00:00:01 (MUSIC PLAYING)
00:00:05 Dr. Stiles: Hello. Today's medcast is on
00:00:08 atrial fibrillation in the acute care setting. My
00:00:11 name is Dr. Melissa styles at the Department of Family
00:00:14 Medicine, University of Wisconsin. I'm joined here by
00:00:17 Dr. Kathleen Walsh, Clinical Instructor. Thank you
00:00:19 for joining us Dr. Walsh.
00:00:22 Dr. Walsh: Thank you for the invitation.
00:00:25 Dr. Stiles: What is your initial approach to
00:00:26 a patient who presents with atrial fibrillation?
00:00:27 Dr. Walsh: In the acute setting, we look to
00:00:29 see whether the patient's stable or unstable. What we
00:00:31 mean by that is looking at the vital signs, heart
00:00:34 rate, blood pressure, respiratory rate, also
00:00:37 associated symptoms including shortness of breath,
00:00:40 chest pain, dizziness. And then we ask questions
00:00:43 regarding their past medical history if there is any
00:00:46 history of heart disease, hypertension.
00:00:49 Dr. Stiles: You mentioned heart disease and
00:00:50 hypertension. Are there any other risk factors for
00:00:52 atrial fibrillation?
00:00:52 Dr. Walsh: Yes, there are including thyroid
00:00:55 disease, either hypo or hyperthyroidism, lung disease,
00:00:59 COPD, history of pulmonary emboli and male gender and
00:01:04 advancing age.
00:01:06 Dr. Stiles: What are the major issues one
00:01:08 needs to address in the treatment of atrial
00:01:11 fibrillation in the acute setting?
00:01:13 Dr. Walsh: When looking at the patient you
00:01:15 really want to control the rate. Many times the heart
00:01:17 rate is above 130. You want to control that with
00:01:19 medications, then you choose between rate and rhythm
00:01:22 control. You rule out secondary causes such as
00:01:25 myocardial infarction, PE, thyroid disease, and then
00:01:30 you also worry about prevention of systemic
00:01:33 embolization.
00:01:35 Dr. Stiles: Many people have questions about
00:01:36 direct cardioversion in the acute setting. In what
00:01:39 situations would this be indicated?
00:01:39 Dr. Walsh: In those patients who are
00:01:41 hemodynamically unstable, blood pressure is too high
00:01:45 or too low, or those patients with acute ischemia on
00:01:49 ECG tracing.
00:01:51 Dr. Stiles: What are the main medications
00:01:51 used for rate control?
00:01:51 Dr. Walsh: The two main medications include
00:01:55 calcium channel blockers and beta blockers, the other
00:01:58 group of medication includes digoxin, but we primarily
00:02:01 consider these in patients with hypotension and those
00:02:04 with CHF. In patients with rapid atrial fibrillation,
00:02:07 medications are many times given intravenously to
00:02:11 control their rate and then subsequently put an IV
00:02:14 drip and then converted to PO medications.
00:02:17 Dr. Stiles: There's been a lot of recent
00:02:19 studies showing between rate and rhythm control that
00:02:22 both are equal in terms of outcomes. But in what
00:02:25 situations is rhythm control indicated and what are
00:02:28 the considerations for that?
00:02:30 Speaker: Good question. Rhythm control
00:02:31 should be considered for patients with persistent
00:02:33 symptoms despite rate control and the inability to
00:02:37 attain adequate rate control or if patients prefer
00:02:40 this option. Also the timing, if the patient has been
00:02:43 in atrial fibrillation greater than 48 hours or less
00:02:46 than 48 hour with a history of mitral stenosis or
00:02:50 history of atrial thrombi, you will want the patient
00:02:52 on anticoagulation for at least four weeks with a
00:02:56 target INR of between 2 and 3. In addition, you want
00:02:59 to obtain an echocardiogram, in particular, a
00:03:03 transesophageal echocardiogram to assess the atrial
00:03:07 size and also to rule out any type of thrombi that may
00:03:10 be present. Atrial fibrillation for shorter periods
00:03:13 of time have greater success in cardioversion. There
00:03:18 are some protocols where cardioversion is performed
00:03:22 earlier if there is a negative echocardiogram for
00:03:23 thrombi.
00:03:23 Dr. Stiles: So in summary, what is your
00:03:25 bottom line for the treatment of atrial fibrillation
00:03:27 in the acute setting?
00:03:29 Speaker: Is the patient stable or unstable?
00:03:30 Look at the vital signs. Do they have any underlying
00:03:35 risk factors and consider rate control with a chronic
00:03:39 anticoagulation which is highly recommended for the
00:03:42 majority of patients with atrial fibrillation.
00:03:45 Dr. Stiles: Thank you very much, and that
00:03:46 concludes our medcast for today. (music playing)
