High-Yield Dysrhythmia Flashcards

Which cardiac rhythms are shockable during cardiac arrest?

Shockable rhythms:

• Ventricular fibrillation (VF)

• Pulseless ventricular tachycardia (pVT)

Management:

• Immediate defibrillation

• CPR

• Epinephrine

• Amiodarone if rhythm persists

These rhythms occur because of chaotic ventricular electrical activity, which can sometimes be reset with defibrillation.

Which cardiac arrest rhythms are non-shockable?

Non-shockable rhythms:

• Asystole

• Pulseless electrical activity (PEA)

Management:

• CPR

• Epinephrine

• Oxygenation

• Identify and treat reversible causes (H’s and T’s)

Defibrillation is not effective because there is no disorganized electrical activity to reset.

What is the difference between cardioversion and defibrillation?

Cardioversion

• synchronized shock

• delivered with the QRS complex

• used when patient has a pulse

• lower energy

Used for:

• atrial fibrillation

• atrial flutter

• supraventricular tachycardia

• ventricular tachycardia with pulse

What are the characteristics of defibrillation?

Defibrillation:

• unsynchronized shock

• higher energy

• used when patient has NO pulse

Indications:

• ventricular fibrillation

• pulseless ventricular tachycardia

Goal:

• stop chaotic electrical activity so the SA node can regain control.

How can you quickly recognize normal sinus rhythm (NSR) on an ECG?

Key features:

• rate 60–100 bpm

• rhythm regular

• P wave before every QRS

• 1:1 P:QRS ratio

What are quick ECG recognition clues for sinus tachycardia?

Characteristics:

• heart rate >100 bpm

• regular rhythm

• normal P waves

• normal QRS

• PR interval normal

The rhythm is essentially normal sinus rhythm but faster.

What ECG findings indicate sinus bradycardia?

Key features:

• heart rate <60 bpm

• regular rhythm

• normal P waves

• normal QRS

• normal PR interval

Often seen with:

• athletes

• vagal stimulation

• beta blockers.

What ECG finding helps identify a premature atrial contraction (PAC)?

PAC recognition:

• early abnormal P wave

• beat occurs earlier than expected

• rhythm briefly disrupted

• followed by a pause

PACs originate from an atrial focus outside the SA node.

What ECG finding helps identify a premature ventricular contraction (PVC)?

PVC characteristics:

• early beat

• wide abnormal QRS

• no P wave before beat

• followed by compensatory pause

PVCs originate from the ventricles instead of the SA node.

What ECG pattern indicates atrial flutter?

Atrial flutter characteristics:

• saw-tooth pattern

• flutter waves replace P waves

• atrial rate 250–350 bpm

• ventricular response may be 2:1 or 3:1

What ECG findings indicate atrial fibrillation?

Atrial fibrillation characteristics:

• no P waves

• irregularly irregular rhythm

• chaotic baseline

• variable ventricular rate

Loss of atrial contraction causes loss of atrial kick and decreased cardiac output.

What ECG findings indicate supraventricular tachycardia (SVT)?

SVT recognition:

• heart rate >150 bpm

• rhythm regular

• P waves often hidden in T waves

• narrow QRS

Often treated with vagal maneuvers or adenosine.

What ECG pattern suggests ventricular tachycardia?

Ventricular tachycardia characteristics:

• rate >150–170 bpm

• wide QRS complexes

• P waves often absent

• rhythm usually regular

Can quickly progress to cardiac arrest.

What ECG pattern indicates ventricular fibrillation?

Ventricular fibrillation characteristics:

• chaotic electrical activity

• no identifiable QRS complexes

• no organized rhythm

• no pulse

This rhythm causes immediate cardiac arrest.

What ECG pattern indicates asystole?

Asystole characteristics:

• flatline ECG

• no electrical activity

• no pulse

• no cardiac output

Confirm in two leads to rule out equipment failure.

Which medication is first-line for symptomatic bradycardia?

Atropine

Mechanism:

• blocks vagal stimulation

• increases SA node firing

Dose:

• 0.5 mg IV every 3–5 minutes

• max dose 3 mg

Which medication is used to treat supraventricular tachycardia (SVT)?

Adenosine

Key points:

• rapid IV push

• temporarily blocks AV node conduction

• resets heart rhythm

Dose:

• 6 mg rapid IV push

• repeat 12 mg if needed

Which medication is commonly used for ventricular tachycardia and ventricular fibrillation?

Amiodarone

Uses:

• ventricular tachycardia

• ventricular fibrillation

• atrial fibrillation

Works by prolonging cardiac action potential and slowing conduction.

Which medications are commonly used to control atrial fibrillation rate?

Rate-control medications:

• beta blockers

• diltiazem

• verapamil

• digoxin

These drugs slow AV node conduction, reducing ventricular rate.