A<unk>  <unk>  is a heart block in the<unk>  bundle branch of the electrical conduction system. During a<unk> , the<unk>  ventricle is not directly activated by impulses travelling through the<unk>  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<unk>  ventricle and depolarize the<unk>  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<unk>  ventricle.
Right bundle branch block
Left bundle branch block
Bundle branch block
Sinoatrial block
Pre-excitation syndrome
Atrioventricular block
Sinoatrial arrest
Torsades de pointes