Left Ventricular Function

Presentation on echocardiographic assessment of LV function

More on assessment of LV function in the subsections of the Normal echocardiography section (Apical views, Parasternal Long Axis, Parasternal Short Axis).

More information in the section related to inotropic support. 

Classification of left ventricular systolic function

Tissot C, Singh Y, Sekarski N. Echocardiographic Evaluation of Ventricular Function-For the Neonatologist and Pediatric Intensivist. Front Pediatr. 2018 Apr 4;6:79. doi: 10.3389/fped.2018.00079. PMID: 29670871; PMCID: PMC5893826.

This article classifies left ventricular function based on LV-EF in pediatric:

• Normal LV systolic function (EF ≥ 55%), 

• Mild LV systolic dysfunction (EF 41–55%), 

• Moderate LV systolic dysfunction (EF 31–40%),

• Severe LV systolic dysfunction (EF ≤ 30%)

• LV-EF is based on estimation of End Diastolic and End Systolic volumes of the LV. These may be estimated using various methods (link to outside great article): Simpson's Biplane Method, Simpson's Disc method only applied to one of the apical views, 5/6 Area-Length Bullet Method, 3D echocardiography using Speckle-Tracking Echocardiography, 2D estimation using Speckle-Tracking Echocardiography, Teichholz formula from linear dimensions (discouraged).

Tissot et al. also provides normal and abnormal values based on shortening fraction (SF). SF (same as fractional shortening - FS) can be obtained from the M-Mode at the tip of the mitral valve in the parasternal long or short axis view. The LV end diastolic and end systolic diameters can also be obtained from the B-Mode obtained in the same view. The use of this measurement is discouraged by the recent guidelines of the American Society of Echocardiography.

• Normal values in pediatric: 28 and 46%. 

• Normal LV systolic function (SF 26–45%), 

• Mild LV systolic dysfunction (SF 20–25%), 

• Moderate LV systolic dysfunction (SF 15–19%), 

• Severe LV systolic dysfunction (SF ≤14%).

Caveat about shortening fraction: relies on 2 point in the LV and many guidelines recommend against its use in comprehensive evaluation of the LV considering the tendency to have dyskenesis of the LV that may not be homogenous, as well as the septal flattening often found in the context of high PVR due to the transitional period of the newborn. The American Society of Echocardiography mentions: "Fractional Shortening (use is discouraged)" - complete article here.

As per the American College of Cardiology (ACC), mostly geared at adult functional classification but applied often in pediatric: 

• Hyperdynamic left ventricle = LV-Ejection Fraction (EF) greater than 70% 

• Normal LV systolic function -= LVEF 50% to 70% (midpoint 60%) 

• Mild LV systolic dysfunction = LV-EF 40% to 49% (midpoint 45%) 

• Moderate LV systolic dysfunction = LV-EF 30% to 39% (midpoint 35%) 

• Severe LV systolic dysfunction = LV-EF less than 30%.

As per the American College of Cardiology, in adults, there is the context of heart failure (HF) with reduced ejection fraction (HFrEF) and HF with preserved EF (HFpEF).

"Heart failure (HF) encompasses a broad range of left ventricular (LV) function. New treatment guidelines address the entire spectrum of HF. The classification of HF is as follows: 

• HFrEF (HF with reduced ejection fraction [EF]): LVEF ≤40%; 

• HFimpEF (HF with improved EF): Previous LVEF ≤40% and follow-up measurement of LVEF >40%; 

• HFmrEF (HF with mildly reduced EF): LVEF 41-49%; 

• HFpEF (HF with preserved EF): LVEF ≥50%."

Other methods to evaluate LV systolic function include: 

• Deformation analysis using speckle-tracking echocardiography

• dp/dT of the mitral insufficiency jet (particularly useful in the context of distorted LV architecture - such as in single LV physiology)

• Estimation of LV stroke distance by LVOT velocity time integral (VTI), or cardiac output (using LVOT-VTI, HR and LVOT diameter)

• Systolic velocities at the lateral and septal wall by tissue Doppler imaging.

• Fractional area change of the LV from the Apical view (similar to the RV-FAC, but applied to the LV (particularly useful in the context of distorted LV architecture - such as in single LV physiology).

List of LV functional markers by Echocardiography

• M-Mode Echocardiography:

  • Fractional Shortening (FS)

  • Ejection Fraction (EF) by Teichholz

  • LV dimensions (LVIDd, LVIDs)

  • End systolic wall stress (see: Mean velocity of circumferential fiber shortening)

• Two-Dimensional Echocardiography (2D):

  • Global LV systolic function

  • Regional wall motion abnormalities - Often used in adult scoring systems.

    • Normal motion (score 1),  Hypokinesia (score 2), Akinesia (score 3), Dyskinesia (Score 4). The Wall Motion Score Index (WMSI) is calculated for the 17 segments of the left ventricle. The score is calculated by cumulating the number of points (a score for each segment) and dividing this by 17. When all segments move normally, the ratio is 1 (17 divided by 17). In adults, a WMSI >1.7 is indicative of heart failure.

    • Assessment of wall motion abnormalities during systole and diastole

  • LV volumes (end-diastolic and end-systolic)

  • LV mass

  • LV wall thickness

  • LV shape and geometry

• Doppler Echocardiography:

  • Pulsed-wave Doppler:

    • LV inflow velocities (E/A ratio, E wave deceleration time)

    • Tissue Doppler Imaging (TDI) velocities (S', E', A')

    • Index of Myocardial Performance (IMP / MPI / Tei Index): Combined measure of systolic and diastolic function - can also be calculated by TDI

  • Continuous-wave Doppler:

    • LV outflow tract velocities (velocity-time integral)

  • Color Doppler:

    • Assessment of regurgitant flow (mitral or aortic valve regurgitation)

• Tissue Doppler Imaging (TDI):

  • Systolic (S'), early diastolic (E'), and late diastolic (A') velocities of myocardial segments

  • TDI-derived indices (e.g., E/E' ratio for assessing LV filling pressure)

  • LV Dyssynchrony: Assessing temporal coordination of LV contraction (by TDI or strain imaging)

  • Index of Myocardial Performance (IMP / MPI / Tei Index): Combined measure of systolic and diastolic function

• Speckle Tracking Echocardiography (STE):

  • Global longitudinal strain (GLS)

  • Radial and circumferential strain

  • Segmental strain analysis

  • Strain rate imaging

  • Other deformational markers by STE

  • LV Twist and Torsion: Measures of LV rotational mechanics (more challenging than by 3D echocardiography due to temporal/loading changes during image acquisition)

  • LV Dyssynchrony: Assessing temporal coordination of LV contraction (by TDI or strain imaging)

• Myocardial Performance Indices (Tei Index):

  • Tei index (MPI) is a combined systolic and diastolic index of myocardial performance

• 3D Echocardiography:

  • 3D assessment of LV volumes, ejection fraction, and deformation (strain)

  • Better visualization of complex cardiac structures

  • LV Twist and Torsion: Measures of LV rotational mechanics

  • LV Dyssynchrony: Assessing temporal coordination of LV contraction (by TDI or strain imaging)

• LV Sphericity Index:

  • Evaluates LV shape and remodeling

• Endocardial Velocity Gradient (EVG):

  • Evaluates changes in LV contraction patterns

• Papillary Muscle Function:

  • Assessment of papillary muscle movement and mitral valve function

• Estimation of Stroke Work and Cardiac Output:

  • Calculations based on LV volumes and velocities - Article 1; Article 2.

Left ventricular Diastolic Function

LV dysfunction in a newborn with septic shock

Significant left ventricular dysfunction and significant tachycardia (heart rate 220 - in an attempt to maintain output in the context of significant systolic dysfunction) in a newborn with sepsis from a TnECHO performed by Dr Brahim Bensouda at Hôpital Maisonneuve-Rosemont from the TnECHO-Quebec Collaborative. Big thanks for sharing this example. Now in the LV Function section. 

The heart rate of 220 bpm (tachycardia) can be appreciated as a compensatory mechanism to maintain cardiac output in the context of significant left ventricular (LV) systolic dysfunction. The LV appears well-filled, and the left atrium (LA) is appropriately sized, suggesting adequate preload. This highlights the importance of thoroughly evaluating cardiac function in neonatal sepsis before selecting a specific treatment approach. While many neonates with sepsis will develop "warm shock" characterized by decreased systemic vascular resistance (SVR), others may exhibit an element of cardiac dysfunction. Additionally, a drop in SVR can sometimes "mask" underlying LV dysfunction, as the reduced afterload makes it less strenuous for the LV to eject blood, giving the appearance of normal function. If a vasopressor is introduced and the clinical condition does not improve, it is essential to reassess LV function. These patients may have LV systolic compromise exacerbated by the increase in SVR, necessitating adjustments to their management plan.

LV dysfunction in neonatal Permanent Junctional Reciprocating Tachycardia

Infant who had episodes of protracted arrhythmias secondary to PJRT with residual LV dysfunction in A5C, A2C and A4C.

LV dysfunction in a term newborn with HIE on therapeutic hypothermia

Premature newborn with asphyxia, RDS and hypoxic respiratory failure

Parasternal short axis demonstrating some degree of LV performance anomaly (moderate to severe). The flow through the aortic valve is almost completely filtered at a Nyquist of 68 cm/second, indicating that the systolic dysfunction impairs flow velocity generation in the outflow tract (possibly with secondary decreased output). 

Sweep in parasternal short axis indicates that the apex seems to be more affected than the papillary area and base. 

Degree of biventricular dysfunction with a depressed TAPSE. 

Unobstructed LV outflow tract. This patient also has some mild MR and TR, indicating some suffering of the underlying ventricle during the asphyxiated event (papillary muscle subendocardial ischemia)

Bidirectional PDA from isosystemic pulmonary pressure (PVR) and possibly decreased LV output from LV dysfunction. 

Altered TDI profile, with S' depressed for both ventricles. 

LV dysfunction in the context of Congenital Diaphragmatic Hernia

Abnormal strain (deformation) using speckle tracking echocardiography for the LV. 

Case of biventricular dysfunction in the context of HIE

Echocardiography on day 1 - "normal" BP (mean BP 45)

RV FAC is decreased at 19%

LV focuse view. Colour shows that there is some mild mitral insufficiency, possibly from subendocardial ischemia to the papillary muscles (proxy that this LV has suffered an event of perinatal asphyxia).  

LV lateral wall and septal wall with depressed systolic peak velocities by tissue doppler imaging. 

Depressed EF by Simpson's in A4C (33%)

No obvious coarctation with appropriate aortic caliber and laminar flow. A restrictive PDA may be observed (bidirectional in nature, although not fully appreciated from these clips). 

Echocardiography after Epinephrine IV

Echocardiography on day 2 - after addition of Milrinone IV

Improved LV and RV function on the A4C

Lung ultrasound - showcasing some degree of free fluid around the heart. 

Neonatal Heart Failure and Cardiomyopathy by Dr Alami

Presented at the McGill Neonatal Conference 2022