Supraventricular arrhythmias in intensive care unit patients: short and long-term consequences.

BACKGROUND: Supraventricular arrhythmias (SVA), including atrial fibrillation and flutter, are common in surgical and nonsurgical intensive care unit (ICU) patients. There is increased mortality among surgical ICU patients who develop new-onset atrial arrhythmias after noncardiac, non-thoracic surgery. We sought to determine the preadmission and intra-ICU factors associated with the development of new-onset SVA and mortality in these patients.
METHODS: Consecutive patients (n = 611) admitted to a general ICU of a tertiary care hospital were prospectively followed until hospital discharge for evidence of SVA, potential etiologies of these arrhythmias, and consequences of the arrhythmias. Excluded were patients who sustained recent cardiac/thoracic surgery or trauma to the thorax. Long-term survival rates (48 mo from the date of hospitalization) were also determined.
RESULTS: Fifty-two (9%) patients developed new-onset SVA and 75 (12%) had prehospital admission histories of SVA. Eighty-seven (18%) of those without SVA died while hospitalized, while 29 (56%) and 23 (31%) of those with new-onset and histories of SVA, respectively, died while hospitalized. ICU mortality in all groups was associated with sepsis, acute renal failure, myocardial ischemia, and high APACHE II scores. The APACHE II scores were higher (23 +/- 8 [sd]) in new-onset SVA than in the group without SVA (16 +/- 8, P < 0.05). Within a year of hospital admission 65% in the new-onset, 50% in the SVA history, and 20% in the no-SVA groups died.
CONCLUSIONS: New-onset SVA occur frequently in ICU patients and are markers of extremely high in-hospital and 1-yr mortality.