Epidemiology and management of atrial fibrillation in medical and noncardiac surgical adult intensive care unit patients

Purpose: The aim of the study was to describe the epidemiology and management of atrial fibrillation (AF) in noncardiac surgery critically ill patients in a retrospective, observational study at 3 mixed medical-surgical, university-affiliated intensive care units (ICUs).

Methods: Consecutive patients admitted during a 1-year period with any documentation of AF during ICU stay were identified. Demographic data, risk factors, interventions, and outcomes were collected from the medical record.

Results: A total of 3081 patients were admitted during the 1-year study period in which 348 consecutive patients (10.5%) had documented AF. Atrial fibrillation was of new onset in 139 patients (4.5%) and preexisting in 186 patients (6.0%). Hemodynamic instability developed in 37% and 10% of patients with new-onset AF and patients with preexisting AF, respectively. Most (73%) patients with new-onset AF had at least 1 modifiable risk factor. Pharmacologic rhythm conversion was attempted in 76% and 26% of patients with new-onset AF and patients with preexisting AF, respectively. Although initially successful in 87% of new-onset cases, 42% reverted back to AF. Electrical conversion was successful in 7 (27%) of 26 and 0 (0%) of 5 of patients with new-onset AF and patients with preexisting AF, respectively. In total, 18% and 62% of patients with new-onset AF and patients with preexisting AF, respectively, who survived to ICU discharge left the ICU in AF.

Conclusions: Atrial fibrillation is common but transient in most ICU patients. Electrical cardioversion is often unsuccessful, and pharmacologic rhythm conversion is often only transiently effective. Modifiable risk factors are common among these patients. Future studies are needed to address the management of AF in the ICU.