LV systolic function.pptx

left ventricular function, step by step

1. Step by step approach for LV systolic function TAHER SAID Consultant Cardiology Nizwa Hospital Ministry of Health Nizwa Hospital Cardiology Department

2. Agenda Introduction: Arrangement of Myocardial fibrils. Step 1 : Measure Left Ventricular Size. Left Ventricular Chamber Dimensions 2D and 3D Left Ventricular Chamber Volumes Left Ventricular Wall Thickness and Mass Step 2: Evaluate Left Ventricular Systolic Performance 2D and 3D Ejection Fraction Stroke Volume and Cardiac Output Global Longitudinal Strain Step 3 : Assess Regional Ventricular Function Step 4 : Other Measures of Left Ventricular Systolic Function Ejection Acceleration Times Left Ventricular dP / dt Other Measures

3. Introduction: Arrangement of Myocardial fibrils .

4. Arrangement of Myocardial fibrils .

5. Step 1: Measure Left Ventricular Size

6. Step 1 : Measure Left Ventricular Size Dimensions Volumes Wall thickness and LV mass

7. Step 1 (a): LV dimensions 2D measurement of left ventricular (LV ) minor axis internal dimensions 2D guided M-mode measurement of LV minor axis internal dimensions at end-diastole and end-systole. Ultrasound beam is perpendicular to the blood-myocardial interface, providing high axial resolution. The posterior LV wall is identified on M-mode as the steepest, most continuous line . Identification of the endocardial border on 2D images is less reliable. Measurements of LV internal dimensions and wall thickness are made at the level of the mitral valve chords just apical to the mitral leaflet tips.

8. Step 1 (b): 2D and 3D Left Ventricular Chamber Volumes 2D Biplane disc's summation. Area–length method Endocardial border enhancement (contrast echo) 3DE imaging: The 3D-guided biplane technique. The Triplane technique. Direct volume quantification.

9. 1- 2D Biplane disc's summation . Based on tracings of the blood tissue interface in the AP4CV and 2CV . Trace endocardial borders excluding papillary muscles . Connect MV insertions on the annulus with straight line. LV length is defined as the distance between the middle of this line and the most distant point of the LV contour. Acquiring LV views at a reduced depth in order to focus on the LV cavity will reduce the likelihood of foreshortening and minimize errors in endocardial border tracings

10. How to Trace End-diastole = frame preceding MV closure or the frame in the cardiac cycle, in which the LV dimension/volume is the largest. End-systole = frame following AV closure or the frame in which the LV dimension/volume is the smallest.

11. Advantage and limitations Advantages Corrects for shape distortions Less geometrical assumptions compared to linear dimensions Limitations Apex frequently foreshortened Endocardial dropout Blind to shape distortions not visualized in the AP 2CV and 4CV

12. B- Area–length method Indications ◆ When apical endocardial definition precludes accurate tracing Advantages ◆ Partial correction for shape distortion Limitations ◆ Apex frequently foreshortened ◆ Heavily based on geometrical assumptions ◆ Limited data on normal population

13. How to measure

14. C- Endocardial border enhancement Indications ◆ Indicated to improve endocardial delineation when ≥ 2 contiguous LV endocardial segments are poorly visualized Advantages ◆ Helpful in patients with suboptimal acoustic window ◆ Provides volumes that are closer to those measured with cardiac magnetic resonance

15. Endocardial border enhancement

16. D- Using 3D echo imaging Advantages No geometrical assumption Unaffected by foreshortening More accurate and reproducible compared to other imaging modalities Limitations Lower temporal resolution Image quality dependent

17. 1-The 3D-guided biplane technique . 3DE pyramidal dataset of the LV, anatomically correct, non-foreshortened two-dimensional echocardiography apical four- and two-chamber views. The biplane Simpson method of discs is then applied to calculate LV volumes from non-foreshortened apical views. Because this method still relies on geometric modeling to calculate LV volumes, it is likely to be inaccurate in distorted ventricles

18. 2- The tri-plane technique . After manual orientation of the reference view (conventionally the four-chamber view ), the two additional views (two-chamber and apical long-axis) are automatically selected at 60° and 120° from the four-chamber view. The Echocardiographer can adjust the acquisition angles in order to optimize view orientations, but only during acquisition. This technique also relies on the same geometric assumptions about LV shape of the biplane discs’ summation rule (even if they are mitigated by the addition of the third apical view).

19. Advantages the echocardiographers can immediately realize if any foreshortening has occurred during acquisition. Wall motion abnormalities occurring in the infero -lateral LV wall and anterior septum are accounted in LV ejection fraction computation. So it is more accurate than conventional biplane algorithms in assessing LV volumes and ejection fraction. Feasible in patients with irregular atrial fibrillation or other arrhythmias, too. More user friendly approach.

20. 3- Direct volume quantification. Based on semi-automated detection of LV endocardial surfaces throughout the cardiac cycle followed by measurement of LV volume contained within this surface. This approach has the important advantage over the 3D-guided bi-plane and the tri-plane methods of not relying on geometric modeling. Transthoracic 3DE volumes are generally accurate even in very dilated and aneurysmal ventricles, provided that the sonographer takes care to include the entire ventricle within the acquisition volume

21. Acquisition (FR More than 25)

22. Normal values 3DE LV volumes and function EDV 79 mL/m2 for men EDV 71 mL/m2 for women ESV 32 mL/m2 for men ESV 28 mL/m2 for women EF 52 % for men EF 54 % for women

23. Normal 2D Values

24. Step 1 (c) Left Ventricular Wall Thickness and Mass 2D or 2D-guided M-mode measurement of LV septal and posterior wall thickness at end-diastole are usually are sufficient for clinical care. LV mass and wall stress can be calculated from 2D images. Measured from the parasternal window . The septal wall thickness measurement does not include trabeculations on the right ventricular (RV ) side of the septum and does not mistake the midseptal stripe for the right-sided endocardium. The posterior LV wall thickness is measured from the endocardium to the posterior epicardium . LV mass is calculated from endocardial and epicardial border tracing in a short-axis view at the papillary muscle level and measurement of LV length .

25. Normal values Wall thickness less than 11mm. 11- 12mm equal to mild thickening. More than 15mm is marked thickening Asymmetrical septal wall hypertrophy means septal to free wall thickness ratio between 1.3 (non HTN) and 1.5 (HTN patient ). LV hypertrophy using M mode formula:- LV mass index > 115 g/m2 in men LV mass index > 95 g/m2 in women. LV hypertrophy using M mode formula:- LV mass index > 102 g/m2 in men LV mass index > 88g/m2 in women.

26. How to differentiate

27. Step2 : Evaluate Left Ventricular Systolic Performance

28. 1- 2D and 3D Ejection Fraction LV ejection fraction is an essential part of the echo examination and should be measured by 2D or 3D methods whenever possible. If the ejection fraction cannot be measured due to poor endocardial definition, a visual estimate may be reported EF = [(EDV− ESV)/EDV] × 100 S cale as follows: Normal (EF ≥55%) Mildly reduced (EF 45% to 53%) Moderately reduced (EF 30% to 44%) Severely reduced (EF <30%)

29. 2- Stroke Volume and Cardiac Output Used when: Ventricular function is abnormal Valve stenosis, valve regurgitation An intracardiac shunt is present SV = CSA × VTI LVOT diameter (D) is measured from a parasternal long-axis view in mid-systole, from inner edge to inner edge, immediately adjacent to the base of the aortic valve leaflets CSA=(radius)2 = 3.14(D/2)2 Stroke volume can be calculated at any site where diameter and velocity can be measured but most often is measured in ( LVOT ). CO = [SV (mL) × heart rate (beats/m in)] /1000 mL/L = L/min Normal SV is about 80 Ml N ormal COP is about 6 L/min. A normal stroke volume index is >35 mL/m2

30. How to measure

31. Velocity time integral (VTI) = stroke distance= the length of the cylinder of blood ejected by the LV on each beat

32. 3- Global Longitudinal Strain Strain is a measure of myocardial shortening that reflects LV systolic performance Measured in apical 4,2 and 3 chamber view. Normal GLS is about -20%. Strain is more sensitive than ejection fraction for detection of early myocardial dysfunction. Strain is less dependent on loading conditions compared with ejection fraction.

33. Step 3: Assess Regional Ventricular Function

34. Methods for Assessment of Regional Left Ventricular Systolic Function

35. Step 4: Consider Other Measures of Left Ventricular Systolic Function

36. Other methods for evaluation of LV performance 1- Ejection acceleration time. 2- Left Ventricular dP / dt 3- E-point septal separation 4- Decreased aortic root anterior–posterior motion 5- Decreased mitral annular apical motion.

37. 1-Ejection Acceleration Time In the absence of a significant AV disease, the time taken by the blood column to accelerate and reach the peak velocity through the LVOT is inversely related to the contractile function of the LV. LVOT ACC (m/s 2 ) = Vmax (m/s)/ACT (s ). When systolic function is normal, the LV ejection curve resembles a sharp-angled triangle. With impaired left ventricular function, the ejection curve becomes flattened and rounded, i.e., with a decreased peak velocity and an increased ACT. LVOT ACC is quite sensitive to global LV function and is not load-dependent. Normal range: 8–14 m/s 2 .

38. How to measure

39. 2- Left Ventricular dP / dt The rate of rise of ventricle pressure, or change in pressure ( dP ) over time ( dt ), is a load-independent measure of ventricular function. LV dP / dt can be calculated from the rise in velocity of the mitral regurgitant -jet This measurement is useful in selected patients with evidence of ventricular dysfunction or with significant mitral regurgitation. The time interval ( dt ) between the points on the mitral regurgitant velocity curve at 1 and 3 m/s is measured in seconds The pressure difference ( dP ) between 1 and 3 m/s, calculated using the Bernoulli equation, is: dP = 4(3)2 – 4(1)2 = 32mmHg Thus, dP / dt is 32 mm Hg divided by the time interval in seconds . A normal dP / dt is more than 1200 mm Hg/s.

40. How to measure and Ex

41. dP / dt Values

42. 3- E-point septal separation The distance between the most anterior motion of the mitral leaflet and the most posterior motion of the septum normally is only 0 to 5 mm. An increased mitral E-point to septal separation occurs with LV dilation or systolic dysfunction , aortic regurgitation, or mitral stenosis . This finding is best appreciated on M-mode tracings

43. How to do

44. 4- Decreased aortic root anterior–posterior motion The movement of the aortic root in an anteriorposterior direction on M-mode reflects the filling and emptying of the left atrium (LA), which is confined between the aortic root and spine. A decrease in atrial filling/emptying (e.g., with a low forward stroke volume) results in decreased motion of the aortic root

45. How to do

46. 5- Decreased mitral annular apical motion . Ventricular contraction occurs along the long axis of the ventricle, in addition to circumferential shortening . The mitral annulus moves apically with longitudinal contraction of the LV , with the magnitude of motion reflecting ventricular function. Reduced apical motion of the annulus (<8 mm) indicates an ejection fraction less than 50%

47. How to measure