* Patients with<unk>  require complete cardiac evaluation, and those with<unk>  and syncope or near-syncope may require a pacemaker. * Some patients with<unk> , a markedly prolonged QRS (usually > 150 ms), and systolic heart failure may benefit from a biventricular pacemaker, which allows for better synchrony of heart contractions.
Left bundle branch block
Right bundle branch block
Bundle branch block
Sinoatrial block
Pre-excitation syndrome
Atrioventricular block
Sinoatrial arrest
Ventricular flutter