Cardiac Arrhythmias Flashcards
Cardiac arrhythmias are defined as what?
abnormalities in cardiac rhythm and/or
conduction.
When are Arrhythmias usually caught and diagnosed
Detected because patients present with symptoms or detected during a routine screening
What is the gold standard for monitoring and diagnosing cardiac arrhythmias.
ECG
True/False
Depending on the dysrhythmia and patient presentation, treatment can be just ABCs, IV, Oxygen, Monitor.
True
Symptoms for arrhythmias can range from asymptomatic to what?
palpations, dizziness
Presyncope and syncope
What Rhythm
Beat originates in the SA node and follows the appropriate conduction pathways. The intrinsic rate is 60-100 beats/min and the rhythm is regular. Every beat has a P wave, and every P wave is followed by a QRS complex.
1) PR interval remains constant.
2) R-R interval is regular and constant.
3) P-P interval is constant.
Normal Sinus Rhythm
Heart rate slower than 60 beats/min due to increased vagal tone on normal pacemaker, organic disease of the SA node, or due to medications.
Sinus Bradycardia
Severe Bradycardia may cause weakness, chest pain, lightheadedness, N/V, confusion, or syncope. The rate usually increases with exercise or administration of Atropine. What beats per min is severe brady
< 45 beats/min
Normal or abnormal?
In healthy individuals in excellent physical condition sinus bradycardia to rates of 50 beats/min or lower.
Normal
EKG Finding of what
1) Heart rate < 60 beats/min
2) Normal and consistent P wave morphology followed by QRS complex.
3) Normal PR interval
Sinus Brady
Unstable is defined as what?
(1 Changes in mental status. (2 Ischemic chest discomfort. (3 Hypotension (4 Signs of shock. (5 Acute heart failure.
Treatment for Sinus brady UNSTABLE pt
1st give Atropine 0.5 mg IV push and repeat q 3-5 minutes for a maximum of 3 mg.
- If Atropine ineffective prepare for transcutaneous pacing OR
- Consider Dopamine IV infusion at 2-10 mcg/kg/min OR
- Epinephrine IV infusion 2-10 mcg/min (use 1:10,000 epinephrine
mixture) .
Treatment for Sinus brady Stable pt
obtain vitals, obtain 12 lead if able, attempt to identify and treat underlying causes.
Atropine does not work for any patient that has undergone what surgery? and why?
Heart Transplant
Vagus Nerve is cut and not put back together, the heart is essentially innervated
What medication works by inhibiting all vagal input into the SA node.
l
Atropine
What rhythm
Heart rate faster than 100 beats/min caused by rapid impulse formation from the SA node.
The rate infrequently exceeds 150 beats/min
Tachycardia
EKG Findings for what?
1) HR > 100 beats/min
2) P wave is followed by a QRS complex and each QRS has a P wave preceding it.
3) QRS complex is normal duration (< .12 seconds).
Sinus Tachycardia
Treatment for Sinus Tachycardia
1) ABCs, monitor, IV, Oxygen to maintain saturation > 94%.
2) Assess appropriateness of clinical condition.
3) Usually Sinus Tachycardia has an identifiable etiology. Once identified then treat accordingly (dehydration, fever, stimulants, infection, pain, etc.)
If no identifiable etiology for sinus tachycardia is determined and patient is unstable then what?
start ACLS protocol
Unstable is defined as what?
(1 Changes in mental status (2 Ischemic chest discomfort (3 Hypotension (4 Signs of shock (5 Acute heart failure
Term:
Paroxysmal
comes and goes
Term:
Supraventricular
originating above the ventricles
True/false
Psvt is the Most common paroxysmal tachycardia and often occurs in patients with structural heart disease
False
often occurs in patients without structural heart disease
EKG Findings for what?
1) HR 150-240 (commonly HR is 160-220)
2) Regular R-R interval
3) Narrow QRS complex
4) P wave often buried in the narrow QRS complex
Paroxysmal Supraventricular Tachycardia (PSVT)
What rhythm?
Paroxysmal Supraventricular Tachycardia (PSVT)
Physical findings for PVST include what?
1) May be asymptomatic
2) Frequently associated with palpitations, mild chest pain or
shortness of breath.
3) Episodes usually begin and end abruptly
4) May cause syncope
5) May cause AMI
Psvt
What Mechanical Measures should be attempted if patient is stable. what does it do?
Vagus stimulation
increase Vagal tone
Vagus stimulation methods
Valsalva
Breath hold
Dunk face in bowl of ICE cold water
Carotid sinus massage
_______ will interrupt up to 50% of PSVT (firm but gentle pressure over the right carotid sinus for 10-20 seconds, if unsuccessful then attempt over the left carotid sinus)
Carotid sinus massage
True/False
For a more effective carotid sinus massage you can apply pressure on both carotid sinuses at the same time
FALSE.
U NO DO BOTH SIDES
Psvt
If vagal maneuvers fail in a hemodynamically stable patient, then use what? How effective are these?
IV AGENTS 90% effective
What are the IV meds you would use for PSVT? what one is first line?
Adenosine - use first line if available Beta Blockers – second line -Metoprolol 5 mg IV repeat dose every 5 minutes up to 15 mg max -Metoprolol 50mg PO BID Calcium Channel Blockers – second line -Diltiazem: 0.25 mg/kg IV over 2 minutes
What are the IV meds you would use for PSVT? what one is first line?
Adenosine - use first line if available Beta Blockers – second line -Metoprolol 5 mg IV repeat dose every 5 minutes up to 15 mg max Calcium Channel Blockers – second line -Diltiazem: 0.25 mg/kg IV over 2 minutes
What is the dose for adenosine?
6 mg IV push very quickly followed by saline flush quickly. Repeat next dose with 12 mg IV push quickly if 6 mg dose did not
work. May repeat once more 12 mg dose if needed but that is the max you can use.
30mg MAX
MOA of what medication.
Slows AV node conduction time, interrupts AV node reentry pathways. Metabolized by erythrocytes and vascular endothelial cells
Adenosine
In a patient with PSVT who is hemodynamically unstable what intervention would be most successful?
synchronized electrical cardioversion at 50-150 J
What is an accessory electrical pathway or bypass tract between the atrium and the ventricle bypassing the AV node and can predispose to reentrant arrhythmias.
Wolf Parkinson White Syndrome (WPW)
Can Wolf Parkinson White Syndrome (WPW) be Associated with PSVT rhythm
Yes
EKG findings for what?
1) Short PR interval ( < 0.12 seconds).
2) Wide, slurred QRS complex called a delta wave.
Wolf Parkinson White Syndrome (WPW)
What is the arrow pointing to? What could arrhythmia could this be?
- Wide, slurred QRS complex called a delta wave
- WPW
If your pt with WPW arrhythmia is unstable what intervention would you do?
immediate synchronized cardioversion with 50-150 J
If your WPW pt is stable what interventions are used?
- vagal maneuvers just like in PSVT treatment
- Adenosine
- Metoprolol
What is the most common arrhythmia characterized as Multiple areas of atrial myocardium continuously discharging causing the atrium to fibrillate rather than contract in an organized manner
Atrial Fibrillation
Afib
True/False
The heart rate may vary but the R-R pattern is Normal.
False
R-R Rate is irregularly…. irregular
EKG of what?
A Fib
EKG finding for what?
1) R-R interval is irregularly irregular
2) Atrial rate ~ 400 beats/min and presents as fibrillation waves (wavy baseline).
3) Ventricular rate will depend upon how many of the atrial beats get conducted from the AV node which can range from bradycardia to tachycardia (with rates as high as 170-180 beats/min).
A Fib
Up to 2/3 of patients experiencing their 1st episode of A-fib will spontaneously revert to sinus rhythm within how long?
24 hours.
Patients with AF > 48 hours are at risk for what?
cardioembolic events
Patients with AF > 48 hours not be cardioverted until what?
anti-coagulated for a minimum of 3 weeks prior to attempting elective cardioversion.
If the A FIB pt is unstable what is the intervention
synchronized Cardioversion at 100-200 J
Can you cardiovert an unstable pt who has been in AF for longer than 48 hours and has not been anticoagulated?
Yes
What Anticoagulant would you give for A fib? What is the dose?
Enoxaoarin (Lovenox)
Dose: 1mg/kg SC q12 hours
Your pt has one of these can you give Lovenox?
Hypersensitivity to pork, active bleeding, hepatic or renal impairment, coagulopathy, GI bleeding, recent surgery or trauma.
no, contraindicated
What arrhythmia would you suspect from this strip?
A FIB
EKG findings for what?
1) Saw tooth flutter waves between QRS complexes.
2) Atrial rate between 250-350 beats/min.
3) AV block 2:1, 3:1, 4:1 (4 flutter waves per 1 QRS complex, meaning that for every 4 atrial depolarizations only one will go through the AV node to depolarize the ventricle).
A flutter
What arrhythmia?
A Flutter
A-flutter predisposes patients to what?
thromboembolic events
A-flutter If UNSTABLE what is your intervention?
cardioversion with 100-200 J.
A-flutter anticoaculant treatment is what?
Enoxaoarin (Lovenox)
Dose: 1mg/kg SC q12 hours
What arrhythmia?
A-flutter
What rhythim?
Normal sinus rhythm
What rhythm
V tach
What are the common Symptoms for Afib/Aflutter
1) Palpitations
2) Dyspnea on exertion
3) Lightheadedness
4) Fatigue
5) Weakness
6) Chest pain
Most common causes of V-tach is what?
AMI,
ischemic heart disease,
electrolyte abnormalities
EKG findings for what?
1) Wide QRS complex (longer than 0.12 seconds).
2) Absence of p waves
3) Tachycardia, usually HR 160-240 beats/min.
4) Moderately regular R-R interval.
V-tach
Can V-tach pts present as asymptomatic?
Yes if they are stable
V-tach interventions If stable
MEDADVICE and possibly treat with
Antiarrhythmic medication
V-tach interventions If unstable
immediately perform synchronized
cardioversion 100-200 J.
What are the medications for V-tach
-Lidocaine 0.5-0.75 mg/kg IV repeat every 5-10 minutes to a max dose of 3 mg/kg total.
-Amiodarone 150 mg IV over 10 minutes followed by 1 mg/min x 6
hours then 0.5 mg/min for the next 18 hours.
-Magnesium 2 grams IV if you suspect low magnesium levels
Your pt in V-tach has suspected low magnesium levels. What Med would you administer?
Magnesium…..
-2 grams IV
What is the dose/interval for IV lidocane for your V-tach PT
0.5-0.75 mg/kg IV repeat every 5-10 minutes to a max dose of 3 mg/kg total.
What is the dose/interval for IV Amiodarone for your V-tach PT
150 mg IV over 10 minutes followed by 1 mg/min x 6 hours then 0.5 mg/min for the next 18 hours.
What is the dose/interval for IV Amiodarone for your V-tach PT
150 mg IV over 10 minutes followed by 1 mg/min x 6 hours then 0.5 mg/min for the next 18 hours.
How would you be able to determine a suspected low magnesium level in your V-tach PT
HX of diuretic therapy, alcoholism, diarrhea, acute pancreatitis
When administering IV lidocane for a V-tach patient what should you monitor?
Continuous monitoring, Vital signs q 5 minutes, electrolyte levels.
Interventions for Tachyarrhythmia per ALS
If stable with HR > 150 then you need to determine if they have a NARROW QRS complex (<0.12 sec) or WIDE QRS complex (greater than or equal to 0.12 sec).
- If Narrow complex and stable then attempt vagal maneuvers
- If Wide complex and stable, then.
- Consider antiarrhythmic infusion of Procainamide, Amiodarone, or Sotalol if available.
Interventions for Tachyarrhythmia per ALS
If stable with HR > 150 then you need to determine if they have a NARROW QRS complex (<0.12 sec) or WIDE QRS complex (greater than or equal to 0.12 sec).
- If Narrow complex and stable then attempt vagal maneuvers
- If Wide complex and stable, then.
- Consider antiarrhythmic infusion of Procainamide, Amiodarone, or Sotalol if available.
- Cardio consult
What rhythm
Premature Ventricular contraction
Premature ventricular contractions are due to impulses originating from the _____
ventricles.
PVCs are very common, even in patients without heart disease, but occur most in patients with ______ disease
ischemic
Patients with underlying structural heart disease with PVCs are at increased risk of development of __________, especially following AMI.
Ventricular Fibrillation
Your Pt presents with the below what would you suspect
Symptoms
1) Palpitations
2) Dizziness
EKG
1) Wide QRS complex without a preceding P-wave.
2) Occurs before then next predicted QRS complex is set to occur
Premature Ventricular Contraction (PVC)
can Premature Ventricular Contraction (PVC) usually present as Asymptotic?
yes
True/false
If the patient with PVC is asymptomatic and has no organic/structural heart disease; then treat with EPI and lidocaine drips, consider cardioversion.
False
no treatment is necessary for an asymptomatic pt.
In the case of frequent PVCs in a patient with underlying structural heart disease, what would you treat with?
Metoprolol 50 mg PO BID
Disposition for your PVC pt
- If asymptomatic send MEDADVICE message and possibly retain.
- f symptomatic MEDEVAC.
What rhythm
V-Fib
What rhythm?
1) Totally disorganized depolarization of small areas of the ventricular myocardium.
2) No effective ventricular pumping and thus no cardiac output.
3) Life threatening arrhythmia.
4) Seen most commonly with severe ischemic heart disease.
V-fib
EKG findings for what?
1) Fine to course zigzag pattern without p waves or QRS
complexes.
V-fib
If a patient is awake and responsive with this V-fib then what?
check the ECG leads to see if connected correctly
What are S/s for V-fib
1) Patient will not have a pulse
2) Hypotensive
3) Unconsciousness
What would you do for V-fib
Initiate ACLS Protocol for cardiac arrest
What Rhythm
Torsades de Pointes
Torsades is what type of rhythm
polymorphic Ventricular tachycardia
What can cause Torsades de pointes.
-hypomagnesemia, hypocalcemia,
hypokalemia
also starvation, anorexia nervosa, liquid protein diets, and hypothyroidism.
What can cause Torsades de pointes.
-hypomagnesemia, hypocalcemia,
hypokalemia
also starvation, anorexia nervosa, liquid protein diets, and hypothyroidism.
EKG findings for what?
1) HR greater than 100 beats/min.
2) Wide QRS complex (greater than 0.12 seconds).
3) Frequent variations of the QRS axis, morphology, or both.
Torsades
Torsades rhythm
Need to first determine if they have a pulse. If PULSELESS then what?
initiate ACLS Protocol
Torsades de Pointes Stable pt interventions
continue to monitor, Vitals every 5 minutes and 2 grams of Magnesium Sulfate IV, Check electrolyte panel and EKG if able.
How many degrees of heart block are there?
3
What rhythm
1st Degree AV Block
1st Degree AV Block represents what?
It represents delayed conduction between the SA node and the AV node
Is 1st Degree AV Block a true heart block? should you worry about this progressing to a worse block?
no It is a benign finding
What EKG finding
Prolonged PR interval > 0.2 seconds
1st degree AV block
What S/S are seen in pts with 1st degree AV block? Should you Med advice/medevac?
Mostly asymptomatic
No need to call for MEDADVICE or MEDEVAC
What rhythm
2nd Degree AV Block Type I
2nd Degree AV Block Type I is commonly referred to as?
Wenckebach block (longer longer drop wenkebach)
Where is the block?
2nd Degree AV Block Type I
above the AV node
EKG findings for what?
(1 Progressive PR interval prolongation until a QRS complex is not conducted.
(2 This represents failure of a conducted atrial beat to reach the ventricle.
(3 QRS complex is narrow (because the disease is above the AV node).
(Wenckebach block)
2nd Degree AV Block Type I
2nd Degree AV Block Type I
S/S
(1 Typically patient will only be symptomatic if they are bradycardic with HR < 50 beats per min.
(2 If bradycardic then may have lightheadedness, dizziness, presyncope, syncope or evidence of shock.
2nd Degree AV Block Type I
Tx for unstable pt
Atropine 0.5mg IV and prepare for transcutaneous pacing.
2nd Degree AV Block Type I
interventions if stable
look for possible causes
-if no serious causes then okay to continue duty. Call for MEDADVICE.
Med algorithm for:
2nd Degree AV Block Type I
Atropine 0.5 mg IV bolus and can repeat every 3-5 minutes if needed for a total max dose of 3 mg.
if no results Epinephrine IV 2-10 mcg/min.
If no results then transcutaneous pacing.
What rhythm
2nd Degree AV Block Type II
Type II blocks usually imply what?
They have a high likelihood of progressing to a what?
structural heart damage to the nodal conduction system and are usually permanent
3rd degree AV block.
EKG findings for what?
(1 PR interval remains unchanged prior to a P wave that fails to
conduct to the ventricles.
(2 Because the disease is below the AV node the QRS complex tends
to be more prolonged (> 0.10 seconds in duration).
2nd Degree AV Block Type II
2nd Degree AV Block Type II
Where is the block?
just below the AV node in the HIS bundle
2nd Degree AV Block Type II
if transcutaneous pacing is unavailable what do you use
Dopamine Infusion or Epinephrine infusion
What rythm?
3rd Degree AV Block
What rhythm?
3rd Degree AV Block
what arrhythmia is known as complete heart block due to no AV conduction
3rd Degree AV Block
EKG findings for what?
(1 Patient’s will have evidence of atrial (p waves) and ventricular (QRS complex) activity which are independent of each other on the EKG.
(2 There will be no association or pattern to PR intervals.
(3 Disease in 2/3 of patient’s is at the AV node which leads to narrow QRS complexes.
3rd Degree AV Block
Atropine
