Unit 1 Day 7 Tue. (3/31/15)

Question 1

• persistent slow rate from SA node
• rate = 55bpm
• PR interval = 180ms

Answer 1

Sinus Bradycardia

Question 2

• failure of sinus node to discharge resulting in the absence of atrial depolarization and periods of ventricular asystole
• rate= 75 bpm
• PR interval = 180 ms

Answer 2

Sinus Arrest

Question 3

• intermittent episodes of slow and fast rates from the SA node or atria

Answer 3

Brady Tachy

Question 4

Tx for AV Block

Answer 4

• tx reversible causes: ischemia, infarction, hypothyroidism, Lyme disease
• stop offending medications
• acute tx fo unstable pt:
  
  • beta agonists (dopamine or isoproterenol)
  • transcutaneous pacing
  • temporary transvenous pacing
  • long term: pacemaker

Question 5

Where in the conduction system can bradyarrhythmias develop?

Answer 5

• sinus node
  
  • sinus bradycardia
  • sinus arrest
  • tachy brady
  • chronotropic incompetence
• AV node
  
  • first degree AV block
  • mobitz 1/Wenkebach
• below AV node (infranodal/His Purkinje system)
  
  • mobitz 2 2nd degree AV block (intermittently dropped ventricular beats with constant PR intervals)
  • complete heart block

Question 6

Sinus Node Dysfunctions

Answer 6

• sinus bradycardia
• sinus arrest/pause
• tachy/brady
• chronotropic incompetence- inability to mount age-appropriate HR with exercise

Question 7

AV Node Conduction Problems

Answer 7

• first degree AV block
• mobitz 1/ wenkebach (inc. PR interval)

Question 8

Infranodal Dysfunctions

Answer 8

• mobitz 2 2nd degree AV block (intermittently dropped ventricular beat with constant PR intervals)
• complete heart block

Question 9

Tachyarrhymia Origin

Answer 9

• above ventricle
  
  • supraventricular tachycardias (SVT)
    
    • regular
      
      • ST
      • AVNRT
      • AVRT
      • AFL
      • AT
      • JT
    • irregular
      
      • AF
      • MAT
      • AFL
• ventricle
  
  • ventricular tachycardia
  • ventricular fibrillation

Question 10

Tx for Supraventricular Tachycardias

• ST
• AVNRT
• AVRT
• AFL
• AT JT

Answer 10

• adenosine

Question 11

Tx for Irregular Supraventricular Tachycardia

• AF
• MAT
• AFL

Answer 11

• rate control
• antiarrhythmics
• cardioversion
• if unstable, shock

Question 12

Ventricular Tachyarrhythmias Treatment

Answer 12

• common with coronary artery disease
• stable
  
  • meds
    
    • amiodarone
    • lidocaine
    • procainamide
    • tx underlying causes
• unstable
  
  • shoch
  • tx underlying causes
  • medications

Question 13

Tx for Sudden Cardiac Death

Answer 13

• BLS
• early defibrillation

Question 14

Rhythm Control

Answer 14

• to achieve and maintain sinus rhythm (cardioversion)
• try first in pts who are
  
  • symptomatic
  • younger
  • presenting for first time with lone AF
  • secondary to treated precipitant
  • w/ congestive HF
• more likely to succeed if
  
  • recent onset AF
  • no structural heart disease
  • tx precipitating causes
  • young age
  • acute onset AF (MI)

Question 15

Rate Control

Answer 15

• to achieve resting HR 60-80/min
• to reduce undue inc. of HR during exercise
• pts unsuiable for cardioversion
• all pts with rapid AF initially to relieve sx
• control achieved in slowing
  
  • resting HR
  • HR during exercise