Priority Topic: Atrial Fibrillation

Key Feature 1: In a patient who presents with new onset atrial fibrillation, look for an underlying cause (ex: ischemic heart disease, acute myocardial infarction, congestive heart failure, cardiomyopathy, pulmonary embolus, hyperthyroidism, alcohol, etc.).
Skill: Clinical Reasoning
Phase: Hypothesis generation

In a patient who presents with new onset atrial fibrillation, either picked up because they are symptomatic (ex: palpitations, decreased exercise tolerance, dyspnea), as an incidental finding on physical examination (ex: irregularly irregular pulse), or on an ECG done for another reason (ex: presurgical baseline), it is important to look for an underlying cause. This is important so as to treat any underlying disease that has its own cluster of negative consequences, but also to identify any possible reversible reason for having atrial fibrillation. Atrial fibrillation increases the risk of stroke and peripheral embolisation, can decrease quality of life, and may increase the risk of death. Although these risks can be mitigated with medications, medications do not eliminate them altogether. 

Potential causes of reversible atrial fibrillation to assess for include: 

1. Associated alcohol or caffeine consumption
2. Associated exercise
3. Associated emotional stress
4. Hyperthyroidism

Note: Most patients will not have any identifiable reversible triggers

Important associated disease processes to look for include:

1. Cardiovascular disease
   
2. Cerebrovascular disease
   
3. Diabetes
4. Hypertension
   
5. COPD
   
6. Obstructive sleep apnea