How to manage palpitations and atrial fibrillation (A Fib) triggered by hyperglycemia?

Management of Palpitations and Atrial Fibrillation Triggered by Hyperglycemia

For patients experiencing palpitations and atrial fibrillation triggered by hyperglycemia, the most effective management approach is to prioritize glycemic control with SGLT2 inhibitors while simultaneously implementing appropriate rate control therapy for atrial fibrillation.

Understanding the Hyperglycemia-AF Connection

Hyperglycemia can trigger or exacerbate atrial fibrillation through several mechanisms:

• Elevated blood glucose levels can trigger sympathetic activation
• Hyperglycemia can cause electrolyte disturbances affecting cardiac conduction
• Metabolic stress from hyperglycemia may directly affect atrial electrical properties

This relationship is bidirectional, as documented in case reports where atrial fibrillation has also been shown to worsen glycemic control, with one patient requiring a ten-fold increase in insulin needs during symptomatic AF episodes 1.

Management Algorithm

Step 1: Acute Management of AF with RVR

For patients presenting with symptomatic AF with rapid ventricular response:

• If hemodynamically unstable: Immediate electrical cardioversion with concurrent heparin administration 2
• If stable but symptomatic:
  • For patients without heart failure: IV beta-blockers (metoprolol 2.5-5 mg IV) or non-dihydropyridine calcium channel blockers (diltiazem 0.25 mg/kg IV) 2
  • For patients with HFrEF: Beta-blockers or digoxin (calcium channel blockers contraindicated) 2
  • For patients with HFpEF: Beta-blockers or non-dihydropyridine calcium channel antagonists 2

Step 2: Glycemic Control

• SGLT2 inhibitors (empagliflozin, canagliflozin, or dapagliflozin) are recommended as first-line therapy for patients with diabetes and cardiovascular disease to reduce cardiovascular events and specifically to lower risk of heart failure hospitalization 3
• SGLT2 inhibitors have been shown to reduce the risk of atrial fibrillation/flutter events by 19.33% compared to placebo, with dapagliflozin showing the strongest evidence for AF/AFL reduction 4
• Metformin should be considered in patients with diabetes and heart failure if eGFR >30 mL/min/1.73 m² 3
• Avoid hypoglycemia as it can also trigger arrhythmias 3

Step 3: Long-term Rate or Rhythm Control

For long-term management:

• Target heart rate of 60-80 beats per minute at rest and 90-115 beats per minute during moderate exercise 2
• For patients with adrenergic AF (triggered during daytime, with exercise or emotional stress):
  • Beta-blockers are the treatment of choice 3
• For patients with vagal AF (occurring at night, after meals, or after alcohol):
  • Avoid beta-blockers and digitalis as they may worsen symptoms 3
  • Consider non-dihydropyridine calcium channel blockers

Step 4: Anticoagulation Assessment

• Assess stroke risk using CHA₂DS₂-VASc score 2
• Initiate oral anticoagulation if:
  • CHA₂DS₂-VASc score ≥2 in men or ≥3 in women 2
  • Direct oral anticoagulants are preferred over warfarin except in patients with mechanical heart valves or moderate-to-severe mitral stenosis 5

Monitoring and Follow-up

• Regular monitoring of blood glucose levels and HbA1c
• ECG monitoring to assess heart rate control and rhythm status
• Follow-up within 1-2 weeks after initial management 2
• Regular assessment of renal function, particularly if on SGLT2 inhibitors

Special Considerations

• Avoid thiazolidinediones (pioglitazone and rosiglitazone) in patients with heart failure as they are not recommended and may worsen AF 3
• Avoid saxagliptin in patients with high risk of heart failure 3
• For patients with thyrotoxicosis and AF, beta-blockers are first-line treatment 2
• For patients with COPD and AF, non-dihydropyridine calcium channel antagonists should be used 2

Pitfalls to Avoid

1. Failing to address hyperglycemia: Treating only the AF without addressing the underlying trigger (hyperglycemia) will lead to recurrent episodes.

2. Using inappropriate rate control agents: Using beta-blockers in vagally-mediated AF or calcium channel blockers in patients with HFrEF can worsen symptoms.

3. Neglecting anticoagulation: Stroke prevention is crucial regardless of whether AF is triggered by hyperglycemia.

4. Overlooking hypoglycemia as a trigger: Both hyperglycemia and hypoglycemia can trigger AF 6, so avoid aggressive glucose lowering that might cause hypoglycemic episodes.

By following this comprehensive approach that addresses both the arrhythmia and its metabolic trigger, patients with hyperglycemia-induced AF can achieve better symptom control and reduced cardiovascular risk.