Clinical Treatment of Arrhythmias

Question 1

1. Recognize clinical arrhythmia syndromes in relation to underlying etiologies.
2. Describe acute treatment of arrhythmias when encountered in clinical practice.
3. Discuss long-term options for arrhythmia treatment especially as it relates to individualization of patient care.
4. Discuss the advantages and limitations of different arrhythmia treatment strategies.

Answer 1

a

Question 2

Where in the conduction system do bradyarrhythmias develops?

Answer 2

• SA node
• AV node
• Below AV node

Question 3

Which types of bradyarrhythmias are due to SA node dysfunction?

Answer 3

1) Sinus bradycardia
2) Sinus arrest/puase
3) Tachy-brady syndrome
4) Chronotropic incompetence

Question 4

Describe sinus bradycardia

Answer 4

• Persistent slow rate from SA node
• HR = 55
• PR interval = 180ms

Question 5

Describe sinus arrest

Answer 5

• failure of SA node to discharge => absence of atrial depolarization and periods of ventricular asystole (flat line)
• HR = 75
• PR interval = 180ms
• 2.8 second arrest

Question 6

Describe brady-tachy syndrome

Answer 6

• Intermittent episodes of slow and fast rates from SA node or atria
• HR during brady = 43
• HR during tachy = 130

Question 7

Describe chronotropic incompetence

Answer 7

• Inability to mount age-appropriate HR w/ exercise

- Remember the graph? Can barely reach and can’t stabilize appropriate HR

Question 8

Which types of bradyarrhythmias are due to AV node dysfunction?

Answer 8

1) First degree AV block

2) Mobitz I 2nd degree AV block (Wenkebach)

Question 9

Describe first-degree AV block

Answer 9

• AV conduction is delayed
• PR interval is prolonged (>200ms)
• HR = 79

Question 10

Describe Mobitz I 2nd degree AV block (Wenkebach)

Answer 10

• Progressive prolongation of PR interval until ventricular beat is dropped
• Ventricular rate = irregular
• Atrial rate = 90

Question 11

Which types of bradyarrhythmias are due to dysfunction below the AV node (infranodal/His Purkinje system)

Answer 11

1) Mobitz II 3rd degree AV block (Wenkebach)

2) Complete heart block

Question 12

Describe Mobitz II 3rd degree AV block (Wenkebach)

Answer 12

• No impulse conduction from atria to ventricles
• Atrial rate > Ventricular rate
• Vent rate = 37
• Atrial rate = 130
• PR interval is variable

Question 13

At what point should you be concerned about bradyarrhythmias?

Answer 13

1) When the pt is symptomatic (doesn’t matter which part of conduction system is affected)
2) When rhythm is intranodal

Question 14

Describe the treatment methods of bradyarrhythmias

Answer 14

• Treat reversible causes (ischemia, hypothyroidism, lyme disease)
• Stop offending meds if possible
• Acute tx in unstable pt: beta-agonists, temporary transvenous pacing
• Long term: pacemaker (only option)