Cardiac arrhythmias in the intensive care unit

Cardiac arrhythmias are a common problem encountered in the intensive care unit (ICU) and represent a major source of morbidity. Arrhythmias are most likely to occur in patients with structural heart disease. The inciting factor for an arrhythmia in a given patient may be an insult such as hypoxia, infection, cardiac ischemia, catecholamine excess (endogenous or exogenous), or an electrolyte abnormality. Management includes correction of these imbalances as well as medical therapy directed at the arrhythmia itself. The physiological impact of arrhythmias depends on ventricular response rate and duration, and the impact of a given arrhythmia in a given situation depends on the patient's cardiac physiology and function. Similarly, urgency and type of treatment are determined by the physiological impact of the arrhythmia as well as by underlying cardiac status. The purpose of this review is to provide an update regarding current concepts of diagnosis and acute management of arrhythmias in the ICU. A systematic approach to diagnosis and evaluation will be presented, followed by consideration of specific arrhythmias.