In which of the following a ‘Coeur en Sabot’ shape off the heart is seen –
**Core Concept**
The 'Coeur en Sabot' (French for "heart in a sabot") sign refers to a characteristic radiographic appearance of the heart in the presence of a specific cardiac condition. This sign is indicative of right atrial enlargement, which can be caused by various conditions such as tricuspid regurgitation, pulmonary hypertension, or right heart failure.
**Why the Correct Answer is Right**
The 'Coeur en Sabot' sign is classically described as a boot-shaped or rounded cardiac silhouette, with the right atrium appearing enlarged and rounded. This occurs due to the accumulation of blood in the right atrium, causing it to dilate and assume a characteristic shape. The right atrium's enlarged shape is often visible on chest radiographs, particularly in the anterior-posterior (AP) view.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is not relevant to the 'Coeur en Sabot' sign, which is specifically associated with right atrial enlargement.
**Option B:** While tricuspid stenosis can cause right atrial enlargement, it is not the primary condition associated with the 'Coeur en Sabot' sign.
**Option C:** Pulmonary embolism may cause right ventricular dysfunction, but it is not directly associated with the characteristic 'Coeur en Sabot' sign.
**Option D:** This option is not relevant to the 'Coeur en Sabot' sign.
**Clinical Pearl / High-Yield Fact**
The 'Coeur en Sabot' sign is a valuable radiographic finding that can indicate right atrial enlargement, which may be caused by various conditions. This sign is often seen in patients with tricuspid regurgitation or pulmonary hypertension, and it can be a useful clue in diagnosing these conditions.
**Correct Answer:** C.