2.4 Conducting Abnormalities

Question 1

Conduction Abnormalities

Answer 1

Examples
- Bundle Branch Block (BBB)
- Heart Blocks
- Long QT Syndrome (LQTS)

Question 2

First Degree HeartBlock

Answer 2

• Concerning because it is a precursor of higher degrees of block
• Recognized by prolonged PR Interval on ECG

Question 3

Second Degree Heartblock

Answer 3

• Atrial impulse through AV node or Bundle of His is interrupted (Results in dropped/skipped beats)

Type 1 (Wenckebach)
- Occurs in AV node and caused by myocardial ischemia or MI

Type 2
- Associated with decreased cardiac output, hypertension, myocardial ischemia
- Usually progresses to higher grades of block
- Occurs after AV node (Bundle of HIS or Purkinje Fibers)

Question 4

Third Degree AV Block

Answer 4

• Complete heart block
• Complete dissociation between atria and ventricles
• Usually blocked in AV Junction or Bundle of HIS
• P and R waves occur at regular intervals but they are not in sync
• Abnormal slow heartbeat
• Ventricles usually pump at their “lifesaving” rhythm (20-40 bpm)

SYMPTOMS
- Ventricles pump slowly which means they do not effectively pump blood to the rest of the body
- Lightheadedness/Dizziness/Extreme Fatigue
- Loss of Consciousness

TREATMENT
- Pacemaker

Question 5

Third Degree AV Block

Answer 5

ASSOCIATIONS
- Systemic Diseases
(Amyloidosis - Buildup of amyloid in organs)
(Scleroderma - Hardening/Tightening of Skin)
- Sever Heart Disease (CAD, MI, Myocarditis, Cardiomyopathy)
- Drugs (Digoxin, Beta-Blockers, Calcium Channel Blockers)

RISKS (Priority Assessment is How Stable They Are)
- Significant Decrease in CO
- Ischemia
- HF
- Shock
- Syncope due to severe bradycardia and sometimes asystole

Question 6

3rd Degree AV Block Interventions

Answer 6

• Atropine to raise HR
• Epinephrine to raise HR
• External Pacemaker
  (Pads that supply transcutaneous electrical impulses to maintain HR. Used until they can implement a permanent pacemaker)
• Permanent Pacemaker is usually the best treatment