Ewart sign This sign describes a particular situation that can occur in patients with
pericardial effusion. Ewart sign occur when the pericardial sac is large enough to
compress the lower part of the left lung. When the left lung is compressed percussion below the left scapula becomes
dull, and also ausculation here will sound
like wind going through a pipe (bronchial breathing).
The coexistence of pericardial effusion plus dull percussion and bronchial breathing below the left scapula is thus referred to as
Ewart's sign. Above figure shows the
flask shaped heart shadow in pericardial effusion.
Typically ECG shows small complexes because electric activity has to travel through fluid and become attenuated, and the electric axis (direction of normal electric current flow) keeps on changing as the heart swings side to side in the pericardial fluid, this phenomenon is called
electric alternans.
