Abnormal Cardiac Position
	Cardiac Location	Apex Location
Left Right Midline	Levoposition Dextroposition	Levocardia Dextrocardia Mesocardia

Anomalies of Cardiac Situs

Right atrium

Right ventricle

Cardiac apex

Right side

Left side

CHD

1. Situs solitus.

Right

Left

Left

Trilobed lung

Liver

Gallbladder

IVC

Bilobed ling

Stomach

Aorta

Single spleen

Apex of heart

0.6-.8%

2. Situs inversus.

(2%)

Left

Right

Right

Bilobed lung

Stomach

Single spleen

Aorta

Apex of heart

Trilobed lung

Liver

Gallbladder

IVC

3-5%

AV canal

Univentricle

TGV

TAPVD

Dextrocardia = situs inversus

3. Situs Ambiguus
(heterotaxy)
(75% dextrocardia

- asplenia

Bilateral LA

Trilobed lung

Eparterial bronchi

Central liver

Aorta and IVC in same side of spine

Trilobed lung

Central liver

Stomach in indeterminate position

50-100%

- polysplenia

Bilateral RA

Bilobed lung

Midline liver

Hyparterial bronchi

IVC interruption with azygous continuation

Bilobed lungs

Midline liver

Stomach position variable (Lt or Rt)

Multiple spleens (always on same side as stomach)

Less common than asplenia

AV canal

ASD

PAPVD

4. Visceral

Heterotaxia
(95%)

Heart and / or viscera are not on one side but tend to be in the middle.

5. Mesocardia

Heart in a midline position, stomach on left. Usually associated with a normal heart.

Case 1
Case 2

Index

• Percentages in brackets refer to the frequency of associated congenital anomalies.
• CHD – congenital heart disease
• IVC – inferior vena cava
• AV canal – atrio-ventricular canal defect
• TGV – transposition of the great vessels
• TAPVD – total anomalous pulmonary venous drainage
• LA – left atrium
• Ra – right atrium
• ASD – atrial septal defect
• PAPVD – partial anomalous pulmonary venous drainage

Normal Situs (Situs solitus) · Stomach on left. · Descending aorta on left. · Inferior vena cava on right.
Dextrocardia and Situs Inversus