Please confirm topic selection

Are you sure you want to trigger topic in your Anconeus AI algorithm?

Please confirm action

You are done for today with this topic.

Would you like to start learning session with this topic items scheduled for future?

Updated: Sep 27 2021

Atrial Fibrillation fibrillation.jpg
  • A 68-year-old male presents with palpitations, lightheadedness, and weakness. These symptoms appear to worsen with increased alcohol intake. Medical history is significant for hypertension being treated with hydrochlorothiazide. On physical exam, the patient appears uncomfortable. There is an irregularly irregular pulse when palpating the radial artery. On cardiac auscultation, the first heart sound (S1) is of variable intensity. There is mild bibasilar crackles on pulmonary auscultation and an absence of peripheral edema.  An electrocardiagram is obtained. 
  • A supraventricular tachyarrhythmia secondary to uncoordinated atrial contractions
    • results in an irregularly irregular rhythm
      • non-repetitive pattern in the RR interval
    • may reduce cardiac output
    • may result in thrombus formation in the atrium
    • most common site of origin for ectopic foci is pulmonary veins
  • Pathogenesis
    • usually due to an underlying cause 
      • e.g., atrial enlargement and inflammation or infiltrative disease affecting the atrium
  • Causes include
    • structural abnormalities
      • e.g., left atrial enlargement, mitral and aortic stenosis, mitral and aortic regurgitation, and malignancy
    • conduction abnormalities
      • e.g., Wolff-Parkinson-White (WPW) syndrome
    • medications
      • theophylline and digoxin
    • cardiac functional abnormalities
      • e.g., myocardial infacrtion, pulmonary embolism, and coronary artery disease
    • hyperthyroidism
    • electrolyte disturbances
      • e.g., hypomagnesemia and hypokalemia
    • cardiomyopathies
      • e.g., dilated and hypertrophic cardiomyopathy
    • alcohol abuse ("holiday heart syndrome")
    • post-operatively after heart surgery
      • especially after coronary artery bypass grafting (CABG)
  • Epidemiology
    • most common arrhythmia
  • Symptoms
    • asymptomatic
    • in symptomatic cases
      • palpitations
      • shortness of breath (suggesting heart failure)
      • lightheadedness
  • Physical exam
    • irregularly irregular pulse
    • focal neurological deficit if this results in an embolic stroke
    • in cases of atrial fibrillation leading to heart failure
      • elevated jugular venous pulse (JVP)
      • bibasilar rales on pulmonary auscultation
      • peripheral edema
  • Electrocardiogram (EKG or ECG) 
    • irregularly irregular rhythm
    • absent P waves
    • if arrhythmia is not captured on ECG then
      • Holter monitoring in the outpatient setting
        • these patients are hemodynamically stable
      • telemitry in the inpatient setting
  • Transthoracic echocardiogram (TTE)
    • can assess atrial size and ventricular function, thickness, and size
    • can also assess for valvular and pericardial disease, and peak right ventricular pressure
    • transesophageal echocardiogram (TEE) is more sensitive in detecting thrombi in the left atrium
  • Laboratory testing
    • thyroid stimulating hormone (TSH) and free T4 level 
      • hyperthyroidism is a possible cause of atrial fibrillation
    • electrolyte level
  • Multifocal atrial tachycardia (MAT)
    • commonly seen in patients with pulmonary disease
      • e.g., chronic obstructive pulmonary disease (COPD)
  • Premature atrial contractions (PACs)
    • associated with alcohol, caffeine, and nicotine use 
  • Atrial flutter
  • Wolff-Parkinson-White syndrome
  • Hemodynamically unstable patients
    • synchronized cardioversion  
  • Hemodynamically stable patients
    • slowing of the ventricular rate
      • patients with new onset atrial fibrillation become symptomatic due to rapid ventricular response (except in cases of stroke)
      • intravenous β-blockers or nondihydropyridine calcium channel blocker 
        • wheezing (COPD/asthma) 
          • use calcium channel blocker or titratable beta blocker (esmolol)  
    • long-term management
      • rate control (preferred)
        • β-blocker or nondihydropyridine calcium channel blocker
          • treatment is chosen based on patient's comorbidities 
          • beta blocker preferred in coronary artery disease  
        • digoxin 
          • in heart failure with reduced ejection fraction 
      • rhythm control
        • antiarrhythmics
          • depends on patient's comorbidities
      • anticoagulation
        • in order to decrease the risk of thromboembolism
        • stroke risk stratification CHA2DS2-VASc score
          • Congestive heart failure = 1 point
          • Hypertension = 1 point
          • Age (75 years or older) = 2 points
          • Diabetes = 1 point
          • Stroke/transient ischemic attack/thromboembolism = 2 point
          • Vascular disease = 1 point
            • e.g., previous myocardial infarction and peripheral artery disease
          • Age (65 - 74 years) = 1 point
          • Sex category (female) = 1 point
        • score of 0 or 1 use
          • aspirin
          • conservative monitoring
        • score of 2 or more use oral anticoagulation   
          • dabigatran
          • rivaroxaban
          • apixaban
            • novel anticoagulants contraindicated in renal failure
          • warfarin 
            • international normalized ratio (INR) target of 2-3
            • only warfarin should be used with vascular lesions (eg. mechanical valves)
Prognosis, Prevention, and Complications
  • Prognosis
    • increased risk of stroke
  • Complications
    • atrial mural thrombi emboli to cerebral vessels
      • can cause ischemic stroke and transient ischemic attack
    • atrial thrombus to common iliac artery
      • requires immediate embolectomy to remove occlusion and preserve limb
    • renal infarction 
      • sudden flank pain and tenderness
      • wedge-shaped infarct on CT
1 of 14
Private Note

Attach Treatment Poll
Treatment poll is required to gain more useful feedback from members.
Please enter Question Text
Please enter at least 2 unique options
Please enter at least 2 unique options
Please enter at least 2 unique options