Arrhythmias PRE

True or false: you can have a normal rate but abnormal rhythm or a normal rhythm and abnormal rate

true

What is the order of cardiac conduction?

1. SA node

2. Atria

3. AV node

4. Bundle of His

5. Right/Left bundle

6. ventricles

What node is the pacemaker of the heart

SA node

What does the P wave represent?

atrial depolarization

Beginning and end of diastole

What does the PR wave represent?

Delay at the AV node

What does the QRS wave represent?

ventricular depolarization (AV)

What does the ST wave represent?

time between ventricular depolarization and the start of repolarization

What does the T wave represent?

ventricular repolarization

What does the QT wave represent?

time between ventricular depolarization and repolarization

What waves represent the beginning and end of systole

QRS to T

What are the common subcategories of bradyarrhythmias?

• sinus bradycardia

• AV block

  • 1st to 3rd degrees

What are the common subcategories of tachyarrhythmias?

• ventricular

  • Ventricular tachycardia

  • Ventricular fibrillation

• supraventricular (above ventricles)

• A fib

• A flutter

What are the 3 ways to treat arrhythmias?

1. medications

2. electricity

3. surgical procedures

What are some of the etiologies behind bradyarrhythmia?

• too much AVV nodal blocking agent

• Non-DHP CCB

• Digoxin

• BB

• Structural heart disease

What are some common treatments for bradyarrhythmias?

• adjust meds

• transcutaneous pacing, atropine, catecholamines (temporary/acute)

• permanent pacemaker (PPM) (chronic)

MOA of atropine

• blocks acetylcholine at parasympathetic sites

• increases firing of SA node

• increases oxygen demand

Dosing of atropine

1mg at one time and may repeat every 3-5 minutes to max total dose of 3mg

MOA of catecholamines

stimulate B1 receptors in the heart to increase HR and contractility (vasopressors)

Examples of catecholamines

• Epi

• dopamine (best effect)

• continuous infusion

What are the etiologies with tachyarrhythmias?

• hypotension

• shock

• hypoxia

• MI, structural heart disease

• pain or anxiety

Treatment options for tachyarrhythmias

• electricity

  • synchronized cardioversion

  • defibrillation

  • ICD

• medications

  • antiarrhythmics

What are the different types of ventricular tachyarrhythmias?

• monomorphic V-tach

• polymorphic V-tach

• Ventricular fibrillation

What treatment options should you use in a hemodynamically stable monomorphic V-tach?

AICD and/or BB

What treatment options should you use in a hemodynamically UNstable monomorphic V-tach?

amiodarone and/or electricity

Torsades de Pointes, TdP is which type of ventricular tachyarrhthmia?

polymorphic V-tach

What causes Torsades de pointes/ polymorphic V-tach?

prolongation of QT interval

What is the drug of choice for polymorphic V-tach?

magnesium

True or false: monomorphic and polymorphic V-tach can occur with and without a pulse

true

Ventricular fibrillation is always a ______ rhythm

non-perfusing/pulseless

Ventricular fibrillation is also known as

cardiac arrest

Treatment for ventricular fibrillation

defibrillation + amiodarone/lidocaine

What are some common medications that cause QT prolongation?

• antiarrhythmics

• anti-infectives (azoles, quinolones, macrolides, pentamidine)

• cancer chemotherapy/biologics

• psychotropics (antidepressants, atypical anti-psychs)

• chloroquine, methadone, IV ondansetron, tacrolimus

• toxins

This is drug of choice in supraventricular tachyarrhythmias

adenosine

Dosing of adenosine

6mg IV push wit saline flush, may repeat 12mg x1 if needed

MOA of adenosine

slows AV nodal conduction to restore sinus rhythm

What do you do in UNstable SVT?

synchronized cardioversion

What is seen in atrial flutter?

• rapid but regular atrial activation

• sawtooth pattern

• regular atrial rate with IRRegular ventricular rate (2:1, 3:1, etc.)

• 2 P waves before each QRS complex

True or false: you can treat atrial flutter with similar treatment plans as A fib

true

What is seen in A fib?

• Structural and/or electrophysiological abnormalities alter atrial tissue to promote abnormal impulse formation and/or propagation

• chaotic firing and disorganized atrial activity

• No P waves

• atria does not contract effectively

A fib is often referred to as an ________

irregularly irregular rhythm

What is the most common sustained cardiac arrthymia?

A fib

There is an increased risk of _______ with A fib

• stroke

• death from stroke

• permanent disability

• dementia

• HF

• cardiac death

Describe the nomenclature of A fib

• stages 1-4

• sub-stages in stage 3

What are the sub stages in stage 3?

1. paroxysmal (transient, <7days)

2. Persistent (> 7 days with intervention )

3. Long-standing persistent (>12 months)

4. Successfully controlled through ablation

What happens in stage 4 of A fib?

accept AF as permanent and make no further attempts of control rhythm but treat symptoms

Risk factors of A fib

1. atrial distention

2. high adrenergic tone

What can cause high adrenergic tone?

• alcohol withdrawal, intoxication

• hyperthyroidism

• sepsis

• drugs

• surgery

• hypoxia

• COPD

What can cause atrial distension?

• HTN

• valvular disease

• cardiomyopathy

• CHF

• left atrial enlargement

• acute PE

• CAD

What are the 3 main pillars of AF management?

“S.O.S”

1. stroke risk

2. optimize

3. symptom management

What does head-toes stand for and relate to in AF?

• Risk factors and enacting of behavioral change

• HF, Exercise, Arterial HTN, Diabetes, Tobacco, Obesity, Ethanol, Sleep

The goal serum concentration of magnesium is _____

Greater or equal to 2.0 mg/dL

The goal serum concentration of potassium is ____

Greater or equal to 4.0 mEq/L

What are the 2 strategies to focus on when treating ventricular arrhythmias?

1. rate control

2. rhythm control

Lenient rate-control strategy of resting HR is < _______ to ______bmp

100-110

Strict goal of HR is < ______ if symptomatic with lenient goal OR reduced EF

80 bmp

What medications of 1st line for ventricular rate control?

• BB

• non-DHP CCB

What medications of 2nd line for ventricular rate control?

Digoxin or amiodarone

In AF, you titrate based on what?

symptoms and HR goal

True or false: you can use digoxin (2nd line agent) for both ventricular rate and rhythm control

false; amiodarone

What agents do you utilize if the patient has decompensated HF?

• IV amiodarone

• verapamil, diltiazem

What agents do you utilize if the patient does NOT have decompensated HF?

• BB, Verapamil, Diltiazem

• Digoxin

• Amiodarone

What do you look at when determining long-term rate control?

LVEF

Avoid ______ in reduced ejection fraction

CCB

Which non-DHP agent is less cardioselective?

diltiazem

Digoxin total daily dose

8-12 mcg/kg

maintenance dose of digoxin

125-250mcg/day

therapeutic drug monitoring range of digoxin

<1.2 ng/mL

Is rate or rhythm control preferred more?

rate control

What characteristics would benefit more from rhythm control?

• younger

• shorter hx of AF

• more symptoms

• difficulty controlling HR

• smaller LA

• more LV dysfunction

• more AV regurgitation

What characteristics would benefit from more rate control?

• older

• longer hx of AF

• fewer symptoms

• easily controlled HR

• larger LA

• less LV dysfunction

• less AV regurgitation