Echocardiogram

simple ppt

1. ECHOCARDIOGRAPHY

2. DEFINITION Echocardiogram  is a diagnostic test which uses ultrasound waves to make images of the heart chambers, valves and surrounding structures. It can measure cardiac output and is a sensitive test to find fluid around the heart (pericardial effusion ).

3. TYPES

4. TRANSTHORACIC ECHO A  transthoracic echocardiogram  ( TTE ) is the most common type of  echocardiogram . In this case, the probe (or  ultrasonic transducer ) is placed on the  chest  or  abdomen  of the subject to get various views of the heart. It is used as a non-invasive assessment of the overall health of the heart, including a patient's heart valves and degree of heart muscle contraction (an indicator of the  ejection fraction ).

5. TRANSTHORACIC ECHO

6. TRANSESOPHAGEAL ECHO(TEE) A specialized probe containing an ultrasound transducer at its tip is passed into the patient's  oesophagus . 

7. Advantages of TEE The advantage of TEE over TTE is usually clearer images, especially of structures that are difficult to view transthoracically (through the chest wall) since heart rests directly upon the esophagus leaving only millimeters that the ultrasound beam has to travel This reduces the attenuation (weakening) of the ultrasound signal, generating a stronger return signal.

8. In adults, several structures can be evaluated and imaged better with the TEE, including the  aorta , pulmonary artery, valves of the heart, both atria, atrial septum,  left atrial appendage , and  coronary arteries . TEE has a very high sensitivity for locating a blood clot inside the left atrium. DISADVANTAGES It takes longer to perform a TEE than a TTE. It may be uncomfortable for the patient, who may require  sedation  or general anesthesia. Some risks are associated with the procedure, such as esophageal perforation around 1 in 10,000, and adverse reactions to the medication.

9. PROCESS OF TEE Before inserting the probe, mild to moderate  sedation  is induced in the patient to ease the discomfort and to decrease the  gag reflex , thus making the ultrasound probe easier to pass into the esophagus. Mild to moderate Sedation is produced by   midazolam  (a  benzodiazepine ) , fentanyl  (an opioid)  or  propofol  Usually a local anesthetic spray is used for the back of the throat, such a  xylocaine  /or a jelly /lubricant anesthetic for the esophagus. Children are  anesthetized

10. CLINCAL USES TEE can be performed by a cardiac anesthesiologist to evaluate, diagnose, and treat patients in the perioperative period.  . TEE is very useful during many cardiac surgical procedures (e.g., mitral valve repair and in aortic dissections). It is actually an essential monitoring tool and to assess the results of surgery immediately after the procedure.

11. STRESS ECHOCARDIOGRAM A stress test may be accompanied by  echocardiography .  The echocardiography is performed both before and after the exercise so that structural differences can be compared. A resting echocardiogram is obtained prior to stress. The images obtained are similar to the ones obtained during a full surface echocardiogram, commonly referred to as transthoracic echocardiogram.

12. The patient is subjected to stress in the form of exercise or chemically (usually  dobutamine ). After the target heart rate is achieved, 'stress' echocardiogram images are obtained. The two echocardiogram images are then compared to assess for any abnormalities in wall motion of the heart. This is used to detect obstructive coronary artery disease.

13. Doppler echocardiography Doppler echocardiography  is a procedure that uses  Doppler ultrasonography to examine the  heart .  An  echocardiogram  uses high frequency sound waves to create an image of the heart while the use of Doppler technology allows determination of the speed and direction of  blood flow  by utilizing the  Doppler effect . Velocity measurements allow assessment of  cardiac valve  areas and function, any abnormal communications between the left and right side of the heart, any leaking of blood through the valves ( valvular regurgitation ), calculation of the  cardiac output  and calculation of  E/A ratio (a measure of  diastolic dysfunction ).

14. ADVANTAGES OF DOPPLER An advantage of Doppler echocardiography is that it can be used to measure blood flow within the heart without  invasive procedures such as  cardiac catheterization .  The method can measure tissue velocities by  tissue Doppler echocardiography . The combination of flow and tissue velocities can be used for estimating left ventricular filling  pressure , although only under certain conditions

15. DOPPLER ECHO

16. Doppler Echo An abnormal echocardiogram : Image shows a midmuscular  ventricular septal defect . The trace in the lower left shows the  cardiac cycle  . Colors are used to represent the velocity and direction of blood flow.

17. AXES IN ECHOCARDIOGRAPHY Two key axes of the heart are the long axis and short axis. The long axis is an imaginary line from the apex of the heart through the centre of the mitral valve. The short axis is perpendicular to the long axis and shows the heart in cross section.

18. WINDOWS OF ECHO Evaluation of the heart with echocardiography requires "acoustic windows" of the heart. Bone reflects the ultrasound waves and so all structures directly behind bone are not visible with ultrasound. This requires that the heart be viewed between bones and, in particular, between ribs. The most common views are the parasternal, apical, subcostal, and suprasternal windows.

19. Para sternal : Adjacent to the sternum.. Apical : At the apex of the heart. Sub costal : Below the sternum at the top of the abdomen Supra sternal : Above the sternal at the base of the neck

20. VIEWS There are several typical views obtained during a routine TTE. Views outside of the typical views can be considered "off axis" and may be obtained for specific purposes.

21. Parasternal long axis (PLAX) This view is obtained to the left of the sternum and views the heart in its long axis. In this view, the mitral valve, aortic valve, right ventricular outflow tract, base of the left ventricle, and the left atrium can be visible. In this view, it is possible to appreciate the long-axis cross section of the mitral and aortic valves. The classic "hockey stick" shape of rheumatic mitral stenosis can be appreciated in this view. The parasternal long view of the pulmonary valve is the only view of the posterior leaflet.

22. PLAX

23. Structures visible : Anterior septal and inferior lateral walls of the left ventricle Left atrium Mitral valve in long-axis with chordae Aortic valve in long-axis Tricuspid valve in long-axis (angulated) and right ventricular inflow tract Pulmonary valve in long-axis (angulated) and right ventricular outflow tract

24. Measurements in this view can be used to quantify the heart: Left ventricular size and wall thickness Left atrial linear dimension (as opposed to area) Left ventricular outflow tract diameter (used to calculate aortic valve area by the continuity equation) Aortic annulus, sinus of Valsalva , and aortic root sizes Color doppler of all four valves Spectral doppler of tricuspid and pulmonary valves

25. Parasternal short axis (PSAX) This view is obtained in the same window as the parasternal long, but with the probe rotated 90°. In this view, the aortic valve is seen in cross-section with the right ventricular inflow & outflow tracts visible with the tricuspid valve as well . Pulmonary valve is not visible in this view. Both the right and left atria are visible. The standard PSAX view is at the level of the aortic valve, but moving the probe along the long-axis can review the LV outflow tract, LV at the base, and LV at the mid section.

26. PSAX

27. Structures visible : Aortic valve in short-axis Aortic valve dysfunction, aortic sclerosis/ stenosis Tricuspid valve in long-axis Right ventricle including inflow and outflow tracts Left ventricle in short-axis Closer to the base can reveal the left ventricular outflow tract At the level of the base can show the movement of the mitral valve leaflets in short-axis At the level of mid-LV can show papillary muscles

28. Apical four chamber (A4C) This view is obtained at the apex of the heart and looking toward the base of the heart (where the valves are). In this view, the mitral valve, tricuspid valve, and all four chambers are visible. This view shows the right ventricle from base to apex and is a useful view to estimate RV systolic function

29. A4C

30. Structures visible : Inferior septum and anterior lateral segments of the left ventricle Right ventricle Left atrium Right atrium Mitral valve Tricuspid valve

31. Measurements in this view can be used to quantify the heart: RV size and function Left atrial size Right atrial size Mitral valve flow is best seen in this view and has the best angle with probe to estimate flows Tricuspid valve flow Tissue doppler at the mitral valve annulus (septum & lateral wall) for diastolic function Agitated saline bubble study for right to left shunting (PFO, ASD, VSD) With contrast, apical and mural LV thrombi can be easily seen

32. Apical three chamber (A3C) This view is obtained at the same window as the apical four chamber and then rotation of the probe. In this view, the mitral valve and aortic valve are in view and is roughly similar to the parasternal long axis. In this view, the LV outflow tract is best in alignment with the probe and so gives the best estimate of flow through the LVOT, which is commonly used to estimate aortic stenosis.

33. A3 CHAMBER

34. Structures visible : Aortic valve Mitral valve Left ventricle Left atrium Measurements in this view can be used to quantify the heart: Left ventricle outflow tract volume-time integral (LVOT VTI) used in conjunction with aortic valve VTI for aortic valve area and stenosis Mitral valve flow

35. Apical two chamber (A2C) This view is obtained at the same window as the apical four chamber and then rotation of the probe. In this view, the mitral valve is visible with the left atrium and left ventricle. Structures visible : Anterior and inferior segments of the left ventricle Mitral valve in long-axis Left atrium Measurements in this view can be used to quantify the heart: Mitral valve flow Spectral doppler of the mitral valve

36. A2C

37. Subcostal This view is obtained below the sternum and at the top part of the abdomen. In this view, the junction of the inferior vena cava with the right atrium is best seen. From this window, it is possible in some people to see roughly equivalent views of the apical four chamber and parasternal short views. In some people, this may afford these common views but at a subcostal window that may not be obtained through the parasternal and/or apical windows because of various reasons such as chest wall trauma, open wounds, or poor acoustic windows

38. . However, the subcostal window is the only window to view the inferior vena cava that can help support an estimation of the central venous pressure based on size and collapsibility during respiration. Other non-cardiac structures are visible in this view and some pathologies — such as ascites — can be observed.

39. Subcostal

40. Suprasternal (SSN) This view is obtained above the sternum in the suprasternal notch. In this view, the aortic arch and portion of the descending aorta can be seen. Color and spectral doppler through the descending aorta can show signs of  coarctation of the aort a .

41. USES OF ECHO HELPS IN IDENTIFICATION OF : Blood clots in the heart Fluid in the sac around the heart Problems with the aorta, which is the main artery connected to the heart Cardiomyopathy : dilated, restrictive, and hypertrophic Pulmonary hypertension (requires some degree of tricuspid regurgitation) Septal defects including ASD & VSD Stenosis and regurgitation/insufficiency of valves

42. Structure and function of prosthetic valves Thoracic ascending aortic aneurysm Infiltrative diseases such as amyloidosis Cardiac tamponade (it can suggest subclinical diagnosis) Evaluation of congenital diseases (eg: Tetralogy of Fallot, transposition) Pulmonary embolism Endocarditis (sensitivity is higher with TEE)

43. Cardiac amyloidosis Cardiac amyloidosis is a disorder caused by deposits of an abnormal protein (amyloid) in the heart tissue. These deposits make it hard for the heart to work properly.

44. CARDIAC TAMPONADE In this condition there is right venticular or atrial compression that is accompanied with the opening or closure of valves.

45. DIALATED CARDIOMYOPATHY The ventricles are dilated more than the normal.

46. HYPERTROPHIC CARDIOMYOPATHY The intra ventricular septum appears thickened

47. RESTRICTIVE CARDIOMYOPATHY The ventricles are smaller when compared to the atrium

48. LEFT VENTRICULAR HYPERTROPHY

49. MITRAL VALVE PROLAPSE

50. PAPILLARY MUSCLE RUPTURE

51. INFECTIVE ENDOCARDITIS