Dysrhythmias Flashcards
What part of the cardiac cycle is atrial depolarization?
P-wave
What part of the cardiac cycle is ventricular depolarization?
QRS complex
What part of the cardiac cycle is ventricular repolarization?
T wave
Inherent rate of SA node
60-100 bpm
inherent rate of AV node
40-60 bpm
Inherent rate of Bundle of HIS and Purkinje fibers
20-40 bpm
Where ECG leads go on a 5 lead system
- white “White over right”
- Green “clouds over grass”
- Black “smoke over fire”
- Red “fire”
- Brown “Chocolate is close to the heart’
PR interval timing
0.12-0.20 seconds
QRS timing
0.06-0.12 seconds
ST segment timing
0.08-0.12 seconds
Q timing
< 0.04 seconds
How to calculate HR on a 6 second strip
count QRS complexes and multiply by 10
Normal Sinus Rhythm rate
60-100 bpm
sinus tachycardia rate
100-150 bpm
causes of tachycardia (9)
- hyperthyroidism
- hypovolemia
- heart failure
- anemia
- exercise
- use of stimulants
- fever
- pain
- anxiety
treatment for sinus tachycardia
treat cause
What question to ask patient with tachycardia?
do you have any symptoms?
rate for bradycardia
< 60 bpm
causes of bradycardia- 7
- vagal response
- drugs
- ischemia
- disease of the nodes
- ICP
- hypoxemia
- athletes
question to ask about bradycardia patients
are they symptomatic?
emergency drug for bradycardia
atropine
atropine dose, frequency, and max dose
1mg q 3-5 minutes max 3 mg
3 treatments for bradycardia
- atropine
- transcutaneous pacing
- epinephrine or dopamine infusion
Drug class for atropine
anticholinergic/antimuscarinic
What does atropine do?
increases HR
Other uses for atropine besides bradycardia (2)
- surgery
- end of life care to decrease salivation/secretions
What is sinus arrhythmia?
a sinus rhythm where the rate varies with respirations
causes of Sinus Arrest-5
- MI
- hyperkalemia
- digoxin
- OD
- physiologic response to increased vagal tone
On an EKG, where do you see atrial dysrhythmias?
P wave
In a PAC, the QRS is ___
narrow
in a PVC, the QRS is ___
wide
Atrial Tachycardia rate
150-250 bpm
outward s/s atrial tachycardia- 3
- low BP
- Low SaO2
- Low CO
Atrial tachycardia AKA
supraventricular tachycardia (SVT)
main difference between SVT and Paroxysmal SVT
SVT is continuous while PSVT starts and stops
What does Adensine do?
conversion of PSVT to SR
Adenosine dose, route for 1st dose
6mg IVP FAST
Adenosine dose, route for 2nd dose
12mg IVP fast
What needs to happen after every dose of adenosine?
20ml rapid saline flush IVP
What needs to be at the bedside when adenosine is given?
crash cart
causes of atrial flutter-6
- lung disease
- ischemic heart disease
- hyperthyroidism
- hypoxemia
- heart failure
- alcoholism
What is the pattern of atrial flutter referred to as?
sawtooth pattern
someone with Afib has a high risk for ….
pulmonary or systemic emboli
Afib treatment –> rate control CCB-2
cardizem, verapamil
Afib treatment –> rate control beta blockers-4
-atenolol, carvedilol, metoprolol, propanolol
Afib treatment –> rate control-AV Node blocker-1
digoxin
Afib treatment –> rate control-antidysrhythmics-2
amiodarone, sotalol
Afib treatment –> rhythm control-2
amiodarone or cardio version
Afib treatment –> anticoagulants-4
- warfarin (Coumadin)
- apixaban (eliquis)
- dabigratan (Pradaxa)
- rivaroxaban (Xarelto)
Non-pharmacological a fib tx-2
cardioversion, ablation
Junctional escape rhythm rate
40-60
accelerated junctional rate
60-100
junctional Bradycardia rate
< 40
Where do conductions begin from in a junctional rhythm?
AV node
in the junctional escape rhythm what happens to the p wave
may be inverted, absent, or may follow the QRS
patient response in accelerated junctional
decrease CO and hemodynamic instability
Causes of accelerated junctional-7
- SA node disease
- ischemic heart disease
- electrolyte imbalances
- dig toxicity
- acute MI
- hypoxemia
tx of accelerated junctional rhythm
tx tachycardia if hemodynamically unstable. alert provider for change of rhythm
Main characteristics of ventricular dysrhythmias
wide and bizarre QRS
Types of PVCs –> pair
2 sequential PVCs
Types of PVCs –> runs or bursts
3 or more sequential PVCs
Types of PVCs –> bigeminy
every other beat is a PVC
Types of PVCs –> trigeminy
every third beat is a PVC
Types of PVCs –> quadreminy
every fourth beat is a PVC
When are PVCs dangerous? -4
- Frequent, multifocal
- Two or more in a row, frequent repeat
- PVC falls into the vulnerable period of the T wave
- May lead to ventricular tachycardia (pulseless VT) or ventricular fibrillation (VF)
Causes of Vtach-10
hypoxemia acid-base imbalance exacerbation of heart failure ischemic heart disease cardiomyopathy hypokalemia hypomagnesemia valvular heart disease genetic abnormalities QT prolongation
rate of vtach
> 100 but may go up to 300
cause of torsades de pointes
magnesium deficiency
tx for v fib
CPR and Dfib
rate for idioventricular rhythm
15-40 bpm
How is vfib described
chaotic pattern
Description of vtach
3 or more PVCs in a row with wide QRS complexes
Question to ask for vtach
pulse or no pulse
how do you treat pulseless vtach
CPR and Dfib
epinephrine dose, frequency
1mg IVP q 3-5 min
amiodarone dose, route, frequency
150mg IV (may repeat once)
Magnesium dose, route
1-2 g diluted in 10ml of D5W IV
Sodium Bicarb dose/route
1 mEq/kg IV
For PEA what do you do first?
apical and carotid pulse check
PEA causes: 5 H’s
- hypoxemia
- hypovolemia
- hypothermia
- H+ ions (acidosis)
- Hypo and hyperkalemia
PEA causes: 5 T’s
- tablets (OD)
- tamponade (cardiac)
- Tension pneumothorax
- thrombosis (coronary)
- thrombosis (pulmonary)
First-degree heart block…what is the defining characteristic
regular, prolonged PR interval > 0.20 seconds
causes of First degree heart block (6)
- AV node trauma
- hypoxemia
- MI
- digitalis tooxicity
- ischemic disease
- hyperkalemia
2nd degree heart block type 1 aka (2)
- Mobitz 1
- Wenckebach
2nd degree block type 1..what is the defining characteristics…
steadily increasing PR interval then skipped beat (p wave without QRS complex)
2nd degree block type 2 aka ….
Mobitz 2
2nd degree heart block defining characteristics (2)
- regular PR interval
- more P’s than Q’s
2nd degree block can lead to ____ and may cause patient to become ____
3rd degree, symptomatic
3rd degree block defining characteristics (2)
- regular PP and RR intervals
- P waves not associated with QRS complex
defining characteristic of LBBB
“bunny ears”
defining characteristic of RBBB
“2 R’s”
3 types of pacemakers
- Atrial paced
- ventricular paced
- A-V paced
Pacemaker rate definition
number of impulses delivered per minute to atrium, ventricle, or both.
Pacemaker mode definition
demand mode or fixed-rate (asynchronous) mode
Pacemaker electrical output definition
milliamperes (mA): energy needed to stimulate depolarization
pacemaker sensitivity defintiion
ability of the pacemaker to recognize the body’s intrinsic electrical activity, measured in millivolts (mV).
pacemaker AV interval definition
time between atrial and ventricular stimulation (dual chamber pacemakers only)
failure to pace
no pacer spikes
failure to capture
- electrical impulse is generated and no depolarization is noted.
- There are pacer spikes but no P wave (atrial) or QRS complex (ventricular)
Failure to sense
the pacemaker does not sense patient’s own heartbeat.
Pacer spikes that are too close to the patient’s own rhythm
most common cause of pacemaker issues
displacement of pacemaker electrode wire
2 nursing interventions to help with displacement of pacemaker electrode
- turn to left side
- adjust sensitivity
What is an implantable Cardioverter-Defibrillator (ICD/AICD)?
- Does everything a pacemaker does plus
- Treat life threatening dysrhythmias
- Pace and shock
therapeutic dose of electric current to the heart at a specific moment in the cardiac cycle, restoring the activity of the electrical conduction system of the heart
synchronized electrical cardioversion
therapeutic dose of electric current to the heart at a random moment in the cardiac cycle; most effective resuscitation measure for cardiac arrest associated with ventricular fibrillation and pulseless ventricular tachycardia.
defibrillation
also called chemical cardioversion, uses antiarrhythmia medication instead of an electrical shock.
pharmacologic cardioversion
