Echocardiographic evaluation of left ventricular diastolic function in adults

INTRODUCTION — Left ventricular (LV) diastolic dysfunction is a condition of impaired LV relaxation and increased LV chamber stiffness, which can lead to elevated LV filling pressures.

This topic summarizes available echocardiographic methods for assessment of LV diastolic function. Recommendations in this topic are generally in agreement with the American Society of Echocardiography guidelines for the evaluation of LV diastolic function by echocardiography [1].

Diastolic dysfunction by echocardiography is one of the criteria for the diagnosis of heart failure with preserved ejection fraction (HFpEF) [2]. Diagnosis, management, and prognosis of HFpEF are discussed separately. (See "Heart failure with preserved ejection fraction: Clinical manifestations and diagnosis" and "Treatment and prognosis of heart failure with preserved ejection fraction".)

DIASTOLIC PHASES AND THEIR MEASUREMENT — Diastole is conventionally divided into the following phases:

●Isovolumic relaxation (both aortic and mitral valves are closed, and LV pressure is declining)

●Opening of the mitral valve and early LV filling

●Mid-diastolic phase (often noted in patients with bradycardia)

●Late or atrial filling phase with left atrial (LA) contraction

In normal hearts, LV filling occurs predominantly in early diastole. With impaired LV relaxation, LV filling shifts to late diastole and becomes dependent on LA systolic function. This accounts for the significant clinical deterioration that is seen in patients with diastolic dysfunction (such as hypertrophic cardiomyopathy) in the presence of atrial fibrillation.

LV diastolic function can be characterized by invasive and noninvasive methods. Invasive measures of diastolic function include the peak instantaneous rate of LV pressure decline (-dP/dt), the time constant of LV relaxation (tau), and the stiffness modulus. Although echocardiography does not directly measure these parameters, echocardiography is the most practical routine clinical approach for evaluating LV diastolic function given clinical and experimental evidence supporting its use as well as its safety, versatility, and portability. (See "Pathophysiology of heart failure with preserved ejection fraction".)

DETECTION AND EVALUATION

When to evaluate diastolic function — An evaluation for diastolic function should be performed as a part of all standard complete echocardiographic examinations.

Assessment of diastolic function is particularly important in the echocardiographic examination of patients referred for evaluation of dyspnea or suspected or known HF. (See "Heart failure: Clinical manifestations and diagnosis in adults", section on 'Diagnosis'.)

There is an elevated risk of diastolic dysfunction in asymptomatic individuals with certain cardiovascular risk factors (including hypertension, diabetes mellitus, or obesity). Asymptomatic diastolic dysfunction is a predictor of adverse clinical outcomes including HF and death. (See "Asymptomatic left ventricular diastolic dysfunction", section on 'Prognosis'.)

Approach to evaluation — The diagnostic evaluation of diastolic dysfunction involves identification of evidence of diastolic dysfunction, and evaluation of its severity, cause, and clinical sequelae, exclusion of confounding factors, and identification of concurrent conditions. The echocardiogram is the key diagnostic modality for identifying diastolic dysfunction, concurrent or associated disorders, and confounding factors. (See "Asymptomatic left ventricular diastolic dysfunction", section on 'Detection'.)

Diagnosis and evaluation of HF with preserved EF (HFpEF) is discussed separately. Patients with HFpEF frequently have multiple findings suggestive of diastolic dysfunction including LV hypertrophy, left atrial (LA) enlargement, and elevated pulmonary artery (PA) pressures [1]. (See "Heart failure with preserved ejection fraction: Clinical manifestations and diagnosis".)

●Evaluate the patient’s clinical presentation, including symptoms and signs (including evidence of HF), demographics, risk factors for cardiovascular disease, history of known cardiac disease, and the reason for the echocardiographic examination. At the time of the echocardiogram, it is important to record heart rate and blood pressure, as these parameters affect diastolic function and LV filling. (See "Heart failure: Clinical manifestations and diagnosis in adults".)

●All standard complete echocardiographic examinations should include the following indices related to diastolic function:

•Measures of LV structure and function (LV dimensions, LV wall thickness, volumes, segmental function, global longitudinal strain, and mass) are assessed, as well as LA maximum volume. These are not direct indices of LV diastolic function but are helpful in identifying evidence of cardiac disease commonly associated with diastolic dysfunction. Common findings include presence of LV hypertrophy and LA enlargement in patients with hypertensive cardiovascular disease and segmental LV systolic dysfunction in patients with coronary artery disease. (See "Echocardiographic evaluation of the atria and appendages" and "Transthoracic echocardiography: Normal cardiac anatomy and tomographic views" and "Tests to evaluate left ventricular systolic function", section on 'Echocardiography'.)

•Indices of diastolic function include mitral inflow velocities (at annulus and tips), mitral annular velocities by tissue Doppler (septal and lateral), and pulmonary vein velocities. (See 'Indicators of diastolic function' below.)

Optional additional helpful parameters include isovolumic relaxation time (IVRT), tricuspid inflow velocities, and color Doppler early diastolic flow propagation velocity (Vp). In addition, there is growing information to support assessment of LA strain, particularly in cases with incomplete/suboptimal Doppler signals or indeterminate diastolic function. (See 'Indicators of diastolic function' below.)

•PA pressures (systolic, diastolic, and mean) are estimated to determine whether pulmonary hypertension is present, recognizing that LV diastolic dysfunction is one of a number of causes of pulmonary hypertension. (See "Clinical features and diagnosis of pulmonary hypertension of unclear etiology in adults" and "Pulmonary hypertension due to left heart disease (group 2 pulmonary hypertension) in adults".)

-PA systolic pressure is estimated from the tricuspid regurgitation (TR) peak velocity along with the estimated right atrial pressure (RAP). As discussed separately, multiple windows should be used (with use of microbubble agitated saline or commercial ultrasound contrast agents, if needed) to obtain an optimum TR velocity recording. (See "Echocardiographic assessment of the right heart", section on 'Pulmonary artery pressure' and "Contrast echocardiography: Contrast agents, safety, and imaging technique".)

-RAP is estimated by physical examination as well as by echocardiographic parameters, including inferior vena cava size and collapsibility during inspiration and hepatic venous flow. (See "Examination of the jugular venous pulse", section on 'To estimate right atrial pressure' and "Echocardiographic assessment of the right heart", section on 'RA pressure'.)

-Pulmonic regurgitation peak velocity and end-diastolic velocity are used to estimate PA mean and diastolic pressures, respectively. (See "Echocardiographic assessment of the right heart", section on 'Other measures of pulmonary artery pressure'.)

●Standard complete echocardiographic examinations include other components that provide context for the above indices, including examination of valve structure and function and assessment of right ventricular function. Careful examination of left-sided valvular function is essential, as mitral valve disease can lead to an increase in LA pressure (LAP) with and without LV diastolic dysfunction. In patients with mitral valve disease, an increase in PA pressures, in the absence of pulmonary parenchymal or vascular disease, is usually related to increased LAP. (See "Echocardiographic evaluation of the mitral valve".)

Diagnosis of diastolic dysfunction — Next, the echocardiogram is reviewed to identify parameters suggestive of diastolic dysfunction. Interpretation of parameters differs depending upon whether or not the LV ejection fraction (LVEF) is <50 percent.

All patients with LVEF <50 percent (with or without symptoms) have diastolic dysfunction due to impaired LV relaxation. Given the usual development of diastolic dysfunction before systolic dysfunction in the course of myocardial disease, patients with systolic dysfunction generally have diastolic dysfunction. Mitral inflow indices (peak early [E] and late [A] diastolic velocities) are very useful in this patient subgroup for estimating LAP (algorithm 1). (See 'Estimation of left atrial pressure' below.)

Patients with LVEF ≥50 percent can have normal or abnormal diastolic function. To determine whether diastolic dysfunction is present in these patients, we use the following approach based on the 2016 American Society of Echocardiography and European Association of Cardiovascular Imaging guidelines (algorithm 2) [1]:

●Diastolic dysfunction is present if one or more of the following diagnostic findings is present:

•Pathologic LV hypertrophy (most reliably confirmed by LV mass indexed to body size that exceeds the sex-specific normal range [3]; this criterion should not be applied to athletes).

•Pulmonary vein atrial reversal velocity duration exceeds mitral A velocity duration by ≥30 ms. This criterion suggests elevated LV end-diastolic pressure and diastolic dysfunction and is not affected by age. (See 'Pulmonary venous flow' below.)

•Mitral inflow pattern changing from a pseudonormal or restrictive pattern to an impaired LV relaxation pattern with Valsalva maneuver. (See 'Mitral inflow velocities and isovolumic relaxation time' below.)

●In the absence of any of the above diagnostic findings, the following echocardiographic parameters are assessed:

•Average E/e’ >14; the E/e’ is the ratio of E to mitral annular early diastolic velocity (e’). (See 'Mitral inflow velocities and isovolumic relaxation time' below and 'Tissue Doppler imaging' below.)

•Septal e’ velocity <7 cm/s or lateral e’ velocity <10 cm/s. (See 'Tissue Doppler imaging' below.)

•TR velocity >2.8 m/s (this criterion should not be used in patients with significant pulmonary disease or other cause of pulmonary hypertension). (See "Echocardiographic assessment of the right heart", section on 'Pulmonary artery pressure'.)

•LA maximum volume index >34 mL/m² (this criterion should not be applied to athletes or patients with more than mild mitral regurgitation, any degree of mitral stenosis, or those with atrial fibrillation).

●Of the four echocardiographic parameters above, determine how many can be adequately evaluated and how many of these are abnormal (ie, meet the specified criteria):

•Diastolic function is indeterminate

-If <2 of the above parameters can be adequately evaluated, or

-If two parameters can be adequately evaluated, and one is abnormal and one is normal, or

-If four parameters can be adequately evaluated, and two are abnormal and two are normal

•Diastolic function is normal

-If two parameters can be adequately evaluated, and both are normal, or

-If three or four parameters can be adequately evaluated, and one or none are abnormal, and the rest are normal

•Diastolic dysfunction is present

-If two parameters can be adequately evaluated, and both are abnormal, or

-If three parameters can be adequately evaluated, and ≥2 are abnormal, or

-If four parameters can be adequately evaluated, and ≥3 are abnormal

The rationale for the above approach in patients with LVEF >50 percent is that identification of myocardial disease is key to diagnosis of diastolic dysfunction in this population. The presence of myocardial disease can be inferred from findings such as abnormally reduced early diastolic mitral annulus velocities and structural abnormalities such as LA enlargement. In the absence of mitral valve disease and atrial arrhythmias, LA enlargement reflects the consequences of chronically elevated LV diastolic pressures. (See "Echocardiographic evaluation of the atria and appendages", section on 'Left atrium'.)

Grading diastolic dysfunction — Diastolic dysfunction is graded from mild (grade I) to severe (grade III) with increasing likelihood of symptomatic HF and worse prognosis with higher grade dysfunction [1,4]. (See 'Indicators of diastolic function' below and "Asymptomatic left ventricular diastolic dysfunction".)

●In patients with grade I (mild) diastolic dysfunction, the following findings are usually present: mitral E/A ratio is ≤0.8, predominant systolic flow in the pulmonary venous flow (forward systolic flow [S] > forward diastolic flow [D]), average E/e’ ratio (derived from the early mitral inflow velocity [E] and tissue Doppler peak velocity at the level of the mitral annulus in early diastole [e’]) <10 (septal and lateral), tricuspid regurgitation (TR) peak velocity ≤2.8 m/s, and LA maximum volume index can be normal or increased. A reduced mitral E/A ratio in the presence of normal annular tissue Doppler velocities can occur in normal older adults (>60 years) and should not be used to diagnose diastolic dysfunction [1].

●In patients with grade II diastolic dysfunction, mitral E/A ratio is >0.8 but <2, average E/e' ratio (septal and lateral) is usually 10 to 14, LA maximum volume index is increased, and TR peak velocity is >2.8 m/s.

●With severe diastolic dysfunction (grade III), restrictive LV filling occurs with an E/A ratio ≥2, deceleration time (DT) <160 ms, isometric relaxation period ≤70 ms, systolic filling fraction ≤40 percent, average E/e' ratio ≥14, LA maximum volume index is increased, and peak TR velocity is >2.8 m/s. LV filling may revert to one of impaired relaxation with successful therapy in some patients, whereas in others, LV filling remains restrictive. The latter response predicts increased morbidity and mortality [1].

The relationship between grade of diastolic dysfunction and LAP is described below. (See 'Estimation of left atrial pressure' below.)

Limitations and caveats — A limitation of the above diagnostic approach is that technical difficulties may prevent adequate assessment of some or all of the echocardiographic parameters for diastolic dysfunction. Even when the parameters can be assessed, some patients have indeterminate results since there is overlap between indices in healthy individuals and those in individuals with diastolic dysfunction [1]. Age should be taken into account when interpreting diastolic parameters. (See 'Grading diastolic dysfunction' above.)

Further technical limitations are discussed below. (See 'Indicators of diastolic function' below.)

ESTIMATION OF LEFT ATRIAL PRESSURE

In the presence of LV dysfunction — We agree with the following approach recommended in 2016 American Society of Echocardiography and European Association of Cardiovascular Imaging guidelines (algorithm 1) for estimation of left atrial pressure (LAP; which is equivalent to LV filling pressure in the absence of significant mitral valve gradient) in patients with LV systolic dysfunction (LVEF <50 percent) and patients with normal LVEF but diastolic dysfunction [1].

The following algorithm should not be applied to patients with normal LV systolic and diastolic function (ie, those with LVEF ≥50 percent and no diastolic dysfunction), significant mitral valve disease (moderate or severe mitral annular calcification, any mitral stenosis, greater than moderate mitral regurgitation, mitral valve repair, or a prosthetic mitral valve), LV mechanical circulatory support, left bundle branch block, ventricular paced rhythm, or constrictive pericarditis. In individuals with these conditions, Doppler signals relate poorly to LAP, so LAP cannot generally be adequately estimated by Doppler findings; an alternate approach may be helpful. (See 'Alternate approach' below.)

For patients with normal LVEF and diastolic dysfunction or LVEF <50 percent (algorithm 1):

●An E/A ratio ≤0.8 along with peak E velocity ≤50 cm/s is associated with normal mean pulmonary capillary wedge pressure (grade I diastolic dysfunction). (See 'Mitral inflow velocities and isovolumic relaxation time' below.)

●In patients with an E/A ratio >0.8 but <2, or when E/A ratio is ≤0.8 but the peak E velocity is >50 cm/s, then additional indices are needed. These include LA maximum volume index (>34 mL/m²), average E/e’ ratio (>14), and peak tricuspid regurgitation velocity (>2.8 m/s). (See 'Approach to evaluation' above and "Echocardiographic evaluation of the atria and appendages" and "Echocardiographic assessment of the right heart", section on 'Pulmonary artery pressure'.)

•If <50 percent of the available variables are below the cutoff, LAP is normal, and the patient is assigned grade I diastolic dysfunction.

•However, if >50 percent of the variables are abnormal, then LAP is elevated, and the patient has grade II diastolic dysfunction.

•LAP is indeterminate if no more than one variable is negative and no more than one variable is positive (ie, one out of two available variables falls in the abnormal range or if only one variable is available or suitable for analysis).

●When the E/A ratio is ≥2, LAP is elevated (grade III diastolic dysfunction). (See 'Mitral inflow velocities and isovolumic relaxation time' below.)

●For patients with missing or unsatisfactory Doppler or two-dimensional recordings, pulmonary vein S/D ratio can be used to draw inferences on LAP. (See 'Pulmonary venous flow' below.)

For patients who are suitable candidates for this algorithm, an expression that may quickly estimate LAP based on E/e’ ratio is LAP = 1.24 (E/e’) + 1.9 [5,6].

Alternate approach — The interatrial septum bows in the direction of the atrial chamber with lower pressure. Normally, mean LAP is slightly higher than mean right atrial (RA) pressure, and the septum bows to the right during most of the cardiac cycle. During inspiration, RA pressure rises higher than LAP, and the septum briefly reverses its curvature. Since RA pressure can be estimated using the inferior vena cava diameter and its change with respiration, as well as hepatic venous flow [7], if the septal curvature behaves as described above and RA pressure is normal, one can infer the presence of a normal LAP. However, if RA pressure is increased and the septum continues to bow to the right, then LAP is likely elevated.

INDICATORS OF DIASTOLIC FUNCTION — Indicators of diastolic function are used to determine whether diastolic dysfunction is present, grade the severity of diastolic dysfunction, and estimate LV filling pressure.

Mitral inflow velocities and isovolumic relaxation time — Transmitral Doppler flow is acquired by placing a 1 to 2 mm pulsed wave Doppler sample volume at the level of the tips of the mitral leaflets in the apical four-chamber view (image 1). Proper alignment with mitral inflow without angulation is essential, even if foreshortening of the LV results. The normal inflow pattern consists of early (E) and late (A) filling (figure 1). In patients with bradycardia, flow can occur into the LV between early filling and atrial contraction. In normal young individuals, predominant forward flow occurs in early diastole, largely due to the rapid decline in LV pressure during the previous phase of isovolumic relaxation period (IVRT).

Recording of the IVRT is obtained by placing the continuous wave Doppler cursor midway between LV outflow tract and mitral valve tips in the apical long axis or five-chamber view [8]. Normally, there is a rapid rise and fast decline in E velocity, which are identified by short acceleration (AT) and deceleration (DT) times, respectively. With aging and diastolic dysfunction, more flow occurs with atrial contraction, and there is a prolongation in IVRT, AT, and DT.

There are three major patterns of abnormal mitral inflow (figure 2) [4]:

●An impaired relaxation pattern is characterized by a reduced E velocity, an E/A ratio <1, and prolonged IVRT (>90 ms) and DT (>220 ms). Diseases that impair LV relaxation (such as hypertension, coronary artery disease, and cardiomyopathy) in the presence of normal filling pressures can lead to this inflow pattern. Patients with impaired relaxation may be asymptomatic or have reduced exercise tolerance as tachycardia reduces the diastolic filling period leading to a rise in left atrial pressure (LAP) and a reduction in LV stroke volume. A pattern of impaired relaxation is common in older adults (over age 60 years).

●A "pseudonormal" pattern is present when LAP increases in the setting of impaired LV relaxation, leading to an inflow pattern in which the E/A ratio is >1 (but less than 2), and the DT and IVRT are shorter than in patients with impaired relaxation. A pseudonormal pattern may revert to an impaired relaxation pattern when a Valsalva maneuver is performed during echocardiography. In patients with a pseudonormal pattern with associated increased LAP, straining leads to a brief reduction in venous return and LAP, and the inflow pattern reverts to one with predominant late diastolic filling (ie, E/A ratio <1).

●Restrictive filling occurs when a further rise in LAP leads to an increased E/A ratio (≥2) and shortening of the IVRT (<70 ms) and DT (<150 ms). In patients with HF, as well as in the post-myocardial infarction setting, the presence of a persistent restrictive pattern despite appropriate medical therapy is associated with increased mortality (image 2 and figure 3) [1,9].

The hemodynamic determinants of mitral inflow velocities and time intervals include LAP, LV relaxation, heart rate, ventricular interaction, mitral valve disease, and aortic regurgitation [10]. Despite the many variables that influence mitral velocities, several studies have indicated that mitral inflow patterns predict outcomes and exercise tolerance in patients with HF with reduced EF and may be more predictive than LVEF [1]. (See "Predictors of survival in heart failure with reduced ejection fraction", section on 'Other echocardiographic findings'.)

Pulmonary venous flow — Pulmonary venous flow can be recorded reliably from the right pulmonary vein in most ambulatory patients by transthoracic imaging [8]. The recording is obtained from the apical four-chamber view with the guidance of color Doppler by placing the sample volume 1 to 2 cm into the vein. Pulmonary venous flow signals can be enhanced by intravenous ultrasound contrast agents. The pulmonary venous flow pattern is characterized by three velocities in patients with sinus rhythm (image 3):

●Initial forward systolic flow (S) is related to LA relaxation and LV systolic contraction with mitral annular descent to the apex.

●During diastole, another phase of forward flow (D) occurs from the veins into the LA. This velocity has hemodynamic determinants that are similar to those of the mitral E velocity [11,12].

●During atrial systole, there is retrograde flow from the LA into the pulmonary veins (Ar).

The peak velocity, the duration, and the velocity time integral (VTI) of all three waves can be measured. The systolic filling fraction (SFF) is computed as S / (S + D). It is computed using VTI of the above signals (figure 4), though peak velocities may be used.

In healthy young subjects, predominant forward flow occurs in diastole. This decreases with age, and predominant systolic flow is frequently observed in subjects over 60 years old. On the other hand, a prolonged Ar duration indicates elevated late LV diastolic pressures irrespective of age [13-15]. An SFF <40 percent in patients with depressed LVEF is a reliable marker of increased LAP [16]. Similarly, a short deceleration time of pulmonary venous diastolic velocity has been reported in patients with increased LV filling pressures whether in sinus rhythm or atrial fibrillation [17,18].

There are limitations to the clinical application of pulmonary venous flow, which include mitral valve disease (which limits use of SFF but not Ar duration), pericardial compression syndromes, heart block, and tachycardia [1].

Tissue Doppler imaging — Tissue Doppler imaging (TDI) enables measurement of high amplitude, low frequency Doppler shifts caused by myocardial motion. Segmental and global function can be measured. For global function, the region of interest is placed at the septal and lateral borders of the mitral annulus. During systole, the annulus descends towards the apex, whereas it recoils back toward the base in early (e') and late (a') diastole (waveform 1). The early diastolic velocity decreases with age and is significantly related to LV relaxation in animal and human studies (figure 5) [19-21]. Importantly, it is minimally affected by preload in patients with impaired LV relaxation [20,21].

The E/e' ratio (derived from the early mitral inflow velocity [E] and e’) can be used to estimate LV filling pressures and has been studied in a variety of clinical settings [1,5,22]. An average E/e' ratio below 8 is associated with normal filling pressures and a ratio >14 is associated with elevated filling pressures.

For diagnosis of HF with preserved EF, the E/e' ratio (using the lateral e') has been identified as the best parameter for diagnosis when compared with other Doppler measures [1,23]. The ratio was found to be clinically useful in patients in tachycardia with merged diastolic velocities and in patients with atrial fibrillation, though additional studies are needed [24,25]. Changes in E/e' ratio and pulmonary artery pressures with exercise can be used to identify patients with a suspected cardiac etiology for dyspnea (diastolic stress test) [26]. (See "Heart failure with preserved ejection fraction: Clinical manifestations and diagnosis".)

Attention to technical aspects is essential for obtaining high-quality signals that can be used for drawing reliable clinical conclusions. In particular, the sample volume must be carefully placed in ventricular myocardium at or within 1 cm of the lateral and septal insertion sites of the mitral leaflets, angulation between the ultrasound beam and the annular plane of motion should be minimized, and gain and filter settings must be optimized for satisfactory signal acquisition.

A limitation of TDI is that the E/e' ratio is not helpful for estimating LV filling pressures in certain populations:

●The E/e' ratio does not reliably estimate LV filling pressures in individuals with normal diastolic function.

●The E/e’ ratio does not reliably estimate LV filling pressures in individuals with mitral valve disease (mitral stenosis or significant regurgitation, or prosthetic mitral valve). In patients with native mitral valve disease, some studies have shown that the ratio of IVRT to the time interval between the onset of mitral E and annular e' (T[E-e]) can be used to predict pulmonary capillary wedge pressure (PCWP) [27].

●The E/e' ratio does not estimate LV filling pressures in patients with mitral annular calcification. In these patients, mitral E/A ratio is helpful: E/A <0.8 denotes normal LV filling pressure, and an E/A ratio >1.8 implies elevated filling pressures. In patients with E/A ratio between 0.8 and 1.8, IVRT is helpful: ≥80 ms is consistent with normal filling pressure, whereas IVRT <80 ms usually denotes elevated filling pressure [28].

●In patients with constrictive pericarditis, an inverse relationship between E/e' and PCWP was observed [29]. (See "Constrictive pericarditis: Diagnostic evaluation", section on 'Echocardiography'.)

The relationship between E/e’ ratio and PCWP is stronger in patients without left bundle branch block or biventricular pacing than in patients with left bundle branch block or biventricular pacing [30-33].

Color flow mapping — Color M-mode provides a spatio-temporal display of the inflow of blood into the LV. Early and late filling signals are observed during diastole (image 4). In patients with tachycardia, merging between early and late diastolic signals occurs. A single filling velocity is also observed in patients with atrial fibrillation.

The flow propagation velocity (Vp) is measured in the apical four-chamber view by placing the M-mode scan line through the center of the column of LV inflow [1]. The color flow baseline is shifted to lower the Nyquist limit so that the central highest velocity jet is blue. The Vp is the slope of the first aliasing velocity during early filling measured from the mitral valve plane to 4 cm apically into the LV cavity, or the slope of transition from no color to color (image 4).

A Vp >50 cm/s is considered normal. Studies in animals and humans have shown that Vp is inversely related to the time constant of LV relaxation and is not affected by preload. Therefore, the presence of an abnormally reduced Vp can help distinguish patients with pseudonormal filling from those with normal LV relaxation [34]. Furthermore, the ratio of peak E-wave velocity to Vp (E/Vp) correlates with LV filling pressures, particularly in patients with depressed EF [1,35-37]. In a small study, E/Vp ≥2.5 predicted a PCWP of >15 mmHg with a sensitivity and specificity of 78 and 77 percent in patients with LVEF <50 percent and 71 and 73 percent in patients with LVEF ≥50 percent [36].

Use of Vp is subject to limitations, particularly in patients with normal LVEF. Patients with normal LV volumes and LVEF but impaired LV relaxation can have a misleadingly normal Vp [38]. In addition, some reports have shown that increased preload can increase Vp in patients with normal or reduced LVEF.

Diastolic dysfunction as assessed by Vp may have prognostic value. In a study of 313 patients undergoing vascular surgery, Vp was an independent predictor of postoperative adverse outcomes, due primarily to an increased incidence of HF [39].

Tricuspid inflow velocities — Transtricuspid Doppler flow is acquired by placing a 1 to 2 mm pulsed wave Doppler sample volume at the level of the tips of the tricuspid leaflets. This is a means of assessing right ventricular filling [1].

Left atrial strain — There is growing evidence to support assessment of LA strain as a marker of LV diastolic dysfunction, particularly for indeterminate cases [1,40]. LA strain is assessed by speckle tracking. Standardized methods for LA strain assessment were included in a European Association of Cardiovascular Imaging/American Society of Echocardiography/Industry Task Force document [41,42]. A multicenter study found reduced accuracy of LA reservoir strain in patients with normal LVEF, and LA reservoir strain was not related to LV filling pressures in patients with LV global strain >18 percent [43].

SUMMARY AND RECOMMENDATIONS

●An evaluation for diastolic function should be performed as a part of all standard complete echocardiographic examinations. Assessment of diastolic function is particularly important in the echocardiographic examination in patients referred for evaluation of dyspnea or suspected or known heart failure (HF). Asymptomatic diastolic dysfunction is common in patients with cardiovascular risk factors such as hypertension, diabetes mellitus, and obesity. (See 'When to evaluate diastolic function' above and "Heart failure: Clinical manifestations and diagnosis in adults", section on 'Diagnosis'.)

●The diagnostic evaluation of diastolic dysfunction involves identification of evidence of diastolic dysfunction, evaluation of its severity, cause, and clinical sequelae, exclusion of confounding factors, and identification of concurrent conditions. The echocardiogram is the key diagnostic modality for identifying diastolic dysfunction as well as identification of confounding factors and concurrent disorders.

●All patients with left ventricular ejection fraction (LVEF) <50 percent (with or without symptoms) have diastolic dysfunction due to impaired LV relaxation.

●Patients with LVEF ≥50 percent can have normal or abnormal diastolic function. To determine whether diastolic dysfunction is present in these patients, we follow an algorithmic approach (algorithm 2).

●Diastolic dysfunction can be graded from mild (grade I) to severe (grade III) with increasing likelihood of symptomatic HF and worse prognosis with higher grade dysfunction. (See 'Grading diastolic dysfunction' above.)

●We use an algorithmic approach to estimate left atrial pressure in normal LVEF and diastolic dysfunction or LVEF <50 percent (algorithm 1). This algorithm should not be applied to patients without LV systolic dysfunction or diastolic dysfunction (See 'Estimation of left atrial pressure' above.)

ACKNOWLEDGMENT — The UpToDate editorial staff acknowledges Warren J Manning, MD, who contributed to earlier versions of this topic review.