Idiopathic Pericardial Effusion in Patients with Hypertrophic Cardiomyopathy

Abstract Objectives: The aims of this study were to examine the prevalence of moderate to large (moderate-large) idiopathic pericardial effusion (i-PEF) in patients with hypertrophic cardiomyopathy (HCM) and to identify clinical and echocardiographic hemodynamic profiles associated with pericardial effusion. Methods: A total of 292 adult patients with HCM were studied. Fifteen patients with a history of factors associated with pericardial effusion including myocardial infarction, heart surgery or cardiac procedure within the last 12 months, autoimmune disease, hydralazine use, chronic kidney disease stage 3-4, tuberculosis, and malignancy were excluded. Results: Of 277 eligible patients with HCM, 11 patients (4%) with moderate-large i-PEF were identified. Clinical tamponade was present in 1 patient. Compared to patients with HCM who had no or small pericardial effusion, patients with moderate-large i-PEF were younger and more likely to have right ventricular (RV) hypertrophy and reverse septal curvature. These patients also exhibited a greater maximal septal thickness, mean and systolic pulmonary pressure, and right atrial pressure (p<0.05 for all). Pericardial fluid analysis and histopathological exams were performed in 7 and 3 patients, respectively. All examinations revealed transudative and nonspecific etiology of pericardial effusion. Conclusions: Idiopathic pericardial effusion and cardiac tamponade in patients with HCM was uncommon. The pathophysiology involved in pericardial effusion remains undetermined. Patients with moderate-large i-PEF frequently exhibited a phenotype of pulmonary hypertension and RV pressure overload.