The Anatomic Basis of Echocardiography Krishna Kumar AIMS, Cochin

1. The Anatomic Basis of Echocardiography Krishna Kumar AIMS, Cochin

2. Ensuring Reliability in Echocardiography for CHD Echo is a observer dependent investigation. For accurate echocardiography the “observer” should: • Have an excellent understanding of normal and abnormal cardiac anatomy and physiology • Follow a thorough and systematic approach

3. Why Is It Necessary to Follow a Systematic and a Uniform Approach for CHD? • Allows a more thorough evaluation: minimizes chances of error • Uniformity of approach allows easier understanding of images • Allows easier review images (one person can more easily review another person’s study)

4. Echo for CHD Vs. Acquired Heart Disease • Children allow a clearer view of their hearts than adults! • More windows are available for imaging • The focus is on sweeping across all planes in a view rather than getting a few representative images in a view • Correct anatomical display helps

5. Imaging (USG/CT/MR) • Essentially involves obtaining cross sections in different planes • For the human body the planes are • Coronal • Sagittal • Axial

6. Axial Coronal Sagittal

7. Why Conventional Imaging Planes Are Not Useful for the Heart? • The heart is asymmetrically located • The heart itself is largely asymmetric except for the great vessels, and semilunar valves that have some radial symmetry

9. S I p L R A 3-Dimensional Orientation of the Human Heart

10. S I p L R A Cross Sectional Planes of the Heart

11. Anatomically Correct Display

12. S L R I P/S Ao L R LV RA A/I RV A comparison between a MRI scan in the coronal plane with an echocardiogram in the sub-xiphoid long-axis view. Anatomically correct display of structures allows a better orientation at all times while performing an echocardiogram

13. Anatomically Correct Display

14. The Window for Trans-Thoracic Echocardiography The window available for transthoracic echocardiography is limited by lung tissue that surrounds it.

15. Expiration Inspiration Transducer Positions: Levocardia Supra sternal High-parasternal Parasternal Apical Subxiphoid

16. Transducer Positions:Dextrocardia Inspiration Expiration

17. The Sub-xiphoid “Long-Axis” Sweep The sub-xiphoid long axis sweep starts in the axial plane in the abdomen and moves superiorly in the direction of the coronal plane

18. The first structures to be seen in the sub-xiphoid long axis sweep are the IVC and the hepatic veins along with the aorta. The side-side relationship of the IVC and the abdominal aorta is first identified and the IVC/hepatic veins are traced to the heart

19. Ao IVC IVC Ao Liver: Right lobe Stomach Right Lung Left Lung Sp

20. LA LV RA RUPV LA RA cs IVC Hep. Vs

21. The Sub-xiphoid Long-axis Sweep:Anterior Cuts Sweeping further in a cranial direction allows visualization of progressively anterior structures

22. These are three cuts in the coronal plane. These views cannot be recreated by transthoracic echo echocardiography and ideally require MRI.

23. PA RA RV Ao LA LV LV RA RA RV RV By sweeping cranially, progressively anterior structures are visualized

24. The Subxiphoid “Short –Axis” Sweep The transducer is positioned in the sub-xiphoid region and the tip marker points to the feet. Serial cross sectional views of the heart are obtained as the transducer is swept from right to left (arrow)

25. The Subxiphoid “Short –Axis” Sweep Representative cross sectional views in the sub-xiphoid short-axis sweep are shown here. • Modified and Reproduced with permission from: Geva T. Echocardiography and Doppler Ultrasound. • In: Garson A.Jr, Bricker JT, Fisher DJ, Neish SR (editors), The Science and Practice of • Pediatric Cardiology. Baltimore, MD: Williams & Wilkins; 1997;789-843

26. PA RPA RVOT LV SVC LA Ao RA LV RV MSeptum RV LV IVC LV RV Subxiphoid short-axis sweep: echo-anatomy correlations

27. Atrial Septum: Subxiphoid Views Aorta The atrial septum can be examined in greater detail by doing a careful right-left sweep

28. Left septum Mid-septum SVC Ao LA LA Right septum RA RA LA RA : Rt upper pulm vein Atrial Septal Evaluation

29. Subxiphoid Short-axis Sweep: Ventricular Septum

30. S Septal band P A I LV Anterior IVS Mid IVS RV Posterior IVS Cross Section of the Ventricles Below Mitral Valve Apparatus

31. Mid cavity PA Ao RVOT LV LV LV RV RV RV Basal At RVOT level LV RV Apical Subxiphoid Short-axis Sweep of the : Ventricular Septum

32. The Apical Views The transducer is positioned at the apex and sweeps are made in the anterior-posterior direction

33. The Apical Views

34. LA RA LV RV cs RA LV RV The apical 4 chamber view The Apical Views Inferior sweeps reveal posterior structures

35. The Apical Views: Anterior Cuts Ao LA RV Sweeping superiorly allows examination of progressively anterior structures.

36. The Apical “5 Chamber” View LA RA Ao RV The echo-anatomy correlations in the apical view (anterior sections) obtained by sweeping superiorly are shown here

37. The Apical Long Axial Views The apical long axial views are obtained after clock wise rotation and superior angulations from the apical 4 chamber view

38. PA RV LA LA Ao Ao LV RV The Apical Long Axial Views The apical long axial view is obtained after clock wise rotation and superior angulations from the apical 4 chamber view. This allows an excellent view of the left ventricular outflow Sweeping leftward and further superiorly from the apical long-axial view reveals the right ventricular outflow tract

39. The Parasternal Long –Axis Sweep Sweeping towards the left and superiorly allows visualization of the right ventricular outflow tract By sweeping rightwards and inferiorly the tricuspid valve and the adjacent RV inflow is seen

40. Parasternal long axis view: middle position Parasternal long axis view: left-superior (anterior) sweep RV RV Ao LV PA LA Parasternal long axisview: right-inferior (posterior) sweep RV RA

41. The transducer points towards the left. Serial cross sections of the heart are obtained by sweeping superiorly and inferiorly. Superior sweeps show the great vessels and inferior sweeps show serial cross section of the ventricles from base-apex The Parasternal Short-axis Views

42. Branch PAs PA RV RCC LCC STL NCC LAA RA LA Mid-cavity Apex Parasternal Short Axis Views Section just below the AV valves

43. AO MPA AO RPA LAA LPA LA Superior RV LV

44. RCA LCA Ao Ao LAA LAA Parasternal Short Axis Views:Coronary Arteries The origin of the two coronary arteries are often best imaged in the parasternal short-axis views. They are often seen in the same imaging planes that demonstrate the left atrial appendage. Both coronaries are usually not demonstrable in the same view. To see the right coronary artery the transducer needs to be swept a little superiorly from the position where the left coronary artery is seen.

45. Right superior and inferior pulmonary veins Left superior Ao LA LA Left inferior Ao LAA Parasternal Short Axis Views:Pulmonary Veins Often, at least three pulmonary veins (occasionally all four as shown here) can be seen in the parasternal short axis views by subtle adjustments in the transducer postion.

46. PDA PDA Asc Aorta MPA LPA LPA Desc Aorta Desc Aorta The High Parasternal or “Ductal View” The high parasternal or the ductal view is obtained by placing the transducer high in the precordium (usually in the first intercostal space) and obtaining a section of the MPA-LPA and the descending aorta in the parasagittal plane.

47. MPA MPA Ao The High Parasternal or “Ductal View”: Echo-Anatomy Correlation To understand the echo images the picture in the previous figure has been rotated by 900 in a clockwise direction. The anterior structures are displayed closest to the transducer.

48. MPA Ao The High Parasternal or “Ductal View”

49. High Parasternal Short-axis Views Often the pulmonary artery bifurcation is better visualized from a high parasternal short axis view

50. Suprasternal Short -axis View