Med/Surg: Arrhythmias and Pacemakers

Question 1

What are the normal durations for each of the ECG waveforms and intervals?

Answer 1

• P wave: 0.06 - 0.12
• PR Interval: 0.12 - 0.20
• QRS Interval: < 0.12
• ST Segment: 0.12
• T wave: 0.16
• QT Interval: 0.34 - 0.43

Question 2

What are the intrinsic rates of the conduction system?

Answer 2

• SA node: 60-100 times/min
• AV node: 40-60 times/min
• Bundle of His, Purkinje fibers: 20-40 times/min

Question 3

What are the common cardiac conditions that causes dysrhythmias?

Answer 3

• Accessory pathways
• Cardiomyopathy
• Conduction defects
• Heart failure
• Myocardial ischemia, infarction
• Valve disease

Question 4

What are the initial interventions for dysrhythmias?

Answer 4

1. Ensure ABCs
2. Administer 0₂ via nasal cannula or non-rebreather mask
3. Obtain baseline vital signs, including O₂ saturation
4. Obtain 12-lead ECG
5. Initiate continuous ECG monitoring
6. Identify underlying rate and rhythm
7. Identify dysrhythmia
8. Establish IV access

Question 5

What are the ongoing monitoring interventions for dysrhythmia?

Answer 5

1. Monitor vita signs, level of consciousness, O₂ saturation, and cardiac rhythm.
2. Anticipate need for administration of antidysrhythmia drugs and analgesics.
3. Anticipate need for intubation if respiratory distress is evident.
4. Prepare to initiate cardiac support (eq. CPR, defibrillation, transcutaneous pacing)

Question 6

What are the common states associated with sinus bradycardia?

Answer 6

• Hypothyroidism
• Increased intracranial pressure
• Hypoglycemia
• Inferior wall myocardial infarction (MI)

Question 7

What is the common ECG characteristics and treatment for sinus bradycardia?

Answer 7

Characteristics:

• HR less than 60. Normal ECG

Treatment:

• Administration of atropine (anticholinergic drug).
• Pacemaker may be required
• If caused by drugs, held or discontinued.

Question 8

What is the common ECG characteristics and treatment for sinus tachycardia?

Answer 8

ECG Characteristics:

• HR 101 - 200 beats/min
• Normal characteristics

Treatment:

• If from pain, effective pain management
• Treating hypovolemia
• if clinically stable, vagal maneuvers
• In addition, beta blockers