Myocardial performance after coronary re-implantation in pediatric patients assessed with conventional echocardiographic and 2D-speckle tracking analysis: a case-control study

Introduction

reduced exercise capacity, coronary artery abnormalities and reversible myocardial ischemia have been demonstrated after arterial switch operation (ASO) and coronary reimplantation. Despite this, indices of systolic function, assessed by standard and Doppler echocardiography, are within the normal range. The aim of this study was to highlight the long-term changes in myocardial function following coronary reimplantation using Doppler and speckle-tracking imaging (STI) echocardiography.

Methods

this observational case control study included 36 patients and 20 gender and age-matched healthy controls. A group study was performed using patients who were followed for at least 6 months after the operation and who visited the pediatric cardiology outpatient between October 2015 and May 2016. Systolic and diastolic parameters, left ventricle (LV) and right ventricle (RV) myocardial performance were assessed in each group.

Results

the LV global peak strain parameters revealed a significant decrease in the longitudinal and circumferential strain components. The LV global longitudinal strain (GLS) values were lower in both groups of operated patients than controls (-19.9 ± 2.2% (group 1) versus -20.9 ± 1.6% (group 2) versus -22.9 ± 2.3% (group 3), p<0.001). The patients with coronary reimplantation had the lowest values. The LV global circumferential strain was also decreased in the group 1 patients as compared with the 2 other groups (-16.6 ± 4.1% (group 1) versus -19.4 ± 3.9% (group 2) versus -19.8 ± 4.0% (group 3), p<0.001).

Conclusion

although global LV function, assessed with conventional echocardiographic parameters, was normal, the 2D-STI analysis showed slight but significant decrease in the global and segmental longitudinal and circumferential LV strain during the long-term follow-up after coronary arteries reimplantation.

Left and Right Ventricular Impairment Shortly After Correction of Tetralogy of Fallot

Surgical repair of Tetralogy of Fallot (ToF) is usually performed in the first months of life with low early postoperative mortality. During long-term follow-up, however, both right (RV) and left ventricular (LV) performances may deteriorate. Tissue Doppler imaging (TDI) and speckle tracking echocardiography (ST) can unmask a diminished RV and LV performance. The objective of the current study was to assess the cardiac performance before and shortly after corrective surgery in ToF patients using conventional, TDI and ST echocardiographic techniques. Thirty-six ToF patients after surgery were included. Transthoracic echocardiography including TDI and ST techniques was performed preoperatively and at hospital discharge after surgery (10 days to 4 weeks after surgery). Median age at surgery was 7.5 months [5.5-10.9]. Regarding the LV systolic function there was a significant decrease in interventricular septum (IVS) S' at discharge as compared to preoperatively (pre IVS S' = 5.4 ± 1.4; post IVS S' = 3.9 ± 1.2; p < 0.001) and in global longitudinal peak strain (GLS) (pre = - 18.3 ± 3.4; post = - 14.2 ± 4.1; p = 0.003); but not in the fractional shortening (FS). Both conventional and TDI parameters showed a decrease in diastolic function at discharge. Tricuspid Annular Plane Systolic Excursion and RV S' were significantly lower before discharge. When assessing the RV diastolic performance, only the TDI demonstrated a RV impairment. There was a negative correlation between age at surgery and postoperative LV GLS (R = - 0.41, p = 0.031). There seems to be an impairment in left and right ventricle performance at discharge after ToF corrective surgery compared to preoperatively. This is better determined with TDI and ST strain imaging than with conventional echocardiography.

Assessment of Function of the Left Heart Myocardium by Tissue Doppler Imaging and Speckle Tracking Echocardiography in Patients with Chronic Heart Failure with Preserved Left Ventricular Ejection Fraction

AIM

to study myocardial function in patients with chronic heart failure (CHF) with preserved left ventricular ejection fraction (PEF) by speckle tracking echocardiography and tissue doppler imaging.

MATERIALS AND METHODS

We examined 80 patients aged 50-70 years with verified NYHA class I-IIa CHF and PEF due to arterial hypertension and ischemic heart disease, and 35 healthy persons. Examination included echocardiography, and speckle-tracking echocardiography.

RESULTS

According to 6-min walk test 26.9 % of patients had functional class (FC) I CHF, 48.3 % - FC II CHF, and 24.8 - FC III CHF. The mean left ventricular ejection fraction (Simpson's method) was 62.3±5.35 %, mean end systolic left atrial volume index - 45±8.1 ml / m2. All patients had left ventricular diastolic dysfunction: 60 patients - abnormal relaxation pattern, 20 patients - pseudonormal pattern. Other findings were reduced global longitudinal strain (GLS, -16.56±2.61 %) and GLS rate (GLSR, -0.75±0.11 s-1) of the left ventricle and reduced segmental strain and strain rate in basal anteroseptal (-13.62±3.44 % and -0.77±0.04 s-1, respectively) and basal anterolateral (-14.17±3.31 % and -0.81±0.11 s-1, respectively) segments. Lowering of global circular left ventricular strain and strain rate (-15.63±4.8% and -1.4±0.23 s-1, respectively) was found to be smaller than that of GLS (p&lt;0.05). There was positive correlation between left ventricular systolic GLS and left atrial volume (r=0.601, р&lt;0.01).

CONCLUSIONS

In patients with CHF and PEF we revealed alterations of diastolic function (abnormal relaxation and pseudonormal patterns), reductions of global and segmental strain and strain rate of the left ventricle. More pronounced lowering of segmental strain and strain rate was registered in left ventricular basal anteroseptal and basal anterolateral segments. Circular strain was found to be slightly reduced, while radial strain was unchanged.

Speckle tracking stress echocardiography in children: interobserver and intraobserver reproducibility and the impact of echocardiographic image quality

Speckle tracking echocardiography (STE) is increasingly used during functional assessments. However, reproducibility and dependence on echocardiographic image quality for speckle tracking stress echocardiography in pediatric patients have not been studied to date. 127 consecutive normotensive children without structural heart disease (mean age 13.4 ± 3.0 years, 50.4% female) underwent a stepwise semisupine cycle ergometric protocol. Left ventricular (LV) myocardial peak strain and strain rate were assessed at rest and during exercise. Interobserver and intraobserver assessments were performed and analyzed regarding echocardiographic image quality. LV peak global strain and strain rate were well reproducible with narrow limits of agreement without any significant bias both at rest and during all stages of exercise testing. Moreover, strain rate reproducibility slightly deteriorated in values between -1.5 and -3 s^-1. Surprisingly, there was no significant difference in reproducibility between optimal, intermediate and poor quality of echocardiographic images. STE derived strain and strain rate measurements in children are feasible and highly reproducible during semisupine cycle ergometric stress echocardiography. Echocardiographic image quality does not seem to influence strain (rate) reproducibility. Myocardial deformation measurements in images with suboptimal visualization quality must be interpreted with caution.

Novel functional advanced echocardiography for the assessment of myocardial mechanics in children with neurocardiogenic syncope - a blinded prospective speckle tracking head-up tilt-table challenge study

Background

Data on left ventricular (LV) function in patients with neurocardiogenic syncope (NS) is conflicting in adults and lacking in children. The aim of this study was to analyze LV myocardial performance in children with NS at rest and during head-up tilt-table (HUTT) testing.

Methods

This is the first study to combine HUTT and speckle-tracking echocardiography (STE) in children with NS. 43 consecutive normotensive pediatric patients with NS (mean age 13.9 ± 2.6 years, 51% female) and 41 sex- and age-matched healthy controls were included in the study. The study groups consisted of 21 patients with a positive HUTT reaction (HUTT+) and 22 with a negative HUTT reaction (HUTT-). STE was used to analyze peak systolic LV myocardial strain and strain rate.

Results

Conventional echocardiographic parameters were similar in all analyzed groups. When compared to healthy controls, children with NS had depressed levels of circumferential strain rate (p = 0.032) and significantly depressed longitudinal strain rate (p <  0.001) at rest. Interestingly, during HUTT testing LV global strain and strain rate were similar in both groups. LV strain rate was lowest in HUTT+ followed by HUTT- and control subjects both at rest and during HUTT.

Conclusions

Resting LV longitudinal strain rate is attenuated in children with NS, especially in those with a positive HUTT response. This is further evidence that NS patients feature altered cardiac mechanics rendering them prone to vasovagal perturbations that can ultimately result in collapse.

Trial registration

Witten/Herdecke University ethics committee clinical study number: UWH-73-2014.

Speckle Tracking Stress Echocardiography Uncovers Early Subclinical Cardiac Involvement in Pediatric Patients with Inflammatory Bowel Diseases

Inflammatory bowel disease (IBD) is an established risk factor for cardiovascular disease (CVD). However, whether cardiac consequences present early in IBD is unknown. This is the first study in children aiming to unmask altered myocardial mechanics in IBD. We enrolled 50 consecutive normotensive children with Crohn’s disease (CD) (n = 28) or ulcerative colitis (UC) (n = 22). The study groups consisted of 18 patients with active inflammatory disease (mean age 14.6 ± 2.5 years) and 32 children with IBD in remission (14.3 ± 2.3 years). 60 age- and gender-matched children served as healthy controls. Speckle tracking stress echocardiography (STE) was used to assess left ventricular (LV) myocardial strain and strain rate. Circumferential strain rate was significantly decreased in children with active IBD (−1.55 ± 0.26 s⁻¹) and IBD in remission (−1.49 ± 0.26 s⁻¹) versus healthy controls (1.8 ± 0.4 s⁻¹) both at rest (p < 0.001) and during exercise (p = 0.021). Moreover, longitudinal strain rate, circumferential strain and E/E′ ratio were significantly impaired in IBD. Pediatric patients with IBD feature subclinical signs of LV systolic and diastolic myocardial impairment early in the course of CD and UC. This may not be reversible even when IBD is clinically controlled. Patients with IBD should be regularly screened for signs of CVD.

Biomechanics of Cardiac Function

The heart pumps blood to maintain circulation and ensure the delivery of oxygenated blood to all the organs of the body. Mechanics play a critical role in governing and regulating heart function under both normal and pathological conditions. Biological processes and mechanical stress are coupled together in regulating myocyte function and extracellular matrix structure thus controlling heart function. Here, we offer a brief introduction to the biomechanics of left ventricular function and then summarize recent progress in the study of the effects of mechanical stress on ventricular wall remodeling and cardiac function as well as the effects of wall mechanical properties on cardiac function in normal and dysfunctional hearts. Various mechanical models to determine wall stress and cardiac function in normal and diseased hearts with both systolic and diastolic dysfunction are discussed. The results of these studies have enhanced our understanding of the biomechanical mechanism in the development and remodeling of normal and dysfunctional hearts. Biomechanics provide a tool to understand the mechanism of left ventricular remodeling in diastolic and systolic dysfunction and guidance in designing and developing new treatments.

Perioperative assessment of myocardial deformation

Evaluation of left ventricular performance improves risk assessment and guides anesthetic decisions. However, the most common echocardiographic measure of myocardial function, the left ventricular ejection fraction (LVEF), has important limitations. LVEF is limited by subjective interpretation that reduces accuracy and reproducibility, and LVEF assesses global function without characterizing regional myocardial abnormalities. An alternative objective echocardiographic measure of myocardial function is thus needed. Myocardial deformation analysis, which performs quantitative assessment of global and regional myocardial function, may be useful for perioperative care of surgical patients. Myocardial deformation analysis evaluates left ventricular mechanics by quantifying strain and strain rate. Strain describes percent change in myocardial length in the longitudinal (from base to apex) and circumferential (encircling the short-axis of the ventricle) direction and change in thickness in the radial direction. Segmental strain describes regional myocardial function. Strain is a negative number when the ventricle shortens longitudinally or circumferentially and is positive with radial thickening. Reference values for normal longitudinal strain from a recent meta-analysis by using transthoracic echocardiography are (mean ± SD) -19.7% ± 0.4%, while radial and circumferential strain are 47.3% ± 1.9% and -23.3% ± 0.7%, respectively. The speed of myocardial deformation is also important and is characterized by strain rate. Longitudinal systolic strain rate in healthy subjects averages -1.10 ± 0.16 s. Assessment of myocardial deformation requires consideration of both strain (change in deformation), which correlates with LVEF, and strain rate (speed of deformation), which correlates with rate of rise of left ventricular pressure (dP/dt). Myocardial deformation analysis also evaluates ventricular relaxation, twist, and untwist, providing new and noninvasive methods to assess components of myocardial systolic and diastolic function. Myocardial deformation analysis is based on either Doppler or a non-Doppler technique, called speckle-tracking echocardiography. Myocardial deformation analysis provides quantitative measures of global and regional myocardial function for use in the perioperative care of the surgical patient. For example, coronary graft occlusion after coronary artery bypass grafting is detected by an acute reduction in strain in the affected coronary artery territory. In addition, assessment of left ventricular mechanics detects underlying myocardial pathology before abnormalities become apparent on conventional echocardiography. Certainly, patients with aortic regurgitation demonstrate reduced longitudinal strain before reduction in LVEF occurs, which allows detection of subclinical left ventricular dysfunction and predicts increased risk for heart failure and impaired myocardial function after surgical repair. In this review, we describe the principles, techniques, and clinical application of myocardial deformation analysis.

Perioperative Diastolic Dysfunction

Left ventricular diastolic dysfunction (LVDD) has only recently been recognized as an important determinant of perioperative morbidity. Intraoperative echocardiographers have been slow to adopt assessment of LVDD into clinical practice. This has been partly attributable to the complex measurements required to characterize LVDD, which are in turn related to how our understanding of diastole has evolved. Additionally, the lack of effective therapeutic options has left many wondering whether it is worthwhile to characterize this pathology in the first place. However, therapies are developed more rapidly once a problem can be identified reliably. The assessment of LVDD is centered on how effectively the left ventricle can fill. Diastolic dysfunction affects intraventricular pressures and stiffness, which in turn affect the pressure relationship between the left atrium and the left ventricle thereby affecting transmitral flow. Since echocardiography can enable the measurement of flow velocities, transmitral diastolic filling flow patterns provide robust information on diastolic function. The impact of abnormal diastolic function on left atrial pressure has consequences for pulmonary venous flow, which can also be measured with echocardiography. However, given the limitations of flow velocity, direct measurement of tissue velocity can significantly improve the characterization of diastolic dysfunction. The evolution of Doppler and speckle-based methods of assessing tissue motion have vastly improved our understanding of diastolic function. With the development of simpler algorithms for categorization, and their gradual adoption by perioperative echocardiographers, LVDD should be better diagnosed and treated to improve postoperative outcomes.

Tissue Doppler imaging detects impaired biventricular performance shortly after congenital heart defect surgery

Cardiac surgery with cardiopulmonary bypass is associated with the development of a systemic inflammatory response, which can lead to myocardial damage. However, knowledge concerning the time course of ventricular performance deterioration and restoration after correction of a congenital heart defect (CHD) in pediatric patients is sparse. Therefore, the authors perioperatively quantified left ventricular (LV) and right ventricular (RV) performance using echocardiography. Their study included 141 patients (ages 0-18 years) undergoing CHD correction and 40 control subjects. The study assessed LV systolic performance (fractional shortening) and diastolic performance (mitral Doppler flow) in combination with RV systolic performance [tricuspid annular plane systolic excursion (TAPSE)] and diastolic performance (tricuspid Doppler flow). Additionally, systolic (S') and diastolic (E', A', E/E') tissue Doppler imaging (TDI) measurements were obtained at the LV lateral wall, the interventricular septum, and the RV free wall. Echocardiographic studies were performed preoperatively, 1 day postoperatively, and at hospital discharge after 9 ± 5 days. Although all LV echocardiographic measurements showed a deterioration 1 day after surgery, only LV TDI measurements were impaired in patients at discharge versus control subjects (S': 5.7 ± 2.0 vs 7.1 ± 2.7 cm/s; E': 9.8 ± 3.9 vs 13.7 ± 5.1 cm/s; E/E': 12.2 ± 6.4 vs 8.8 ± 4.3; p < 0.05). In the RV, TAPSE and RV TDI velocities also were impaired in patients at discharge versus control subjects (TAPSE: 9 ± 3 vs 17 ± 5 mm; S': 5.2 ± 1.7 vs 11.4 ± 3.4 cm/s; E': 7.3 ± 2.5 vs 16.3 ± 5.2 cm/s; E/E': 12.5 ± 6.8 vs 4.8 ± 1.9; p < 0.05). Furthermore, longer aortic cross-clamp times were associated with more impaired postoperative LV and RV performance (p < 0.05). In conclusion, both systolic and diastolic biventricular performances were impaired shortly after CHD correction. This impairment was detected only by TDI parameters and TAPSE. Furthermore, a longer-lasting negative influence of cardiopulmonary bypass on myocardial performance was suggested.

Assessment of early diastolic strain-velocity temporal relationships using spatial modulation of magnetization with polarity alternating velocity encoding (SPAMM-PAV)

A novel MR imaging technique, spatial modulation of magnetization with polarity alternating velocity encoding (SPAMM-PAV), is presented to simultaneously examine the left ventricular early diastolic temporal relationships between myocardial deformation and intra-cavity hemodynamics with a high temporal resolution of 14 ms. This approach is initially evaluated in a dynamic flow and tissue mimicking phantom. A comparison of regional longitudinal strains and intra-cavity pressure differences (integration of computed in-plane pressure gradients within a selected region) in relation to mitral valve inflow velocities is performed in eight normal volunteers. Our results demonstrate that apical regions have higher strain rates (0.145 ± 0.005 %/ms) during the acceleration period of rapid filling compared to mid-ventricular (0.114 ± 0.007 %/ms) and basal regions (0.088 ± 0.009 %/ms), and apical strain curves plateau at peak mitral inflow velocity. This pattern is reversed during the deceleration period, when the strain-rates in the basal regions are the highest (0.027 ± 0.003 %/ms) due to ongoing basal stretching. A positive base-to-apex gradient in peak pressure difference is observed during acceleration, followed by a negative base-to-apex gradient during deceleration. These studies shed insight into the regional volumetric and pressure difference changes in the left ventricle during early diastolic filling.

Physiological homology between Drosophila melanogaster and vertebrate cardiovascular systems

The physiology of the Drosophila melanogaster cardiovascular system remains poorly characterized compared with its vertebrate counterparts. Basic measures of physiological performance remain unknown. It also is unclear whether subtle physiological defects observed in the human cardiovascular system can be reproduced in D. melanogaster. Here we characterize the cardiovascular physiology of D. melanogaster in its pre-pupal stage by using high-speed dye angiography and optical coherence tomography. The heart has vigorous pulsatile contractions that drive intracardiac, aortic and extracellular-extravascular hemolymph flow. Several physiological measures, including weight-adjusted cardiac output, body-length-adjusted aortic velocities and intracardiac shear forces, are similar to those in the closed vertebrate cardiovascular systems, including that of humans. Extracellular-extravascular flow in the pre-pupal D. melanogaster circulation drives convection-limited fluid transport. To demonstrate homology in heart dysfunction, we showed that, at the pre-pupal stage, a troponin I mutant, held-up2 (hdp2), has impaired systolic and diastolic heart wall velocities. Impaired heart wall velocities occur in the context of a non-dilated phenotype with a mildly depressed fractional shortening. We additionally derive receiver operating characteristic curves showing that heart wall velocity is a potentially powerful discriminator of systolic heart dysfunction. Our results demonstrate physiological homology and support the use of D. melanogaster as an animal model of complex cardiovascular disease.

Statin therapy decreases myocardial function as evaluated via strain imaging

OBJECTIVES

The purpose of this study was to evaluate the effects of statin therapy on myocardial function as measured with echocardiography with tissue Doppler imaging (TDI) and strain imaging (SI) independent of its lipid-lowering effect.

BACKGROUND

Statin use is known to improve outcomes in the primary and secondary prevention of ischemic heart disease, but their use is also associated with myopathy, muscle weakness and in rare cases, rhabdomyolysis. We sought to evaluate whether TDI and SI is able to identify changes in myocardial function associated with statin use.

METHODS

Myocardial function was evaluated in 28 patients via echocardiography with TDI and SI. We identified 12 patients (5 females) without overt cardiovascular disease (including hypertension, smoking, and diabetes) that were on statin therapy and compared their echocardiographic findings with 16 (12 females) age, sex, and cholesterol-profile-matched controls. Tissue Doppler imaging parameters of diastolic (E(')/A(') and E/E(')) and systolic (S') function were measured. Regional systolic function was obtained by SI in 4-chamber, 2-chamber, long axis, and average global views.

RESULTS

There was no significant difference in myocardial function as measured by Doppler and minor differences as measured via TDI among the 2 groups. There was significantly better function noted with SI in the control group vs the statin group in the 4-chamber (-19.05% +/- 2.45% vs -16.47% +/- 2.37% P = 0.009), 2-chamber (-20.30% +/- 2.66% vs -17.45% +/- 4.29% P = 0.03), long axis (-17.63% +/- 3.79% vs -13.83% +/- 3.74% P = 0.01), and average global (-19.0% +/- 2.07% vs -15.91% +/- 2.81% P = 0.004) views.

CONCLUSION

Statin therapy is associated with decreased myocardial function as evaluated with SI.