Right bundle branch block

A right bundle branch block (RBBB) is a heart block in the right bundle branch of the electrical conduction system.RBBB with associated first degree AV blockRBBB with associated tachycardiaRBBB A right bundle branch block (RBBB) is a heart block in the right bundle branch of the electrical conduction system. During a right bundle branch block, the right ventricle is not directly activated by impulses travelling through the right bundle branch. The left ventricle however, is still normally activated by the left bundle branch. These impulses are then able to travel through the myocardium of the left ventricle to the right ventricle and depolarize the right ventricle this way. As conduction through the myocardium is slower than conduction through the Bundle of His-Purkinje fibres, the QRS complex is seen to be widened. The QRS complex often shows an extra deflection that reflects the rapid depolarisation of the left ventricle followed by the slower depolarisation of the right ventricle. It is seen in healthy individuals in about 1.5-3%. Common causes are Normal variant, Right ventricular hypertrophy or strain, Congenital heart disease such as atrial septal defect and Ischemic heart disease. In addition, a right bundle branch block may also result from Brugada syndrome, pulmonary embolism, rheumatic heart disease, myocarditis, cardiomyopathy, or hypertension. The criteria to diagnose a right bundle branch block on the electrocardiogram: