Frequency of atrial fibrillation: about 1%
Key risk factors:
(1) history of atrial fibrillation (AF)
(2) history of congestive heart failure (CHF)
|
History of AF
|
History of CHF
|
Odds Ratio for AF with Stress Test
|
|
present
|
present
|
8.0
|
|
present
|
absent
|
18.4
|
|
absent
|
present
|
1.3
|
|
absent
|
absent
|
1
|
Additional factors identified on univariate analysis:
(1) older age
(2) abnormal baseline ECG changes
(3) right bundle branch block
(4) lower resting heart rate
(5) higher peak heart rate durng the stress test
Most patients who develop atrial fibrillation do so during the dobutamine infusion. A few patients may develop AF within 10 minutes of discontinuing the infusion.
A patient who is hemodynamically unstable should be admitted for observation and monitoring.
Most patients spontaneously revert to their usual rhythm within 1 hour. A patient with persistent AF can be dismissed with followup as an outpatient later in the day or the next morning if ALL of the following are absent:
(1) hypotension
(2) suboptimal heart rate
(3) markedly abnormal findings on the stress test
(4) significant clinical symptoms with chest pain or dyspnea
If any of these findings are present then the patient should be admitted for observation and monitoring.
A patient with persistent AF and outpatient followup may benefit from a low-dose beta-blocker if not taking an oral AV nodal-blocking drug.
