib, a flutter, V tach, and unresponsive to meds
What must you do before an elective cardioversion?
Must “sync” prior to shocking
What should you do if an initial cardioversion is unsuccessful?
Repeat using higher voltage
Defibrillation is an __ procedure
emergency
When is defibrillation used?
Pulseless ventricular tachycardia
Ventricular fibrillation
Torsades de pointes
What is defibrillation?
Unsynchronized electrical shock that administers large amount of joules
What must the nurse do before administering the shock during defibrillation?
Announce “all clear”
What is this dysrhythmia?
An example of synchronized cardioversion
How many joules is given during synchronized cardioversion?
100 joules, up to 200 joules
What should the nurse say to the patient before elective cardioversion?
Obtain consent
Educate patient regarding cardioversion and what to expect during procedure
What does the nurse want IV wise for a patient undergoing an elective cardioversion?
At least two good working IVs, large bore greater than 20g
If a patient is hemodynamically stable, what should the nurse administer before cardioversion?
Light sedation
When is light sedation before a cardioversion contraindicated?
If the patient is hemodynamically unstable
What should the nurse make sure is done before starting an elective cardioversion?
Ensure optimal pad placement
Make sure Oxygen/Ambu bag in place
Ensure BP is cycling every 2-3 minutes
What is the exception to making sure a patient has blood pressure readings taken every 2-3 minutes during a cardioversion?
If the patient has an arterial line
What should be obtained both before and after an elective cardioversion?
EKG strip for documentation
Who should assist the nurse with an elective cardioversion?
RT, physician or APP at bedside
What is the difference between pulseless ventricular tachycardia and pulseless electrical activity?
PEA has a normal rhythm
Pulseless VT has a disorganized rhythm
Why is there no pulse in pulseless cardiac output?
The heart is not contracting effectively enough to generate a pulse, which means no cardiac output
