Differential Diagnosis for AFIB with Bradycardia
- Single most likely diagnosis
- Atrial fibrillation with a controlled ventricular rate: This is the most likely diagnosis as AFIB is often characterized by an irregularly irregular rhythm, and the presence of bradycardia suggests that the ventricular rate is being controlled, either by the patient's natural atrioventricular (AV) node or by medications such as beta blockers or non-dihydropyridine calcium channel blockers.
- Other Likely diagnoses
- Sick sinus syndrome: This condition involves dysfunction of the sinoatrial node, leading to abnormal heart rhythms, including AFIB with bradycardia.
- AV nodal blockade: This can occur due to medications (e.g., beta blockers, calcium channel blockers) or AV nodal disease, leading to a slow ventricular response in the setting of AFIB.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Hyperkalemia: High levels of potassium can cause cardiac arrhythmias, including AFIB with bradycardia, and is a life-threatening condition if not promptly treated.
- Cardiac tamponade: Although less common, cardiac tamponade can present with AFIB and bradycardia due to impaired cardiac filling and output.
- Rare diagnoses
- Wolff-Parkinson-White (WPW) syndrome with AFIB and a slow anterograde conduction: This is a rare condition where an accessory electrical pathway in the heart can cause AFIB, and in some cases, the conduction down this pathway can be slow, leading to a bradycardic ventricular response.
- Infiltrative cardiac diseases (e.g., amyloidosis, sarcoidosis): These conditions can affect the heart's electrical conduction system, leading to various arrhythmias, including AFIB with bradycardia, although they are less common causes.