Right Sided Isomerism is associated with:
Cardiosplenic syndrome or Heterotaxy Syndrome 

Normal arrangement of organs and vessels within the body is called 'Sims solitus Complete reversal of organs and vessels within the body is called "situs invertus". Incomplete reversal/Random reversal of body organs is called "Situs ambiguous".
Heterotaxy refers to the variation in the normal arrangement of organs and vessels within the body.
Visceral heterotaxy (Situs ambiguous) is primarily classified on the bases of the position of spleen which is embryologically destined to be a left sided organ. Other normal assymetrical viscera are placed more or less sym­metrically.
Situs ambiguous or situs indeterminus is generally expressed in two major forms based on the position of spleen and whether the body resembles the normal right side or normal left side of the body.

(i) Right isomerism (Asplenia)

The spleen is typically absent and hence either side of midline resembles right side.
Therefore, it is also called bilateral right sidedness.
It is usually associated with severe complex cardiac abnormalities and has poor prognosis.

(ii) Left isomerism (Polysplenia)

There are multiple small spleens placed on either side of midline, therefore, either side of the midline resembles the left (splenic) side.
Thus, it is also called bilateral left sideness.
It is associated with less severe cardiac abnormalities and has relatively better prognosis.
Asplenia
One spleen
Two spleens
Polysplenia