Diastolic dysfunction of left ventricle
Diastolic dysfunction is understood as impaired left ventricular relaxation with increased stiffness of the LV and elevated filling pressures.
1 Etiology
Possible causes of diastolic dysfunction are various such as structural heart diseases (hypertrophy, constriction, fibrosis) or functional heart disease (ischemia).
Hypertension, coronary artery disease, and valvular disease are the most common causes.
2 Pathophysiology
Although diastolic dysfunction is a central feature in HFpEF, the pathophysiology is complex with variable contributions from diastolic dysfunction, impaired contractile reserve, damaged atrial function, relative pericardial restraint and abnormal ventricular vascular coupling which all contribute to the elevation in pulmonary venous and left sided filling pressures.
The pathogenesis of diastolic dysfunction involves abnormalities of active ventricular relaxation and passive ventricular compliance, which lead to ventricular stiffness and higher diastolic pressures.
These pressures are transmitted through atrial and pulmonary venous systems, reducing lung compliance.
A combination of decreased lung compliance and cardiac output leads to symptoms.
Physiologic stressors, such as a hypertensive crisis, can affect compensatory mechanisms and result in pulmonary edema.
3 Diagnosis
The diagnosis of HFpEF requires clinical symptoms and/or signs of heart failure, as well as evidence of preserved LVEF and diastolic dysfunction.
Heart failure with preserved ejection fraction dissembles as heart valve disease, CAD, arrhythmias, and pericardial constriction, so they need to be ruled out.
Common symptoms of HFpEF include fatigue, weakness, dyspnea, orthopnea, paroxysmal nocturnal dyspnea, and edema.
If physical examination findings suggest heart failure (jugular venous distention, S3 heart sound, or displaced apical impulse) or fulfill the clinical criteria for the MICE or Framingham rules, the patient should be referred for TTE.
Natriuretic peptide levels should always be interpreted in context. The main trigger for release of NPs is high LV end-diastolic wall stress, which is inversely proportional to wall thickness.
3.1 ECG
Patients may have ECG features of LVH (such as a Sokolow-Lyon Index ≥3.5 mV; abnormal repolarization) and/or LA enlargement, but there are no pathognomonic signs and the diagnostic value of an ECG to identify HFpEF is poor.
The most significant indication is to detect atrial fibrillation (AF), which is highly predictive of underlying HFpEF.
3.2 ECHO
Echocardiogram is indicated in all patients with HF symptoms.
Preserved EF is defined as an EF >50%. HFpEF is suggested by normal EF, nondilated left ventricle with concentric remodeling, or left ventricular hypertrophy and left atrial enlargement.
Your first goal should be to assess whether there is diastolic dysfunction present or not - but there is no need to further grade it.
What do you need to measure to assed diastolic dysfunction ?
3.2.1 Mitral Inflow signal to assess diastolic dysfunction
3.2.2 Tissue Doppler for the assessment of diastolic dysfunction
3.2.3 Pulmonary vein flow
3.2.4 Other signs of diastolic dysfunction
Image 1 Echocardiography assessment of diastolic dysfunction
3.2.1 Mitral Inflow signal to assess diastolic dysfunction
The mitral inflow signal visualizes the individual phases of filling as well as displays the contribution of each individual phase in filling.
Early filling = E wave
Late filling = A wave
E-wave deceleration time = DT
Length of the isovolumetric relaxation time = IVRT (time of how long it takes for filling of the ventricle to start after the ventricle relaxes).
E/A ratio
Image 2 How to measure E and A waves
How to measure E wave ?
Peak velocity in early diastole
A4C view
Early diastole (ECG: the end of T-wave)
PW doppler
Sample volume (1-3 mm axial size) between mitral leaflet tips.
Colour doppler (helps with blood flow identification)
How to measure A wave ?
Peak velocity in late diastole
A4C
Late diastole (ECG: right after P wave)
PW doppler
Sample volume (1-3 mm axial size) between mitral leaflet tips.
Colour doppler (helps with blood flow identification)
How to measure E/A ratio ?
In the A4C view, place the PW Doppler sample volume (1–3 mm) at the level of the mitral leaflets.
Colour flow Doppler must be used to align the sample with the centre of trans-mitral flow (this is especially important when the LV is dilated as LV inflow may be directed posterolaterally due to mitral valve leaflet tethering).
Values ≤0.8 (where the E-wave is also ≤ 50 cm/s) indicate normal LAP (diastolic dysfunction grade I).
Values ≥ 2 suggest significantly raised LAP abnormal (diastolic dysfunction grade III).
Otherwise, additional criteria are required to determine the grade. The ratio declines with age.
Image 3 E/A changes in different stages of Diastolic dysfunction of LV
3.2.1.1 Normal diastolic function
- E/A ratio = E-wave is taller than the A-wave
- E/A ratio - cut off values 0.8-2
- Normal deceleration time (DT) - cut off value: 140 - 240 msec.
- Isovolumetric relaxation time (IVRT) - a normal IVRT is about 70 ± 12 ms (approximately 10 ms longer in people over forty years).
- In abnormal relaxation, IVRT is usually in excess of 110 ms. With restrictive ventricular filling, it is usually under 60 ms.
Image 4 Normal E and A pattern
3.2.1.2 Impaired relaxation - grade 1 diastolic dysfunction
First stage of diastolic dysfunction.
Early filling of the stiff ventricle is impaired = magnitude of the E-wave is decreased.
E/A ratio is ≤ 0.8
DT is prolonged ≥ 240 ms.
IVRT is increased > 100 ms
Image 5 Impaired relaxation (red colour)
Image 6 Impaired relaxation of the LV - dominant A wave and smaller E wave, E/A ratio 0,7 and deceleration time 201 ms
3.2.1.3 Pseudonormal filling pattern - grade 2 diastolic dysfunction
Progressive diastolic dysfunction leads to further rise in left atrial pressure.
The gradient between the left atrium and the left ventricle increases and acts as a driving force to fill the ventricle during early diastole.
The size of E-wave relative to the A-wave will increase, and the E/A ratio, hence the ratio is back to 0.8 to 1.5.
DT decreases compared to grade 1 diastolic dysfunction = DT >140ms.
IVRT also decreases compared to grade 1 diastolic dysfunction = IVRT< 90 ms.
This phase of diastolic dysfunction looks similar to normal diastolic function, therefore it is called “pseudonormal”.
Image 7 Pseudonormalisation (grade 2 diastolic dyfsunction), red colour
Image 8 Pseudonormal filling (Grade II diastolic dysfunction) in dilated cardiomyopathy, PW Doppler mitral inflow - E/A 1,29, deceleration time 96ms
Image 9 Pseudonormal filling pattern in a patient with HFpEF - E/A ratio 1,19, deceleration time 167 ms
Valsalva maneuver
The Valsalva maneuver increases intrathoracic pressure and thus reduces venous return to the atrium.
This “unloads'' the ventricle and causes a drop in filling pressure.
Thus, the Valsalva maneuver permits the investigator to differentiate Grade 2 from normal.
In the presence of pseudonormal filling one will see a “reversal” of the pattern to that of impaired relaxation (the E/A ratio will drop below 1).
Valsalva maneuver unmasks diastolic dysfunction and alters pseudonormal filling into impaired relaxation.
To perform a Valsalva maneuver let the patient press while he is in mid-breathing level and observe the mitral inflow signal.
Decrease in 20 cm/s in E wave velocity generally indicates a good Valsalva technique.
Decrease in mitral E/A ratio of >50% is highly specific to raised LV filling pressure.
Image 10 HFpEF patient with a pseudonormal filling pattern of mitral inflow at rest with E/A ratio of 1,88.
Image 11 Valsalva Maneuver in the same HFpEF patient unmasks the impaired relaxation pattern of mitral inflow.
3.2.1.4 Reversible restrictive filling pattern - grade 3 diastolic dysfunction
A further increase in filling pressure is observed = the gradient between the left atrium and the left ventricle during early diastole is increased.
The E-wave will become taller and the A-wave shorter.
The E/A ratio is ≥ 2.
Filling pressures are high = flow into the ventricle starts early and filling terminates quickly = DT (<140 ms) and IVRT (≤ 70 ms).
In case that Valsalva maneuver (reduction of left atrial pressure) is able to reverse restrictive filling to a “pseudonormal” pattern = diastolic dysfunction as “grade III”.
Image 12 Restrictive pattern - grade 3 diastolic dysfunction, red colour
Image 13 PW Doppler, transmitral inflow with restrictive filling pattern with dominant E wave and very small A wave in dilated cardiomyopathy - E/A ratio is 9,88 and the deceleration of E wave (MV DecT) is only 114 ms.
Image 14 PW Doppler measurement of mitral inflow in RKMP, restrictive filling pattern - E/A ratio 4,00, E/e’ is 19,5, reduced deceleration time (85 ms).
3.2.1.5 Irreversible restrictive filling Pattern - grade 4 diastolic dysfunction
The most severe form of diastolic dysfunction (grade 4).
Compared to grade 3 diastolic dysfunction Valsalva maneuver is unable to reverse to pseudonormal one.
Image 15 Restrictive filling pattern in severe diastolic dysfunction caused by cardiac amyloidosis - dominant E wave with E/A ratio of 4,17, E/e’ 28,9. No change after Valsalva maneuver
L wave
L wave corresponds to continued pulmonary vein flow through the left atrium into the left ventricle after early rapid filling.
Mid-diastolic forward flow velocity of transmitral flow whose velocity is more than 20 cm/sec and is a marker of diastolic dysfunction and/or elevation of left ventricular (LV) filling pressure.
L wave more frequently occurs in patients with bradycardia.
Image 16 Pulsed Doppler echocardiographic recording of mitral inflow velocity showing a mid-diastolic flow, L wave (arrows), between the E and A filling waves. L wave is due to elevated filling pressure and delayed myocardial relaxation.
3.2.2 Tissue Doppler for the assessment of diastolic dysfunction
Mitral valve annulus movement mirrors systolic and also diastolic events.
In a 4-chamber view, the motion of the annulus may be visualized using PW tissue Doppler (TDI) at the medial (septal) as well as the lateral ring.
How to measure the the velocity of mitral annular motion use tissue Doppler (TDI)?
Place the sample volume approximately 1 cm within the insertion of the mitral valve leaflets.
Image 17 Position of the sample volume at the medial ring.
What can you measure by mitral annular motion use tissue Doppler (TDI)?
On the Doppler imaging the diastolic signal represents a negative deflection.
As in conventional Pulse doppler imaging, E-wave and an A-wave are present.
In Tissue Doppler imaging they are called e´ (e prime) and a´ (a prime).
In Tissue Doppler imaging of the mitral annulus allows us to measure also IVRT and deceleration time.
Septal and lateral mitral annular peak early diastolic velocity (e′)
The main determinant of e′, the early diastolic velocity of mitral annular motion, is LV relaxation.
It reflects LV lengthening and is influenced by preload.
Left ventricular longitudinal e′ velocity declines with age.
Normal e’ velocity ≥ 7 cm/s (med) and 10 cm/s (lat)
How to measuure Septal e’ :
Septal mitral annulus velocity (Early diastole)
A4C
Early diastole (ECG: The end of T wave)
PW tissue doppler
Sample volume on septal basal regions
Image 18 Septal mitral annular motion use tissue Doppler (TDI), S′ = systolic motion, e´ and a´ = diastolic motion.
How to measure Lateral e’ :
Lateral mitral annulus velocity (Early diastole)
A4C
Early diastole (ECG: The end of T wave)
PW tissue doppler
Sample volume on septal basal regions
Image 19 Lateral mitral annular motion use tissue Doppler (TDI)
Image 20 Tissue Doppler imaging wave intervals (IVCT- isovolumic contraction time)
Average septal-lateral E/e′ ratio
The ratio of the peak velocity of mitral inflow during early diastole (E), recorded by pulsed Doppler between the tips of the mitral leaflets, over the average of septal and lateral mitral annular early diastolic peak velocities (e′) recorded by pulsed tissue Doppler, reflects the mPCWP.
The mitral E/e′ index correlates with LV stiffness and fibrosis, and is less age-dependent than e′.
It also has diagnostic value during exercise.
The E/e′ index is little influenced by changes in volume but it is influenced by the severity of LVH.
In normal individuals the E/e´ ratio is <8.
In the presence of diastolic dysfunction / impaired relaxation, e´ will be rather low. In contrast, the E-wave increases with elevated filling pressures.
Thus the E/e´ ratio will increase in the presence of diastolic dysfunction.
An E/e´ratio >14 is highly suggestive of elevated filling pressures.
Image 21 Normal E/e´ratio values
Image 22 how to measure and calculate E/e′ ratio - E= 1,27 m/s (Pulse Doppler Imaging), e′= 0,05 m/s (Tissue Doppler Imaging), E/e´ ratio = 25.4 (elevated filling pressures).
Image 23 Septal and lateral mitral annular peak early diastolic velocity by Tissue Doppler Imaging in a patient with mitral inflow impaired relaxation pattern - e’ septal 5 cm/s, e’ lateral 7 cm/s, E/e’ 6.8 = normal filling pressures
Image 24 Tissue Doppler Imaging (TDI) in a patient with restrictive filling pattern - e’ septal 4 cm/s, e’ lateral 6 cm/s, E/e’ 17.8 =elevated filling pressures
Image 25 Septal (left side) and lateral (right side) mitral annular peak early diastolic velocity (e′) in Amyloidosis- note the reduced velocities of the s’, e’ and a’ waves that are below 5 cm/s. The E/e’ ratio of 28.9 is highly suggestive of increased filling pressures in accordance with the diastolic dysfunction.
Image 26 Unreliable E/e´ratio interpretation
3.2.3 Pulmonary vein flow
If the diastolic dysfunction and impairment of left atrial filling is present, blood flow in the pulmonary veins will be shifted from systole to diastole.
In that case, the systolic wave will become smaller and the diastolic wave larger.
S wave
- a systolic component shows usually two peaks (S1 and S2).
- S1 corresponds to atrial relaxation while S2 occurs between atrial relaxation and the beginning of diastole (opening of the mitral valve).
D wave
- a diastolic component shows positive deflection during the early (passive) filling phase and a small negative wave (AR) during atrial contraction.
AR wave (atrial reversal wave)
- is caused by a small fraction of blood which is pushed back into the pulmonary veins during atrial contraction.
Reduced compliance of the LV is associated with in increased resistance to flow during atrial contraction, hence more blood will be returned “backwards” into the pulmonary veins as the atrium contracts.
Thus, the atrial reversal wave (AR) wave will become larger and its duration will increase.
Image 27 Pulmonary venous flow pattern in diastolic dysfunction
How is the pulmonary vein flow measured?
1. Apical four-chamber with colour flowimaging to help position pulsed
2. Display the inflow of the right (or left) upper pulmonary vein with Color Doppler, place the sample volume 1-2 cm inside the vein accordingly and apply Pulsed Doppler Imaging.
Image 28 Pulmonary vein Pulse Doppler assessment - sample volume in Right upper pulmonary vein (S wave higher than D wave)
3.2.4 Other signs of diastolic dysfunction
3.2.4.1 Tricuspid regurgitation peak velocity or pulmonary arterial systolic pressure
Elevated PASP and reduced RV function are important predictors of mortality in HFpEF.
A PASP >35 mmHg discriminates HFpEF from hypertensives and controls.
A TR peak velocity >2.8 m/s indicates increased PASP and is an indirect marker of LV diastolic dysfunction
How to measure Vmax Tricuspid regurgitation?
A4C
Systole (ECG: R wave - the end of T wave)
CW doppler
Place the cursor between tricuspid leaflet tips
Colour doppler (helps with blood flow identification)
Image 29 Vmax measurement
To calculate the PASP, we also need the estimated right atrial pressure, which is based on inferior vena cava (IVC) diameter and its collapsibility with respiration.
Image 30 Right atrial pressure estimation
Video 1 Moderate tricuspid regurgitation (2/4) in a patient with diastolic dysfunction - eccentric regurgitant jet
Image 31 Measurement of tricuspid regurgitation peak velocity with CW Doppler in A4C view - Peak TR velocity in this patient is 3,68 m/s. RVSP = 4(V max )2 + RAP. In the absence of pulmonic stenosis: RVSP = PASP. Peak TR velocity depends on pressure gradient between right ventricle and right atrium [difference between peak RVSP and RA pressure] provided there is no tricuspid valve obstruction. In this case, the calculated PASP is around 69 mmHg.
Image 32 Dilated inferior vena cava (IVC) with diameter of 28 mm.
Video 2 Subcostal view of the IVC shows almost no collapsibility with respiration.
3.2.4.2 Left atrial volume index (LAVI)
The maximal volume of the LA, measured at end-systole from biplane or three-dimensional images and indexed to body surface area [left atrial volume index (LAVI)] is an indirect correlate of LV filling pressures.
A LAVI of 29–34 mL/m2 is considered as a minor criterion since it represents the upper limit in healthy subjects.
In patients without AF or heart valve disease, LAVI >34 mL/m2 independently predicts death, heart failure, AF, and ischaemic stroke.
How to measure LA volume ?
A4C
End-systole (ECG: The end of T wave)
Volume can be calculated by the area-length method or disk summation technique (modified biplane) which is preferred.
Trace the LA inner border, excluding the area under the MV annulus, pulmonary veins, and LA appendage.
Volume is calculated from A4C and A2C by echocardiography machine.
Image 33 LA volume measurement by Simpson’s biplane method in A4C (left) and A2C (right) view - the LA is significantly dilated with 29,6 cm2 in A4C and 28 cm2 in A2C, then the LAVi is calculated - 71.8 cm3/m2.
3.2.4.3 Left ventricular mass index (LVMI) and relative wall thickness
Increased LV diastolic wall thickness in a non-dilated heart implies that the patient has LVH.
Left ventricular geometry is often classified using relative wall thickness (RWT), calculated as twice the LV posterior wall thickness divided by the LV internal diameter at end‐diastole (LVPW × 2/LVIDD), and using left ventricular mass index (LVMI) normalized to body surface area or height. Four patterns are described:
- normal (normal LVMI, RWT ≤0.42),
- concentric remodelling (normal LVMI, RWT >0.42)
- concentric hypertrophy (increased LVMI, RWT >0.42)
- eccentric hypertrophy (increased LVMI, RWT ≤0.42).
In patients with HFpEF, both concentric LVH and concentric remodelling can be observed.
The absence of LVH on echocardiography does not exclude HFpEF. We therefore recommend the finding of concentric hypertrophy (increased LVMI and increased RWT) as a major criterion, or any one of a lesser degree of LVH, RWT, and LV end-diastolic wall thickness as a minor criterion.
If LAVI, LVMI, or wall thickness cannot be assessed by echocardiography, it is recommended using measurements obtained from CMR imaging instead.
Image 34 Echo assessment of LV diastolic dysfunction
Adapted from: Nagueh SF, Smiseth OA, Appleton CP, Byrd BF 3rd, Dokainish H, Edvardsen T, Flachskampf FA, Gillebert TC, Klein AL, Lancellotti P, Marino P, Oh JK, Popescu BA, Waggoner AD. Recommendations for the Evaluation of Left Ventricular Diastolic Function by Echocardiography: An Update from the American Society of Echocardiography and the European Association of Cardiovascular Imaging. J Am Soc Echocardiogr. 2016 Apr;29(4):277-314. doi: 10.1016/j.echo.2016.01.011. PMID: 27037982
Image 35 Algorithm for diagnosis of LV diastolic dysfunction in subjects with normal LVEF
Nagueh SF, Smiseth OA, Appleton CP, Byrd BF 3rd, Dokainish H, Edvardsen T, Flachskampf FA, Gillebert TC, Klein AL, Lancellotti P, Marino P, Oh JK, Popescu BA, Waggoner AD. Recommendations for the Evaluation of Left Ventricular Diastolic Function by Echocardiography: An Update from the American Society of Echocardiography and the European Association of Cardiovascular Imaging. J Am Soc Echocardiogr. 2016 Apr;29(4):277-314. doi: 10.1016/j.echo.2016.01.011. PMID: 27037982.
Image 36 Algorithm for estimation of LV filling pressures and grading LV diastolic function in patients with depressed LVEFs and patients with myocardial disease and normal LVEF after consideration of clinical and other 2D data
Nagueh SF, Smiseth OA, Appleton CP, Byrd BF 3rd, Dokainish H, Edvardsen T, Flachskampf FA, Gillebert TC, Klein AL, Lancellotti P, Marino P, Oh JK, Popescu BA, Waggoner AD. Recommendations for the Evaluation of Left Ventricular Diastolic Function by Echocardiography: An Update from the American Society of Echocardiography and the European Association of Cardiovascular Imaging. J Am Soc Echocardiogr. 2016 Apr;29(4):277-314. doi: 10.1016/j.echo.2016.01.011. PMID: 27037982.
3.3 Invasive cardiopulmonary exercise testing
This modality emerged as the gold standard to definitively identify or exclude HFpEF. This supports the fact that filling pressures are often normal at rest but become elevated only during the stress of exercise.
Image 37 Advanced HFpEF workup
https://academic.oup.com/eurheartj/article/40/40/3297/5557740?
A shows the diastolic stress test workup with exercise echocardiography. If key haemodynamic abnormalities are identified, a definite heart failure with preserved ejection fraction diagnosis can be made. (B, lower panel) It shows the invasive haemodynamic measurements at rest (left) or during exercise (right) that may complement stress echocardiography and are recommended in cases with remaining diagnostic uncertainty.
The final step consists of establishing HFpEF aetiology. This includes assessment of blood pressure control, chronotropic competence, arrhythmias, and ischemia. When a specific cause, such as amyloidosis or hypertrophic cardiomyopathy, is suspected, cardiac magnetic resonance imaging should be considered (Image 38).
https://academic.oup.com/eurheartj/article/40/40/3297/5557740?
(A) shows the role of ergometry to detect underlying causes such as inadequate blood pressure response, chronotropic incompetence, or myocardial ischaemia during exercise. (B) shows the aetiological workup using CMR, CT, PET.
References
- Burkert Pieske, Carsten Tschöpe, Rudolf A de Boer, Alan G Fraser, Stefan D Anker, Erwan Donal, Frank Edelmann, Michael Fu, Marco Guazzi, Carolyn S P Lam, Patrizio Lancellotti, Vojtech Melenovsky, Daniel A Morris, Eike Nagel, Elisabeth Pieske-Kraigher, Piotr Ponikowski, Scott D Solomon, Ramachandran S Vasan, Frans H Rutten, Adriaan A Voors, Frank Ruschitzka, Walter J Paulus, Petar Seferovic, Gerasimos Filippatos, How to diagnose heart failure with preserved ejection fraction: the HFA–PEFF diagnostic algorithm: a consensus recommendation from the Heart Failure Association (HFA) of the European Society of Cardiology (ESC), European Heart Journal, Volume 40, Issue 40, 21 October 2019, Pages 3297–3317, https://doi.org/10.1093/eurheartj/ehz641
- Martin Altersberger, MD, Prof. Thomas Binder, MD, FESC. Diastolic Function & Diastolic Dysfunction | 123 Sonography. Online Echocardiography Course & Sonography Training | 123 Sonography [online]. https://www.123sonography.com/diastolic-function-and-diastolic-dysfunction
- Gazewood JD, Turner PL. Heart Failure with Preserved Ejection Fraction: Diagnosis and Management. Am Fam Physician. 2017 Nov 1;96(9):582-588. PMID: 29094875.
- Masaru Obokata, Yogesh N.V. Reddy, Barry A. Borlaug. Diastolic Dysfunction and Heart Failure With Preserved Ejection Fraction: Understanding Mechanisms by Using Noninvasive Methods. JACC: Cardiovascular Imaging, Volume 13, Issue 1, Part 2, 2020, Pages 245-257, ISSN 1936-878X. https://doi.org/10.1016/j.jcmg.2018.12.034.
- Obokata M, Reddy YNV, Borlaug BA. The Role of Echocardiography in Heart Failure with Preserved Ejection Fraction: What Do We Want from Imaging?. Heart Fail Clin. 2019;15(2):241-256. doi:10.1016/j.hfc.2018.12.004
- Marc A. Pfeffer, Amil M. Shah, and Barry A. Borlaug. Heart Failure With Preserved Ejection Fraction In Perspective. Circulation Research. Volume 124, Issue 11, 24 May 2019; Pages 1598-1617. https://doi.org/10.1161/CIRCRESAHA.119.313572
- Echocardiography (Free learning platform) - TECHmED. EKG, kardiológia, medicína a IT | TECHmED [online]. Online from: https://www.techmed.sk/en/echo/new-examination/
- HENEIN, Michael Y a Per LINDQVIST. Diastolic function assessment by echocardiography: A practical manual for clinical use and future applications. Echocardiography (Mount Kisco, N.Y.) [online]. United States: Wiley Subscription Services, 2020, 37(11), 1908-1918 [cit. 2021-10-23]. ISSN 0742-2822. Dostupné z: doi:10.1111/echo.14698
