All of the following are seen in cardiac tamponade except:

Answer is D (Kussmaul's sign): Harrison 17th/ 1490, 1491; Harrison 18th/p 1975; Repeat Pulsus paradoxus clinically, electrical alternans on ECG and R t DC on Echocardiography are chracteristic features of cardiac tamponade. A positive Kussmaul's sign is rare in cardiac tamponade. Its presence suggests that an organizing process and epicardial constriction are present in addition to effusion' Characteristic Tamponade Constrictive Pericarditis Restrictive Cardiomyopathy RVMI Clinical Pulsus paradoxus Common Usually absent Rare Rare Jugular veins Prominent y descent Absent Usually present Rare Rare Prominent x descent Present Usually present Present Rare Kussmaul's sign Absent (Rareie Present Present Present Third hea sound Absent Absent Rare May be present Pericardial knock Absent Often present Absent Absent Electrocardiogram Low ECG voltage May be present May be present May be present Absent Electrical alternans May be present Absent Absent Absent Echocardiography Thickened pericardium Absent Present Absent Absent Pericardial calcification Absent Often present Absent Absent Pericardial effusion Present Absent Absent Absent RV size Usually small Usually normal Usually normal Enlarged Myocardial thickness Normal Normal Usually increased Normal Right atrial collapse and Present Absent Absent Absent RVDC Increased early filling, Absent Present Present May be present "I mitral flow velocity Exaggerated respiratory variation in flow velocity Present Present Absent Absent CT/MRI Thickened/calcific pericardium Absent Present Absent Absent Cardiac catheterization Usually present Usually present Usually absent Absent or present Equalization of diastolic procedures Cardiac biopsy helpful? No No Sometimes .. No .. *RV, right ventricle; RVMI, right ventricular myocardial infarction; electrocardiograph. Note: *`A positive Kussmaul's sign is rare in cardiac tamponade. Its presence suggests that an organizing process and epicardial constriction are present in addition to effusion'