Diagnosis and therapy of perioperative arrhythmias.

Cardiac arrhythmias are extremely common in the perioperative setting. They only require treatment when they (1) interfere significantly with normal tissue perfusion; (2) adversely affect the normal balance between myocardial oxygen supply and demand; or (3) predispose the patient to ventricular tachycardia or fibrillation. Usually, the treatment is simple: correct the underlying cause or causes. In some instances, either the cause will not be apparent or time will not permit adequate identification of the precipitating events. In these instances, drug treatment or electrical therapy is indicated. The classification of arrhythmias and the actions, indications, dosages and routes, and major side effects of the drugs commonly used in their treatment are summarized in Tables 1 through 3. The indications for electrical therapy, including pacemakers and cardioversion, were discussed in the sections dealing with bradyarrhythmias, tachyarrhythmias, and AV conduction block.