Heart Block Flashcards
what are the different types of heart block?
• 1st Degree AV Block • 2nd Degree AV Block o Mobitz Type I o Mobitz Type II • 3rd Degree (Complete) AV Block
what are the risk factors of heart block?
• MI or ischaemic heart disease (MOST COMMON) • Infection infective endocarditis • Drugs digoxin • Metabolic hyperkalaemia • Infiltration of conducting system sarcoidosis • Degeneration of the conducting system
presenting symptoms of ast and 2nd degree heart block?
- 1st Degree - asymptomatic
* 2nd Degree - usually asymptomatic
what are other signs of 3rd degree heart block?
o may cause Stokes-Adams Attacks = syncope
o heart failure
o regular bradycardia
o wide pulse pressure
o JVP cannon waves
- This occurs when the atria and ventricles contract simultaneously
o Variable intensity of S1
o Reduced cardiac output
what is the nature of a first degree heart block on ECG?
fixed prolonged PR interval (> 0.2 s)
what is the nature of a second degree M1 heart block on ECG
Progressive prolongation of the PR interval unit until a dropped beat occurs.
what is the nature of a second degree M2 heart block on ECG
The PR interval is constant but the P wave is often not followed by a QRS complex.
what is the nature of a complete heart block on ECG
- no relationship between P waves and QRS complexes.
what might be seen on ECG for a stokes adams attack?
o P and QRS complexes are completely separate
o Strange wide inverted T waves can be seen
when should a pacemaker be inserted?
o Permanent pacemaker is recommended in:
• Complete heart block
• Advanced Mobitz Type II
• Symptomatic Mobitz Type I
how should an acute block be managed?
IV atropine
what are the possible complications of heart block?
- Asystole
- MI – often of the right coronary artery
- Heart failure
- Complications of any pacemaker inserted
prognosis of heart block?
- mobitz type II and 3rd degree have a bad prognosis
