Can sepsis cause atrial fibrillation (afib)?

Sepsis as a Cause of Atrial Fibrillation

Yes, sepsis is a well-established cause of new-onset atrial fibrillation, occurring in approximately 8% of patients with sepsis and more than 20% of patients with septic shock. 1

Pathophysiological Mechanisms

Sepsis can trigger atrial fibrillation through several mechanisms:

1. Systemic inflammation: The primary pathomechanism linking sepsis and atrial fibrillation is systemic inflammation 1. Inflammatory mediators can directly affect atrial electrophysiology and promote arrhythmogenesis.

2. Calcium handling abnormalities: Sepsis can cause calcium overload in atrial cardiomyocytes, which plays a key role in initiating AF by increasing calcium leak into the cytosol during diastole 2.

3. Oxidative stress: Sepsis increases cardiac oxidative stress and production of reactive oxygen species (ROS), which can damage mitochondrial DNA, cause calcium overload, and activate pathways leading to myocyte apoptosis and contractile dysfunction 2.

4. Autonomic dysfunction: The dysregulation of the autonomic nervous system during sepsis can contribute to the development of atrial fibrillation.

Epidemiology and Risk Factors

The incidence of new-onset AF varies according to sepsis severity:

• 8% in patients with sepsis
• 10% in patients with severe sepsis
• 23% in patients with septic shock 3

High-level evidence risk factors for new-onset AF during sepsis include:

• Advanced age (weak association)
• White race (moderate association)
• Respiratory tract infection (weak association)
• Organ failure (moderate association)
• Pulmonary artery catheter use (moderate association) 4

Protective factors include:

• History of diabetes mellitus (weak association)
• Urinary tract infection (weak association) 4

Notably, risk factors for sepsis-associated AF differ from those for community-associated AF, with sepsis-related factors having the strongest association 4.

Clinical Impact

New-onset atrial fibrillation during sepsis is associated with:

• Increased mortality (adjusted relative effect estimates ranging from 1.07 to 3.28)
• Prolonged ICU length of stay (weighted mean difference of 9 days)
• Increased risk of ischemic stroke 3

Management Considerations

When managing patients with sepsis who develop AF:

1. Treat underlying sepsis: Address potential triggers contributing to AF, including sepsis itself, anemia, and pain 2.

2. Rate control: Beta-blockers appear to be associated with better outcomes compared to calcium channel blockers, digoxin, or amiodarone in patients with AF during sepsis 5.

3. Hemodynamic stability: The necessity for rhythm control therapy depends on the patient's hemodynamic stability. For hemodynamically unstable patients, electrical cardioversion may be necessary, and its success rate can be increased by administering amiodarone 1.

4. Blood pressure targets: Targeting a mean arterial pressure (MAP) of 65 mmHg rather than higher targets (e.g., 85 mmHg) in septic patients may reduce the risk of arrhythmias, including atrial fibrillation 2.

5. Anticoagulation: Consider the competing risks of thromboembolism and perioperative bleeding when deciding on anticoagulation therapy 2.

Long-term Considerations

Patients who develop new-onset AF during sepsis should receive outpatient follow-up for thromboembolic risk stratification and AF surveillance, as there is a high risk of AF recurrence 2. Recent data suggest significantly higher recurrence rates than previously thought, which may impact decisions regarding long-term anticoagulation 6.

Conclusion

Sepsis is a significant cause of new-onset atrial fibrillation through mechanisms including inflammation, calcium handling abnormalities, and oxidative stress. This complication is associated with increased mortality, longer ICU stays, and increased stroke risk. Management should focus on treating the underlying sepsis while providing appropriate rate or rhythm control based on hemodynamic stability.