The 'moguls of the heart' refer to the bulges of the cardiomediastinal contour on frontal chest radiographs. The cardiomediastinal bulges are likened to skiing moguls (bumps of packed snow on a mountainside sculptured by turning skis). Awareness of their usual locations and aetiologies is helpful in their recognition. 

Radiographic features

On the right cardiomediastinal border:

• the right atrium is the only normal bulge

  • double right heart shadow suggests double density sign in left atrial enlargement.

On the left cardiomediastinal border:

• first mogul

  • uppermost, located paratracheally above the carina, and formed by the aortic arch (aortic knob)

  • prominence may be due to ectasia, aneurysm, or hypertension

  • notching or a "figure 3" sign suggests coarctation of the aorta

• second mogul

  • located just above the left main bronchus and represents the main pulmonary artery segment

  • excessive convexity is seen in poststenotic dilatation, pulmonary arterial hypertension, significant left-to-right shunts and pericardial defects

  • concavity suggests right-to-left shunts, pulmonary atresia, or malposed great vessels

• third mogul

  • never normal

  • if present, it lies below the left main bronchus and is usually formed by a prominent left atrial appendage, which is commonly seen in rheumatic heart disease

  • other causes include cardiac aneurysm, pericardial cyst, coronary artery aneurysm, mediastinal tumour, pericardial defect, sinus of Valsalva aneurysm, and dilated right ventricular outflow tract

• fourth mogul

  • bulge just above the diaphragm formed by the left ventricular margin or cardiac apex

• fifth mogul

  • bulge at the cardiophrenic angle

  • may be caused by prominent pericardial fat pad, pericardial cyst, or adenopathy

History and etymology

The term was popularised by M Daves in the 1970s ^1-3.