Atrial fibrillation and flutter Flashcards
The most common sustained arrhythmia
Atrial Fibrillation
Atrial Fibrillation - Risk Factors
■ Acute alcohol excess/”Holiday Heart” - Usually transient, self-limited
■ Pericarditis
■ Chest trauma or thoracic surgery
■ Thyroid disorders (thyrotoxicosis)
■ Obstructive Sleep Apnea
■ Pulmonary Embolism
■ COPD
■ Obesity
■ Some medications (theophylline, adenosine, digitalis, etc.)
■ Post-operative (cardiac surgery/catheterization)
Risks of Untreated Atrial Fibrillation
- Thrombus formation and embolization
- Tachycardia à impaired LV filling
- persistent tachycardia (weeks) can
lead to cardiomyopathy and heart failure - Loss of the atrial kick
Atrial Fibrillation - Pathophysiology
● Atrial fibrillation is a chaotic rapid, irregular atrial rhythm.
● It results from ectopic electrical signals mostly in the pulmonary veins of the left atrium.
● When these signals are conducted through the AV node the result is an irregular tachyarrhythmia
When the heart is in A-Fib, stasis within the atria
occurs especially in the _____
Left atrial appendage
Atrial Fibrillation - Presentation
■ Palpitations
■ Tachycardia
■ Hypotension
■ Fatigue (common) or weakness
■ Dizziness/lightheadedness
■ Dyspnea
■ Angina
■ Decreased exercise tolerance
■ Presyncope or (infrequently) syncope
Atrial Fibrillation - vital signs
● A-Fib can present with slow, normal, or fast rates;
● If the HR is greater than 100, it is A-Fib with Rapid Ventricular Response (RVR)
_____ - difference between apical rate and
pulse rate
Pulse deficit
Atrial Fibrillation – Work Up & EKG findings
- H&P
- Electrocardiogram (EKG) establishes the diagnosis with
characteristic findings:
● An Irregularly Irregular R-R Interval (no repetitive pattern)
● Fibrillatory waves replace discernable P waves
What is this rhythm showing?
Atrial fibrilation
● An Irregularly Irregular R-R Interval (no repetitive pattern)
● Fibrillatory waves replace discernable P waves
A-Fib often presents with ____
Rapid Ventricular Response, with a ventricular heart rate of 100 to 180 bpm (commonly around 120)
_____ provides valuable information about the size and function of the atria and ventricles.
Echocardiogram
Ancillary Testing for A-fib
■ Transthoracic Echo (TTE) is more commonly ordered.
■ Transesophageal Echo (TEE) is more sensitive for detection of
thrombi formation in the left atrium or left atrial appendage
Atrial Fibrillation -Management of at risk patients
- Lifestyle Modifications
a. Modifying risk factors is FOUNDATIONAL
Atrial Fibrillation -Management of those diagnosed with atrial fibrilation
- Assess risk of stroke and implement treatments
- Continue to optimize modifiable risk factors
- Manage symptoms
- Primary Prevention of Atrial fibrilation
Modifications targeting: obesity,
sedentariness, unhealthy EtOH use, smoking,
diabetes and HTN
(1B recommendation)
Secondary Prevention of atrial fibrilation
- Weight loss target of at least 10% (1B)
- Moderate to vigorous exercise target 210 mins/week (1B)
- Smoking Cessation (1B)
- Minimize/eliminate EtOH (1B)
- Caffeine – eliminating showed no benefit
- Optimal BP control (1B)
- Screen for sleep apnea (2B)
Validated scoring assessment for stroke risk
CHA 2 DS2 -VASC2
When to start Direct oral anticoagulation (DOACs) vs. warfarin?
DOACs > warfarin for patients without history of moderate to severe
rheumatic mitral valve disease, or a mechanical valve (1A)
■ Or, valvular disease that is NOT listed above (1B
When to start warfarin vs. DOACs for patients with A-fib
Warfarin >DOACs for patients with history of above independent of score
(1B)
Don’t use dual or single antiplatelet therapy in patients with _____
thromboembolic risk qualifying for OAC – HARM
For the acute* management of stable AF:
Rate ____ Rhythm Control
>
______: an acute rhythm control strategy, done
either electrically or pharmacologically
Cardioversion
Atrial Fibrillation: Cardioversion goals in a stable patient
Rate control à Anticoagulation à Rhythm control
● If onset ≥48 hrs: OAC x 3 weeks and get echo before elective CV and
continue AC for 4 weeks afterward
● If onset < 48 hrs: start AC, consider echo if high risk score
● If duration <12 hrs: start AC, precardioversion echo low benefit
● If thrombus on echo, AC for 3-6 weeks, repeat echo and then CV
Atrial Fibrillation: Cardioversion in unstable patient
Benefit of immediate cardioversion outweighs risk for thromboembolism
Rate control: 1 st line IV meds: BB or CCB
● Sedate
● Cardiovert à synchronous shock 100-200 J (on the R wave)
○ May repeat at 360 J
○ May need to load pt with anti-arrhythmic medications
A more invasive strategy for rhythm control is
called ______ and can be used to scar portions of cardiac tissue believed to be the area(s) of active foci
Radiofrequency Catheter Ablation
GOAL of subsequent management in A-fib patients:
maintaining normal sinus rhythm, reducing
thromboembolic events, and managing risk factors
Antiarrhythmic medications
■ Sodium channel blockers (ie. Propafenone or Flecainide)
■ Potassium channel blockers (ie. Sotalol, Ibutilide, Amiodarone)
What happens if A-fib is left untreated?
can result in permanent damage to the electrical conduction system and structure of the atria, and can also lead to heart failure.
Atrial Flutter
● A-Flutter is another atrial arrhythmia,
similar to Atrial Fibrillation.
○ Like A-Fib, it’s commonly tachycardic. Unlike A-Fib, it’s characteristically regular on EKG.
● Much less common than A-Fib, incidence of 88 per 100,000 person- years, increases with age
Atrial Flutter risk factors:
■ Any of the disorders that can cause A-Fib
■ Commonly occurs after starting an antiarrhythmic for suppression of A-Fib
(up to 15% of those on flecainide, propafenone, etc.)
■ Post Cardiac Surgery (can be early complication or late development)
■ Heart failure (16%)
■ COPD (12%)
■ Male sex (about 80% of A-Flutter patients are male)
Typical Atrial Flutter
■ The more common of the two types, this is a
Macroreentrant Circuit within the right atrium
includes the Cavotricuspid Isthmus (CTI).
■ The circuit is generally counterclockwise and creates a classic sawtooth appearance best seen in the inferior leads (but can be reversed ↓).
Atypical Atrial Flutter
■ The less common of the two types.
■ While it is also a macroreentrant circuit, it does not involve the CTI.
■ May form around a patch from a surgery or scar tissue (surgical or ablated)
Atypical Atrial Flutter EKG findings
■ The appearance on EKG may not be quite as obviously A-Flutter as we see
with Typical type. May see sawtooth waves in only 1 or 2 leads
Atrial Flutter S/S
■ Palpitations
■ Fatigue
■ Lightheadedness
■ Mild or (rarely) severe dyspnea
■ Hypotension
■ Anxiety
■ Presyncope and (infrequently) syncope
○ Because of the rapid atrial and (often) ventricular rates, several
hemodynamic changes can occur, which can result in decreased cardiac
output and blood pressure
Atrial Flutter Treatment
○ Because ventricular rates can be sustained at around 150 bpm, rate control is an important component of treatment
○ Pharmacologic cardioversion to NSR is also difficult to achieve with most antiarrhythmics
○ Electrical cardioversion is a very effective treatment for about 90% of patients with A-Flutter, converting with shocks as low as 25-50 J.
○ Catheter Ablation of the CTI is a highly
successful treatment for Typical A-Flutter,
Complications of atrial flutter
○ Serious complications include myocardial infarction, syncope, heart failure, and thromboembolism
○ Another complication of A-Flutter with RVR is tachycardia-induced cardiomyopathy, which can lead to chronic heart failure
