Fistulas do not always cause pericardial effusion.
Spodick
D H
DH
D004937:Esophageal Fistula / Q000150:complications*; D005402:Fistula / Q000150:complications; D006331:Heart Diseases / Q000150:complications; D006801:Humans; D010490:Pericardial Effusion / Q000209:etiology*