This EKG is striking in several ways…
Atrial fibrillation with slow ventricular response at 54/min
Right axis deviation
Extreme low voltage in the limb leads

Exam revealed…
VS: 138/68 66 24 O2sat 90% 982
Clear lungs, distant heart sounds, +JVD, 2+ pretibial edema

CXR

Hopefully you were concerned with the possibility of a large pericardial effusion, or even tamponade, with the low voltage on the EKG, some aspects of the physical exam, and then the “waterbottle” cardiomegaly on CXR! The next step in managing this patient was bedside ultrasound (not pericardiocentesis as hemodynamically stable).

Bedside ultrasound revealed no pericardial fluid but a massively dilated right ventricle?!