Evaluation of myocardial deformation in patients with sickle cell disease and preserved ejection fraction using three-dimensional speckle tracking echocardiography

Global left ventricular strains and left atrial volumes are not associated in healthy adults - Detailed analysis from the three-dimensional speckle-tracking echocardiographic MAGYAR-Healthy Study

Introduction

During the heart cycle, left ventricular (LV) contractility is characterized by complex deformation and rotational mechanics, resulting in LV ejection. The present study seeks to expand our knowledge by examining dependence of LV strains representing LV deformation on left atrial (LA) volumes in healthy circumstances. Therefore, the aim of this study was to evaluate the associations between LA volumes and LV strains as assessed simultaneously by three-dimensional speckle-tracking echocardiography (3DSTE) in normal healthy adults.

Methods

The present study consisted of 302 healthy adults, but according to exclusion criteria, 137 subjects were excluded due to inferior image quality. The final population comprised 165 individuals (mean age: 33.1 ± 12.3 years, 75 males) who were voluntarily recruited for screening. Two-dimensional echocardiography extended with 3DSTE was performed in all subjects for detailed LV/LA analysis.

Results

Overall feasibility for simultaneous assessment of LV strains and LA volumes proved to be 55 % with excellent intra- and interobserver correlations. All global LV strains were similar, regardless of the LA volumes examined. All LA volumes and volume-based functional properties respecting the cardiac cycle were similar, regardless the global LV strains examined.

Conclusions

LV strains and LA volumes can be simultaneously assessed by 3DSTE. Global LV strains and LA volumes are not associated in healthy adults.

Complexity of left ventricular strains in response to elevated volumes in healthy adults - Detailed analysis from the three-dimensional speckle-tracking echocardiographic MAGYAR-Healthy Study

Introduction

Cardiac haemodynamics is described by the Frank-Starling law, which states that the strength of the left ventricular (LV) systolic contraction is related to the LV diastolic filling, with other words LV stroke volume increases as LV volume increases due to the stretching of the myocyte. The purpose of the present study was to examine how the increasing LV volumes affect LV contractility represented by three-dimensional (3D) speckle-tracking echocardiography (3DSTE) -derived LV strains in healthy adults.

Methods

This is post-hoc analysis of the MAGYAR-Healthy Study employing a novel method for technical analysis of echocardiographic datasets. The present study consisted of 301 healthy adults. Due to inferior image quality, 127 subjects have been excluded, therefore the remaining population included 174 subjects (mean age: 32.9 ± 12.1 years, 80 males). All cases have undergone complete two-dimensional Doppler echocardiography extended with 3DSTE.

Results

LV global longitudinal (gLS) and area (gAS) strains were lowest in case of the highest LV end-diastolic volume (EDV). LV global radial (gRS) and 3D (g3DS) strains tendentiously increased with increasing LV-EDV. When segmental analysis was performed, increased LV-EDV was associated with increase of basal LV-RS and LV-3DS. Increased LV strains were associated with increased LV ejection fraction (EF) due to higher LV-EDV for LV-gRS (and LV-g3DS), lower LV-ESV for LV-gCS and lower LV-EDV and LV-ESV for LV-gLS (and LV-gAS). With increasing LV-gRS, LV-gCS and LV-g3DS, all LV strains increased except LV-gLS. With increasing LV-gLS, LV-gRS did not show any increase, LV-gCS and LV-g3DS were the highest when LV-gLS was the highest, while LV-gAS increased simultaneously. With increasing LV-gAS, all LV strains increased.

Conclusions

There is a complex contractility pattern of LV segments/regions in response to elevated LV volumes in healthy circumstances.

Longitudinal effect of disease-modifying therapy on left ventricular diastolic function in children with sickle cell anemia

Cardiac abnormalities seen in sickle cell anemia (SCA) include diastolic dysfunction, which has been shown to be associated with high morbidity and early mortality. The effect of disease-modifying therapies (DMT) on diastolic dysfunction is poorly understood. We prospectively evaluated the effects of hydroxyurea and monthly erythrocyte transfusions on diastolic function parameters over 2 years. A total of 204 subjects with HbSS or HbSβ0-thalassemia (mean age 11 ± 3.7 years), unselected for disease severity, had diastolic function assessed with surveillance echocardiograms twice, 2 years apart. During this 2-year observation period, 112 participants received DMTs (hydroxyurea, n = 72, monthly erythrocyte transfusions, n = 40), 34 initiated hydroxyurea, and 58 did not receive any DMT. The entire cohort showed an increase in left atrial volume index (LAVi) of 3.40 ± 10.86 mL/m2, p = .001 over 2 years. This increase in LAVi was independently associated with anemia, high baseline E/e' or LV dilation. Individuals not exposed to DMT were younger (mean age 8.8 ± 2.9 years), but at baseline their prevalence of abnormal diastolic parameters was similar to that of the DMT-exposed participants who were older (mean age 12 ± 3.8 years). Participants on DMTs saw no improvement in diastolic function over the study period. In fact, participants on hydroxyurea saw a possible worsening in diastolic parameters (14% increase in LAVi and ~5% decrease in septal e') but also a ~9% decrease in fetal hemoglobin (HbF) levels. Further studies are needed to evaluate if exposure to DMT for a longer duration or achieving higher HbF might be beneficial in alleviating diastolic dysfunction.

Evaluation of left ventricular systolic function in children with sickle cell anemia: contribution of 2D strain

BACKGROUND

Children with sickle cell anemia (SCA) are at an increased risk of cardiovascular complications. The aim of this study was to assess the role of speckle tracking echocardiography in detecting subclinical myocardial damage in children with SCA.

METHODS

A cross-sectional case-control study was conducted at the echocardiography laboratory of the military hospital of Tunis between July and December 2018. Thirty patients with SCA were included. A control(C) group including 30 normally developing children was selected and matched to the SCA group by sex and age. We compared between the two groups: conventional echocardiographic parameters including cardiac output, left ventricular ejection fraction (LVEF), thickness and the global longitudinal strain (GLS). The echocardiographic measurements were indexed according to body surface area. The left ventricular (LV) GLS association with clinical characteristics and echocardiographic parameters were also evaluated.

RESULTS

Patients and controls were matched for age and sex: the mean age was (11± 2years) in SCA group versus (12± 1 years) in C group with a sex ratio of (1.31 versus 1.27, respectively). Body surface area was comparable. LV hypertrophy and dilation were revealed in the SCA group, whereas measurements were normal in the C group. No significant differences were observed for cardiac output (p=0.4). LVEF were preserved in both groups. However, two-dimensional (2D) LVGLS was impaired in 46% of SCA group (n=14) with mean value of (-21%±3.07 vs -25%±2.98; p<0.01).In SCA group, impaired LVGLS was significantly associated with LV mass (r = - 0.399, p<0.01), LV tele diastolic diameter(r= -0.419, p<0.01) and left atrial volume (r= - 0.399, p< 0.04). In multivariate analysis, LV mass was the only independent factor.

CONCLUSIONS

In the present study, LVGLS measurement revealed subclinical LV systolic impairment in patients with SCA. Therefore, 2D strain could be beneficial to detect the natural history of LV dysfunction in SCA.

Evaluation of subclinical left ventricular systolic dysfunction using two-dimensional speckle-tracking echocardiography in patients with Child-Pugh A and B cirrhosis: A case-control study

BACKGROUND

Although studies have proven that liver cirrhosis affects cardiac hemodynamics by means of circulatory overload, they present with definite cardiac functional alteration mostly with end-stage disease. There is limited data on relationship between progression of cirrhosis, cardiac mechanics and sub-clinical dysfunction. This study was done to assess ventricular myocardial mechanics using speckle tracking and deformation imaging among Child-Turcotte-Pugh (CTP) classification A and B cirrhosis.

METHOD

Seventy patients with cirrhosis of Child-Pugh A/B class and sixty-two healthy subjects were prospectively evaluated by standard conventional echocardiography and deformation imaging with rotational echocardiography. Clinical stage of liver cirrhosis was assessed by model for end-stage liver disease (MELD) scores and CTP classification.

RESULTS

Mean ages of patients with cirrhosis and controls were 55.64±14 years and 52.24±12 years, respectively. Though left ventricular (LV) dimensions (end diastolic dimension: 47.27±4.6 mm vs. 45.03±3.8 mm, p = 0.003; end systolic dimension: 30.33±4.9 mm vs. 28.40±2.91 mm, p = 0.006) and volumes (end diastolic volume: 82.08±22.53 mL vs. 68.18±15.75 mL, p = 0.001; end systolic volume: 28.60±8.42 mL vs. 22.18±7.48 mL, p = 0.001) were significantly higher in patients with cirrhosis, mean ejection fraction (EF) by Simpsons method was higher among controls (65.83±5.79% vs. 68.35±5.79%, p = 0.009). Left atrial volume was higher in cirrhosis group indicating presence of diastolic dysfunction (41.24±14.10 mL vs. 26.08±6.4 mL, p = 0.001). Global longitudinal strain as assessed by speckle tracking echocardiography did not show statistical significant difference between two groups (-22.35±4.08% vs. -21.80±2.54%, p = 0.348). Median value of torsion parameters in patients with cirrhosis did not differ compared to controls (torsion in degrees: 2.46 vs. 2.79, p = 0.268).

CONCLUSION

Patients with Child-Pugh A and B stages of cirrhosis present with preserved longitudinal strain, normal torsion but with subtle diastolic dysfunction. Higher MELD score may correlate with increased longitudinal strain possibly due to hyperdynamic state.

Sickle cell disease and ventricular myocardial strain: A systematic review

Cardiac disease is the primary cause of death in sickle cell disease (SCD). Cardiac abnormalities begin in childhood and progress throughout life. Right and left ventricular (RV, LV) myocardial strain are early markers of systolic dysfunction but are not well investigated among individuals with SCD. The objectives of this review were to (1) identify all published studies that have evaluated ventricular myocardial strain, (2) summarize their values, and (3) compare findings with those obtained from controls. From search results of four electronic databases-Medline, Embase, Scopus, and Web of Science-42 potential articles were identified, of which 18 articles and 17 studies met eligibility criteria for inclusion. The evaluated studies demonstrate that RV and LV myocardial strain are generally abnormal in individuals with SCD compared with controls, despite having normal ejection/shortening fraction. Myocardial strain has been inconsistently evaluated in this population and should be considered any time an echocardiogram is performed.

Reversal of a rheologic cardiomyopathy following hematopoietic stem cell transplantation for sickle cell disease

Cardiac complications have been well-described in sickle cell disease; however, it has been rare to see improvements in cardiac abnormalities following any interventions. Previous work has shown no significant structural changes after treatment with hydroxyurea. The cardiac effects of red blood cell exchange transfusion (RBCx) and hematopoietic stem cell transplantation (HSCT) have not been well described. We studied 56 patients undergoing HSCT (41 HLA-matched, 15 haploidentical), of whom 32 had RBCx within 3 months before HSCT. Echocardiograms and laboratory parameters were obtained at baseline, and at 3, 6, and 12 months following HSCT. Although hemolytic parameters and anemia improved following RBCx, there was a small increase in left ventricular volume index. Following successful HSCT, however, there were significant improvements in cardiac size, function, and diastolic filling parameters at 3 months followed by continued smaller improvements up to 1 year. There was a significant improvement in N-terminal pro B-type natriuretic peptide levels and a trend toward improvement in 6-minute walk time 1 year after HSCT. The magnitude of cardiac improvement seen following HSCT was comparable to that observed following correction of a volume overload state as seen in pregnancy or after repair of chronic valvular regurgitation. Further studies in sickle cell disease patients will help delineate which cardiac complications and what level of severity should be considered indications for HSCT.

Prognostic value of left ventricular longitudinal strain by speckle-tracking echocardiography in patients with sickle cell disease

Cardiovascular complications have been increasingly detected in patients with sickle cell disease (SCD). Two-dimensional speckle-tracking echocardiography (STE) detects early myocardial changes in a number of pathophysiological processes, which may be useful in SCD. This study was designed to examine the value of STE in predicting clinical outcome in adult patients with SCD. A total of 219 patients, mean age 33 ± 12 years were prospectively enrolled. Several clinical, laboratory and echocardiographic variables including left ventricular global longitudinal strain (LVGLS) by STE were assessed. The endpoint was a composite of the following events: (1) all-cause mortality, (2) three or more acute painful episodes that require hospitalization in one year, (3) acute chest syndrome and (4) hospitalization due to disease complication. The majority of the patients had enlargement of LV and left atrial (LA) with preserved ejection fraction. During the mean follow-up of 30 months, 69 patients (32%) had reached the endpoint, including eight deaths (3.7%). No difference was observed in the parameters of diastolic function comparing the patients with and without events. LVGLS ranged from - 12.25 to - 25.44 (mean - 20.26 ± 2.5), with higher values in the patients who had events compared with those who did not. In the multivariable analysis, higher LVGLS values were associated with adverse events (adjusted OR 1.25; 95% CI 1.04-1.51; p = 0.021), independently of the TR maximal velocity and LV ejection fraction. In patients with SCD, higher LV global longitudinal strain was a predictor of adverse outcome, independently of age, TR velocity and LV function.

Evaluation of Cardiac Function in Patients with Sickle Cell Disease with Left Ventricular Global Longitudinal Strain

Background and Objectives

The importance of myocardial dysfunction in sickle cell disease (SCD) is currently debated. It is difficult to find a reliable index of function in patients with chronic overload as in SCD. Speckle tracking echocardiography, a new mean of evaluating cardiac function, might be a useful tool in SCD. It has been applied in many fields to detect early cardiac function deterioration, and it is less load dependent compared with other function parameters. Studies in patients with SCD are rare, and the results are conflicting. The present study aimed to determine whether left ventricular global longitudinal strain (LV-GLS) was abnormal in a population of adults with SCD and whether it was correlated with clinical or biological parameters.

Methods

We prospectively enrolled 37 patients and 34 age- and sex-matched healthy controls. Echocardiography was performed in patients and controls.

Results

We found that the left ventricular diameter and mass were higher and the ejection fraction and longitudinal strain were lower in patients compared with controls. Diastolic dysfunction was uncommon. LV-GLS was abnormal in 21% of the patients. No correlation was observed between strain and clinical or biological parameters.

Conclusions

We concluded that LV-GLS could be a useful tool for evaluating these patients. However, the clinical impact of reduced LV-GLS remains to be determined.

Subclinical Cardiac Dysfunction Is Associated With Extracardiac Organ Damages

Background: Several studies conducted in America or Europe have described major cardiac remodeling and diastolic dysfunction in patients with sickle cell disease (SCD). We aimed at assessing cardiac involvement in SCD in sub-Saharan Africa where SCD is the most prevalent.

Methods: In Cameroon, Mali and Senegal, SCD patients and healthy controls of the CADRE study underwent transthoracic echocardiography if aged ≥10 years. The comparison of clinical and echocardiographic features between patients and controls, and the associations between echocardiographic features and the vascular complications of SCD were assessed.

Results: 612 SCD patients (483 SS or Sβ⁰, 99 SC, and 19 Sβ⁺) and 149 controls were included. The prevalence of dyspnea and congestive heart failure was low and did not differ significantly between patients and controls. While left ventricular ejection fraction did not differ between controls and patients, left and right cardiac chambers were homogeneously more dilated and hypertrophic in patients compared to controls and systemic vascular resistances were lower (p < 0.001 for all comparisons). Three hundred and forty nine SCD patients had extra-cardiac organ damages (stroke, leg ulcer, priapism, microalbuminuria or osteonecrosis). Increased left ventricular mass index, cardiac dilatation, cardiac output, and decreased systemic vascular resistances were associated with a history of at least one SCD-related organ damage after adjustment for confounders.

Conclusions: Cardiac dilatation, cardiac output, left ventricular hypertrophy, and systemic vascular resistance are associated with extracardiac SCD complications in patients from sub-Saharan Africa despite a low prevalence of clinical heart failure. The prognostic value of cardiac subclinical involvement in SCD patients deserves further studies.

Ventricular global longitudinal strain is altered in children with sickle cell disease

Cardiac disease is the primary cause of death in sickle cell disease (SCD). Right and left ventricular global longitudinal strain (RVGLS, LVGLS) are early markers of systolic dysfunction but are not well investigated among children with SCD. One hundred and forty-three patients with HbSS or HbSβ⁰ -thalassaemia (median age 11 years, range 5-19 years) and 71 controls matched for age and sex were compared. RVGLS and LVGLS were measured and compared with conventional measures of echocardiography and markers of haemolysis and inflammation. RVGLS was higher in children with SCD than in controls (-25·72% ± 3·45% vs. -24·54% ± 2·41%, P = 0·005); LVGLS was not different. RVGLS decreased with older age in children with SCD (ρ = 0·338, P < 0·001) but not among controls. Decreased RVGLS was associated with increased left atrial end diastolic volume (ρ = 0·181, P = 0·04); RVGLS increased with cardiac output (r = -0·279, P = 0·01). RVGLS and LVGLS were not associated with disease-modifying therapies, degree of anaemia or haemolysis markers. Elevated RVGLS may indicate an early RV compensatory mechanism in response to upstream myocardial insults and elevated cardiac output. Global longitudinal strain may serve as an early marker of altered myocardial function in children with SCD.

Left ventricular structural and functional changes evaluated by echocardiography and two-dimensional strain in patients with sickle cell disease

INTRODUCTION

Patients with sickle cell disease have increased left ventricular size, which is not usually accompanied by changes in systolic function indexes. We assessed echocardiographic abnormalities present in patients with sickle cell anemia (SCA) and compared echocardiographic parameters to other sickle cell diseases (OSCD).

MATERIAL AND METHODS

A blind cross-sectional study with 60 patients with SCA and 16 patients with OSCD who underwent transthoracic echocardiography was performed.

RESULTS

Echocardiographic findings were: left atrial volume index 47.7 ±11.5 ml/m² in SCA group and 31.7 ±8.42 ml/m² in OSCD group (p < 0.001); left ventricular diastolic diameter index 3.47 ±0.37 cm/m² in SCA group and 2.97 ±0.41 cm/m² in OSCD group (p < 0.001); left ventricular systolic diameter index 2.12 ±0.31 cm/m² in SCA group and 1.86 ±0.28 cm/m² in OSCD group (p < 0.001). There were no differences in the left ventricular ejection fraction: 68.2 ±6.69% in SCA group and 67.1 ±6.21% in OSCD group (p = 0.527). The ratio between mitral E wave and mean mitral annulus e' wave velocities was higher in the SCA group (7.72 ±1.54 vs. 6.70 ±1.65; p = 0.047). Mitral A wave correlated significantly with hemoglobin levels (r = -0.340; p = 0.032).

CONCLUSIONS

There was an increase of left ventricular and left atrial sizes in patients with SCA, compared to patients with OSCD, without changes in systolic or diastolic function in both groups. This could be due to the hyperkinetic state due to the more severe anemia in the SCA subjects.

Applications of cardiac magnetic resonance imaging in sickle cell disease

Cardiac magnetic resonance imaging (CMR) has evolved from an effective research tool to a non-invasive clinical modality with versatile applications. The accuracy of volume measurements and functional assessment and the ability to identify unique myocardial tissue characteristics non-invasively are the primary advantages of CMR. The use of CMR in sickle cell disease (SCD) has been limited clinically to myocardial iron assessment. The use of other CMR applications to characterize the cardiac pathology in SCD is slowly emerging but remains limited to research level. In this review, we discuss some of the applications of CMR in studying cardiovascular diseases and its potential uses in SCD for research and clinical purposes.

Associations of Prolonged QTc in Sickle Cell Disease

Sudden death is a leading cause of mortality in sickle cell disease, implicating ventricular tachyarrhythmias. Prolonged QTc on an electrocardiogram (ECG), commonly seen with myocardial ischemia, is a known risk for polymorphic ventricular tachycardia (VT). We hypothesized that prolonged QTc is associated with mortality in sickle cell disease. ECG were analyzed from a cohort of 224 sickle patients (University of Illinois at Chicago, UIC) along with available laboratory, and echocardiographic findings, and from another cohort of 38 patients (University of Chicago, UC) for which cardiac MRI and free heme values were also measured. In the UIC cohort, QTc was potentially related to mortality with a hazard ratio (HR) of 1.22 per 10ms, (P = 0.015), and a HR = 3.19 (P = 0.045) for a QTc>480ms. In multivariate analyses, QTc remained significantly associated with survival after adjusting for inpatient ECG status (HR 1.26 per 10ms interval, P = 0.010) and genotype status [HR 1.21 per 10ms interval, P = 0.037). QTc trended toward association with mortality after adjusting for both LDH and hydroxyurea use (HR 1.21 per 10ms interval, P = 0.062) but was not significant after adjusting for TRV. In univariate analyses, QTc was related to markers of hemolysis including AST (P = 0.031), hemoglobin (P = 0.014), TR velocity (P = 0.036), higher in inpatients (P<0.001) and those with an SS compared to SC genotype (P<0.001) in the UIC cohort as well as to free heme in the UC cohort (P = 0.002). These findings support a relationship of prolonged QTc with hemolysis and potentially mortality in sickle cell disease.

Abnormalities in aortic properties: a potential link between left ventricular diastolic function and ventricular-aortic coupling in sickle cell disease

Left ventricular (LV) diastolic dysfunction in patients with sickle cell disease (SCD) is associated with increased mortality. However, its mechanisms are not well known, preventing the development of effective therapies. We hypothesized that patients with SCD have altered aortic properties despite normal blood pressure, which may contribute towards the development of diastolic dysfunction. We studied 31 stable adult patients with SCD (32 ± 7 years) and 12 healthy controls of similar age (29 ± 10 years) who underwent echocardiography and cardiovascular magnetic resonance (CMR) imaging on the same day. Echocardiographic measurements of mitral inflow and mitral annulus velocities were used to evaluate LV diastolic function. CMR imaging included standard LV function evaluation and myocardial tissue characterization as well as velocity-encoded images of the ascending aorta to measure aortic diastolic cross-sectional area, distensibility, as well as peaks and volumes of the global, forward and backward blood flow rate. Compared to controls, SCD patients had increased aortic diastolic area, global stroke volume, and both forward and backward flow, while aortic distensibility and peripheral blood pressure were similar. Furthermore, peak backward flow rate and volume were able to discriminate between patients with and without diastolic dysfunction. Our findings show that some aortic properties are altered in SCD patients and may be associated with diastolic dysfunction despite normal systolic blood pressure. If confirmed in larger studies, these aortic changes could be a novel therapeutic target to prevent or delay the development of LV diastolic dysfunction in SCD and thus potentially improve outcomes in these patients.

Left ventricular rotational mechanics in Tanzanian children with sickle cell disease

Background

Sickle cell disease (SCD) is a common inherited hemoglobinopathy. Adults with SCD manifest both systolic and diastolic cardiac dysfunction, though the age of onset of dysfunction has not been defined. Left ventricular (LV) rotational mechanics have not been studied in children with SCD. The aim of this study was to investigate whether cardiac rotational mechanics differed between children with SCD and age-matched controls.

Methods

Basal and apical LV short-axis images were acquired prospectively in 213 patients with SCD (mean age, 14.1 ± 2.6 years) and 49 controls (mean age, 13.3 ± 2.8 years) from the Muhimbili Sickle Cohort in Dar es Salaam, Tanzania. The magnitude of basal and apical rotation, net twist angle, torsion, and untwist rate were obtained by two-dimensional speckle-tracking. The timing of events was normalized to aortic valve closure.

Results

Mean basal rotation was significantly lower in patients with SCD compared with controls (P = .012), although no difference was observed in apical rotation (P = .37). No statistically significant differences in torsion or net twist angle were detected. Rotation rate at the apex (P = .001) and base (P = .0004) were significantly slower in subjects with SCD compared with controls. Mean peak untwisting rate was also significantly slower in patients with SCD (P = .006). No associations were found between hemoglobin concentration and apical rotation, basal rotation, net twist, and torsion.

Conclusion

This study demonstrates alterations in LV rotational mechanics in children with SCD, including lower basal rotation, peak differential twist, and untwist rate. These abnormalities denote subclinical changes in LV systolic and diastolic performance in children with SCD. Future work may reveal an association between rotational metrics and long-term patient outcomes.

Exercise-Induced Abnormal Increase of Systolic Pulmonary Artery Pressure in Adult Patients With Sickle Cell Anemia: An Exercise Stress Echocardiography Study

BACKGROUND

Pulmonary hypertension (PH) at rest is a risk factor for death in patients with sickle cell anemia (SCA). Exercise echocardiography (EE) can detect latent PH. We sought to investigate the occurrence of exercise-induced abnormal response of systolic pulmonary artery pressure (SPAP) in adult patients with SCA and normal SPAP at rest, and to identify the independent predictors of this abnormal response.

METHODS AND RESULTS

Forty-four adult patients with SCA and normal SPAP at rest (tricuspid regurgitant jet flow velocity [TRV] <2.5 m/sec) were studied and divided into 2 groups: exhibiting normal SPAP after treadmill EE (TRV ≤ 2.7 m/sec) (G1), and exhibiting abnormal exercise-induced increase of SPAP (TRV > 2.7 m/sec) (G2). TRV cutoff points at rest and during EE were based on data from healthy-matched control subjects. Abnormal response of SPAP with exercise occurred in 57% of the sample (G2), with mean TRV level of 3.39 ± 0.41 m/sec (range 2.8-4.5 m/sec), significantly higher than those of G1 (2.29 ± 0.25 m/sec, range 2.0-2.7 m/sec; P < 0.001). Multivariate analysis identified TRV value in resting conditions ≥2.25 m/sec (P < 0.05), left atrial volume index ≥41 mL/m² (P < 0.05), and a E/e'-waves ratio ≥6.3 (P < 0.05) as independent predictors of exercise-induced increase of SPAP.

CONCLUSION

We concluded that adult patients with SCA and normal SPAP at rest may exhibit abnormal exercise-induced increase in SPAP, which was independently related to resting TRV levels, and indices of diastolic impairment and left ventricular filling pressure.

Endothelial Function and Vascular Properties in Children with Sickle Cell Disease

BACKGROUND

Sickle cell disease (SCD) is an inherited disorder characterized by recurrent painful crises with ischemia resulting from vascular occlusion. Adults with SCD have increased arterial stiffness and reduced flow-mediated dilation (FMD), due to impaired release of substances such as nitric oxide.

AIM

We aimed to assess the vascular properties of carotid and brachial arteries in children with SCD compared with a control group without cardiovascular risk factors.

METHODS

Thirty patients with SCD, mean age 12.3 ± 4.5 years, were prospectively enrolled. A control group was made up of 30 age- and gender-matched healthy subjects. Carotid intima-media thickness (IMT), cross-sectional compliance (CSC), cross-sectional distensibility (CSD), diastolic wall stress (DWS), incremental elastic modulus (Einc), and FMD were determined in both groups.

RESULTS

There was no significant difference in FMD between the two groups (8.2 ± 5.0% in the SCD group vs. 9.3 ± 4.2% in the control group, P = 0.15). There was no significant correlation between FMD and age, hemoglobin, LDH level, or transcranial Doppler findings. CSD was significantly elevated in the SCD group (0.96 ± 0.44 vs. 0.59 ± 0.21, P = 0.0002), whereas DWS and Einc were significantly lower in the SCD group. CSC did not differ significantly between the two groups.

CONCLUSIONS

Children with SCD have no marked endothelial dysfunction or change in arterial stiffness. These manifestations may be related to disease severity and duration. Changes may become evident later in life as the disease progresses.

Subclinical left ventricular systolic impairment in steady state young adult patients with sickle-cell anemia

Chronic volume overload in sickle-cell anemia (SCA) is associated with left ventricular (LV) enlargement and hypertrophy. The effect of the disease on LV systolic function remains debated. The aim of our study was to investigate LV systolic function in SCA patients using 2D speckle-tracking imaging. We compared 30 steady state asymptomatic adult SCA patients (17 women, mean age 24.7 ± 5.1 years) with 30 age and sex-matched healthy subjects (17 women, mean age 25.0 ± 4.9 years). In addition to conventional echocardiographic parameters including LV ejection fraction (LVEF) and LV mass index (LVMi), global longitudinal strain (GLS) and strain rate (GLSR) were measured. GLS (-17.9 ± 2.0 vs. -19.7 ± 2.5 %, p = 0.004) and GLSR (-0.92 ± 0.09 vs. -1.07 ± 0.17 s(-1), p < 0.0001) values were lower in SCA patients while LVEF values (60.1 ± 3.8 vs. 61.7 ± 4.7 %, p = 0.30) were not different. LVMi was increased in SCA patients (100.7 ± 23.5 vs. 72.4 ± 15.2 g/m(2), p = 0.0001) and GLSR was significantly lower in the subgroup of patients with LV hypertrophy (-0.88 ± 0.09 vs. -0.96 ± 0.08 s(-1), p = 0.02). In SCA patients LVMi was correlated to GLS (r = 0.58, p = 0.001) and GLSR (r = 0.45, p = 0.015) pleading in favor of a pathological LV remodeling. Asymptomatic SCA patients exhibited a subclinical alteration of LV systolic function. Myocardial dysfunction appears to be linked to the degree of LV hypertrophy. 2D speckle-tracking imaging might be useful for long-term follow-up and to study the natural course of LV dysfunction in SCA patients.

The pathophysiological relationship and clinical significance of left atrial function and left ventricular diastolic dysfunction in β-thalassemia major

Iron deposition in combination with inflammatory and immunogenetic factors is involved in the pathophysiology of cardiac dysfunction in β-thalassemia major. We investigated the mechanical and endocrine function of the left atrium and ventricle to identify early signs of dysfunction. We studied 90 patients (mean age: 29 ± 11 years) with β-thalassemia and normal left ventricular function and 90 age and sex-matched healthy controls. Patients and controls underwent a thorough cardiac echocardiographic study and measurements of the b-type (NT-proBNP) and atrial natriuretic peptides (proANP). Patients underwent 24-hr Holter recordings for arrhythmia monitoring. In the patient group, atria were affected early during the course of the disease, prior to diastolic and systolic left ventricular dysfunction. The E/E'ratio (E Doppler mitral fast inflow to the corresponding tissue Doppler E) continually increased with age (P < 0.05) and reached levels indicating left ventricular diastolic dysfunction (E/E' > 15) in the third decade whereas indexes of active and passive atrial function decreased gradually throughout life. In controls, the E/E' ratio continually increased with age but with later (fifth decade) appearance of diastolic dysfunction and a compensatory increase in atrial active function. Both natriuretic peptides were significantly increased in patients compared to controls (558 ± 141 and 2,580 ± 1,830 fmol/mL for NT-proBNP and proANP versus 332 ± 106 and 1,331 ± 1,134 fmol/mL, respectively). Atrial fibrillation was found in a subgroup of 23 (26%) patients, older in age with mild diastolic function and enlarged, depressed atria. In conclusion, atrial mechanical depression seems to be a very early sign of cardiac damage. It may become echocardiographically evident even before diastolic and systolic dysfunction and is associated to supraventricular arrhythmias.

Two- and three-dimensional speckle tracking echocardiography: clinical applications and future directions

Two-dimensional speckle tracking echocardiography (2D STE) is a novel technique of cardiac imaging for quantifying complex cardiac motion based on frame-to-frame tracking of ultrasonic speckles in gray scale 2D images. Two-dimensional STE is a relatively angle independent technology that can measure global and regional strain, strain rate, displacement, and velocity in longitudinal, radial, and circumferential directions. It can also quantify rotational movements such as rotation, twist, and torsion of the myocardium. Two-dimensional STE has been validated against hemodynamics, tissue Doppler, tagged magnetic resonance imaging, and sonomicrometry studies. Two-dimensional STE has been found clinically useful in the assessment of cardiac systolic and diastolic function as well as providing new insights in deciphering cardiac physiology and mechanics in cardiomyopathies, and identifying early subclinical changes in various pathologies. A large number of studies have evaluated the role of 2D STE in predicting response to cardiac resynchronization therapy in patients with severe heart failure. However, the clinical utility of 2D STE in the above mentioned conditions remains controversial because of conflicting reports from different studies. Emerging areas of application include prediction of rejection in heart transplant patients, early detection of cardiotoxicity in patients receiving chemotherapy for cancer, and effect of intracoronary injection of bone marrow stem cells on left ventricular function in patients with acute myocardial infarction. The emerging technique of three-dimensional STE may further extend its clinical usefulness.

Left ventricular dyssynchrony is an early manifestation of heart involvement in sickle cell anemia

BACKGROUND

Sickle cell anemia (SCA) is the most common inherited anemia. Although heart involvement in SCA is well-established, there is no data about changes of contraction synchrony in SCA. Therefore, we aimed to study the left ventricular contraction synchrony in SCA patients with narrow QRS and normal ejection fraction (EF).

METHODS

Thirty-six patients with SCA and 37 age- and gender-matched control subjects were included in the study. Left ventricular dyssynchrony was investigated by color-coded tissue Doppler imaging.

RESULTS

The SCA patients had lower hemoglobin (Hb) and higher ferritin, left ventricular end-diastolic diameter, left ventricular end-systolic diameter, left ventricular mass index (LVMI), and pulmonary artery pressure. Peak A velocity, Dt, and E/E' values were higher in the SCA group however, E/A ratio and average Em were higher in the control group. LV systolic dyssynchrony parameters including Ts-SD-12, Ts-12, Ts-SD-6, and Ts-6 were found to be higher in SCA group when compared with controls. In addition to that, the patients with ventricular dyssynchrony (a Ts-SD-12 > 34.4 msec) were higher in the SCA group than the control group (55.6% vs. 8.1%, P < 0.001). In the correlation analysis, systolic dyssynchrony parameters were found to be correlated with Hb, ferritin, LVMI, E/A, Dt, Em.

CONCLUSION

Our results revealed that in SCA patients with normal EF and narrow QRS, left ventricular systolic dyssynchrony was an early manifestation of heart involvement and might be coexisted with or preceding diastolic dysfunction.

Three-dimensional speckle-tracking echocardiography – a further step in the non-invasive three-dimensional cardiac imaging

Three-dimensional speckle-tracking echocardiography is a new cardiac imaging methodology, which allows three-dimensional non-invasive evaluation of the myocardial mechanics. The aim of this review is to present this new tool emphasizing its diagnostic potentials and demonstrating its limitations, as well. Orv. Hetil., 2012, 153, 1570–1577.