Atrial Fibrillation (AFIB) and AFIB RVR are common conditions that you’ll see as a nurse within both inpatient and outpatient settings. These patients are often asymptomatic, but may have severe symptoms and even be unstable, especially with AFIB RVR.
Recognizing AFIB on the monitor/EKG and knowing how to treat it is important as the nurse, as you’ll be on the front line with these patients!
What is Atrial Fibrillation (AFIB)?
Atrial Fibrillation (AF or AFIB) is an “irregularly irregular” arrhythmia that usually occurs in a structurally diseased heart.
AFIB occurs when too many atrial impulses are usually coming from the pulmonary veins, causing rapid fibrillation or “quivering” of both the left and right atria.
Remember, the heart has four chambers: left and right atria on the top and left and right ventricle on the bottom. With AFIB, the top chambers are in a constant state of fibrillation.
During a normal heartbeat, the atria first contract, pushing blood into the ventricles, and the ventricles then pump the blood to the rest of the body. In AFIB, the atria lose this “atrial kick,” leading to ineffective atrial filling and decreased cardiac output, especially at rapid rates.
Cardiac Conduction Review
It is helpful to remember how the cardiac conductions system works to understand what is going on with AFIB.
Remember, the heart has specific electrical conduction tissue, which creates and moves the electrical signal throughout the heart to produce an organized rhythm. This organization lets the heart fill and pump effectively.
The heart’s pacemaker is the sinus node located in the right atrium. This region of cells creates the “normal” impulse and sends it throughout the atria and then through the AV node. This AV node normally slows the conduction to allow for ventricular filling. The PR interval on the EKG denotes this slowing of the conduction.
Once traveling through the AV node, the impulse goes through the Bundle of His. It splits down the left and right bundle branches towards each ventricle, then through the Purkinje fibers and eventually the ventricles, causing a heartbeat.
In AFIB, rapid-firing comes from the atria, usually where the pulmonary veins meet the left atria. This leads to the quivering of both atria and ineffective atrial filling and atrial kick.
While the AV node does slow down conduction, it can only do so much on its own. With such rapid firing from the atria, many of these impulses want to make it down to the ventricles and cause heartbeats.
As you can imagine, this can lead to very fast heart rates – what we call AFIB RVR or rapid ventricular response.
What is AFIB RVR?
AFIB RVR (Rapid Ventricular Response) occurs due to the frequent electrical impulses from the atria.
The AV node is only able to slow the frequent electrical impulses down so much, so many of the impulses are conducted through to the ventricles, leading to a rapid ventricular response or a fast heart rate >100bpm and often much faster.
Patients with these fast rates are often symptomatic and may become hypotensive. These patients will usually require IV medications to slow down their rate, and possibly even electrical cardioversion (more on that later!).
What Causes AFIB?
AFIB usually occurs in predisposed hearts and is often set off by reversible triggers.
Chronic diseases which predispose the heart to AFIB include:
Usually, some reversible trigger throws the patient into AFIB. These reversible triggers include:
Although caffeine is often thought of as contributory to ectopy and AFIB, there is no direct evidence it does trigger AF. However, it is something to consider.
Nursing Assessment of AFIB RVR
SYMPTOMS OF AFIB
Up to 44% of patients with Afib are asymptomatic. Patients with faster rates are more likely to develop symptoms, and those with CHF are more likely to experience hemodynamic instability and severe symptoms (aka low BP and possible code situation).
Some symptoms of AFIB can include:
The Physical Exam
Identifying AFIB RVR on the ECG
AFIB will NOT have visible P waves. Instead, there will be a fibrillatory baseline. There is no depolarization wave throughout the atria, but rather rapid twitching and many “small” depolarizations, firing at rates 350-600 times per minute.
The QRS complex should be narrow unless an underlying intraventricular conduction delay is present, such as a bundle branch block.
The T waves may be difficult to decipher between the F-wave baseline completely. T wave abnormalities are common, including T wave flattening.
AFIB is irregularly irregular. This means that the R-R interval is continuously changing, and there is no pattern.
AFIB can be at any rate, but faster than 100 is considered AFIB RVR. Without medications to slow it down, rates are usually between 90-170 bpm.
Initial Nursing Interventions
When your patient is in AFIB RVR, you should do the following:
Remember that any unstable tachyarrhythmia should follow ACLS guidelines. This means the patient may need electrically cardioverted. If they are unstable (Low BP, impending arrest), then place the defibrillation pads on the patient and hook them up to the defibrillator.
Workup For AFIB RVR
The workup will depend if the patient is in new-onset AF or already has chronic AF and if they are in RVR or not.
Patients with a known history of AFIB who have controlled rates don’t need any specific testing. They are usually on chronic medications to control their heart rates and anticoagulants to prevent blood clots.
Patients with new AFIB or AFIB RVR require more extensive testing, and the workup may depend on their symptoms.
General workup for new AFIB includes:
Complications of AFIB
So why do we even care about AFIB? Well, there can be disastrous consequences if we do not treat it appropriately.
Treatment of AFIB RVR
Treatment of AFIB differs and depends on the patient’s symptoms and quality of life. This will involve at least one, but possibly all three of the following:
- Rate control: Control the heart rate with AFIB (preventing RVR)
- Rhythm Control: Convert and maintain the patient in a normal sinus rhythm
- Anticoagulation: Giving blood thinners to prevent blood clot formation within the atria
Which the Provider team and Cardiology will ultimately choose treatment options. We’ll dive a little deeper into each of these treatment options.
Rate-control is achieved via medications to slow down the ventricular response to the AFIB. Common medications include Metoprolol, Diltiazem, Digoxin, Esmolol, Amiodarone, and even magnesium sulfate.
For AFIB RVR, we often give the following medications to control the rate:
Low BP and RVR
One thing to point out is that those patients with significant left ventricular heart failure and AF RVR may paradoxically improve their blood pressure with rate control, so it still may be wise to administer a low dose of metoprolol or cardizem in these select patients if borderline hypotension is present. Always verify with the Physician/APP.
Rhythm-control is achieved via medications or electrical cardioversion. If the patient is unstable, they will be electrically cardioverted. Otherwise, the cardiologist may choose to start the patient on an antiarrhythmic such as amiodarone, Flecainide, multaq, etc.
Many elderly patients who do not have significant symptoms will not undergo rhythm control. This is ultimately up to the cardiologist.
Anticoagulation is almost always used in patients with AFIB, unless there is acute bleeding or a significant risk of bleeding.
Anticoagulation is used to prevent thrombus formation which can cause PEs and Strokes as explained above. Within the hospital, anticoagulation will include either:
Coumadin is much less commonly prescribed than it used to be because it requires frequent blood checks of INR, as well as dietary changes and medications, can significantly impact its therapeutic levels
Before being discharged, the patient is then transitioned onto an oral anticoagulant such as coumadin, Eliquis, Xarelto, Pradaxa, or ASA/Plavix.
The CHADSVASC score is used to gauge risk for thrombus formation, which factors in age, sex, h/o CHF, HTN, Stroke/TIA/DVT/PE, Vascular disease, or Diabetes. If the patient does not have a high risk of bleeding such as intracranial bleeding, GIB, or frequent falls, then they are usually started on an anticoagulant.
WANT TO LEARN MORE?
If you want to learn more about cardiac arrhythmias, I have a complete video course “ECG Rhythm Master”, made specifically for nurses which goes into so much more depth and detail.
With this course you will be able to:
- Identify all cardiac rhythms inside and out
- Understand the pathophysiology of why and how arrhythmias occur
- Learn how to manage arrhythmias like an expert nurse
- Become proficient with emergency procedures like transcutaneous pacing, defibrillation, synchronized shock, and more!
I also include some great free bonuses with the course, including:
- ECG Rhythm Guide eBook (190 pages!)
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