Anatomy of the Right Ventricle

Objectives
 
 At the completion of this chapter, the user will be able to: 
 
  • Discuss the normal anatomy of the right ventricle
  • Obtain the standard and nonstandard TEE acoustic views
  • Evaluation of RV Systolic Function with 2-D Mode
  • Calculate RVSP
  • Describe RV Dilation
  • Describe RV Hypertrophy
 
Anatomy
The right ventricular cavity is a triangular or crescent shaped cavity that wraps around the right and anteroseptal side of the left ventricle and appears about 2/3 as large as the left ventricle.  Unlike the smooth left ventricular cavity, the right ventricular chamber is filled with trabeculations and muscle bands.  The complex and unusual shape, irregular endocardial wall, and the difficulty of obtaining standardized imaging planes, causes difficulties when measuring the volume of the right ventricle.  The 2D measurements of right ventricular volumes and volume related calculations (i.e. ejection fraction) are not as accurate as similar measurements of the left ventricle.  Most methods of evaluating the right ventricle are qualitative, not quantitative.
 


 
The irregular endocardial border is due to the lining of the right ventricle with trabeculae carneae and muscle bundles.  The right ventricular inflow (RVI) tract is located posteroinferiorly and contains the tricuspid valve.  The right ventricular inflow tract (RVOT) is heavily populated with trabeculae carneae.  The outflow tract contains the pulmonary valve and pulmonary artery and is located anterosuperiorly.   The outflow tract, or infundibulum, is smooth.  Muscular bands separate the inflow and outflow tracts.  Four muscular bands, which form a ring, are the parietal band, crista superventricularis, septal band, and the moderator band.  The moderator band can become large and simulate a thrombus or tumor.  The tricuspid valve has papillary muscles that arise from the interventricular septum and the right ventricular free wall.  The papillary muscles are relatively small and numerous.  The septal papillary muscle tends to originate from the posteroinferior margin of the septal band.