A 62 years old man with carcinoma of lung presented to emergency depament with respiratory distress. His EKG showed electrical alternans. The most likely diagnosis is
Electrical alternans is an electrocardiographic phenomenon of alternation of QRS complex amplitude or axis between beats and a possible wandering base-line. It is seen in cardiac tamponade and severe pericardial effusionMassive pericardial effusion produces a triad of:Low QRS voltageTachycardiaElectrical alternansRef: Harrison's 18/e p1972
Pneumothorax.
Pleural effusion
Cardiac tamponade
Constrictive pericarditis.
All India exam