RV-1

Right Ventricular Systolic Function 14th Annual Comprehensive Review & Update of Perioperative Echo Clinical Decision Making in the Cardiac Surgery Patient San Diego, California February 7-12, 2011 Jonathan B. Mark, M.D. Duke University Medical Center Veterans Affairs Medical Center Durham, North Carolina Right Ventricle Compared to TEE assessment of left ventricular function, echocardiographic evaluation of the right ventricle (RV) is complicated by the non-geometric, asymmetric, crescent-shape of this chamber, which precludes easy application of quantitative methods. Since the long and short axes of the RV are defined by the corresponding views of the left ventricle (LV), standard echocardiographic scan planes often transect the RV in an oblique fashion. As a result, TEE evaluation of the RV focuses on a qualitative assessment guided by knowledge of certain normal anatomic and functional features. Anatomically, the RV may be divided into inflow and outflow regions. The RV inflow portion begins with the tricuspid valve, is located inferoposteriorly, and is heavily trabeculated with the trabeculae carnae. The outflow portion is located more anterosuperiorly, is smooth-walled, and forms the RV infundibulum (conus arteriosus) that ends with the pulmonic valve. An encircling muscular band divides these regions of the RV. Four distinct structures contribute to this muscular circle: parietal band, crista supraventricularis (supraventricular crest), septal band, and moderator band. The latter may be seen to give rise to the anterior papillary muscle and is often identified as a prominent, mobile, echo dense structure within the RV cavity that should not be diagnosed erroneously as a ventricular thrombus. The primary TEE views for RV assessment are the mid-esophageal 4-chamber view* and the mid-esophageal right ventricular inflow-outflow view. The latter view is often termed the wrap-around view, owing to the fact that the right atrium, right ventricle, and pulmonary artery appear to “wrap around” the aortic valve and left atrium, circumscribing a 180o to 270o arc.

4-Chamber View

RV Inflow-Outflow View

* Note that all the scan planes described herein conform to the standards described by the ASE/SCA Practice Guideline (Reference #10).

RV-2

The RV consists of a free wall and a septum that it shares with the LV. The RV may also be described in terms of its inflow and outflow tracts, which reflects the separate embryologic origins of these portions of the RV. In functional terms, the inflow and outflow portions of the RV contract in sequence, further confounding quantitative TEE assessment of RV contraction patterns. Although there is no standardized approach for describing regional RV function, the free wall of the RV may be divided into basal, mid-, and apical segments corresponding to the adjacent LV segments in the mid-esophageal 4-chamber view. Normal RV free wall thickness is less than half that of the LV and measures