Impact of Chronic Left Ventricular Preload and Afterload on Doppler Tissue Imaging Velocities: A Study in Congenital Heart Disease

Therapeutic Approaches in Heart Failure with Preserved Ejection Fraction (HFpEF) in Children: Present and Future

For a long time, pediatric heart failure (HF) with preserved systolic function (HFpEF) has been noted in patients with cardiomyopathies and congenital heart disease. HFpEF is infrequently reported in children and instead of using the  HFpEF terminology the HF symptoms are attributed to diastolic dysfunction. Identifying HFpEF in children is challenging because of heterogeneous etiologies and unknown pathophysiological mechanisms. Advances in echocardiography and cardiac magnetic resonance imaging techniques have further increased our understanding of HFpEF in children. However, the literature does not describe the incidence, etiology, clinical features, and treatment of HFpEF in children. At present, treatment of HFpEF in children is extrapolated from clinical trials in adults. There are significant differences between pediatric and adult HF with reduced ejection fraction, supported by a lack of adequate response to adult HF therapies. Evidence-based clinical trials in children are still not available because of the difficulty of conducting trials with a limited number of pediatric patients with HF. The treatment of HFpEF in children is based upon the clinician's experience, and the majority of children receive off-level medications. There are significant differences between pediatric and adult HFpEF pharmacotherapies in many areas, including side-effect profiles, underlying pathophysiologies, the β-receptor physiology, and pharmacokinetics and pharmacodynamics. This review describes the present and future treatments for children with HFpEF compared with adults. This review also highlights the need to urgently test new therapies in children with HFpEF to demonstrate the safety and efficacy of drugs and devices with proven benefits in adults.

Peri-operative changes in diastolic function and outcomes in congenital aortic valve surgery

Background

The ratio of early diastolic mitral inflow velocity (E) to early diastolic mitral annular tissue velocity (e’), or E/e’, is an echocardiographic measure of left ventricular filling pressure. Peri‐operative changes in E/e’ and association with outcomes have been demonstrated in adults undergoing surgery for aortic stenosis (AS). We sought to explore changes in E/e’ and other diastolic indices in the setting of congenital AS surgery and to assess for association with post‐operative outcomes among children and young adults.

Methods

A retrospective, single‐center study was performed among patients 6 months to 30 years of age who underwent congenital AS surgery from 2006 to 2018. Tissue Doppler indices were collected from pre‐ and post‐operative echocardiograms. Post‐operative outcomes were reviewed.

Results

Sixty‐six subjects with subvalvar (45%), valvar (47%), and supravalvar (8%) AS underwent surgery at a median age of 9.5 years (IQR: 4.0–14.8). Pre‐operatively, the lateral E/e’ ratio was 8.6 (6.7–11.0); 33% had E/e’≥10. Post‐operatively, the lateral e’ decreased to 9.9 cm/s (8.0–11.4), the E/e’ ratio increased to 10.4 (8.3–13.1); and 53% had E/e’≥10 (p‐values < 0.0001, 0.0072, and < 0.001, respectively). Pre‐operative lateral e’ correlated modestly with duration of intubation (ρ = −0.24, p‐value 0.048) and post‐operative lateral e’ correlated modestly with duration of intubation and length of hospital stay (ρ = −0.28 and −0.26, p‐values = 0.02 and 0.04, respectively).

Conclusions

Children and young adults who underwent congenital AS surgery had echocardiographic evidence of diastolic dysfunction pre‐operatively that worsened post‐operatively. Lateral e’ may be a sensitive indicator of impaired ventricular relaxation in these patients and may impact duration of intubation and hospital stay.

The Impact of Bone Mineral Biomarkers on Cardiac Dysfunction in Predialysis Chronic Kidney Disease Children

Objective

To evaluate the association of bone mineral biomarkers of calcium, phosphorus metabolism, and 25-hydroxy vitamin D with diastolic dysfunction of the left ventricle and left ventricle mass in predialysis chronic kidney children. Patients and Methods. A cross-sectional observational study was conducted on 60 children with chronic kidney disease and treated by conservative treatment from October 2018 to September 2019 in the Pediatric Nephrology and Cardiology Department at our University Hospital.

Results

The most common causes of CKD were congenital renal anomalies accounted for 22 (36.67%) of the studied cases. The mean age of children was 7.05 ± 2.74 years, and 32 (53.33%) were males. The children who had a normal diastolic function were 32 (53.33%), while those who had diastolic dysfunction were 28 (46.67%). There was a statistically significant in serum phosphorus (p value = 0.03), serum PTH (p value = 0.002), and hypertension (p value = 0.03). There was a statistically significant positive correlation between LVMI and iPTH level (r = 0.89, p ≤ 0.0001), 25(OH) cholecalciferol (r = −0.27, p = 0.04), serum Ca (r = −0.37, p = 0.004), and serum phosphorus (r = −0.45, p = 0.0003).

Conclusion

Our results revealed that hyperparathyroidism, hyperphosphatemia, and hypertension were significantly associated with diastolic dysfunction while hypovitaminosis D was not significantly associated. Vitamin D deficiency was prevalent in all children with CKD. Biomarkers of mineral bone density were significantly associated with left ventricular hypertrophy and increased left ventricular mass index.

Association of Anemia and Blood Pressure With Novel Markers of Diastolic Function in Pediatric Sickle Cell Disease

Diastolic dysfunction is a known cause of mortality in adults with sickle cell disease (SCD). Left atrial function (LAf) and strain (LAS) are novel echocardiographic parameters to assess early diastolic dysfunction, which have not been assessed in pediatric SCD. Through a retrospective single-center study, we describe echocardiographic parameters of diastology in children with SCD and evaluate their relationship with clinical variables including anemia and blood pressure. Baseline clinical data, 24-hour ambulatory blood pressure monitoring data and echocardiography results were collected. LAf and LAS were measured using volumetric data and speckle-tracking echocardiography, respectively. Sixty-seven children with SCD (13.5±7 y, 47% male, 7% hypertensive) with a mean hemoglobin of 8.8±1.3 g/dL, LAf of 61±8% (n=53) and LAS of 46.3±7.4% (n=28) were included. LAS was significantly associated with hemoglobin (ρ=0.43, P=0.022) but not with maximal left atrial (LA) volume (ρ=-0.05, P=0.79) or any blood pressure parameters. On multivariate analysis, LAS decreased by 3.2% (1.3, 5.1) and LA volume increased by 1.6 mL/m2 (3.1, 0.08) for every 1 g/dL decrease in hemoglobin. Thus, severity of baseline anemia in pediatric SCD correlates with diastolic function as measured by LAS, independent of LA dilation.

The use of tissue Doppler imaging in the assessment of diastolic dysfunction in children with chronic lung diseases

Background

Chronic lung diseases (CLD) in children such as bronchiectasis and interstitial lung disease represent a major public health problem with limited therapeutic options. These patients develop pulmonary hypertension (and core-pulmonale in severe cases) because of the recurrent hypoxia and chronic inflammation; which results in right heart enlargement and ventricular hypertrophy. The early identification and convenient treatment of diastolic dysfunction can prevent further complications of the disease including diastolic heart failure and death. We aim to demonstrate the usefulness of tissue Doppler imaging echocardiography (TDI) in the detection of subtle myocardial affection in interstitial lung disease and bronchiectasis as subgroups of (CLD) in children. We studied echocardiographic parameters of 40 pediatric patients with chronic lung disease using conventional M mode and tissue Doppler imaging and compared them with 40 healthy controls of matching age and sex distribution.

Results

Myocardial performance index (MPI) showed that 28 subjects had abnormal right ventricular (RV) MPI (10 with severe affection ≥ 0.6) and 21 subjects had abnormal LV MPI (11 severe affections ≥ 0.6). Thirty percent (30%) of the cases had affected lateral E/E' and 47.5% had affected septal E/E' when compared to controls. Grades of diastolic dysfunction were: 0, 1, 2, 3 in 18, 15, 6, and 1 patients, respectively. MPI LV and MPI RV showed statistically higher values in patients compared to controls (P < 0.001).

Conclusion

This study proved that TDI can accurately detect subtle myocardial dysfunction in pediatric CLD patients.

Évaluation de la fonction diastolique du ventricule gauche en réanimation pédiatrique : quelles indications, quels paramètres mesurer ?

L’incidence des patients avec une insuffisance cardiaque diastolique a augmenté au cours des dernières années. De nombreuses études épidémiologiques, physiopathologiques, cliniques ou pronostiques ont été menées pour comprendre cette nouvelle entité. L’étude et l’analyse de la fonction diastolique (FD) sont devenues des temps essentiels de l’examen échocardiographique. Cet article a pour objectifs : 1) de faire le point sur la physiologie de la FD du ventricule gauche (VG) et sur son évaluation chez l’enfant ; 2) d’envisager des applications cliniques en réanimation pédiatrique pour lesquelles son évaluation est importante. L’évaluation de la FD du VG est complexe, en plein essor et encore peu réalisée en pédiatrie. De plus, la tachycardie chez l’enfant et les particularités pédiatriques encore méconnues rendent difficile l’analyse de certains paramètres. L’ETT est l’examen complémentaire incontournable pour évaluer la FD du VG, mais en cours d’étude chez l’enfant. L’évaluation de la FD du VG devrait faire partie intégrante des paramètres échocardiographiques à prendre en considération pour certaines situations (évaluation de la réponse au remplissage vasculaire et de la sevrabilité à la ventilation mécanique, ajustement des traitements…) afin de mieux comprendre sa mesure et l’utiliser en routine clinique. On retiendra que pour l’évaluation échocardiographique chez l’enfant de réanimation : dans un premier temps évaluer la fonction systolique puis s’efforcer d’évaluer l’évolution de la FD par les pressions de remplissage par des paramètres simples (doppler mitral et tissulaire) ajustés au Z-score (urihttp://www.parameterz.comhttp://www.parameterz.com) tels que les rapports E/e’ et E/A, le volume indexé de l’OG, le tout assorti au contexte clinique et à la cinétique des paramètres biologiques (BNP, NT pro-BNP).

Echocardiographic Evaluation of Ventricular Function-For the Neonatologist and Pediatric Intensivist

In the neonatal and pediatric intensive care setting, bedside cardiac ultrasound is often used to assess ventricular dimensions and function. Depending upon the underlying disease process, it is necessary to be able to evaluate the systolic and diastolic function of left and or right ventricles. The systolic function of left ventricle is mostly assessed qualitatively on visual inspection "eye-balling" and quantitatively by measuring circumferential fraction shortening or calculating the ejection fraction by Simpson's planimetry. The assessment of left ventricular diastolic function relies essentially on the mitral valve and pulmonary venous Doppler tracings or tissue Doppler evaluation. The right ventricular particular shape and anatomical position does not permit to use the same parameters for measuring systolic function as is used for the LV. Tricuspid annular plane systolic excursion (TAPSE) and S' velocity on tissue Doppler imaging are more often used for quantitative assessment of right ventricle systolic function. Several parameters proposed to assess right ventricle systolic function such as fractional area change, 3D echocardiography, speckle tracking, and strain rate are being researched and normal values for children are being established. Diastolic function of right ventricle is evaluated by tricuspid valve and hepatic venous Doppler tracings or on tissue Doppler evaluation. The normal values for children are pretty similar to adults while normal values for the neonates, especially preterm infants, may differ significantly from adult population. The normal values for most of the parameters used to assess cardiac function in term neonates and children have now been established.

Noninvasive Imaging in Adult Congenital Heart Disease

Multimodality cardiovascular imaging plays a central role in caring for patients with congenital heart disease (CHD). CHD clinicians and scientists are interested not only in cardiac morphology but also in the maladaptive ventricular responses and extracellular changes predisposing to adverse outcomes in this population. Expertise in the applications, strengths, and pitfalls of these cardiovascular imaging techniques as they relate to CHD is essential. The purpose of this article is to provide an overview of cardiovascular imaging in CHD. We focus on the role of 3 widely used noninvasive imaging techniques in CHD—echocardiography, cardiac magnetic resonance imaging, and cardiac computed tomography. Consideration is given to the common goals of cardiac imaging in CHD, including assessment of structural and residual heart disease before and after surgery, quantification of ventricular volume and function, stress imaging, shunt quantification, and tissue characterization. Extracardiac imaging is highlighted as an increasingly important aspect of CHD care.

Basics of Functional Echocardiography in Children and Neonates

Functional echocardiography has become an invaluable tool in the pediatric and neonatal intensive care unit. "Point-of-care," "target," or "focus" echocardiography allows bedside cardiac ultrasound evaluation of the hemodynamic status of the patient, helps in directing treatment, thus improves patients care. In order to be able to perform functional echocardiography, it is essential to understand the principles of ultrasound, to know the echocardiographic equipment and settings necessary to acquire the images. This article focuses therefore on the basics of cardiac ultrasound. It is meant to give an overview of two-dimensional echocardiographic views, M-mode imaging and Doppler echocardiography for neonatologists and pediatric intensivists. It is richly illustrated for better understanding with some examples of clinical applications of functional echocardiography in the intensive care setting.

Impact of Interatrial Communication on Left Ventricle Performance in Patients with Significant Post-tricuspid Shunt

Infants with post-tricuspid valve shunts (PTS) may benefit from interatrial communication (IAC). The effect of IAC on left ventricular (LV) performance in these patients was studied. IAC was documented prospectively in 55 patients with PTS. Clinical status, echocardiographic dimensions of LV, mitral inflow Doppler, tissue Doppler velocities and time intervals were measured. Creatinine kinase (CK), CKMB, troponin-I and NT pro-brain natriuretic peptide (NT pro-BNP) were measured. Patients were divided into four groups: (A) PTS but no IAC (n = 32); (B) PTS and IAC (n = 23); (C) VSD but no IAC (n = 16); and (D) VSD and IAC (n = 19). Group A had more frequent mitral regurgitation (p = 0.041), larger mitral annulus (1.80 vs. 1.30 cm, p < 0.0001) and larger LV systolic and diastolic dimensions (2.01 vs. 1.40 and 3.28 vs. 2.35 cm, p < 0.001) than group B. The E-wave deceleration time tended to be longer in group A (121.0 vs. 106.8 ms, p = 0.06). By tissue Doppler, group A had E'- and S-waves significantly taller (15.51 vs. 13.14 and 7.69 vs. 6.72 cm, p = 0.04 and p = 0.005, respectively) than group B. Also, NT pro-BNP was significantly higher in group A (1116.15 vs. 458.73 pg/ml, p = 0.028). Group C had significant larger mitral z-score values (1.2 vs. 0.01, p < 0.001), larger LV diameter z-score (p = 0.001) and higher NT pro-BNP level (1477.37 vs. 451.66 pg/ml, p = 0.001) than group D. There was no significant difference in the clinical status between the groups. In children with PTS, the presence of IAC could be beneficial. Their echocardiographic parameters and biomarker show better systolic and diastolic LV performance.

Left Ventricular Diastolic Dysfunction Assessed by Conventional Echocardiography and Spectral Tissue Doppler Imaging in Adolescents With Arterial Hypertension

Compared to conventional echocardiography, spectral tissue Doppler imaging (s-TDI) allows more precise evaluation of diastolic cardiac function. The purpose of this study was to conduct s-TDI to analyze the slow movement of the left ventricular (LV) myocardium in adolescents with systemic arterial hypertension (HT) and to determine whether patients with HT suffer from LV diastolic dysfunction. The study group comprised 69 consecutive patients (48 boys and 21 girls aged 14-17 years [mean, 15.5 ± 1.1 years]) with primary HT, and the control group comprised 48 healthy participants (24 boys and 24 girls aged 14-17 years [mean, 15.8 ± 1.3 years]). Physical examinations, 24-hour arterial blood pressure monitoring, conventional 2-dimensional and Doppler echocardiography, and s-TDIs were performed. Analysis revealed that study group participants were significantly heavier and had greater LV mass indices than controls (P < 0.001). There were no differences between the velocities of E waves (peak early filling of mitral inflow), but the deceleration times of the mitral E waves were significantly shorter whereas the A waves survived longer in the study group than in the control group. The velocities of A waves (peak late filling of mitral inflow) were elevated (P = 0.041), and the E/A wave pattern (E/A = 1.8 ± 0.4) was normal. These results suggest pseudonormalization, a type of LV diastolic dysfunction in adolescents with HT.In the study group, when the sample volume was positioned at the septal or lateral insertion site of the mitral leaflet, the e' wave velocity was significantly depressed whereas the a' wave velocity was elevated, compared to those of the control group (P < 0.001).The e'/a' ratios from the septal and lateral insertion sites were lower, whereas the E/e' ratio from the septal insertion site was significantly higher in the study group, similar to that seen in atrial reversal velocity (P < 0.001).These findings indicate that using sTDI to find and measure diastolic LV failure is valuable when the probe is placed at the septal and lateral mitral valve annuli during examination.Changes in the myocardium appear similar to those seen in adults.

Left ventricular diastolic function and characteristics in fetal aortic stenosis

Fetal aortic balloon valvuloplasty (FAV) has shown promise in averting progression of midgestation aortic stenosis (AS) to hypoplastic left heart syndrome in a subset of patients. Patients who achieve biventricular circulation after FAV frequently have left ventricular (LV) diastolic dysfunction (DD). This study evaluates DD in fetuses with AS by comparing echocardiographic indices of LV diastolic function in fetuses underwent FAV (n = 20) with controls (n = 40) and evaluates for LV factors associated with DD in patients with FAV. We also compared pre-FAV and post-FAV DD variables (n = 16). Median gestational age (24 weeks, range 18 to 29 weeks) and fetal heart rate were similar between FAV and controls. Compared with controls, patients with FAV had universally abnormal LV diastolic parameters including fused mitral inflow E and A waves (p = 0.008), higher E velocity (p <0.001), shorter mitral inflow time (p = 0.001), lower LV lateral annulus E' (p <0.001), septal E' (p = 0.003), and higher E/E' (p <0.001) than controls. Patients with FAV had abnormal right ventricular mechanics with higher tricuspid inflow E velocity (p <0.001) and shorter tricuspid inflow time (p = 0.03). Worse LV diastolic function (lower LV E') was associated with higher endocardial fibroelastosis grade (r = 0.74, p <0.001), large LV volume (r = 0.55, p = 0.013), and sphericity (r = 0.58, p = 0.009) and with lower LV pressure by mitral regurgitation jet (r = -0.68, p <0.001). Post-FAV, fewer patients had fused mitral inflow E and A than pre-FAV (p = 0.05) and septal E' was higher (=0.04). In conclusion, fetuses with midgestation AS have evidence of marked DD. Worse DD is associated with larger, more spherical LV, with more extensive endocardial fibroelastosis and lower LV pressure.

Myocardial assessment using tissue doppler imaging in preterm very low-birth weight infants before and after red blood cell transfusion

OBJECTIVE

To investigate myocardial velocities in anemic very low-birth weight (VLBW) preterm infants, pre and post red blood cells transfusion using tissue Doppler imaging echocardiography.

STUDY DESIGN

Forty-eight VLBW preterm infants34 weeks and>2 weeks old were prospectively divided: Transfused symptomatic infants (Hematocrit (Hct)<0.30 (n=32)) and non transfused asymptomatic controls (control 1, Hct >0.30 (n=9) and control 2, Hct <0.30 (n=7)). Echocardiography was performed before and 3-5 days after transfusion in the transfused, and the controls were studied at similar intervals. Non parametric tests were used for statistical analysis.

RESULT

Left ventricular (LV) systolic velocity increased (transfused (4.6±0.70 vs 6.0±0.65, P<0.01)) as did LV diastolic velocities (P<0.01) without significant difference over time in each control. The percentage change in LV velocity following transfusion correlated negatively (ρ=0.36) with pre transfusion Hct.

CONCLUSION

There is a significant increase in myocardial performance following transfusion, which is related to the severity of the anemia.

New imaging modalities to assess cardiac function: not just pretty pictures

PURPOSE OF REVIEW

The following review will focus on the current advances in both echocardiography and cardiovascular MRI (CMRI) in the assessment of cardiac function.

RECENT FINDINGS

The assessment of cardiac function in pediatric patients and in congenital heart disease (CHD) patients has dramatically improved over the last several years. The advancement of transthoracic echocardiography with tissue Doppler imaging, speckle tracking, and three-dimensional echocardiography has enabled strain assessment and the ability to estimate ventricular volumes in these complex patients. In the last few decades, CMRI has become an imaging modality that is now part of the standard tools used for cardiac assessment. With superb two-dimensional and three-dimensional resolution, CMRI allows clear delineation of cardiac and extracardiac structures as well as accurate and reproducible assessment of ventricular volume and function. The most recent and robust contributions of CMRI are its ability to provide characterization of the myocardium and the development of new measurements of global and regional myocardial mechanics and function.

SUMMARY

Recent advances in echocardiography and CMRI allow a better understanding of myocardial mechanics and composition as well as accurate assessment of ventricular volume and global and regional function in the complex and unique anatomy often found in CHD patients.

Postnatal left ventricular diastolic function after fetal aortic valvuloplasty

Fetal aortic balloon valvuloplasty (FAV) has shown promise in altering in utero progression of aortic stenosis to hypoplastic left heart syndrome. In patients who achieve a biventricular circulation after FAV, left ventricular (LV) compliance may be impaired. Echocardiographic indexes of diastolic function were compared between patients with biventricular circulation after FAV, congenital aortic stenosis (AS), and age-matched controls. In the neonatal period, patients with FAV had similar LV, aortic, and mitral valve dimensions but more evidence of endocardial fibroelastosis than patients with AS. Patients with FAV underwent more postnatal cardiac interventions than patients with AS (p = 0.007). Mitral annular early diastolic tissue velocity (E') was lower in patients with FAV and those with AS and controls in the neonatal period and over follow-up (p <0.001). Septal E' was similar among all 3 groups in the neonatal period. In follow-up patients, with FAV had lower septal E' than patients with AS or controls (p <0.001). Early mitral inflow velocity/E' was higher in patients with FAV as neonates and at follow-up (p <0.001). Mitral inflow pulse-wave Doppler-derived indexes of diastolic function were similar between groups. In conclusion, echocardiographic evidence of LV diastolic dysfunction is common in patients with biventricular circulation after FAV and persists in short-term follow-up. LV diastolic dysfunction in this unique population may have important implications on long-term risk of left atrial and subsequent pulmonary hypertension.

Developments in echocardiographic techniques for the evaluation of ventricular function in children

Echocardiography is a very important tool for the diagnosis and follow-up of children with congenital and acquired heart disease. One of the challenges that remains in paediatric heart disease is the assessment of systolic and diastolic function in children, as this is influenced by growth, morphology and loading conditions. New echocardiographic techniques, such as tissue Doppler, deformation imaging and three-dimensional echocardiography, have great potential application in this field. They may provide new insights into the influence of growth, morphology and loading on cardiac mechanics, and could become useful clinical tools. In this review, we discuss the potential use and limitations of these new echocardiographic techniques in paediatric and congenital heart disease.

Impact of intravenous immunoglobulin infusion on longitudinal left ventricular performance in patients with acute Kawasaki disease of usual course

PURPOSE

To determine the acute change in cardiac performance after intravenous immunoglobulin infusion (IVIG) in patients with acute Kawasaki disease (KD).

MATERIALS AND METHODS

Subjects were 33 patients with KD who were treated with IVIG 2 g/kg and recovered without coronary artery lesion and 27 controls. Subjects underwent combined two-dimensional, Doppler, and tissue Doppler echocardiographic (TDI) studies. In KD, these echocardiographic studies were performed before IVIG, 48 h after IVIG, and in convalescence. Echocardiographic variables were compared between KD and controls as well as among 3 time points in KD.

RESULTS

Before IVIG, KD showed significantly higher peak aortic velocity and shorter aortic ejection time as results of tachycardia and significantly lower E' (p<0.04) but significantly higher E/E' (p<0.02). After IVIG, patients with KD became afebrile and showed significantly lower TDI indices such as S', E', and, A' and isovolumic acceleration (IVA) (163+/-56 vs. 208+/-70 cm/s(2), p<0.01) with higher TDI-derived Tei index (0.50+/-0.10 vs. 0.44+/-0.06, p<0.02) than controls. These differences tended to disappear in convalescence. In analysis of repeated measurements, except for hemodynamic changes associated with tachycardia, S' (7.9+/-1.3 vs. 7.0+/-1.1 vs. 7.4+/-0.9 cm/s, p<0.001), IVA (227+/-72 vs. 163+/-56 vs. 180+/-63, p<0.05), and A' (7.7+/-3.0 vs. 5.6+/-1.3 vs. 6.7+/-2.3 cm/s, p<0.001) were significantly different among these time points.

CONCLUSIONS

In patients with acute KD with usual course, IVIG induced transient sub-clinical longitudinal left ventricular dysfunction.

Tissue velocities, strain, and strain rate for echocardiographic assessment of ventricular function in congenital heart disease

During the last decade tissue Doppler and myocardial deformation imaging has been introduced to quantify myocardial function in patients with congenital heart disease. These methods could have potential benefits for patients where the anatomy makes it difficult to quantify ventricular function using M-mode or two-dimensional volumetric techniques. In this overview, the potential benefits as well as limitations of the techniques are discussed. Looking directly into the myocardium renders the techniques geometry-independent, allowing the quantification of right ventricular as well as univentricular systolic function. The limitations include the influence of variable loading conditions as well as different methodological problems.

Volume loading-related changes in tissue Doppler images derived from the tricuspid valve annulus in dogs

OBJECTIVE

To investigate the relationship between preload and tricuspid valve annulus-derived tissue Doppler imaging (TDI) as an index of right ventricular (RV) filling in dogs.

ANIMALS

7 Beagles.

PROCEDURES

Peak systolic RV pressure and RV end-diastolic pressure (RVEDP) were measured in anesthetized dogs. Pulsed Doppler was used to measure tricuspid valve inflow and pulmonary valve outflow velocities. The TDI velocities were measured at the lateral corner of the tricuspid valve annulus. Lactated Ringer's solution was infused at 200 mL/kg/h for 60 minutes via the cephalic vein.

RESULTS

IV infusion significantly increased heart rate, RV pressure, and RVEDP. Early diastolic flow (E-wave) and ejection time significantly increased. The myocardial performance index (MPI) significantly decreased. Intravenous infusion significantly increased the ratio of the E'-wave (peak myocardial velocity during early diastole) to the A'-wave (peak myocardial velocity during late diastole; E':A' ratio) and myocardial velocity during systole (S'), early diastole (E'), and late diastole (A'). The TDI-isovolumic relaxation time and TDI-MPI decreased significantly. The RVEDP was correlated with late diastolic flow (A-wave), ratio of the E-wave to the A-wave (E:A ratio), E'-wave, A'-wave, S'-wave (peak myocardial velocity during systole), TDI-isovolumic relaxation time, TDI-MPI, and ratio of the E-wave to the E'-wave (E: E' ratio). The A-wave and E:A ratio and TDI-derived isovolumic relaxation time, S' duration, and E'-wave could predict the RVEDP.

CONCLUSIONS AND CLINICAL RELEVANCE

The TDI velocities were affected by RV filling pressure in healthy dogs, whereas other TDI profiles, such as MPI and E':A' ratio, were independent of acute filling abnormalities.

Comparison of the myocardial performance index derived by use of pulsed Doppler echocardiography and tissue Doppler imaging in dogs with volume overload

OBJECTIVE

To investigate the relationship between the myocardial performance index (MPI) determined by use of pulsed Doppler (PD) echocardiography and tissue Doppler imaging (TDI) in the response to volume overload-related changes in left ventricle (LV) performance.

ANIMALS

7 male Beagles.

PROCEDURES

Dogs were anesthetized and intubated. A 6-F fluid-filled catheter was placed in the LV to measure LV peak systolic (LVPs) and LV end-diastolic (LVED) pressures. Preload was increased by IV infusion of lactated Ringer's solution (rate of 200 mL/kg/h for 60 minutes) into a cephalic vein. Transmitral flow velocities and aortic outflow were measured, and TDI velocities were obtained from the 4-chamber view.

RESULTS

Acute volume overload induced a significant increase in heart rate, LVPs pressure, and LVED pressure, compared with baseline values. A significant decrease in the PD-MPI and TDI-MPI values and a significant correlation (r = 0.70) between PD-MPI and TDI-MPI were detected. The PD-derived A-wave velocity, ejection time, and isovolumic relaxation time (IRT) and the TDI-derived IRT, MPI, and ratio of the velocity of the E wave to the velocity of the ventricular portion of the E wave during early diastole had equal ability to predict LVED pressure (r(2) = 0.63).

CONCLUSIONS AND CLINICAL RELEVANCE

The TDI-MPI was closely correlated with LV filling pressure and may be helpful in evaluating global cardiac function in dogs.

Annular and Septal Doppler Tissue Imaging in Children: Normal z-Score Tables and Effects of Age, Heart Rate, and Body Surface Area

The aim of this study was to construct normal z-score tables for longitudinal directed Doppler tissue imaging (DTI) systolic wave (S), DTI early diastolic wave (E'), and DTI late diastolic wave (A') at the mitral valve annulus (MV), superior ventricular septum (VS), and tricuspid valve annulus (TV) in pediatric patients. We analyzed normal echocardiograms from 634 children aged 1 day to 18 years, heart rate (HR) range of 50 to 194/min, and body surface area (BSA) range of 0.1 to 2.8 m2. First we determined the effects of age, HR, and BSA on the S, E', and A' at the MV, VS, and TV sampling sites by univariate analysis. Next we determined which of the 3 factors, age versus HR versus BSA, correlated best with the S, E', and A' at each of the 3 sampling sites by multivariate analysis. Finally, using the specific factor of age versus HR versus BSA that best predicted a particular DTI wave at a particular sampling site, we constructed z-score tables for each of the 3 DTI parameters at each of the 3 sampling sites. The S range was: MV = 2.2 to 23.2 cm/s; VS = 1.6 to 22.3 cm/s; and TV = 1.8 to 31.3 cm/s. By univariate analysis the S correlated negatively with HR and positively with age and BSA with strong correlations at all 3 sites. By multiple regression analysis the S correlated best with age at all 3 sites. The E' range was: MV = 2.4 to 37.1 cm/s; VS = 1.8 to 29.0 cm/s; and TV = 2.4 to 32.4 cm/s. The E' varied negatively with HR and positively with age and BSA with strong correlations by univariate analysis at all 3 sites. By multiple regression, the E' correlated best with age for the VS and TV sites, and correlated best with HR at the MV site. The E' at the MV site also strongly correlated with age by multivariate analysis. The A' range was: MV = 2.9 to 20.7 cm/s; VS = 2.7 to 18.2 cm/s; and TV = 1.1 to 29.3 cm/s. The A' had a strong positive correlation with HR at all 3 sites, a strong negative correlation with BSA and age at the TV site only, with no statistical significant correlation of the MV and VS site A' to BSA or age. Using multiple regression analysis the A' correlated best with HR at all 3 sites. Z-score tables developed from a large sample volume encompassing the entire spectrum of ages, HR, and BSA encountered in pediatric patients and developed using the strongest predicting factor serve as reference data for longitudinal directed DTI annular and septal S, E', and A' normal values in children.

Evaluation of left ventricular diastolic function in pediatric sickle cell disease patients

Although cardiac involvement is common in adult sickle cell disease (SCD) patients, it is unknown when cardiac dysfunction appears in the course of SCD. Diastolic function has not been comprehensively analyzed in children with SCD. Thus, our aim was to evaluate diastolic function in pediatric SCD patients. Echocardiograms were performed in 156 (73 SC and 81 control) patients. Left ventricular and left atrial volumes, left ventricular mass, mitral inflow, and tissue Doppler indices (TDI) were obtained. The right ventricular pressures (RVP) were calculated. For each SCD patient, mean hemoglobin (Hb), fetal hemoglobin (HbF) levels, and blood transfusion encounters were recorded. Data were analyzed using t-test, univariate and multivariate regression, and Spearman correlation analyses. SCD patients had significantly larger left ventricular and atrial volumes than controls. Mitral inflow velocities were significantly higher in the SCD group. Of 73 SCD subjects, 32 had left ventricular dilatation, 11 had hypertrophy, and 25 had elevated RVP. Left ventricular size was inversely related to Hb, but unrelated to HbF or age. The early mitral inflow velocity was correlated negatively with Hb and positively with left ventricular sizes. TDI indices did not differ between the SCD and control groups. They were unrelated to Hg, HgF, transfusion history, or ventricular size; however, Doppler indices of left ventricular stiffness were increased in SCD patients. Pediatric SCD patients demonstrate increased left ventricular stiffness, and a significant percentage of them have left ventricular hypertrophy. There are strong positive relations between left ventricular hypertrophy and right ventricular pressure in these patients. TDI should be employed in the evaluation of SCD patients.

Cardiac dysfunction in children with mulibrey nanism

Mulibrey nanism is an autosomal recessive disease with severe growth failure and multiple organ involvement. Heart manifestations include constrictive pericarditis and restrictive cardiomyopathy. The purpose of this study was to evaluate left ventricular (LV) diastolic and systolic function in children with mulibrey nanism utilizing two- and three- dimensional (2-D and 3-D) echocardiography and measurement of serum levels of natriuretic peptides. Of the 30 children diagnosed with mulibrey nanism in Finland, 26 participated. The control group comprised 26 children. In 2-D echocardiography, the interventricular septum and LV posterior wall were thicker in patients. The left atrium/aorta ratio measured a median 1.8 (range, 1.4-2.5) in patients and 1.3 (range, 1.0-1.7) in controls (p < 0.001). Patients differed from controls in several indices of diastolic LV function. In 3-D echocardiography, LV end diastolic volume measured a median of 51.9 ml/m(2) (range, 33.3-73.4) in patients and 59.7 ml/m(2) (range, 37.6-87.6) in controls (p = 0.040), and serum levels of N-terminal proatriopeptide and N-terminal pro-brain natriuretic peptide measured, respectively, a median of 0.54 nmol/L (range, 0.04-4.7) and 289 ng/L (range, 18-9170) in patients and 0.28 nmol/L (range, 0.09-0.72; p < 0.001) and 54 ng/L (range, 26-139; p < 0.001) in controls. They correlated with several indices of diastolic LV function. In a significant proportion of children with mulibrey nanism, myocardial function is impaired. Significant correlations appeared between indices of LV function, size of the left atrium, and levels of natriuretic peptides, showing that measurement of serum levels of natriuretic peptides is a useful follow-up method despite its dependence on loading conditions.

Relationship between tissue Doppler-derived RV systolic function and invasive hemodynamic measurements

Tissue Doppler imaging (TDI) is effective in assessing right ventricular (RV) function, but the relationship between invasive measurements and RV-TDI remains unclear. We investigated the RV systolic function by using the TDI-derived systolic myocardial (Sa) velocity and myocardial performance index (MPI). Beagles (n = 7) were anesthetized in the right lateral recumbent position. A 3.5-Fr micromanometer-tipped catheter was placed in the RV to determine the hemodynamic changes. Dobutamine (5.0 and 10 microg.kg(-1).min(-1)) and esmolol (50 and 100 microg.kg(-1).min(-1)) were infused intravenously. Pulsed Doppler (PD) and TDI measurements were performed in the apical four-chamber view. Compared with baseline, the PD-MPI decreased significantly with the dobutamine infusion at 5 microg.kg(-1).min(-1) (P < 0.05). Both dobutamine infusions significantly decreased the TDI-MPI (P < 0.01, P < 0.05). Esmolol increased the PD- and TDI-MPI but not significantly. Dobutamine significantly increased the Sa velocity (both P < 0.001), whereas esmolol had no effect. The Sa velocity was strongly correlated with the peak positive derivative of the RV pressure (+dP/dt; r = 0.93). The negative correlation between the +dP/dt and TDI-MPI (r = -086) was greater that with the PD-MPI (r = -0.54). Stepwise regression analysis showed that the Sa velocity and PD-derived isovolumic contraction time were identified to predict the +dP/dt (r = 0.94, r(2) = 0.89; P < 0.001). We determined that the systolic myocardial velocity and TDI-MPI were strongly correlated with the RV contractility. These results suggest that the TDI-derived systolic myocardial velocity and MPI predict RV systolic function.

The impact of hypertension on systolic and diastolic left ventricular function. A tissue Doppler echocardiographic study

BACKGROUND

The purpose of this study is to assess the impact of hypertension on systolic function and diastolic function using 2-dimensional echocardiography, conventional Doppler imaging of the transmitral inflow, and tissue Doppler imaging (TDI) of the mitral annulus.

METHODS

From an outpatient clinic population, 414 consecutive patients underwent 2-dimensional echocardiography, conventional Doppler imaging of the transmitral inflow, and TDI of the septal, lateral, inferior, and posterior walls near the mitral annulus. Parameters of systolic left ventricular (LV) function and diastolic LV function were assessed. Patients were divided according to the presence or absence of systemic hypertension (blood pressure > or = 140/90 mm Hg on > or = 3 measurements or treatment with antihypertensive medication).

RESULTS

A complete echocardiographic evaluation was obtained in 397 patients. Among these, 269 (68%) had hypertension. There was no difference with respect to age between patients with and without hypertension. Patients with hypertension had higher LV mass index and relative wall thickness and lower TDI peak systolic velocity (V(S)) when compared with patients without hypertension. In addition, indices of diastolic LV function were significantly impaired in hypertensive patients.

CONCLUSIONS

Quantitative echocardiography using TDI reveals that hypertensive patients with preserved global LV systolic function often have combined impairment of systolic function and diastolic function.