Bundle Branch Block

Question 1

General rule of thumb of for bundle branch block

Answer 1

Wide QRS complexes

Question 2

Causes of RBBB

Answer 2

Normal variant (isolated RBB)
Pulmonary embolism
Cor pulmonale
VSD
IHD

Question 3

Pathophysiology RBBB

Answer 3

Block in the conduction of the bundle branches, so the ventricles don’t receive impulses at the same time. Right bundle doesn’t conduct. Impulses spreads from left ventricle to right ventricle = LATE ACTIVATION OF RV

Question 4

ECG of RBBB

Answer 4

M = ‘RSR’ pattern in V1 with dominant R
Inverted T waves in V1-V3 or V4
W = Wide slurred S wave in V6
MarroW

Question 5

Auscultation sound for RBBB

Answer 5

Physiological S2 SPLITTING (heart sound)

Question 6

Treatment of RBBB

Answer 6

Pacemaker
Cardiac resynchronisation therapy
Reduce BP

Question 7

Causes of LBBB

Answer 7

IHD,
HTN,
Cardiomyopathy,
Idiopathic fibrosis

Question 8

Pathophysiology of LBBB

Answer 8

Block in conduction of one the bundle branches, so the ventricles don’t receive impulses at the same time. Left bundle branch doesn’t conduct. Impulses spreads from RV -> LV
Late activation of LV

Question 9

ECG of LBBB

Answer 9

‘M’ pattern in V5
Dominant S in V1 (W)
Inverted T waves 1, AVL, V5-V6
WilliaM = Wide QRS + notched top, T wave inversion in lateral leads

Question 10

Auscultation sounds of LBBB

Answer 10

Reversed S2 splitting

Question 11

Treatment

Answer 11

Same as RBBB