Which initial investigations should be performed to confirm the presence of pericardial effusion in a patient with suspected cardiac symptoms?

To confirm the presence of pericardial effusion in a patient with suspected cardiac symptoms, the primary initial investigation is echocardiography NICE CKS,NICE NG106,NICE NG208. This imaging technique is crucial for assessing cardiac function NICE CKS. In the broader context of suspected cardiac symptoms, particularly those suggestive of heart failure, measuring N-terminal pro-B-type natriuretic peptide (NT-proBNP) is also an initial step NICE NG106. Elevated NT-proBNP levels would prompt referral for specialist assessment and transthoracic echocardiography NICE NG106.