Heart block:A blockageinthe conduction of the normal electrical impulses in the heart. Heart block is not uncommon and is detected with an electrocardiogram. Heart block occurs from degeneration or scarring of the electrical pathways in theheart muscle, either naturally or as a result ofdisease．心肌梗死通常不需要治疗,但是can be a factor in the decision of whether or not to put a pacemaker in a heart that is failing or irregularly beating.
