Can Anorexia Nervosa Cause Pericardial Effusion?
Yes, anorexia nervosa is a recognized metabolic cause of pericardial effusion and is explicitly listed in the European Society of Cardiology guidelines as an etiology of pericardial disease. 1
Guideline Recognition
The 2015 ESC Guidelines for the Diagnosis and Management of Pericardial Diseases explicitly categorize anorexia nervosa under metabolic causes of pericardial effusion in their comprehensive etiological classification. 1 This places anorexia nervosa alongside other metabolic disorders like uremia and myxedema as established causes of pericardial disease. 1
Clinical Evidence and Prevalence
Pericardial effusion occurs in approximately 25-27% of severely malnourished patients with anorexia nervosa, making it a relatively common cardiac complication. 2, 3 The meta-analysis by Sachs et al. (2021) demonstrated a pooled incidence of 25% (95% CI 17-34%) across 469 patients with anorexia nervosa. 2
Key Clinical Characteristics:
- Most effusions are small and clinically silent, detected incidentally on echocardiography rather than presenting with symptoms. 4, 5
- Cardiac tamponade is rare but documented, with at least two case reports describing progression to tamponade requiring intervention (one requiring surgical pericardial window). 6, 4
- The effusion typically correlates with severity of malnutrition, particularly with reduced body mass index (mean BMI ~12-15 kg/m²) and decreased fat-free mass index. 2, 3
- Effusions often improve or resolve with weight restoration, suggesting a direct relationship to the metabolic derangements of starvation. 3, 5
Pathophysiology
The exact mechanism remains incompletely understood, but the fluid is non-inflammatory and non-infectious in nature. 4 When pericardiocentesis has been performed, analysis excluded inflammatory or infectious etiologies, suggesting the effusion results from metabolic derangements associated with severe malnutrition rather than pericarditis. 4
Clinical Implications and Screening
Echocardiography should be performed in patients with anorexia nervosa, particularly those who are severely malnourished or undergoing surgical procedures. 6, 4 The recommendation for a low threshold for pre-operative echocardiography is especially important given that these effusions are typically asymptomatic until they become hemodynamically significant. 6
High-Risk Features:
- Severe malnutrition (BMI <13 kg/m²) 2, 3
- Binge-purge subtype (associated with more cardiac dysfunction) 3
- Hypertransaminasemia (AST/ALT ≥2× normal), which correlates with cardiac abnormalities 3
- Reduced fat-free mass index on body composition analysis 3
Important Caveats
- Unlike hypothyroidism (another metabolic cause affecting 5-30% of patients), anorexia nervosa-associated effusions do not present with the characteristic relative bradycardia and low QRS voltage. 1, 7
- The presence of pericardial effusion does not indicate pericarditis—there are typically no inflammatory signs (no chest pain, fever, pericardial rub, or elevated inflammatory markers). 1, 4
- Cardiac tamponade can develop even from initially small effusions during the course of severe malnutrition, warranting serial monitoring in high-risk patients. 6, 4