Electric altemans is seen in:

Answer is A (Cardiac tamponade) Electrical alternans refers to a beat-to-beat alteration in one or more components of the ECG signal. Total electrical alternans (P-QRS-T) with sinus tachycardia is a relatively specific sign for pericardial effusion, often with cardiac tamponade. Feature Cardiac Tamponade Constrictive Pericarditis Restrictive Cardiomyopathy RVMI Electrical Alternans May be present Absent Absent Absent