Bundle Branch Block · • RBBB - RSR in V1 • LBBB - ‘W’ shape in V1, ‘M’ shape in V6 •...
Transcript of Bundle Branch Block · • RBBB - RSR in V1 • LBBB - ‘W’ shape in V1, ‘M’ shape in V6 •...
![Page 1: Bundle Branch Block · • RBBB - RSR in V1 • LBBB - ‘W’ shape in V1, ‘M’ shape in V6 • Cannot diagnose the presence of MI with LBBB. Title: PowerPoint Presentation Created](https://reader034.fdocuments.in/reader034/viewer/2022043001/5f7c6e3843a56547f73342a5/html5/thumbnails/1.jpg)
Bundle Branch Block
Lancashire & South Cumbria Cardiac Network
![Page 2: Bundle Branch Block · • RBBB - RSR in V1 • LBBB - ‘W’ shape in V1, ‘M’ shape in V6 • Cannot diagnose the presence of MI with LBBB. Title: PowerPoint Presentation Created](https://reader034.fdocuments.in/reader034/viewer/2022043001/5f7c6e3843a56547f73342a5/html5/thumbnails/2.jpg)
Phases of Activation
• Phase 1 - septal depolarisation occurring from left to right, 1st and alone
• Phase 2 & 3 - depolarisation of free wall of left & right ventricles, occurring together
![Page 3: Bundle Branch Block · • RBBB - RSR in V1 • LBBB - ‘W’ shape in V1, ‘M’ shape in V6 • Cannot diagnose the presence of MI with LBBB. Title: PowerPoint Presentation Created](https://reader034.fdocuments.in/reader034/viewer/2022043001/5f7c6e3843a56547f73342a5/html5/thumbnails/3.jpg)
1
2
3
![Page 4: Bundle Branch Block · • RBBB - RSR in V1 • LBBB - ‘W’ shape in V1, ‘M’ shape in V6 • Cannot diagnose the presence of MI with LBBB. Title: PowerPoint Presentation Created](https://reader034.fdocuments.in/reader034/viewer/2022043001/5f7c6e3843a56547f73342a5/html5/thumbnails/4.jpg)
RV RV IVS IVS LV LV
V1 V2 V3 V4 V5 V6
![Page 5: Bundle Branch Block · • RBBB - RSR in V1 • LBBB - ‘W’ shape in V1, ‘M’ shape in V6 • Cannot diagnose the presence of MI with LBBB. Title: PowerPoint Presentation Created](https://reader034.fdocuments.in/reader034/viewer/2022043001/5f7c6e3843a56547f73342a5/html5/thumbnails/5.jpg)
Bundle Branch Block
• A delay of conduction in either of the bundle branches.
![Page 6: Bundle Branch Block · • RBBB - RSR in V1 • LBBB - ‘W’ shape in V1, ‘M’ shape in V6 • Cannot diagnose the presence of MI with LBBB. Title: PowerPoint Presentation Created](https://reader034.fdocuments.in/reader034/viewer/2022043001/5f7c6e3843a56547f73342a5/html5/thumbnails/6.jpg)
Right Bundle Branch Block
• In RBBB the right ventricle is stimulated by the impulse from the left ventricle.
![Page 7: Bundle Branch Block · • RBBB - RSR in V1 • LBBB - ‘W’ shape in V1, ‘M’ shape in V6 • Cannot diagnose the presence of MI with LBBB. Title: PowerPoint Presentation Created](https://reader034.fdocuments.in/reader034/viewer/2022043001/5f7c6e3843a56547f73342a5/html5/thumbnails/7.jpg)
![Page 8: Bundle Branch Block · • RBBB - RSR in V1 • LBBB - ‘W’ shape in V1, ‘M’ shape in V6 • Cannot diagnose the presence of MI with LBBB. Title: PowerPoint Presentation Created](https://reader034.fdocuments.in/reader034/viewer/2022043001/5f7c6e3843a56547f73342a5/html5/thumbnails/8.jpg)
Phases of Activation
• The septum depolarises from left to right as normal. (1)
• The left ventricle is depolarised as normal. (2)
• Finally the right ventricle is depolarised late (wide) in an anterior movement. (3)
• Resulting QRS is wide due to slow conduction through myocardial cells.
![Page 9: Bundle Branch Block · • RBBB - RSR in V1 • LBBB - ‘W’ shape in V1, ‘M’ shape in V6 • Cannot diagnose the presence of MI with LBBB. Title: PowerPoint Presentation Created](https://reader034.fdocuments.in/reader034/viewer/2022043001/5f7c6e3843a56547f73342a5/html5/thumbnails/9.jpg)
![Page 10: Bundle Branch Block · • RBBB - RSR in V1 • LBBB - ‘W’ shape in V1, ‘M’ shape in V6 • Cannot diagnose the presence of MI with LBBB. Title: PowerPoint Presentation Created](https://reader034.fdocuments.in/reader034/viewer/2022043001/5f7c6e3843a56547f73342a5/html5/thumbnails/10.jpg)
ECG criteria for RBBB
• (1) QRS duration exceeds 0.12 seconds• (2) RSR complex in V1• (3) Delayed S wave in Ι, V5, V6• (4) ST/T must be opposite in direction to the
terminal QRS(is secondary to the block and does not
predispose primary ST/T changes)
![Page 11: Bundle Branch Block · • RBBB - RSR in V1 • LBBB - ‘W’ shape in V1, ‘M’ shape in V6 • Cannot diagnose the presence of MI with LBBB. Title: PowerPoint Presentation Created](https://reader034.fdocuments.in/reader034/viewer/2022043001/5f7c6e3843a56547f73342a5/html5/thumbnails/11.jpg)
RBBB & MI
• If abnormal Q waves are present they will not be masked by the BBB pattern.
• This is because there is no alteration of the initial part of the complex RS (in V1) and abnormal Q waves can still be seen.
![Page 12: Bundle Branch Block · • RBBB - RSR in V1 • LBBB - ‘W’ shape in V1, ‘M’ shape in V6 • Cannot diagnose the presence of MI with LBBB. Title: PowerPoint Presentation Created](https://reader034.fdocuments.in/reader034/viewer/2022043001/5f7c6e3843a56547f73342a5/html5/thumbnails/12.jpg)
Significance of RBBB
• RBBB is seen in :-(1) occasional normal subjects(2) pulmonary embolus(3) coronary artery disease (4) ASD(5) active carditis(6) RV diastolic overload
![Page 13: Bundle Branch Block · • RBBB - RSR in V1 • LBBB - ‘W’ shape in V1, ‘M’ shape in V6 • Cannot diagnose the presence of MI with LBBB. Title: PowerPoint Presentation Created](https://reader034.fdocuments.in/reader034/viewer/2022043001/5f7c6e3843a56547f73342a5/html5/thumbnails/13.jpg)
Partial / Incomplete RBBB
• is diagnosed when the pattern of RBBB is present but the duration of the QRS does not exceed 0.12 seconds.
![Page 14: Bundle Branch Block · • RBBB - RSR in V1 • LBBB - ‘W’ shape in V1, ‘M’ shape in V6 • Cannot diagnose the presence of MI with LBBB. Title: PowerPoint Presentation Created](https://reader034.fdocuments.in/reader034/viewer/2022043001/5f7c6e3843a56547f73342a5/html5/thumbnails/14.jpg)
Left Bundle Branch Block
• In LBBB the left ventricle is activated from the right bundle.
![Page 15: Bundle Branch Block · • RBBB - RSR in V1 • LBBB - ‘W’ shape in V1, ‘M’ shape in V6 • Cannot diagnose the presence of MI with LBBB. Title: PowerPoint Presentation Created](https://reader034.fdocuments.in/reader034/viewer/2022043001/5f7c6e3843a56547f73342a5/html5/thumbnails/15.jpg)
![Page 16: Bundle Branch Block · • RBBB - RSR in V1 • LBBB - ‘W’ shape in V1, ‘M’ shape in V6 • Cannot diagnose the presence of MI with LBBB. Title: PowerPoint Presentation Created](https://reader034.fdocuments.in/reader034/viewer/2022043001/5f7c6e3843a56547f73342a5/html5/thumbnails/16.jpg)
Phases of Activation
• Impulse passes to the left of the septum below the block (1a) at the same time as the paraseptal region. (1b)
• Activation of the RV follows (small magnitude). (2)
• Finally delayed activation of the LV which is slow due to conduction through normal myocardium. (3)
![Page 17: Bundle Branch Block · • RBBB - RSR in V1 • LBBB - ‘W’ shape in V1, ‘M’ shape in V6 • Cannot diagnose the presence of MI with LBBB. Title: PowerPoint Presentation Created](https://reader034.fdocuments.in/reader034/viewer/2022043001/5f7c6e3843a56547f73342a5/html5/thumbnails/17.jpg)
![Page 18: Bundle Branch Block · • RBBB - RSR in V1 • LBBB - ‘W’ shape in V1, ‘M’ shape in V6 • Cannot diagnose the presence of MI with LBBB. Title: PowerPoint Presentation Created](https://reader034.fdocuments.in/reader034/viewer/2022043001/5f7c6e3843a56547f73342a5/html5/thumbnails/18.jpg)
ECG criteria for LBBB
(1)Prolonged QRS complexes, greater than 0.12 seconds
(2)Wide, notched QRS (M shaped) Ι, AVL, V5, V6
(3)Wide, notched QS complexes are seen in V1 (due to spread of activation away from the electrode through septum + LV)
(4)In V2, V3 small r wave is seen due to activation of paraseptal region
![Page 19: Bundle Branch Block · • RBBB - RSR in V1 • LBBB - ‘W’ shape in V1, ‘M’ shape in V6 • Cannot diagnose the presence of MI with LBBB. Title: PowerPoint Presentation Created](https://reader034.fdocuments.in/reader034/viewer/2022043001/5f7c6e3843a56547f73342a5/html5/thumbnails/19.jpg)
LBBB & MI
• MI should not be diagnosed in the presence of LBBB → Q waves are masked by LBBB pattern.
![Page 20: Bundle Branch Block · • RBBB - RSR in V1 • LBBB - ‘W’ shape in V1, ‘M’ shape in V6 • Cannot diagnose the presence of MI with LBBB. Title: PowerPoint Presentation Created](https://reader034.fdocuments.in/reader034/viewer/2022043001/5f7c6e3843a56547f73342a5/html5/thumbnails/20.jpg)
Significance of LBBB
• LBBB is seen in :-
(1) Always indicative of organic heart disease
(2) Found in ischaemic heart disease
(3) Found in hypertension.
![Page 21: Bundle Branch Block · • RBBB - RSR in V1 • LBBB - ‘W’ shape in V1, ‘M’ shape in V6 • Cannot diagnose the presence of MI with LBBB. Title: PowerPoint Presentation Created](https://reader034.fdocuments.in/reader034/viewer/2022043001/5f7c6e3843a56547f73342a5/html5/thumbnails/21.jpg)
Partial / Incomplete LBBB
• is diagnosed when the pattern of LBBB is present but the duration of the QRS does not exceed 0.12 seconds.
![Page 22: Bundle Branch Block · • RBBB - RSR in V1 • LBBB - ‘W’ shape in V1, ‘M’ shape in V6 • Cannot diagnose the presence of MI with LBBB. Title: PowerPoint Presentation Created](https://reader034.fdocuments.in/reader034/viewer/2022043001/5f7c6e3843a56547f73342a5/html5/thumbnails/22.jpg)
Summary
• BBB - delay/block in either of the bundle branches
• RBBB - RSR in V1• LBBB - ‘W’ shape in V1, ‘M’ shape in V6• Cannot diagnose the presence of MI with
LBBB