MED-SURG---Cardiac Rhythm & Dysrhythmias Flashcards
Mark Lieb, MSN, RN, CEN
Multiple PVC’s in a row (3 or more) is known as ________________
Ventricular Tachycardia
VTACH
what are the “4” rhythms that can be cardioverted?
1) A-Fib
2) A-Flutter
3) SVT
4) V-Tach with pulse
Two main systems in the heart
1) Electrical (Conduction)
2) Mechanical (Contraction)
most common Dysrhythmia?
atrial fibrillation
Delivery of unsynchronized, direct countershock to the heart–Stopping all electrical activity of the heart –allowing the SA NODE to take over nd reestablish a perfusing rhythm.
Defibrillation
Calcium Channel Blocker
- INDICATIONS
- ACTIONS
*RATE \ RHYTHM control of rapid Atrial rhythms (A-fib with RVR) A-Flutter, SVT
- SLOWS SA NODAL FIRING= decreased automaticity
- SLOWS TRANSMISSION THROUGH AV NODE = reduced ventricular rate
TX for VTACH (w/o Pulse)
1) DRUGS (3)
2) Electrical Mangemet
Amiodarone
Lidocaine
Epinephrine
Defibrillation
What is “R on T phenomenon”?
PVC’s falling on the T WAVE
EQUATION FOR CARDIAC OUTPUT?
Heart Rate x Stroke Volume == CO
Vagal Maneuvers (4)
1) blowing through straw
2) Valsalva Maneuver (holding breath and bear down)
3) Ice to face (for babies)
4) Carotid sinus massage (cannot be done by nurse-clot could break off and occlude the carotid)
TX for VTACH (with pulse)
1) Drugs (3)
2) Electrical management
Amiodarone
Adenosine
Verapamil
Synchronized Cardioversion
indications for adenosine
SVT (regular, narrow QRS of 0.10 or less with rate >150)
Immediate intervention needed for V-FIB
CPR / Defibrillation
IF allowed to continue—VTACH can deteriorate into ________________
Ventricular Fibrillation
PVC that is noted to be EVERY THIRD BEAT
Ventricular Trigeminy
INDICATIONS FOR DEFIBRILLATION
1) V-Fibrillation (V-FIB)
2) VTACH (without a pulse)
Cardiac cells possess 4 similar properties
AUTOMATICITY ability to depolarize itself. can start an electrical impulse by themselves without any outside initiation
EXCITABILITY–ability to respond to a stimulus
CONDUCTIVITY–ability to transmit a stimulus to a neighboring cell
CONTRACTILITY–ability to respond to a an electrical impulse with a pump or contraction
Type of ventricular tachycardia associated with LON QT Syndrome
Torsades de Pointes
side effects of ADENOSINE
chest discomfort lightheadedness syncope bradycardia asystole
ability to respond to a stimulus
EXCITABILITY
describe the “action” of adenosine
slows conduction through the AV node and interrupts reentry pathways
EKG complexes and what do they represent
P WAVE—represents atrial depolarization
QRS WAVE–represents ventricular depolarization
T WAVE –represents ventricular repolarization
The EKG reading states that your patient is in ASYSTOLE…what do you do first?
1) Check your patient
2) Check EKG lead (Disconnected lead?)
**IF REAL—BEGIN CPR IMMEDIATELY
INDICATIONS for Cardioversion (3)
1) Elective treatment of atrial dysrhythmias
2) SVT
3) VTACH (with a pulse)
**tx of Choice for Clients that are symptomatic
first line treatment for dsyrhtymias
adenosine, CCB, BB
PVC’s originating at more than one site appear different from one another on the ECG (polymorphic) and are called _____________
MULTIFOCAL
(7) side effects of Beta blockers
Hypotension
Bradycardia
Bronchospasm
Flushing
CHF
Dizziness
Heart block
ability to respond to a an electrical impulse with a pump or contraction
CONTRACTILITY
ability to transmit a stimulus to a neighboring cell
CONDUCTIVITY
ability to depolarize itself. can start an electrical impulse by themselves without any outside initiation
AUTOMATICITY
Name “3” types of Ventricular Dysrhythmias
- Premature Ventricular Contractions (PVC)
- V-Tachycardia
- V-Fibrillation
Which dysrhythmia can be classified by ventricular rate?
ATRIAL FIBBRILATION
Controlled-ventricular rate–<100 bpm
Uncontrolled(RAPID)ventricular rate–> 100 bpm
With PVC’s…when the ventricular impulse arises from one ectopic site all the PVC’s look the same (monomorphic) and are called ___________
UNIFOCAL
Electrical “picture” of what is happening in the conduction system
ECG
Electrocardiogram
Normal Magnesium Lab Values
1.5 - 2.5
Delivery of a direct countershock to the heart synchronized to the QRS complex
Cardioversion
Time when a cell cannot accept another impulse and be stimulated
ABSOLUTE REFRACTORY PERIOD
how does a tachydysrhythmia affect the patient
Excessive Heart rate >100. (TOO FAST)
—–>short diastolic (relaxation / filling) time—–>decreased Cardiac Output
THIS MEANS THERE ISNT VERY GOOD VENTRICULAR FILLING—->resting/filling time is cut short and the ATRIA can not work properly to fill the ventricles which provides for good cardiac output
INCREASED WORKLOAD OF THE HEART & INCREASED MYOCARDIAL O2 DEMAND
(3) Nursing administration for Calcium Channel Blockers
1) Check HR–if <50 call provider for order
2) change position slowly- (orthostatic hypotension)
3) avoid activities that require alertness until effects are known
The life threatening effects of dysrhythmias are generally related to ______________ and ____________.
Decreased cardiac output
ineffective tissue perfusion
Norma Potassium Lab Values
3.5 - 5
implementation of Beta Blockers
Metoprolol \ Propranolol
GIVE IV DOSE OVER 2 MINUTES TO PATIENT WHILE ON CARDIAC MONITOR
Sotalol
- GIVEN OVER 5 HOURS
- PT MUST BE HOSPITALIZED FOR UP TO 3 DAYS
How does a Bradydysrhythmias affect the patient
SLOW HEART RATE <60–negatively affects perfusion because the HR is too slow to provide for adequate output for perfusion to entire body
Dysrhythmias treatment is based on the cardiac rhythm, which can require any of the following (4) forms of treatment
Cardioversion
Defibrillation
Pacemaker insertion
Medication
Dysrhythmias have a disturbance in impulse from _____________ or ______________
FORMATION—where the signal begins
PROPAGATION—how the impulse travels
A PVC that follows every normal beat
Ventricular Bigeminy
If a change is notated on EKG (from the baseline) you should_______
Consider a 12 lead EKG
HOW TO BETA BLOCKERS WORK (ACTION?) WHICH ENDS UP RESULTING IN …(3) THINGS
ACTION: block beta 1 receptor in the heart
OUTCOME: < Heart Rate
Time when a cell needs a “greater than normal” impulse to be stimulated
RELATIVE REFRACTORY PERIOD
5 steps involved in administered adenosine
1) administer at IVP at a site closest to the heart (central line or AC)–only has half life of 10 seconds
2) rapid push with 20 ml of NSS Flush immediately after
3) Raise arm following push
4) Have code cart in room just in case
5) patient must be on monitor
Some potential Causes for AV BLOCK / Heart Blocks
Beta Blockers Calcium channel blockers Digoxin Ischemia Necrosis Myocardial Infarction
Name two Calcium Channel Blockers
Diltiazem (Cardizem)
Verapamil
The “3” steps of “THE ACTION POTENTIAL”
1) RESTING POTENTIAL (unexcited)
* *cells are polarized and ready to accept impulse
* *Mainly (-) inside the cell and (+) outside cell
2) DEPOLARIZATION
* *cells receive and respond to electrical stimulus
* *Movement of charged particles making inside more (+)
3) REPOLARIZATION
* *Cells return to negative state by moving (+) ions out
(TRUE / FALSE)
If HR is elevated it doesn’t permit for proper ventricular filling—which leads to a decrease in cardiac output
TRUE
DEFINE PRELOAD
AMOUNT OF BLOOD LEFT IN VENTRICLES JUST PRIOR TO CONTRACTION
HOW FULL IS THE VENTRICLE BEFORE IT SQUEEZES?
Name “3” Beta Blockers
Metoprolol
Propranolol
Sotalol
uncontrolled (or RAPID) ventricular rate is AKA ___________
RVR
Rapid Ventricular Rate
Side effects of Calcium Channel Blocker (5)
Bradycardia
Constipation
Hypotension
Heart Failure
Peripheral Edema
an extremely rapid, chaotic ventricular depolarization that causes the ventricles to quiver and cease contracting; the heart DOES NOT Pump
Ventricular Fibrillation (AKA: Cardiac Arrest)
“5” Characteristic features of Ventricular Dysrhythmias?
- Wide / Bizarre QRS Complex—– >0.12
- No relationship between the QRS complex and P Wave
- Increased amplitude of QRS complex
- Abnormal ST Segment
- T-Wave deflected in the opposite direction from the QRS complex.
What is a PREMATURE COMPLEX?
Occurs when a cell other than the SA NODE becomes irritable and fires off an impulse.
**Because of automaticity, these cells can depolarize by themselves
DECREASED VENTRICULAR FILLING = DECREASED CARDIAC OUTPUT
Complications of A-Fib (2)
1) Blood pooling in atria can lead to thrombus / clot formation increasing risk of stroke , MI, PE
2) If HR is too rapid and irregular, ventricular filling time is decreased so cardiac output decreases
Clinical Symptoms of Dysrhythmias / poor perfusion
“WASP HAD CPU”
W-eakness
A-ngina
S-OB
P-ale skin
H-ypotension
A-nxiety
D-izziness
C-onfusion
U-rine is decreased
P-alpitations
AV BLOCKS
Where are the electrical impulses delayed?
Does the SA NODE function normally?
- Electrical impulses are delayed or blocked in the AV NODE or INTRAVENTRICULAR conduction system
- Yes, the SA NODE functions normally
