Automated analysis of fetal cardiac function using color tissue Doppler imaging

OBJECTIVE

To evaluate the feasibility of automated analysis of fetal myocardial velocity recordings obtained by color tissue Doppler imaging (cTDI).

METHODS

This was a prospective cross-sectional observational study of 107 singleton pregnancies ≥ 41 weeks of gestation. Myocardial velocity recordings were obtained by cTDI in a long-axis four-chamber view of the fetal heart. Regions of interest were placed in the septum and the right (RV) and left (LV) ventricular walls at the level of the atrioventricular plane. Peak myocardial velocities and mechanical cardiac time intervals were measured both manually and by an automated algorithm and agreement between the two methods was evaluated.

RESULTS

In total, 321 myocardial velocity traces were analyzed using each method. It was possible to analyze all velocity traces obtained from the LV, RV and septal walls with the automated algorithm, and myocardial velocities and cardiac mechanical time intervals could be measured in 96% of all traces. The same results were obtained when the algorithm was run repeatedly. The myocardial velocities measured using the automated method correlated significantly with those measured manually. The agreement between methods was not consistent and some cTDI parameters had considerable bias and poor precision.

CONCLUSIONS

Automated analysis of myocardial velocity recordings obtained by cTDI was feasible, suggesting that this technique could simplify and facilitate the use of cTDI in the evaluation of fetal cardiac function, both in research and in clinical practice. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Tissue Doppler velocity imaging and event timings in neonates: a guide to image acquisition, measurement, interpretation, and reference values

Neonatologists can use echocardiography for real-time assessment of the hemodynamic state of neonates to support clinical decision-making. There is a large body of evidence showing the shortcomings of conventional echocardiographic indices in neonates. Newer imaging modalities have evolved. Tissue Doppler imaging is a new technique that can provide measurements of myocardial movement and timing of myocardial events and may overcome some of the shortcomings of conventional techniques. The high time resolution and its ability to assess left and right cardiac function make tissue Doppler a favorable technique for assessing heart function in neonates. The aim of this review is to provide an up-to-date overview of tissue Doppler techniques for the assessment of cardiac function in the neonatal context, with focus on measurements from the atrioventricular (AV) plane. We discuss basic concepts, protocol for assessment, feasibility, and limitations, and we report reference values and give examples of its use in neonates.

Systolic and Diastolic Function by Tissue Doppler Imaging Predicts Mortality in Patients with Atrial Fibrillation

AIM

Tissue Doppler Imaging (TDI) detects early signs of left ventricular dysfunction. The prognostic potential of TDI in patients with atrial fibrillation (AF) has, however, not yet been clarified. This study evaluates the prognostic value of TDI in patients with atrial fibrillation.

METHODS AND RESULTS

In total, echocardiograms from 313 patients with AF during examination were analyzed offline. Longitudinal systolic velocity (s'), early diastolic velocity (e') and longitudinal displacement (LD) were measured by color TDI. During a median follow-up of 891 days, 64 patients (20%) died. TDI was significantly associated with all-cause mortality, and the risk of dying increased significantly per 1 cm/s decrease in s' (HR of 1.31, 95% CI 1.05-1.63; p=0.018) and e' (HR of 1.17, 95% CI 1.01-1.35; p=0.038) respectively, even after adjustment for age, gender, heart rate, aortic stenosis, DM and LVEF quartiles. LD also proved to be a significant predictor of outcome after multivariate adjustment (HR 1.23; 95% CI 1.05-1.44; p=0.012). The population was stratified according to high or low s' and e'. Patients with low s' and e' had more than three times the risk of mortality compared to the patients with high s' and e' (HR 3.64; 95% CI 1.83-7.26; p<0.001) and remained in significantly higher risk after adjustment for various risk factors.

CONCLUSIONS

Both systolic and diastolic performance, as assessed by TDI, are strong predictors of mortality in patients with atrial fibrillation, and especially the combination of systolic and diastolic dysfunction is a significant prognostic marker.

Intervendor Variabilities of Left and Right Ventricular Myocardial Velocities among Three Tissue Doppler Echocardiography Systems

BACKGROUND

Whether an intervendor discordance of myocardial velocities determined by tissue Doppler echocardiography (TDE) can be generalized remains unclear. We compared intervendor variabilities of left ventricular (LV) and right ventricular (RV) myocardial velocities among three TDE systems.

METHODS

Examinations with TDE were performed in 41 healthy subjects and 11 patients with cardiovascular risk factors (CVR) using α-7 (V1, Hitachi Aloka Medical), Artida (V2, Toshiba Medical Systems), and Vivid E9 (V3, GE Healthcare) on the same day. Peak systolic (s'), early diastolic (e'), and late diastolic (a') myocardial velocities at medial and lateral sites of the mitral annulus and lateral site of the tricuspid annulus were measured using both pulsed-wave TDE and color TDE. Intra-observer and inter-observer variabilities were determined in 10 subjects and test-retest variability in 14 subjects.

RESULTS

As for test-retest variability, reproducibilities of LV and RV myocardial velocities determined by pulsed-wave TDE and color TDE were relatively low but comparable between V1, V2, and V3. Myocardial velocities in healthy subjects determined by both pulsed-wave TDE and color TDE were significantly different among the three TDE systems. Myocardial velocities by pulsed-wave TDE in V3 were 2-12% lower (P < 0.05) than those by V2 and 5-14% lower (P < 0.05) than those by V1. Similar differences in myocardial velocities determined by both pulsed-wave TDE and color TDE were found in patients with CVR.

CONCLUSIONS

LV and RV myocardial velocities determined by both pulsed-wave TDE and color TDE are vendor dependent, and reproducibility of the myocardial velocities determined by both TDE systems is relatively low.

The cardiac state diagram as a novel approach for the evaluation of pre- and post-ejection phases of the cardiac cycle in asphyxiated fetal lambs

The aim of this study was to investigate myocardial wall motion using echocardiography and color-coded tissue velocity imaging and to generate a cardiac state diagram for evaluation of the duration of the pre- and post-ejection phases in asphyxiated fetal lambs. Six near-term lambs were partly exteriorized and brought to cardiac arrest through asphyxia. Echocardiography measurements were recorded simultaneously with arterial blood sampling for lactate and blood gases. All fetal lambs exhibited prolongation of the pre- and post-ejection phases at the time when the most pronounced changes in lactate concentration and pH occurred. The mean change in duration of the pre- and post-ejection phases for all fetal lambs was 36 ± 7 ms (p < 0.002) and 77 ± 17 ms (p < 0.019), respectively, and the percentage change was 50% (p < 0.001) and 38% (p < 0.049), respectively. As asphyxia progressed in fetal lambs, the duration of the pre- and post-ejection phases increased. The cardiac state diagram has the potential to be a comprehensible tool for detecting fetal asphyxia.

Reference values for fetal tissue velocity imaging and a new approach to evaluate fetal myocardial function

OBJECTIVES

Myocardial function can be evaluated using color-coded tissue velocity imaging (TVI) to analyze the longitudinal myocardial velocity profile, and by expressing the motion of the atrioventricular plane during a cardiac cycle as coordinated events in the cardiac state diagram (CSD). The objective of this study was to establish gestational age specific reference values for fetal TVI measurements and to introduce the CSD as a potential aid in fetal myocardial evaluation.

METHODS

TVI recordings from 125 healthy fetuses, at 18 to 42 weeks of gestation, were performed with the transducer perpendicular to the apex to provide a four-chamber view. The myocardial velocity data was extracted from the basal segment of septum as well as the left and right ventricular free wall for subsequent offline analysis.

RESULTS

During a cardiac cycle the longitudinal peak velocities of septum increased with gestational age, as did the peak velocities of the left and right ventricular free wall, except for the peak velocity of post ejection. The duration of rapid filling and atrial contraction increased during pregnancy while the duration of post ejection decreased. The duration of pre ejection and ventricular ejection did not change significantly with gestational age.

CONCLUSION

Evaluating fetal systolic and diastolic performance using TVI together with CSD could contribute to increase the knowledge and understanding of fetal myocardial function and dysfunction. The pre and post ejection phases are the variables most likely to indicate fetuses with abnormal myocardial function.

Tissue Doppler echocardiography improves the diagnosis of coronary artery stenosis in stable angina pectoris

Aim To determine if colour tissue Doppler imaging (TDI) performed at rest in patients with suspected stable angina pectoris (SAP) is able to predict the presence of significant coronary artery disease (CAD).

METHODS AND RESULTS

This study comprises 296 consecutive patients with clinically suspected SAP, no previous cardiac history, and a normal ejection fraction. All patients were examined by colour TDI, exercise electrocardiogram (ECG), and coronary angiography (CAG). Regional longitudinal systolic (s'), early diastolic (e'), and late diastolic (a') myocardial velocities were measured by colour TDI at six mitral annular sites and averaged to provide global estimates. Duke score (DS), including ST depression, chest pain, and exercise capacity, was used as the outcome of the exercise ECG. Patients with an area stenosis of ≥70% in at least one epicardial coronary artery were categorized as having a significant CAD (n= 108) and were compared with patients without significant CAD (n= 188). Both e' [odds ratio (OR): 1.5 (1.1-1.9, P < 0.01) per cm/s decrease] and s' [OR: 1.7 (1.1-2.5, P < 0.05) per cm/s decrease] remained independent predictors of CAD after multivariable adjustment for baseline, exercise ECG, and conventional echocardiographic parameters. Area under the receiver operating characteristic curve (AUC) for exercise ECG and TDI in combination was significantly higher than AUC for exercise ECG alone (0.84 vs. 0.79, P < 0.01).

CONCLUSION

In patients with suspected SAP colour TDI performed at rest is an independent predictor of significant CAD, and colour TDI improves the diagnostic performance of exercise ECG.

Myocardial function in offspring 5-8years after pregnancy complicated by preeclampsia

INTRODUCTION

Preeclampsia and diabetic pregnancies share pathophysiological features suggested to influence epigenetic changes during foetal life with importance for later development and metabolic and cardiovascular diseases.

AIM

Our objective was to study the myocardium in offspring after pregnancy complications.

METHODS

Forty-five children (age 5-8 years) delivered from pregnancies complicated by preeclampsia (n = 25), diabetes mellitus type 1 (n = 8) or gestational diabetes mellitus (n = 12) were included. Fifteen children from uneventful pregnancies served as controls. Myocardial functions of right and left ventricle were examined by conventional Doppler and tissue Doppler imaging (TDI).

RESULTS

No major differences were found in the myocardial function between offspring of pregnancy complications and control group. However, the preeclampsia group had smaller hearts, increased heart rate and increased late diastolic velocity (A'-wave) at mitral valve attachments shown by both pulsed wave and colour TDI compared to the control and diabetic groups together (p ≤ 0.01).

CONCLUSION

Children born after preeclampsia may show effects of a negative impact on the heart already at the age of 5 to 8 years. The numbers of examined children were, however, limited.

Tissue Doppler echocardiography reveals impaired cardiac function in patients with reversible ischaemia

AIMS

To determine if echocardiographic tissue Doppler imaging (TDI) performed at rest detects reduced myocardial function in patients with reversible ischaemia.

METHODS AND RESULTS

Eighty-four patients with angina pectoris, no previous history of ischaemic heart disease and normal left ventricular ejection fraction were examined with colour TDI, single-photon emission computed tomography (SPECT), and coronary angiography (CAG). Patients with a normal SPECT (n= 42) constituted the control group and patients with a positive SPECT (n= 42) were divided into patients with (true-positive SPECT, n= 30) or without (false-positive SPECT, n= 12) significant coronary stenoses assessed by CAG. Regional longitudinal systolic (s'), early diastolic (e'), and late diastolic (a') myocardial velocities were measured by colour TDI at six mitral annular sites and averaged to provide global estimates. In patients with reversible ischaemia both global systolic and diastolic function were impaired in terms of reduced average s' (5.6 ± 0.9 vs. 6.1 ± 1.1 cm/s; P< 0.05), reduced average e' (5.9 ± 1.8 vs. 7.0 ± 1.7 cm/s; P< 0.01) and increased average E/e' (14.2 ± 5.0 vs. 11.5 ± 3.9; P< 0.01). This impairment of the cardiac function was even more evident in patients with a true-positive SPECT with reduced average s' (5.5 ± 0.8 vs. 6.1 ± 1.1 cm/s; P< 0.01), reduced average e' (5.2 ± 1.5 vs. 7.0 ± 1.7 cm/s; P< 0.001), and increased average E/e' (15.5 ± 5.2 vs. 11.5 ± 3.9; P< 0.001), whereas no difference in myocardial velocities could be demonstrated in patients with a false-positive SPECT compared with controls.

CONCLUSION

In patients with stable angina pectoris, preserved ejection fraction, and reversible ischaemia assessed by SPECT, echocardiographic colour TDI performed at rest reveals impaired cardiac function. The impairment of the cardiac function seems to be evident only in patients with a true-positive SPECT and colour TDI may therefore increase its diagnostic value.

Are measurements of systolic myocardial velocities and displacement with colour and spectral Tissue Doppler compatible?

Background

Tissue Doppler (TD) in pulsed mode (spectral TD) and colour TD are the two modalities today available in tissue velocity echocardiography (TVE). Previous studies have shown poor agreement between these two methods when measuring myocardial velocities and displacement. In this study, the concordance between the myocardial velocity and displacement measurements using colour TD and different spectral TD procedures was evaluated.

Methods

Left ventricular (LV) longitudinal systolic myocardial velocities and displacement during ejection period were quantified at the basal septal and lateral wall in 24 healthy individuals (4 women and 20 men, 34 ± 12 years) using spectral TD, colour TD and M-mode recordings. Mean, maximal and minimal spectral TD systolic velocities and the corresponding displacement values were obtained by measurements at the outer and inner borders of the spectral velocity signal. The results were then compared with those obtained with the two other modalities used.

Results

Systolic myocardial velocities derived from mean spectral TD frequencies were highly concordant with corresponding colour TD measurements (mean difference 0.10 ± 0.54 cm/sec in septal and 0.09 ± 0.97 cm/sec in lateral wall). Similarly, the agreement between spectral and colour TD (mean difference 0.22 ± 0.74 mm in septal and 0.02 ± 0.86 mm in lateral wall) as well as M-mode was good when mean spectral velocities were temporally integrated and the results did not differ statistically. Conversely, displacement values from the inner or outer border of the spectral signal differed significantly from values obtained with colour TD and M-mode (p < 0.001, in both cases).

Conclusion

LV systolic myocardial measurements based on mean spectral TD frequencies are highly concordant with those provided by colour TD and M-mode. Hence, in order to maintain compatibility of the results, the use of this particular spectral TD procedure should be advocated in clinical praxis.