Diagnostic criteria

  The QRS width is

                  120 ms or more (at least 3 small squares) in adults,

                  100 ms or more in children between 4-16 years,

                  90 ms or more in children under 4 years.

  Leads I and V6 have wide S waves: S waves are wider than R waves or wider than 40 ms.

  Leads V1 or V2 are expected to have terminal R waves. This may be seen as rsr', rsR' or rSR'. r' or R' waves are usually wider than the R wave.

  If there is no notch in R wave despite the presence of a big R wave, then the R peak time should be more than 50 ms in V1 while it is normal in V5 or V6.


RBBB Pattern - Incomplete RBBB

  The QRS width is between

                  100-120 ms in adults,

                  90-100 ms in children older than 4 years and younger than 16 years,

                  86-90 ms in children under 4 years of age.

  Other criteria of the right bundle branch block should be satisfied.



RBBB and acute myocardial infarction

  In patients with preexisting RBBB, development of ST segment depression in leads C1 to C4 is a common finding and does not suggest a diagnosis of coronary artery disease.

  In patients with preexisting RBBB, development of ST segment depression in leads C5, C6, II and aVF suggests a diagnosis of coronary artery disease.



RBBB and acute myocardial infarction

  RBBB does not interfere with the diagnosis of acute myocardial infarction.

  Presence of RBBB shows poor prognosis in patients with coronary artery disease.

  New-onset RBBB during acute myocardial infarction has a worse prognosis than old RBBB.

      (On the contrary, in acute anterior wall myocardial infarction and left bundle branch block (LBBB),

      the mortality rate with old LBBB is higher than new-onset LBBB.)



Some of the criteria that are suggested for the diagnosis of Left Ventricular Hypertrophy (LVH)
in the presence of right bundle branch block (RBBB) are

  The amplitude of S wave in C1 > 2mm (0.2 mV).

  The R wave amplitude in C5 or C6 > 15 mm (1.5mV).

  QRS axis is left to the -30 degrees.

  RI > 11mm (1.1mV).

  Regarding the amplitudes of S wave in lead III and R wave in any precordial lead, the R/S amplitude > 30 mm (3 mV)



RBBB and treadmill exercise test

  In patients with preexisting RBBB, development of ST segment depression in leads C1 to C4 is a common finding and does not suggest a diagnosis of coronary artery disease.

  In patients with preexisting RBBB, development of ST segment depression in leads C5, C6, II and aVF suggests a diagnosis of coronary artery disease.



References (including links to abstract and full-text articles)

  Circulation 2009;119:e235-e240 .

  Am J Cardiol 1969;23:877.

  Am J Cardiol 1987;59:798.

  Circulation 1975;51:477-484.

  Circulation 1998;98:2494-2500.

  PACE 1998;21:2651.




ECG 1. Right bundle branch block is seen in the above ECG.
It is from a 67 years-old hypertensive woman with normal coronary arteries.
Negative T waves in leads V1 and V2 are not related to ischemia.

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ECG 2. Right bundle branch block pattern in an adult. The QRS width is not increased ( <120ms ). Other criteria of the right
bundle branch block are satisfied.

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ECG 3. Right bundle branch block (RBBB) and left anterior fascicular block (LAFB) in a patient with systemic arterial
hypertension and chronic obstructive pulmonary disease (COPD). RBBB is more prevalent in patients with COPD,
while LAFB is more prevalent in subjects with systemic arterial hypertension.

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ECG 4. The above ECG belongs to an 8 years old boy. He was operated for Transposition of the Great Arteries and Ventricular
Septal Defect (VSD) when he was 1 year old. VSD closure operations increase the risk of right bundle branch block.

Dr. Mahmut Gokdemir has donated this ECG to our website.

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ECG 5. Right bundle branch block in a middle-aged woman with normal coronary arteries.

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ECG 6. Right bundle branch block and nodal rhythm in a patient under Digoxin treatment.
No P waves preceed QRS complexes.

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ECG 7. The ECG above belongs to a 46 years-old hypertensive man who has echocardiographically confirmed left ventricular
hypertrophy. It shows right bundle branch block and left anterior fascicular block.
According to Gubner criteria, there is also left ventricular hypertophy pattern.

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ECG 8a. The ECG above belongs to a 59 years-old man. It was recorded in the Emergency Room. He had undergone
coronary artery bypass graft surgery 2 years ago. The ECG shows right bundle branch block (RBBB) , ST segment elevation
and tall T waves in inferior leads. Thrombolytic therapy with Tenecteplase was administered immediately after recording of
the above ECG. The time of onset of the RBBB in relation to infarction was uncertain in this patient.

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ECG 8b. One hour after tenecteplase, the ST segment elevation and tall T waves in inferior leads have disappeared. He does
not have chest pain now. Disappearance of chest pain with the regression of ECG signs suggest successful recanalization of
the infarct-related artery.

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ECG 9. The ECG above belongs to a 63 years-old man with coronary artery disease. A stent was implanted to his Circumflex
(Cx) coronary artery a year ago. He has never experienced myocardial infarction. The only abnormality in this ECG is RBBB.

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ECG 10. The ECG above belongs to a 76 years-old man with coronary artery disease. He had acute anterior myocardial infarction
12 years ago. Coronary artery bypass graft surgery was planned but he had refused the surgery. Now he has severe left
ventricular systolic dysfunction and all 4 cardiac chambers are dilated. The rhythm is atrial fibrillation.
Q waves in precordial leads and ST segment elevation in leads V5 and V6 are seen.
RBBB does not mask the diagnosis of old anterior myocardial infarction.

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ECG 11. The ECG above belongs to a 65 years-old man who had previously undergone coronary artery bypass graft surgery.
He experienced acute anteroseptal myocardial infarction before surgery. The patient now has left ventricular systolic
dysfunction. Q waves are seen in C1 and C2 .
RBBB does not mask the diagnosis of old anteroseptal myocardial infarction.

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ECG 12. The ECG above was recorded before the 63 years-old male patient underwent coronary artery bypass graft operation.
He previously had acute inferior myocardial infarction. RBBB does not mask the diagnosis of old inferior myocardial infarction.

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ECG 13. The ECG above was recorded when a 63 years-old man was experiencing his second acute anterior wall myocardial
infarction. He had had his acute anterior myocardial infarction 2 months ago after which RBBB developed. Now he has left
ventricular systolic dysfunction with an Ejection Fraction of 35%. The Q waves in leads C1 to C4 are not new but new-onset
ST segment elevation developed in leads C2 to C4 during his anterior RE -infarction.
RBBB does not mask the diagnosis of acute or old anteroseptal myocardial infarction.

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ECG 14. The ECG above belongs to a 63 years-old man with previous coronary artery bypass graft surgery. He also had acute
anterior myocardial infarction inb the past. Now, he has left ventricular systolic dysfunction with an Ejection Fraction of 30%.
Q waves in leads C1 to C3 , negative T waves in leads C4 to C6 and a VPC is seen.
RBBB does not mask the diagnosis of old anteroseptal myocardial infarction.

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ECG 15. The ECG above belongs to a 59 years-old man who previously had acute inferior wall myocardial infarction.
RBBB does not mask the diagnosis of old inferior myocardial infarction.

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ECG 16. The ECG above belongs to a 77 years-old woman who had never underwent diagnostic coronary angiography.
There are no signs of old myocardial infarction. Echocardiography shows left ventricular hypertrophy however the ECG
does not give any clues to that.
RBBB impairs the ECG diagnosis of left ventricular hypertrophy.

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ECG 17. The ECG above belongs to a 60 years-old woman who had had acute anterior myocardial infarction in the past.
She has severe left ventricular systolic dysfunction with an Ejection Fraction of 20%.
Precordial leads show Q waves and negative T waves .
RBBB does not mask the diagnosis of old anterior myocardial infarction.

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ECG 18. The ECG above belongs to an 85 years-old man who had acute inferior wall myocardial infarction in the past.
The ECG shows RBBB and APC. The PR interval i,s at the upper limit of normal.
RBBB does not mask the diagnosis of old inferior wall myocardial infarction.

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ECG 19. The ECG above belongs to a 58 years-old man. The rhythm is atrial fibrillation.
Right bundle branch block pattern (incomplete right bundle branch block) is seen.
The fibrillatory waves in lead V1 make the rSr' pattern hard to notice at first glance.

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ECG 20. The ECG above belongs to an old man with old inferior myocardial infarction and RBBB.

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ECG 21. The ECG above shows right bundle branch block pattern.
It belongs to a 6 months-old infant with a 7 mm wide, unoperated Atrial Septal Defect.
Her pulmonary valve systolic gradient was measured as 15 mmHg.
Crochetage sign in lead aVF is another abnormality in the above ECG.

Pediatric cardiologist Dr. Mahmut Gokdemir has donated the above ECG to our website.

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ECG 22a. The ECG above belongs to a 61 years-old man with subacute inferior myocardial infarction.
His coronary angiography showed proximal complete obstruction of the right coronary artery (RCA).
The LAD and Cx arteries were normal.
Shortly after recording of the above ECG, his RCA was successfully opened by a stent.
There is also right bundle branch block (RBBB).

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ECG 22b. Above is the same patient's ECG which was recorded 3 years after the ECG 22a.
Right bundle branch block persists.
The T wave negativity in lead aVF has disappeared and the amplitude of the q wave has decreased.
T wave negativity in lead III persists.

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ECG 23. The ECG above belongs to an apparently healthy one year-old baby. His echocardiogram is normal.
Incomplete right bundle branch block may be seen as a normal variant in apparently healthy children.

Pediatric cardiologist Dr. Mahmut Gokdemir has donated the above ECG to our website.

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ECG 24. The ECG above belongs to a 4 years-old boy who had been operated for AtrioVentricular Canal Defect (AVCD/AVSD).
He had also undergone prosthetic mitral valve implantation.
His ECHOcardiogram showed a dilated left ventricle.
This ECG shows right bundle branch in association with left ventricular hypertrophy.

Pediatric cardiologist Dr. Mahmut Gokdemir has donated this ECG to our website.




ECG 25. Above is the ECG from a 70 years-old man with old inferior myocardial infarction.
Right bundle branch block is seen.

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ECG 26. The ECG above belongs to a 4 months-old baby with congenital aortic stenosis.
Incomplete right bundle branch block is seen.
The maximum systolic gradient at aortic valve is measured as 50 mm Hg.

Pediatric cardiologist Dr. Mahmut Gokdemir has donated this ECG to our website.

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ECG 27. The above ECG is from an 86 years-old woman who was admitted to the emergency room with the diagnosis of
cardiogenic shock. Right bundle branch block is seen.
The ST segment elevation in leads V1 to V4 denotes acute anterior wall myocardial infarction.
She had been previously diagnosed as pancreas carcinoma. She died minutes after recording the above ECG.

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ECG 28. The ECG above is from a 76 years-old woman. It was recorded one month after her mitral valve replacement.
At first glance, the lead V1 may suggest the presence of right bundle branch block (RBBB).
The R'-like wave immediately after the R wave in lead V1 is actually a flutter wave.
Flutter waves with 2:1 AV block mimick RBBB in this patient. Actually there is no RBBB.

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ECG 29. The ECG above belongs to a woman with Scleroderma and pulmonary hypertension.
PR interval prolongation (first-degree AV block) and P wave widening (140 milliseconds, interatrial block) are seen.
Right bundle branch block is seen. The tall R wave in V1 is suggestive of right ventricular hypertrophy.

Dr. Peter Kukla has donated the above ECG to our website.

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