title: Alternans of loud midsystolic clicks: a unique finding in massive pericardial effusion.
mesh_terms: D006326:Heart Auscultation; D006801:Humans; D008297:Male; D008875:Middle Aged; D010490:Pericardial Effusion / Q000175:diagnosis* / Q000000981:diagnostic imaging; D010701:Phonocardiography; D011859:Radiography