Heart Block Flashcards
1
Q
Which heart blocks commonly need intervention?
A
- 2nd Degree Mobitz Type 2
- 3rd Degree Heart Block
- Left Bundle Branch Block
2
Q
CLASSIFICATION: Atrioventricular Block
A
1. First Degree Heart Block
- Prolonged PR interval (>0.22s)
- Every P wave followed by QR
2. Second Degree Heart Block
a) Mobitz Type 1
- PR prolongation getting bigger each cycle until P wave does not conduct
b) Mobitz type 2
- PR interval constant
- P wave NOT always followed by QRS (2:1 OR 3:1 usually)
3. Third degree heart block
- P waves unconnected to QRS
- Failure of atrial impulses trasmitting to ventricles
3
Q
CAUSES: 2nd Degree Heart Block
A
- Medication (antiarrhytmics)
- Age - fibrosis
- IHD, MI
- Inflammatory Diseases - SLE, RA, ankylosing spondylitis
- Structural Abnormalities - esp aortic stenosis
4
Q
SYMPTOMS, INVESTIGATIONS, MANAGEMENT: Type 2 Mobitz II Block
A
Symptoms
Stokes-Adam Attack
- Syncope followed by ventircular slower rate
- Investigations*
- ECG
- Cardiac imaging/catheterisation
Management
- ATROPINE (symptoms)
- Usually needs cardiac pacemaker
5
Q
CAUSES: 3rd Degree Heart Block
A
- Congenital
- Strongly associated with anti-RO in SLE
6
Q
CLINICAL FEATURES: 3rd Degree Heart Block
A
- syncope
- heart failure
- regular bradycardia (30-50 bpm)
- wide pulse pressure
- JVP: cannon waves in neck
- variable intensity of S1
7
Q
PATHOLOGY: Bundle Branch Block
A
- Abnormal conduction through right or elft bundle branches
- Leads to delay in QRS depolarisation
- = widening of QRS complex (>120ms)
8
Q
How can you distinguish LBBB from RBBB on an ECG?
A
Left Bundle Branch = WiLLiaM
- ‘W’ shape in V1 QRS
- ‘M’ shape in V6 QRS
Right Bundle Branch = MaRRoW
- ‘M’ shape in V1 QRS
- ‘W shape in V6 QRS
9
Q
CAUSES: RBBB
A
Congenital
- Atrial septal defect
- Pulmonary stenosis
- Ventricular septal defect
Pulmonary disease
- Cor pulmonale
- PE
Cardiac Disease
- MI
- Cardiomyopathy
10
Q
CAUSES: LBBB
A
- Aortic stenosis
- HTN
- MI
- Severe coronary disease
