Right Ventricle Size In the P-A projection the normal heart takes up about 30% of the diaphragmatic surface. Similarly in the lateral projection the heart takes up a third of the diaphragmatic surface. In addition the heart takes up the bottom 1/3 of the retrosternal air space.Ashley Davidoff MD If we were to “crack open” the chest of the chest X-ray, the structures that would dominate this bloody, black and white scene, would be the right sided chambers. The right ventricle (RV) would be the dominant anterior chamber, and would form the dominant interface with the diaphragm. The right atrium (RA) would form the border with the right lung. The RA would of course be slightly posterior to the RV. The left border would be formed by the left ventricle. Most the left ventricle is hidden posteriorly in this view. The left anterior descending artery would be visible from this anterior view. It marks the position of the interventricular septum.Ashley Davidoff MD A normal lateral examination of the chest X-ray is shown to exemplify the positioning of the cardiac chambers showing the right ventricular outflow tract (RVOT) anteriorly, the left atrium (LA) posteriorly and superiorly, the left ventricle (LV) posteriorly and inferiorly and the inferior vena cava (IVC) as a separate shadow posterior to the LV.Ashley Davidoff MD DILATED CARDIOMYOPATHY WITH 4 CHAMBER ENLARGEMENT and TRIANGULAR HEART ON CXR57-year-old female with 4 chamber enlargement consistent with a dilated cardiomyopathy.CXR showed cardiomegaly with a triangular shaped heartCT confirmed 4 chamber cardiomegaly with pulmonary hypertension. The left atrium (LA) measured 5cms, the right atrium was 8.2cms, right ventricle 4.9cms, left ventricle 5.7cms, and PA 3.5cms. LV thickness was 1.4cmsOn the coronal view the triangular shaped RV dominated the shape of the heart. There was mild tricuspid regurgitationAshley Davidoff MD RV DOMINATES THE ANTERIOR PART OF THE HEARTDILATED CARDIOMYOPATHY WITH 4 CHAMBER ENLARGEMENT and TRIANGULAR HEART ON CXRAshley Davidoff MD ENLARGED PADILATED CARDIOMYOPATHY WITH 4 CHAMBER ENLARGEMENT and TRIANGULAR HEART ON CXRAshley Davidoff MD RVH By MRI NORMAL RV THICKNESS – 4 CHAMBER 4 Chamber “white blood ” MRI sequence through the normal right ventricle (RV) reveals myocardial thickness in the 5mm range of the anterior wall of the RV sinus.Ashley Davidoff MDkey wordsnormalanatomyright atrium and right ventricle (RV)130630.8 NORMAL RV THICKNESS – SHORT AXIS Short axis “white blood ” MRI sequence through the normal right ventricle (RV) sinus and right ventricular outflow tract (RVOT) reveal normal myocardial thickness in the 5mm range of the anterior wallAshley Davidoff MDkey wordsnormalanatomyright atrium and right ventricle (RV)130627.8 NORMAL RV SINUS AND RVOT –Sagittal “white blood ” MRI sequence through the normal right ventricular (RV) inflow and right ventricular outflow tract (RVOT) reveal myocardial thickness in the 5mm range of the anterior wall of the RV sinus and RVOT..Ashley Davidoff MDkey wordsnormalanatomyright atrium and right ventricle (RV)130631.8 NORMAL RIGHT VENTRICLEParasagittal “white blood ” MRI sequence throuGh the normal reveal myocardial thickness in the 5mm range of the inferior and anterior wallAshley Davidoff MDkey wordsnormalanatomyright atrium and right ventricle (RV)130629.8 MITRAL STENOSIS WITH ENLARGEMENT OF THE LEFT ATRIUM, RIGHT ATRIUM, AND RIGHT VENTRICLE WITH INCREASE IN THE RETROSTERNAL AIRSPACE35 year old patient with severe mitral stenosis . with left atrial enlargement (LAE) characterized by elevation of the left mainstem bronchus, straightening of the left heart border, and prominence of the upper 1/3 of the posterior border of the heart. The right atrium is also enlarged characterized by a rotund right heart border. There is right ventricular enlargement characterized by filling in of the retrosternal airspace.Ashley Davidoff MD References and Links TCV Cases 026H SLE Pulmonary Hypertension Libman Sacks