Adult Health II: Exam 1: ECG/Dysrhythmias

What does depolarization mean on an EKG?

Upward movement showing contraction

What does repolarization mean on an EKG?

Flat or return to baseline showing relaxation

What does the P wave represent?

Atrial contraction/depolarization

What does the QRS complex represent?

Ventricular depolarization

What does the T wave represent?

Ventricular repolarization and electrolyte effects

What electrolyte causes tall peaked T waves?

High potassium

What is the normal PR interval?

0.12-0.20 seconds

What is the normal QRS duration?

0.06-0.10 seconds

What is the normal QT interval?

Less than 0.44 seconds

How long is one small box on EKG paper?

0.04 seconds

How long is one large box on EKG paper?

0.20 seconds

What is the intrinsic rate of the SA node?

60-100 bpm

What is the intrinsic rate of the AV node?

40-60 bpm

What is the intrinsic rate of Purkinje fibers?

20-40 bpm

Which leads view the lateral heart?

I, aVL, V5, V6

Which leads view the inferior heart?

II, III, aVF

Which leads view the septal heart?

V1, V2

Which leads view the anterior heart?

V3, V4

What medication treats many arrhythmias and has the longest name?

Amiodarone

What is the amiodarone dose with a pulse?

150 mg over 10 minutes

What is the amiodarone dose without a pulse?

300 mg

What drug is used for SVT?

Adenosine

What is the first dose of adenosine?

6 mg rapid IV push

What is the second dose of adenosine?

12 mg rapid IV push

When do you try vagal maneuvers first?

Stable SVT

What drug treats bradycardia?

Atropine

What is the atropine dose?

1 mg every 3-5 minutes (max 3 mg)

When should atropine NOT be used?

Type II or third-degree block or heart transplant patients

What drug is given IV during cardiac arrest?

Epinephrine

What is the epinephrine cardiac arrest dose?

1 mg every 3-5 minutes with no max

What does vasopressin do?

Raises blood pressure by retaining fluid

What does dopamine do?

Increases heart rate and blood pressure

How do you treat unstable dysrhythmias?

Electrical cardioversion

How do you treat stable dysrhythmias?

Medications

What is synchronized cardioversion used for?

Tachycardias with a pulse

What rhythms should NOT be cardioverted?

Junctional rhythms; VT, VFIB, PEA, Asystole

When is defibrillation used?

Pulseless VT or ventricular fibrillation

What rhythms should NOT be defibrillated?

Asystole and PEA

What is the pacing rate typically set to?

About 70 bpm

Why do we pace the heart?

To prevent lethal slow rhythms and maintain perfusion

What happens when HR exceeds 180 bpm?

Cardiac output decreases

What is first treatment for stable SVT?

Vagal maneuvers

What is treatment for unstable SVT?

Synchronized cardioversion

What is the treatment of choice for atrial flutter?

Radiofrequency ablation

What is the most common dysrhythmia overall?

Atrial fibrillation

Why is atrial fibrillation dangerous?

Increased stroke risk and decreased cardiac output

How is atrial fibrillation treated?

Rate control drugs, cardioversion, anticoagulation, ablation

What defines junctional rhythm on EKG?

No P wave

How is junctional rhythm treated?

Atropine and treat underlying cause

How is first-degree AV block treated?

No treatment, just monitor

What defines second-degree AV block type I?

Gradually lengthening PR interval until a beat drops

How is second-degree AV block type I treated?

Observe unless symptomatic

What defines second-degree AV block type II?

Dropped QRS without PR prolongation

How is second-degree AV block type II treated?

Pacemaker

What defines third-degree AV block?

Complete dissociation of atria and ventricles

How is third-degree AV block treated?

Pacemaker and epinephrine or dopamine

What causes premature ventricular contractions?

Irritation, hypoxia, or electrolyte imbalance

How are PVCs treated?

Fix cause, give oxygen, replace electrolytes, or antiarrhythmics

How is asystole treated?

CPR, oxygen, epinephrine (do NOT shock)

How is ventricular tachycardia with pulse treated?

Antiarrhythmics or cardioversion

How is pulseless ventricular tachycardia treated?

CPR and immediate defibrillation

What medication treats torsades de pointes?

Magnesium

How is ventricular fibrillation treated?

Immediate CPR and defibrillation

What is PEA?

Electrical activity with no pulse

How is PEA treated?

CPR, airway support, and epinephrine

What are the Hs causes of cardiac arrest?

Hypovolemia, hypoxia, hypothermia, hypoglycemia, hydrogen ions

What are the Ts causes of cardiac arrest?

Tension pneumothorax, trauma, toxins, thrombosis, tamponade

What is a normal MAP goal?

Greater than 65

What is normal sinus rhythm?

All waves and intervals normal

What is sinus bradycardia?

Heart rate below 60 bpm from SA node

What causes sinus bradycardia?

Vagal stimulation or anything slowing the heart

What is sinus tachycardia?

Heart rate above 100 bpm

How is sinus tachycardia treated?

Treat cause, vagal maneuvers, beta blockers, adenosine, or cardioversion

What is a premature atrial contraction?

Early atrial beat from outside the SA node

How are PACs treated?

Monitor and reduce stimulants, possibly beta blockers