Unit 3 A

Question 1

Cation Movement in Depolarzation

Answer 1

• Na moves into cell (first phase)
• Ca moves into cell (second)
• K moves out of cell in response to NA and Ca

Question 2

P Wave

Answer 2

• Atrial depolarization

- 0.12 seconds

Question 3

PR Interval

Answer 3

• Shows SA and AV node fxn
• Normal 0.12-0.2 s
• Greater than 0.2 is indicative of block

Question 4

QRS Complex

Answer 4

• Ventricular depolarization
• Q not always present
• Normal: 0.04-0.10 s

Question 5

Sinus Bradycardia: Tx

Answer 5

• Check meds: Dig, Beta-Blockers, and CCBs can cause bradycardia
• Can be caused by vagal maneuvers (Vomiting, coughing, constipation)
• *If symptomatic give *Atropine (DOC), Epi, Dopamine

Question 6

Sinus Tachycardia: Tx

Answer 6

• *Treat cause, not rate: Anxiety, fear, fever, pain, hypovolemia
• Must have a P wave to be Sinus Tachy

Question 7

Sinus Tachycardia

Answer 7

-HR greater than 100 with regular rhythm
and regular intervals
-Usually asymptomatic, but can worsen to heart failure

Question 8

Second Degree block: Difference in Type I and Type II

Answer 8

• Type 1: PR interval progressively lengthens, then drops a QRS
• Type II: PR interval is constant, then drops a QRS

Question 9

3rd Degree Heart Block v. Sinus Arrest

Answer 9

• 3rd degree heart block, the sinus pause ends with a junctional escape beat (no P wave)
• Sinus arrest, the sinus pause ends with a sinus beat (P wave)

Question 10

Class I Antiarrhythmics

Answer 10

• Lidocaine and Procainamide
• Decreases cellular permeability to Na
• Do not use with AV blocks

Question 11

Class II Antiarrhythmics

Answer 11

• Labetalol (vasodilator), Propranolol (treats SVT and PVCs), Atenolol (used in post MI to prevent Vfib), Metoprolol (Treats MI, increases perfusion to heart)
• B-Blockers
• Increase coronary artery blood flow

Question 12

Class III Antiarrhythmics

Answer 12

• Amiodarone (or Amurowdarun?)
• Treats Vtach and Vfib when other meds are ineffective
• Long half life
• Pt must be admitted

Question 13

Class IV Antiarrhythmics

Answer 13

• Diltiazem, Verapamil
• Treat Afib, Aflutter, and SVT
• May cause AV block
• Caution with CHF, AMI, cardiogenic shock, and B-blockers