Update on cardiac arrhythmias in the ICU.

PURPOSE OF REVIEW To explore recent findings on the treatment and outcome of cardiac arrhythmias and how they affect ICU activities. RECENT FINDINGS The rate vs. rhythm control debate for the treatment of chronic atrial fibrillation continues. It is still unclear whether the postcardiac surgery inflammatory response contributes to the development of atrial fibrillation. In noncardiothoracic surgery/trauma patients hospitalized in an ICU, new-onset supraventricular arrhythmias are associated with markedly elevated mortality when compared with patients with a prior history of such arrhythmias and patients who do not develop arrhythmias. The onset of new supraventricular arrhythmias in such patients appears to be a manifestation of multiple system organ failure as it is closely associated with sepsis. Cardioversion of supraventricular arrhythmias with biphasic waveforms is being studied to determine whether it is more effective than cardioversion with monophasic waveforms. SUMMARY Supraventricular arrhythmias, especially atrial fibrillation, occur frequently in ICU patients. Intensivists not only treat atrial fibrillation itself but also its complications and the complications of the therapies used to prevent these complications. In ICU patients, ventricular arrhythmias have ominous implications because they usually portend either a major cardiac or a systemic dysfunction or both.