Strain and strain rate imaging: a new clinical approach to quantifying regional myocardial function

Hypertension in aortic coarctation

Aortic coarctation (AoC) is a common congenital heart defect, affecting 5%-8% of patients with structural congenital anomalies. Despite advances in surgical and percutaneous interventions, hypertension remains a significant complication in AoC patients, even after successful repair. Chronic hypertension develops in 20%-70% of patients and is a leading cause of long-term cardiovascular morbidity. In these patients, hypertension is associated to renin-angiotensin system activation, residual aortic arch abnormalities, and impaired aortic elasticity. Additionally, exercise-induced hypertension and masked hypertension contribute to adverse outcomes. Management of hypertension in AoC patients requires both perioperative and long-term care. Early after correction, intravenous antihypertensive agents, such as sodium nitroprusside, esmolol, and labetalol, are commonly used to stabilize blood pressure and reduce the risk of complications like cerebral hemorrhage. Oral beta-blockers, ACE inhibitors (ACE-Is), angiotensin receptor blockers (ARBs) and calcium channel blockers (CCBs) are most commonly used for chronic hypertension. In this review, we discussed about diagnostic workup and therapeutical strategies for hypertension in AoC patients.

Non-invasive estimation of left ventricular chamber stiffness using cardiovascular magnetic resonance and echocardiography

BACKGROUND

Preclinical studies exploring the underlying mechanisms of elevated left ventricular (LV) chamber stiffness play a crucial role in developing new therapeutic strategies. However, there is a lack of systematic evaluation of imaging biomarkers of diastolic function against gold standard assessment of LV chamber stiffness in rodents. Therefore, we aimed to evaluate imaging biomarkers of diastolic function from cardiovascular magnetic resonance (CMR) and echocardiography in predicting the slope of the end-diastolic pressure-volume relationship (EDPVR) in rats.

METHODS

Sprague Dawley rats with varying degrees of myocardial stiffness induced by aortic constriction (n=38) and healthy controls (n=9) underwent echocardiography and CMR at approximately 13 weeks post-operation. Imaging biomarkers of diastolic function were evaluated for their ability to predict the EDPVR slope from pressure-volume recordings using regression analysis and receiver operating characteristics analysis.

RESULTS

Both CMR and echocardiographic imaging biomarkers, in particular those related to the left atrium and mitral flow, were able to predict the EDPVR slope in a rat model with varying stiffness. From CMR, native T1 values, peak early diastolic longitudinal strain rate (SRe(long)) and E/SRe(long), left atrial (LA) ejection fraction, isovolumetric relaxation time (IVRT), E/A and peak LA strain, correlated best with the EDPVR slope (|r|=0.54-0.72). From echocardiography, E/A, E, LA diameter, e'/a', E/SRe(long) and IVRT correlated with the EDPVR slope (|r|=0.49-0.67), while E/e', e' and E-wave deceleration time demonstrated poor correlation (|r|=0.17-0.27). Receiver operating characteristics analysis indicated better performance of CMR imaging biomarkers than echocardiography in predicting increased EDPVR slope.

CONCLUSIONS

Several diastolic imaging biomarkers commonly employed in preclinical studies have poor ability to predict cardiac chamber stiffness. Our study identifies several imaging biomarkers obtained from both echocardiography and CMR that are able to estimate LV chamber stiffness non-invasively, providing an important tool for future mechanistic research on myocardial stiffness.

Mechanical memory based biofabrication of hierarchical elastic cardiac tissue

Mimicking the multilayered, anisotropic, elastic structure of cardiac tissues for controlled guidiance of 3D cellular orientation is essential in designing bionic scaffolds for cardiac tissue biofabrication. Here, a hierarchically organized, anisotropic, wavy and conductive polycaprolactone/Au scaffold was created in a facile fashion based on mechanical memory during fabrication. The bionic 3D scaffold shows good biocompatibility, excellent biomimetic mechanical properties that guide myoblast alignment, support the hyperelastic behavior observed in native cardiac muscle tissue, and promote myotube maturation, which holds potential for cardiac muscle engineering and the establishment of anin vitroculture platform for drug screening.

The Sub-Pulmonary Left Ventricle in Patients with Systemic Right Ventricle, the Paradoxical Neglected Chamber: A Cardiac Magnetic Resonance Feature Tracking Study

Background/Objective: The impact of subpulmonary left ventricle (LV) dysfunction in patients with a systemic right ventricle (SRV) is insufficiently characterized, with only a few studies suggesting its prognostic significance. Additionally, its evaluation through imaging techniques is a challenge. To assess the correlation between quantitative cardiac magnetic resonance-feature tracking (CMR-FT) data and the risk of clinical events related to the natural history of SRV failure. Methods: In this cross-sectional study, 21 patients with a diagnosis of transposition of the great arteries (TGA) and atrial switch operation (AtSO) or congenitally corrected transposition (ccTGA) were recruited. All participants underwent CMR-FT analysis. Considered clinical events included NYHA class deterioration (from I-II to III-IV), increased diuretic therapy, arrhythmias, sudden cardiac death, and hospitalizations. Results: The cohort consisted of 52.4% males (mean age: 25.4 ± 11.9 years). Eleven patients were diagnosed with ccTGA. Of the 10 patients with TGA post-AtSO, 50% had undergone Mustard repair. Clinical events occurred in 11 patients, with 47.6% experiencing hospitalizations and 28.6% developing arrhythmias. Left ventricular global longitudinal strain (LV GLS) was significantly associated with event-risk in both univariate and multivariate analyses (p = 0.011; p = 0.025). A cut-off value of LV GLS > -19.24 was proposed to stratify high-risk patients (p = 0.001). Conclusions: Our study confirms the role of subpulmonary LV function in determining outcomes of SRV patients. The assessment of LV GLS by using CMR-FT could significantly enhance clinical management during follow-up.

Influence of Power-Weighted Center of Echo Signal Within Window Function on Local Strain Rate Distribution in Left Ventricular Wall

OBJECTIVE

The deviation of the power-weighted center of the echo signal from the geometric center within the velocity estimation window for calculating strain rate (SR) causes an estimation error. This study aimed to confirm whether an erroneous multilayer pattern in the SR distribution of the left ventricular wall could be corrected by considering the power-weighted center of the echo signal.

METHODS

The SR distributions were measured locally in the transmural direction around the pre-ejection and early diastolic phases in healthy volunteers. The estimation error related to the power-weighted center of the echo signal was corrected using a previously proposed method, and the effectiveness of the correction was confirmed based on the accuracy of the estimated myocardial displacement.

RESULTS

The SR distribution in early diastole was observed as multilayers of low- and high-amplitude negative SRs. However, this multilayer pattern disappeared after correction. In the pre-ejection phase, multilayers of positive and negative SRs were observed in the SR distributions with and without correction. This correction was sufficiently effective in accurately tracking the local peak of the echo signal.

CONCLUSION

The multilayer pattern of low- and high-amplitude positive or negative SRs is caused by estimation errors related to the power-weighted center of the echo signal. The multilayer pattern of positive and negative SRs might not be caused by these errors and might relate to the actual change in myocardial thickness because the estimation errors do not convert the negative (positive) SR to positive (negative) in a homogeneous negative (positive) SR distribution.

The Role of Multimodality Imaging in the Evaluation of Heart Failure and Surgical Transplant Planning of Patients with Adult Congenital Heart Disease

Cardiac imaging is pivotal in evaluating ventricular function, residual lesions, and long-term complications in patients with adult congenital heart disease (ACHD). Longitudinal imaging in ACHD is key for the timely identification of patients requiring evaluation for advanced therapies. The guidelines recommend routine imaging surveillance. In all patients undergoing evaluation with cardiac imaging, it is critical that studies are performed at centers with expertise and that the imaging protocols are tailored to the specific condition. The authors briefly highlight the utility and diagnostic yield of different modalities, review pertinent considerations for special populations, and focus on imaging for transplant planning.

Left ventricular and atrial myocardial strain in heart failure with preserved ejection fraction: the evidence so far and prospects for phenotyping strategy

BACKGROUND

Heart failure with preserved ejection fraction (HFpEF) represents a significant proportion of heart failure cases. Accurate diagnosis is challenging due to the heterogeneous nature of the disease and limitations in traditional echocardiographic parameters.

MAIN BODY

This review appraises the application of Global Longitudinal Strain (GLS) and Left Atrial Strain (LAS) as echocardiographic biomarkers in the diagnosis and phenotyping of HFpEF. Strain imaging, particularly Speckle Tracking Echocardiography, offers a superior assessment of myocardial deformation, providing a more detailed insight into left heart function than traditional metrics. Normal ranges for GLS and LAS are considered, acknowledging the impact of demographic and technical factors on these values. Clinical studies have demonstrated the prognostic value of GLS and LAS in HFpEF, especially in predicting cardiovascular outcomes and distinguishing HFpEF from other causes of dyspnea. Nevertheless, the variability of strain measurements and the potential for false-negative results underline the need for careful clinical interpretation. The HFA-PEFF scoring system's integration of these biomarkers, although systematic, reveals gaps in addressing the full spectrum of HFpEF pathology. The combined use of GLS and LAS has been suggested to define HFpEF phenogroups, which could lead to more personalized treatment plans.

CONCLUSION

GLS and LAS have emerged as pivotal tools in the non-invasive diagnosis and stratification of HFpEF, offering a promise for tailored therapeutic strategies. Despite their potential, a structured approach to incorporating these biomarkers into standard diagnostic workflows is essential. Future clinical guidelines should include clear directives for the combined utilization of GLS and LAS, accentuating their role in the multidimensional assessment of HFpEF.

Evaluation of Intraoperative Left-Ventricular Diastolic Function by Myocardial Strain in On-Pump Coronary Artery Bypass Surgery

OBJECTIVES

Left ventricular (LV) diastolic function strongly predicts outcomes after cardiac surgery, but there is no consensus about appropriate intraoperative assessment. Recently, intraoperative diastolic strain-based measurements assessed by transesophageal echocardiography (TEE) have shown a strong correlation with LV relaxation, compliance, and filling, but there are no reports about evaluation through the entire perioperative period. Therefore, the authors describe the intraoperative course of this novel assessment technique in patients who underwent coronary artery bypass grafting, and compare it with conventional echocardiographic measures and common grading algorithms of LV diastolic dysfunction (LVDD).

DESIGN

Prospectively obtained data.

SETTING

A single university hospital.

PARTICIPANTS

Thirty adult patients scheduled for isolated on-pump coronary artery bypass grafting surgery with preoperative preserved left and right ventricular systolic function, without significant heart valve disease and pulmonary hypertension, and an uneventful intraoperative course were included.

INTERVENTIONS

Transesophageal echocardiography was performed after induction of anesthesia (T1), after termination of cardiopulmonary bypass (T2), and after sternal closure (T3). Echocardiographic evaluation was performed in stable hemodynamic conditions, in sinus rhythm or atrial pacing, and vasopressor support with norepinephrine ≤0.1 µg/kg/min.

MEASUREMENTS AND MAIN RESULTS

Strain-based measurements of peak longitudinal strain rate during isovolumetric relaxation (SR-IVR) and during early (SR-E) and late (SR-A) LV filling were assessed using EchoPAC v204 software (GE Vingmed Ultrasound AS, Norway). Evaluation of conventional echocardiographic parameters included transmitral Doppler measures of early (E) and late (A) LV filling, as well as lateral-tissue Doppler velocity assessed during early (e´) and late (a´) LV filling, tricuspid regurgitation, and left atrial dilatation. Evaluation and grading of LV diastolic function by myocardial strain was feasible in all included patients at all time points of assessment. Using conventional grading algorithms, however, a substantial number of patients could not be sufficiently graded, falling into an indeterminate zone and not reliably estimating LVDD (T1, 40%; T2, 33%; T3, 36%). There was significant impairment of LV diastolic function after bypass, as measured by SR-IVR (T1 v T2, 0.28 s-1 [IQR 0.23; 0.31) v 0.18 s-1 [IQR 0.14; 0.22]; p < 0.001), SR-E (T1 v T2, 0.95 ± 0.34 s-1v 1.28 ± 0.36 s-1; p < 0.001), and E/SR-IVR (T1 v T2, 2.3 ± 1.0 m v 4.5 ± 2.1 m; p < 0.001]. Conventional echocardiographic measures remained unchanged during the same period (E/A T1 v T2, 1.27 [IQR 0.94; 1.59] v 1.21 [IQR 1.03; 1.47] [p = 1] and E/e´ T1 v T2, 7.0 [IQR 5.3; 9.6] v 6.35 [IQR 5.7; 9.9] [p = 0.9]). There were no significant changes in the values of SR-IVR, SR-E, SR-A, E/SR-IVR, E/A, and E/e´ before and after sternal closure (T2 v T3).

CONCLUSION

Intraoperative assessment of strain-based measurements of LV diastolic function and strain-based LVDD grading was feasible in this group of selected patients, whereas conventional parameters failed to describe LVDD sufficiently in a substantial number of patients. Diastolic strain-based measurements showed impairment of LV relaxation and compliance after bypass, which was not detected by conventional echocardiographic parameters. Therefore, diastolic myocardial strain analysis might be more sensitive in detecting myocardial diastolic dysfunction by TEE in the perioperative setting, with its dynamic changes of loading conditions, and might provide valuable and additional information on the perioperative changes of LV diastolic function.

Position Statement on the Use of Myocardial Strain in Cardiology Routines by the Brazilian Society of Cardiology's Department Of Cardiovascular Imaging - 2023

Central Illustration : Position Statement on the Use of Myocardial Strain in Cardiology Routines by the Brazilian Society of Cardiology's Department Of Cardiovascular Imaging - 2023 Proposal for including strain in the integrated diastolic function assessment algorithm, adapted from Nagueh et al.67 Am: mitral A-wave duration; Ap: reverse pulmonary A-wave duration; DD: diastolic dysfunction; LA: left atrium; LASr: LA strain reserve; LVGLS: left ventricular global longitudinal strain; TI: tricuspid insufficiency. Confirm concentric remodeling with LVGLS. In LVEF, mitral E wave deceleration time < 160 ms and pulmonary S-wave < D-wave are also parameters of increased filling pressure. This algorithm does not apply to patients with atrial fibrillation (AF), mitral annulus calcification, > mild mitral valve disease, left bundle branch block, paced rhythm, prosthetic valves, or severe primary pulmonary hypertension.

Cardiopulmonary physiological effects of diuretic therapy in preterm infants with chronic pulmonary hypertension

OBJECTIVE

Using targeted neonatal echocardiography (TNE) to examine cardiopulmonary physiological impact of diuretics in preterm infants with chronic pulmonary hypertension (cPH).

STUDY DESIGN

Retrospective study comparing TNE indices pre- and ≤2 weeks (post) of initiating diuretic therapy in infants born <32 weeks gestational age with cPH.

RESULTS

Twenty-seven neonates with mean gestational age, birthweight and interval between pre-post diuretic TNE of 27.0 ± 2.8 weeks, 859 ± 294 grams, and 7.8 ± 3.0 days respectively were studied. Diuretics was associated with improvement in pulmonary vascular resistance [pulmonary artery acceleration time (PAAT); 34.27(9.76) vs. 40.24(11.10)ms, p = 0.01), right ventricular (RV) ejection time:PAAT ratio [5.92(1.66) vs. 4.83(1.14), p < 0.01)], RV fractional area change [41.6(9.8) vs. 46.4(6.5%), p = 0.03)] and left ventricular myocardial performance index [0.55(0.09) vs. 0.41(0.23), p < 0.01)]. Post-treatment, frequency of bidirectional/right-to-left inter-atrial shunts decreased significantly (24% vs. 4%, p = 0.05).

CONCLUSION

Primary diuretic treatment in neonates with cPH may result in improvement in PVR, RV and LV function and compliance.

Reduced Left Ventricular Twist Early after Acute ST-Segment Elevation Myocardial Infarction as a Predictor of Left Ventricular Adverse Remodelling

BACKGROUND

The left ventricular (LV) remodelling process represents the main cause of heart failure after a ST-segment elevation myocardial infarction (STEMI). Speckle-tracking echocardiography (STE) can detect early deformation impairment, while also predicting LV remodelling during follow-up. The aim of this study was to investigate the STE parameters in predicting cardiac remodelling following a percutaneous coronary intervention (PCI) in STEMI patients.

METHODS

The study population consisted of 60 patients with acute STEMI and no history of prior myocardial infarction treated with PCI. The patients were assessed both by conventional transthoracic and ST echocardiography in the first 12 h after admission and 6 months after the acute phase. Adverse remodelling was defined as an increase in LVEDV and/or LVESV by 15%.

RESULTS

Adverse remodelling occurred in 26 patients (43.33%). By multivariate regression equation, the risk of adverse remodelling increases with age (by 1.1-fold), triglyceride level (by 1.009-fold), and midmyocardial radial strain (mid-RS) (1.06-fold). Increased initial twist decreases the chances of adverse remodelling (0.847-fold). The LV twist presented the largest area under the receiver operating characteristic (ROC) curve to predict adverse remodelling (AUROC = 0.648; 95% CI [0.506;0.789], p = 0.04). A twist value higher than 11° has a 76.9% specificity and a 72.7% positive predictive value for reverse remodelling at 6 months.

Myocardial work in children with Wolff-Parkinson-White syndrome

Wolff-Parkinson-White Syndrome (WPW) has been associated with reduced local myocardial deformation, and when left ventricular dysfunction is present, catheter ablation of the accessory pathway may be required, even in asymptomatic patients. We aimed to evaluate the diagnostic value of non-invasive myocardial work in predicting subtle abnormalities in myocardial performance in children with WPW.Seventy-five paediatric patients (age 8.7 ± 3.5 years) were retrospectively recruited for the study: 25 cases with manifest WPW and 50 age- and sex- matched controls (CTR). Global myocardial work index (MWI) was measured as the area of the left ventricle (LV) pressure-strain loops. From MWI, global Myocardial Constructive Work (MCW), Wasted Work (MWW), and Work Efficiency (MWE) were estimated. In addition, standard echocardiographic parameters of LV function were evaluated. Despite normal LV ejection fraction (EF) and global longitudinal strain (GLS), children with WPW had worse MWI, MCW, MWW, and MWE. At multivariate analysis, MWI and MCW were associated with GLS and systolic blood pressure, and QRS was the best independent predictor of low MWE and MWW. In particular, a QRS > 110 ms showed good sensitivity and specificity for worse MWE and MWW values. In children with WPW, myocardial work indices were found significantly reduced, even in the presence of normal LV EF and GLS. This study supports the systematic use of myocardial work during the follow-up of paediatric patients with WPW. Myocardial work analysis may represent a sensitive measure of LV performance and aid in decision-making.

Systolic function in dogs with pulmonic stenosis of different severities and the effect of balloon valvuloplasty

INTRODUCTION/OBJECTIVES

Pulmonic stenosis (PS) is one of the most common congenital heart diseases in dogs leading to right ventricular (RV) pressure overload, myocardial remodeling, and potential RV dysfunction. Our objectives were to investigate the extent of RV systolic dysfunction in canine PS and to examine the immediate influence of balloon valvuloplasty (BV) on systolic function.

ANIMALS, MATERIALS AND METHODS

This prospective study evaluated 72 dogs with PS and 86 healthy dogs. Echocardiographic parameters of systolic function included normalized tricuspid annular plane systolic excursion (N-TAPSE), normalized systolic myocardial tissue Doppler velocity of the lateral tricuspid annulus (N-RVFW-S'), fractional area change, and speckle-tracking longitudinal endocardial RV strain. Forty-four dogs underwent BV and were re-examined after surgery.

RESULTS

Systolic function at the basal segment of the RV was significantly lower in the PS group when compared to healthy dogs (mean N-TAPSE 4.29 ± standard deviation 1.18 mm/kg^0.285 vs. 5.60 ± 1.29 mm/kg^0.285; median N-RVFW-S' 5.28 [lower-upper 25% quantile 4.35-6.43 cm/s/kg^0.186] vs. 7.82 [6.73-8.79 cm/s/kg^0.186]; all P<0.001). Global longitudinal RV endocardial strain showed no significant difference between the two groups (-28.50 ± 6.23% vs. 28.61 ± 4.64%; P=0.886), but segmental strain analyses revealed basal hypo- and potential compensatory hyperkinesis of the apical RVFW. Furthermore, BV affected most parameters of systolic function, but not the segmental strain values and N-TAPSE.

CONCLUSIONS

Right ventricular basal longitudinal systolic function is decreased in dogs with PS in comparison to a healthy cohort. Regional and global function does not necessarily coincide.

Left Atrial Velocity Vector Imaging Can Assess Early Diastolic Dysfunction in Left Ventricular Hypertrophy and Hypertrophic Cardiomyopathy

BACKGROUND

The function of left atrium (LA) is difficult to assess because of its ventricle-dependent, dynamic movement. The aim of this study was to assess LA function using velocity vector imaging (VVI) and compare LA function in patients with hypertrophic cardiomyopathy (HCMP) and left ventricular hypertrophy (LVH) with normal controls.

METHODS

Fourteen patients with HCMP (72% male, mean age of 52.6 ± 9.8), 15 hypertensive patients with LVH (88% male, mean age of 54.0 ± 15.3), and 10 age-matched controls (83% male, mean age of 50.0 ± 4.6) were prospectively studied. Echocardiographic images of the LA were analyzed with VVI, and strain rate (SR) was compared among the 3 groups.

RESULTS

The e' velocity (7.7 ± 1.1; 5.1 ± 0.8; 4.5 ± 1.3 cm/sec, p = 0.013), E/e' (6.8 ± 1.6; 12.4 ± 3.3; 14.7 ± 4.2, p = 0.035), and late diastolic SR at mid LA (-1.65 ± 0.51; -0.97 ± 0.55; -0.82 ± 0.32, p = 0.002) were significantly different among the groups (normal; LVH; HCMP, respectively). The e' velocity, E/e', and late diastolic SR at mid LA were significantly different between normal and LVH (p = 0.001; 0.022; 0.018), whereas LA size was similar between normal and LVH (p = 0.592). The mean late diastolic peak SR of mid LA was significantly correlated with indices of diastolic function (E/e', e', and LA size).

CONCLUSIONS

The SR is a useful tool for detailed evaluation of LA function, especially early dysfunction of LA in groups with normal LA size.

Observation of plaque behavior and tissue characterization of coronary plaque using speckle tracking intravascular ultrasound (ST-IVUS) and iMap imaging system

Tissue characterization plays an important role in the development of acute coronary syndromes. iMap is an intravascular ultrasound (IVUS) tissue characterization system that provides useful information by reconstructing color-coded maps. Mechanical properties due to dynamic mechanical stress during a cardiac cycle may also trigger vulnerable plaque. Speckle tracking IVUS (ST-IVUS) has been introduced to observe plaque behavior in relation to mechanical properties. We report the case of an 84-year-old woman with stable coronary artery disease who underwent percutaneous coronary intervention, at which time IVUS demonstrated mainly three low echoic areas like lipid pools with thick fibrous caps. Pathological evaluation with iMap revealed that one low echoic area was occupied with necrotic tissue and that the other two areas occupied fibrotic. Although those tissue characterizations were different, they showed similar stretching behavior at systole by ST-IVUS which depicted plaque behavior from IVUS images using a color mapping. The mechanical properties of individual coronary plaques may differ depending on the tissue disposition. It is necessary to consider mechanical properties using ST-IVUS as well as to evaluate tissue characterization in plaque risk stratification.

Two-dimensional speckle tracking echocardiography help identify breast cancer therapeutics–related cardiac dysfunction

Background

Cancer therapeutics–related cardiac dysfunction (CTRCD) from different chemotherapy strategies are underdetermined by echocardiography. As an imaging marker of subclinical cardiac dysfunction, two-dimensional speckle tracking echocardiography (2D-STE) may assist in identifying the impact patterns of different CTRCD.

Methods

A total of 67 consecutive patients with invasive ductal breast carcinoma who will undertake neoadjuvant chemotherapy were enrolled and grouped according to their different chemotherapy regimens based on their biopsy results. Group A included 34 patients who received anthracycline without trastuzumab, whereas Group B had 33 patients who received trastuzumab without anthracycline. Echocardiography was performed at three time-points, i.e., baseline (T0), cycle-2 (T2), and cycle-4 (T4) of chemotherapy. Conventional echocardiographic measurements and 2D-STE strain values, and myocardial work (MW) parameters, were compared between different groups at different time-points.

Results

The mean age had no statistical difference between the two groups. E/e′ was the only conventional echocardiographic parameter that had variation in group A (P < 0.05). Compared with baseline, GLS in group A decreased at T2, and GCS decreased at T4 (P < 0.05). GLS and GCS in group B both decreased at T4 (P < 0.05). More patients in group A had a more than 15% fall of baseline GLS rather than GCS at T2 (P < 0.05), however, there was no difference of either GLS or GCS decline rate at T4 between the two groups. All the MW parameters in group A had variations overtime, whereas only GCW in group B (P < 0.05).

Conclusion

Early subclinical myocardial dysfunction can be identified by 2D-STE in breast cancer patients with chemotherapy, and GLS provides profound value in demonstrating the temporal changes in early myocardial damage induced by anthracycline. LV contractility injury in patients with trastuzumab may be mild at first but increases in severity with exposure time as early as cycle-4. Awareness of these differences may help to stratify the prevention of late cardiovascular events caused by different CTRCDs. In addition, GCW may be the most sensitive myocardial work parameter of CTRCD.

Left atrial strain quantified after myocardial infarction is associated with early left ventricular remodeling

BACKGROUND

Left ventricular remodeling (LVR) is common and associated with adverse outcome after ST-elevation myocardial infarction (STEMI). We aimed to investigate the association between left atrial (LA) mechanical function using speckle tracking imaging and early LVR at follow-up in STEMI patients.

METHODS

Baseline 3D thoracic echocardiograms were performed within 48 h following admission and at a median follow-up of 7 months after STEMI. A > 20% increase in the left ventricular (LV) end-diastolic volume compared to baseline at follow-up was defined as LVR. LA global longitudinal strain was evaluated for the reservoir, conduit, and contraction (LASct) phases.

RESULTS

A total of 121 patients without clinical heart failure (HF) were prospectively included, between June 2015 and October 2018 (age 58.3 ± 12.5 years, male 98 (81%)). Baseline and follow-up LV ejection fraction (LVEF) were 46.8% [41.0, 52.9] and 52.1% [45.8, 57.0] respectively (p < .001). Compared to other patients, those with LVR had significantly lower values of LASct at baseline (-7.4% [-10.1, -6.5] vs. -9.9% [-12.8, -8.1], p < .01), both on univariate and baseline LV volumes-adjusted analyses. Baseline LA strain for reservoir and conduit phases were not associated with significant LVR at follow-up. Intra- and interobserver analysis showed good reproducibility of LA strain.

CONCLUSIONS

Baseline LASct may help identifying patients without HF after STEMI who are at higher risk of further early LVR and subsequent HF and who may benefit from more intensive management.

Role of Cardiovascular Imaging in the Follow-Up of Patients with Fontan Circulation

Since its first description in 1971, the Fontan procedure and its modifications have led to a substantial improvement in the survival rates of patients with a variety of types of complex Congenital Heart Disease (CHD) characterised by the presence of a single, dominant ventricle. However, despite the significant improvement of the prognosis over the years, Fontan patients are still exposed to several cardiovascular and systemic complications. It is, therefore, important to fully understand the pitfalls hidden behind a Fontan anatomy and the potential predictors of ventricular failure. Cardiovascular imaging plays a key role in this context, allowing for the early identification of complications with important prognostic implications. Echocardiography remains the first-line imaging modality for serial evaluation of Fontan patients. However, there is a growing role of cardiovascular magnetic resonance and cardiac computed tomography from pre-operative assessment to longitudinal follow-up. The aim of this paper will be to provide a comprehensive overview of the role, strengths, and weaknesses of each imaging modality in the assessment of congenital cardiac conditions palliated with the Fontan procedure.

Targeted Neonatal Echocardiography in Patients With Hemodynamic Instability

Targeted neonatal echocardiography (TNE) has been increasingly used at the bedside in neonatal care to provide an enhanced understanding of physiology, affecting management in hemodynamically unstable patients. Traditional methods of bedside assessment, including blood pressure, heart rate monitoring, and capillary refill are unable to provide a complete picture of tissue perfusion and oxygenation. TNE allows for precision medicine, providing a tool for identifying pathophysiology and to continually reassess rapid changes in hemodynamics. A relationship with cardiology is integral both in training as well as quality assurance. It is imperative that congenital heart disease is ruled out when utilizing TNE for hemodynamic management, as pathophysiology varies substantially in the assessment and management of patients with congenital heart disease. Utilizing TNE for longitudinal hemodynamic assessment requires extensive training. As the field continues to grow, guidelines and protocols for training and indications are essential for ensuring optimal use and providing a platform for quality assurance.

Antiquated ejection fraction: Basic research applications for speckle tracking echocardiography

For years, ejection fraction has been an essentially ubiquitous measurement for assessing the cardiovascular function of animal models in research labs. Despite technological advances, it remains the top choice among research labs for reporting heart function to this day, and is often overstated in applications. This unfortunately may lead to misinterpretation of data. Clinical approaches have now surpassed research methods, allowing for deeper analysis of the tiers of cardiovascular performance (cardiovascular performance, heart performance, systolic and diastolic function, and contractility). Analysis of each tier is crucial for understanding heart performance, mechanism of action, and disease diagnosis, classification, and progression. This review will elucidate the differences between the tiers of cardiovascular function and discuss the benefits of measuring each tier via speckle tracking echocardiography for basic scientists.

Biomedical Imaging in Experimental Models of Cardiovascular Disease

Major advances in biomedical imaging have occurred over the last 2 decades and now allow many physiological, cellular, and molecular processes to be imaged noninvasively in small animal models of cardiovascular disease. Many of these techniques can be also used in humans, providing pathophysiological context and helping to define the clinical relevance of the model. Ultrasound remains the most widely used approach, and dedicated high-frequency systems can obtain extremely detailed images in mice. Likewise, dedicated small animal tomographic systems have been developed for magnetic resonance, positron emission tomography, fluorescence imaging, and computed tomography in mice. In this article, we review the use of ultrasound and positron emission tomography in small animal models, as well as emerging contrast mechanisms in magnetic resonance such as diffusion tensor imaging, hyperpolarized magnetic resonance, chemical exchange saturation transfer imaging, magnetic resonance elastography and strain, arterial spin labeling, and molecular imaging.

Biventricular strain and strain rate impairment shortly after surgical repair of tetralogy of Fallot in children: A case-control study

Background

Early biventricular dysfunction in repaired tetralogy of Fallot (TOF) children may lead to poor clinical outcomes. We aimed to assess biventricular function in TOF children before and after surgery by speckle tracking echocardiography (STE) and compare them with the controls.

Methods

Twenty repaired TOF children and 20 normal children as controls were assessed by STE. Tricuspid annular plane systolic excursion (TAPSE), left ventricular ejection fraction (LVEF), biventricular strain, and strain rate were compared before and after surgery and between TOF children and controls.

Results

Postoperative LVEF (p = 0.001), strain (p = 0.001), and strain rate (p = 0.001) for left ventricle improved significantly compared to preoperative phase. However, postoperative left ventricular strain (p = 0.05) and strain rate (p = 0.01) in TOF children were significantly impaired compared to controls. Postoperative LVEF was correlated inversely with postoperative strain rate (r = −0.40, p = 0.04). Postoperative TAPSE (p = 0.001), strain (p = 0.001), and strain rate (p = 0.001) for right ventricle significantly worsened when compared with the preoperative phase. Moreover, postoperative TAPSE (p = 0.001), strain (p = 0.001), and strain rate (p = 0.01) were significantly impaired compared to controls. Postoperative right ventricular strain rate was correlated significantly with the weight of children (r = 0.48, p = 0.02), and postoperative left ventricular strain showed significant correlations with aortic clamp time (r = 0.44, p = 0.04) and with ICU stay (r = −0.46, p = 0.04).

Conclusion

Despite normal LVEF, TOF children exhibit impaired left ventricular strain and strain rate after surgery. TAPSE, strain, and strain rate for the right ventricle worsen after surgical repair. STE‐driven strain can be used to detect early ventricular dysfunction and the associated prognostic implications.

Echocardiographic Normal Reference Ranges for Non-invasive Myocardial Work Parameters in Pediatric Age: Results From an International Multi-Center Study

Aims

This international multi-center study aimed to demonstrate the feasibility and reliability of non-invasive myocardial work (MW) parameters in the pediatric population, and to provide normal reference ranges for this useful echocardiographic tool in this specific subset of patients.

Methods and Results

In this retrospective multi-center study involving three pediatric laboratories, 150 healthy children and adolescents (mean age of 10.6 ± 4.5, 91 males) were enrolled. A complete echocardiographic examination has been performed, including global longitudinal strain (GLS) assessment. The following parameters of non-invasive MW have been obtained through a dedicated software: global work index (GWI), global constructive work (GCW), global work waste (GWW), and global work efficiency (GWE), using left ventricular (LV) strain loops and non-invasive brachial artery cuff pressure values. The lowest expected values were for GWI 1,723 mmHg% in males and 1,682 mmHg% in females, for GCW 2,089 and 2,106 mmHg%, for GWE 95.9 and 95.5% whereas the highest expected value for GWW was 78 mmHg% in men and 90 mmHg% in women. The univariable and multivariable analysis showed significant associations between either GWI or GCW with SBP (β coefficient = 0.446, p < 0.001; β coefficient = 0.456, p < 0.001, respectively) and LV GLS (β coefficient = −0.268, p = 0.001; β coefficient = −0.233, p = 0.003, respectively). Inter- and intra-observer variability showed good reproducibility of non-invasive MW parameters.

Conclusion

Non-invasive MW parameters were feasible and reliable in the pediatric population. This study provided normal reference ranges of these useful echocardiographic indices.

Identification of COVID-19-associated myocarditis by speckle-tracking transesophageal echocardiography in critical care

A 68-year-old male presented with flu-like symptoms, fatigue, history of obesity, hypertension, type 2 diabetes and chronic smoking. Chest radiography revealed right basal opacity consisting of infiltrate. With respiratory failure, orotracheal intubation and mechanical ventilation were performed. Patient presented gas exchange alteration. Real-time PCR detected SARS-CoV-2. Treatment with liponavir/ritonavir and hydroxychloroquine was started. Because of poor acoustic window, speckle-tracking transoesophageal echocardiography (TEE) was performed, detecting deterioration in global longitudinal strain. Acute COVID 19 infection led us to suspect myocarditis, with no other signs or symptoms other than elevated troponin and altered strain. On day 15, the patient suffered bacteraemic sepsis at endovascular focus with Serratia marcescens and multiorgan failure. TEE-guided haemodynamic monitoring was repeated showing global longitudinal strain improvement. Acute COVID 19 infection led us to suspect myocarditis, with no other signs or symptoms beyond elevated troponin and altered strain.

Comparison of effects of sevoflurane versus propofol on left ventricular longitudinal global and regional strain in patients undergoing on-pump coronary artery bypass grafting

Background:

Assessment of myocardial deformation by quantifying peak systolic longitudinal strain (PSLS) is a sensitive and robust index to detect subclinical myocardial dysfunction. We hypothesize that sevoflurane by virtue of anesthetic preconditioning preserves myocardial function better than propofol.

Aims:

The authors have assessed the effects of sevoflurane and propofol on global longitudinal strain (GLS) as a primary outcome in patients undergoing on-pump coronary artery bypass grafting. Our secondary aim was to assess the pattern of regional distribution of segmental PSLS between the groups.

Materials and Methods:

Fifty patients with normal left ventricular function undergoing coronary artery bypass grafting were analyzed in this prospective observational study. Consecutive patients received either propofol (P) or sevoflurane (S) anesthesia.

Measurements:

Trans-esophageal echocardiographic images (mid-esophageal four-chamber, two-chamber, and three-chamber (long-axis)) were recorded during the precardiopulmonary bypass (CPB) and post-CPB period. Strain analysis (GLS/segmental PSLS) was done offline by investigators blinded to the study. The inotropic score, duration of inotropic support, and mechanical ventilation required were recorded.

Results:

Following cardiopulmonary bypass and coronary revascularization, GLS reduced significantly in both the groups (P < 0.05). In the S-group, significant reduction in segmental strain was observed only in apical segments including apex, whereas in P-group significant reduction in segmental strain was seen in mid- and apical segments. The postoperative VIS, duration of inotropes/vasopressor required, and mechanical ventilation were similar in both the groups.

Conclusions:

There are no significant differences in global left ventricular function as assessed by GLS between patients anesthetized with sevoflurane or propofol. However, regional PSLS was better preserved in the S-group compared to P-group.

Ultrasonic biomechanics method for vortex and wall motion of left ventricle: a phantom and in vivo study

Background

The non-invasive quantitative evaluation of left ventricle (LV) function plays a critical role in clinical cardiology. This study proposes a novel ultrasonic biomechanics method by integrating both LV vortex and wall motion to fully assess and understand the LV structure and function. The purpose of this study was to validate the ultrasonic biomechanics method as a quantifiable approach to evaluate LV function.

Methods

Firstly, B-mode ultrasound images were acquired and processed, which were utilized to implement parameters for quantifying the LV vortex and wall motion respectively. Next, the parameters were compared in polyvinyl alcohol cryogen (PVA) phantoms with different degree of stiffness corresponding to different freezing and thawing cycles in vitro. Finally, the parameters were computed in vivo during one cardiac cycle to assess the LV function in normal and abnormal subjects in vivo.

Results

In vitro study, the velocity field of PVA phantom differed with stiffness (varied elasticity modulus). The peak of strain for wall motion decreases with the increase of elasticity modulus, and periodically changed values. Statistical analysis for parameters of vortex dynamics (energy dissipation index, DI; kinetic energy fluctuations, KEF; relative strength, RS; and vorticity, W) based on different elasticity (E) of phantom depicted the good viability of this algorithm. In vivo study, the results confirmed that subjects with LV dysfunction had lower vorticity and strain (S) compared to the normal group.

Conclusion

Ultrasonic biomechanics method can obtain the vortex and wall motion of left ventricle. The method may have potential clinical value in evaluation of LV dysfunction.

Screening for dilated cardiomyopathy in dogs

BACKGROUND

Dilated cardiomyopathy (DCM) is the most common cardiac disease in large breed dogs. The disease can start with arrhythmias or with systolic dysfunction of the myocardium.

OBJECTIVE

To describe screening methods for DCM in various breeds and provide a new, modified staging system.

RECOMMENDATIONS

Screening for occult DCM should start at three years of age and use Holter monitoring in Boxers and Dobermans and might be useful also in other breeds. Single ventricular premature complexes (VPCs) can be detected in many healthy dogs, but healthy animals typically have <50 VPCs in 24 h and demonstrate minimal complexity most often occurring only as single ectopic beats. In general, >100 VPCs in 24 h was recommended as the cut-off value for establishing a diagnosis of DCM. However, there are breed-specific recommendations related to Holter recording diagnosis of DCM in Dobermans and Boxers. Yearly screening over the life of a dog is recommended, as a one-time screening is not sufficient to rule out the future development of DCM. Several echocardiographic methods such as M-mode derived measurements, the measurement of the left ventricular (LV) volume by Simpson's method of discs (SMOD), and E-point to septal separation (EPSS) are recommended for screening purposes. The value of additional tests such as cardiac biomarkers (troponin I and N-terminal pro-B-type natriuretic peptide) as well as a 5-min resting electrocardiogram (ECG) or newer echocardiographic methods such as strain measurements is discussed.

CONCLUSION

This review suggests some guidelines for screening for DCM in various breeds.

Prediction of Significant Coronary Artery Disease Through Advanced Echocardiography: Role of Non-invasive Myocardial Work

Background: Non-invasive prediction of critical coronary artery stenosis (CAST) in patients with coronary artery disease (CAD) is challenging. Strain parameters can often capture an impairment of regional longitudinal function; however, they are load dependent. A novel non-invasive method to estimate Myocardial Work (MW) has been recently proposed, showing a strong correlation with invasive work measurements. Our aim was to investigate the ability of non-invasive MW to predict the ischaemic risk area underlying a CAST. Methods and Results: The study population comprises 80 individuals: 50 patients with CAST and 30 controls (CTRL). Echocardiography recordings were obtained before coronary angiography to measure global longitudinal strain (GLS), Myocardial Work Index (MWI), Myocardial Constructive Work (MCW), Myocardial Wasted work (MWW), Myocardial Work Efficiency (MWE). Global MWI (p = 0.048), MWE (p < 0.001), and MCW (p = 0.048) at baseline were significantly reduced in patients with CAST compared to controls (p < 0.05). Regional MWE within the myocardial segments underlying the CAST, but not LS, was significantly reduced compared to non-target segments (p < 0.001). At ROC analysis, the diagnostic performance to predict CAST for regional MWE (AUC = 0.920, p < 0.001) was higher compared to both regional post-systolic shortening index (PSI) (AUC = 0.600, p = 0.129) and regional LS (AUC = 0.546, p = 0.469). Conclusions: Non-invasive estimation of MW work indices is able to predict a CAST before invasive angiography.

Electromechanical Wave Imaging With Machine Learning for Automated Isochrone Generation

Standard Electromechanical Wave Imaging isochrone generation relies on manual selection of zero-crossing (ZC) locations on incremental strain curves for a number of pixels in the segmented myocardium for each echocardiographic view and patient. When considering large populations, this becomes a time-consuming process, that can be limited by inter-observer variability and operator bias. In this study, we developed and optimized an automated ZC selection algorithm, towards a faster more robust isochrone generation approach. The algorithm either relies on heuristic-based baselines or machine learning classifiers. Manually generated isochrones, previously validated against 3D intracardiac mapping, were considered as ground truth during training and performance evaluation steps. The machine learning models applied herein for the first time were: i) logistic regression; ii) support vector machine (SVM); and iii) Random Forest. The SVM and Random Forest classifiers successfully identified accessory pathways in Wolff-Parkinson-White patients, characterized sinus rhythm in humans, and localized the pacing electrode location in left ventricular paced canines on the resulting isochrones. Nevertheless, the best performing classifier was proven to be Random Forest with a precision rising from 89.5% to 97%, obtained with the voting approach that sets a probability threshold upon ZC candidate selection. Furthermore, the predictivity was not dependent on the type of testing dataset it was applied to, contrary to SVM that exhibited a 5% drop in precision on the canine testing dataset. Finally, these findings indicate that a machine learning approach can reduce user variability and considerably decrease the durations required for isochrone generation, while preserving accurate activation patterns.

Strain Rate Distribution in Layered Myocardium Measured Using Local Velocity Estimator with Multifrequency Phase Differences

Measurement of the myocardial strain rate (SR), with high spatial resolution, is useful in evaluation of the transmurality of myocardial infarction. As the SR distribution is calculated using velocities observed at multiple positions in the heart wall, it is necessary to estimate the local velocity to measure SR distribution. In the present study, our previously proposed local velocity estimator, with multifrequency phase differences, was used to measure SR distribution in the heart wall. The SR distribution measured with the proposed local velocity estimator revealed alternate layers of contraction and relaxation, which were not measured with the conventional velocity estimator with spatial averaging. The reproducibility of the SR distributions was confirmed in three consecutive heartbeats with three subjects. High-spatial-resolution SR measurement with the proposed local velocity estimator will allow myocardial layer-specific analysis in the transmural direction.

Global myocardial work: A new way to detect subclinical myocardial dysfunction with normal left ventricle ejection fraction in essential hypertension patients: Compared with myocardial layer-specific strain analysis

OBJECTIVES

The aim of this study was to determine whether global myocardial work (MW), derived from non-invasive left ventricle (LV) pressure-strain loops (PSL) at rest, could predict subclinical LV myocardial dysfunction in preserved left ventricular ejection fraction (LVEF) essential hypertension (EHT) patients.

METHODS

A total of 105 untreated EHT patients and 55 normal controls were enrolled in this study. Apical 4-, 3- and 2-chamber views were acquired by two-dimensional echocardiography. The peak systolic myocardial layer-specific longitudinal strain (epimyocardial: GLSEpi; middle layer: GLSMid; and endomyocardial: GLSEndo), global myocardial work index (GWI), global constructive work (GCW), global wasted work (GWW), and myocardial work efficiency (GWE) were generated by speckle-tracking echocardiography (STE).

RESULTS

The values of GLSEpi, GLSMid, and GLSEndo were significantly lower in EHT patients with LVH than in EHT patients without LVH and normal controls. GWW was significantly increased in EHT patients with LVH compared with without LVH and normal subjects, while GWE was significantly reduced in EHT patients with LVH compared with without LVH and normal subjects. ROC analysis showed that combined global MW values were a more sensitive predictor for detecting the accuracy of LV subclinical dysfunction in EHT patients than layer-specific GLS.

CONCLUSION

From the research, we conclude that global MW is more sensitive to layer-specific GLS in its ability to detect subclinical LV dysfunction even in EHT patients even without LVH.

Abnormal myocardial work in children with Kawasaki disease

Kawasaki disease (KD) can be associated with high morbidity and mortality due to coronary artery aneurysms formation and myocardial dysfunction. Aim of this study was to evaluate the diagnostic performance of non-invasive myocardial work in predicting subtle myocardial abnormalities in Kawasaki disease (KD) children with coronary dilatation (CADL). A total of 100 patients (age 8.7 ± 5 years) were included: 45 children with KD and CADL (KD/CADL) (Z-score > 2.5), 45 age-matched controls (CTRL) and, finally, an additional group of 10 children with KD in absence of coronary dilatation (KD group). Left ventricular (LV) systolic function and global longitudinal strain (GLS) were assessed. Global myocardial work index (MWI) was calculated as the area of the LV pressure-strain loops. From MWI, global Constructive Work (MCW), Wasted Work (MWW) and Work Efficiency (MWE) were estimated. Despite normal LV systolic function by routine echocardiography, KD/CADL patients had lower MWI (1433.2 ± 375.8 mmHg% vs 1752.2 ± 265.7 mmHg%, p < 0.001), MCW (1885.5 ± 384.2 mmHg% vs 2175.9 ± 292.4 mmHg%, p = 0.001) and MWE (994.0 ± 4.8% vs 95.9 ± 2.0%, p = 0.030) compared to CTRL. Furthermore, MWI was significantly reduced in children belonging to the KD group in comparison with controls (KD: 1498.3 ± 361.7 mmHg%; KD vs CTRL p = 0.028) and was comparable between KD/CADL and KD groups (KD/CADL vs KD p = 0.896). Moreover, KD/CADL patients with normal GLS (n = 38) preserved significant differences in MWI and MCW in comparison with CTRL. MWI, MCW and MWE were significantly reduced in KD children despite normal LVEF and normal GLS. These abnormalities seems independent from CADL. Thus, in KD with normal LVEF and normal GLS, estimation of MWI may be a more sensitive indicator of myocardial dysfunction.

Multifrequency Phased Tracking Method for Estimating Velocity in Heart Wall

Local high-accuracy velocity estimation is important for the ultrasound-based evaluation of regional myocardial function. The ultrasound phase difference at the center frequency of the transmitted signal has been conventionally used for velocity estimation. In the conventional method, spatial averaging is necessary owing to the frequency-dependent attenuation and interference of backscattered waves. Here, we propose a method for suppressing these effects using multifrequency phase differences. The resulting improvement in velocity estimation in the heart wall was validated by in vivo experiments. In the conventional method, the velocity waveform exhibits spike-like changes. The velocity waveform estimated using the proposed method did not exhibit such changes. Because the proposed method estimates myocardium velocity without spatial averaging, it can be used for measuring heart wall dynamics involving thickness changes.

What are the echocardiographic findings of acute right ventricular strain that suggest pulmonary embolism?

INTRODUCTION

Pulmonary embolism (PE) is a potentially fatal disease encountered in the hospital setting. Prompt diagnosis and management can improve outcomes and survival. Unfortunately, a PE may be difficult to diagnose in a timely manner. Point-of-care ultrasound (POCUS) can assist in the evaluation for suspected PE by assessing for acute right ventricular strain. Physicians should thus be aware of these echocardiographic findings.

OBJECTIVE

This manuscript will review ten echocardiographic findings of right ventricular strain that may suggest a diagnosis of PE. It will provide a description of each finding along with the associated pathophysiology. It will also summarize the literature for the diagnostic utility of echocardiography for this indication, while providing reference parameters where applicable. Along with labeled images and video clips, the review will then illustrate how to evaluate for each of the ten findings, while offering pearls and pitfalls in this bedside evaluation.

DISCUSSION

The ten echocardiographic findings of right ventricular strain are: increased right ventricle: left ventricle size ratio, abnormal septal motion, McConnell's sign, tricuspid regurgitation, elevated pulmonary artery systolic pressure, decreased tricuspid annular plane systolic excursion, decreased S', pulmonary artery mid-systolic notching, 60/60 sign, and speckle tracking demonstrating decreased right ventricular free wall strain.

CONCLUSIONS

Physicians must recognize and understand the echocardiographic findings and associated pathophysiology of right ventricular strain. In the proper clinical context, these findings can point toward a diagnosis of PE and thereby lead to earlier initiation of directed management.

The strain and strain rate imaging paradox in echocardiography: overabundant literature in the last two decades but still uncertain clinical utility in an individual case

Almost two decades ago strain and strain rate imaging were proposed as a new, potentially more sensitive modality for quantifying both regional and global myocardial function. Until now, however, strain and strain rate imaging have been slow to be incorporated into everyday clinical practice. More recently, two dimensional strain has been claimed as of greater clinical utility, given that it is angle independent, with improved feasibility and reproducibility as compared to tissue Doppler strain. Nevertheless, speckle tracking strain is reliant on 2D image quality and frame rates. Three dimensional speckle tracking could eliminate the problem of through-plane motion inherent in 2D imaging, but 3D strain is currently limited by low frame rates. Another limitation of strain imaging is that the results are dependent on the ultrasound machine on which analyses are performed, with variability in measurements between different vendors. Despite the diagnostic and prognostic advantages of 2D strain, there is a lack of specific therapeutic interventions based on strain and a paucity of long-term large-scale randomized trial evidence on cardiovascular outcomes. After overabundant literature the same definition of normal cut-off values is controversial and not univocal. Further studies are needed, involving both manufacturers and medical professionals, on the additive contribution, possibly different case by case, of interfering and artifactual factors, aside from myocardial function per se. These artifactual determinants and motion artifacts components could be dominant in individual cases and should always be taken into account in the clinical decision making process in a single case.

Non-invasive myocardial work is reduced during transient acute coronary occlusion

Background

During ischemia a close relationship exists between sub-endocardial blood flow and myocardial function. Strain parameters can capture an impairment of regional longitudinal function but are load dependent. Recently, a novel non-invasive method to calculate Myocardial Work (MW) showed a strong correlation with invasive work measurements.

Our aim was to investigate the ability of non-invasive MW indices to identify the ischaemic risk area during transient acute coronary occlusion (TACO).

Methods and results

The study population comprises 50 individuals with critical coronary stenosis (CCS). Echocardiography recordings were obtained before coronary angiography, during TACO and after revascularization to measure global longitudinal strain (GLS), Myocardial Work Index (MWI), Myocardial Constructive Work (MCW), Myocardial Wasted work (MWW), Myocardial work efficiency (MWE).

Compared to baseline, we found a significant reduction of GLS (p = 0.005), MWI, MCW and MWE (p<0.001) during TACO.

Conclusions

The non-invasive measurement of MW parameters is a sensitive and early marker of myocardial ischemia during TACO.

Evaluation of right ventricular performance and impact of continuous positive airway pressure therapy in patients with obstructive sleep apnea living at high altitude

Obstructive sleep apnea syndrome (OSAS) can lead to alterations in right ventricular (RV) performance and pulmonary vascular haemodynamics. Additionally, altitude-related hypoxia is associated with pulmonary vasoconstriction, and the effect of high-altitude on the pulmonary circulation in OSAS patients can be further altered. We sought to assess alterations in RV morphology and function in OSAS patients living at high altitude by way of 2-dimensional speckle tracking echocardiography (2D-STE), real-time 3- dimensional echocardiography (RT-3DE) and cardiac biomarkers. We also evaluate the impact of continuous positive airway pressure (CPAP) treatment on RV performance. Seventy-one patients with newly diagnosed OSAS and thirty-one controls were included in this study. All individuals were assessed for cardiac biomarkers as well as underwent 2D-STE and RT-3DE. Forty-five OSAS patients underwent CPAP therapy for at least 24 weeks and were studied before and after CPAP treatment. RT-3DE was used to measure RV volume, and calculate RV 3D ejection fraction (3D RVEF). Peak systolic strain was determined. Cardiac biomarkers, including C-reactive protein (CRP), N-terminal pro-B-type natriuretic peptide, and cardiac troponin T were also measured. Right atrium volume index, RV volume, RV volume index, systolic pulmonary artery pressure (sPAP), pulmonary vascular resistance (PVR) and level of serum CRP were significantly higher in OSAS group, while OSAS patients showed lower 3D RVEF and RV longitudinal strains. Compared to the patients with sPAP < 40 mmHg, RV longitudinal strains in patients with sPAP ≥ 40 mmHg were lower. Both RV global longitudinal strain and sPAP were associated with apnea–hypopnea index. Patients treated with 6 months of CPAP therapy had significant improvement in RV geometry and performance. RV structural abnormalities and RV function impairments were observed in OSAS patients living at moderate high altitude compared to control highlanders. The reversibility of these changes after application of CPAP were further confirmed.

Cardiac perturbations after high-intensity exercise are attenuated in middle-aged compared with young endurance athletes: diminished stress or depleted stimuli?

Strenuous exercise elicits transient functional and biochemical cardiac imbalances. Yet, the extent to which these responses are altered owing to aging is unclear. Accordingly, echocardiograph-derived left ventricular (LV) and right ventricular (RV) global longitudinal strain (GLS) and high-sensitivity cardiac troponin I (hs-cTnI) were assessed before (pre) and after (post) a 60-min high-intensity cycling race intervention (CRIT₆₀) in 11 young (18-30 yr) and 11 middle-aged (40-65 yr) highly trained male cyclists, matched for cardiorespiratory fitness. LV and RV GLS were measured at rest and during a semirecumbent exercise challenge performed at the same intensity (young: 93 ± 10; middle-aged: 85 ± 11 W, P = 0.60) pre- and post-CRIT₆₀. Augmentation (change from rest-to-exercise challenge) of LV GLS (pre: -2.97 ± 0.65; post: -0.82 ± 0.48%, P = 0.02) and RV GLS (pre: -2.08 ± 1.28; post: 3.08 ± 2.02%, P = 0.01) was attenuated and completely abolished, in the young following CRIT₆₀, while augmentation of LV GLS (pre: -3.21 ± 0.41; post: -3.99 ± 0.55%, P = 0.22) and RV GLS (pre: -3.47 ± 1.44; post: -1.26 ± 1.00%, P = 0.27) was preserved in middle-aged following CRIT₆₀. While serum hs-cTnI concentration increased followingCRIT₆₀ in the young (pre: 7.3 ± 1.6; post: 17.7 ± 1.6 ng/L, P < 0.01) and middle-aged (pre: 4.5 ± 0.6; post: 10.7 ± 2.0 ng/L, P < 0.01), serum hs-cTnI concentration increased to a greater extent in the young than in the middle-aged following CRIT₆₀ (P < 0.01). These findings suggest that functional and biochemical cardiac perturbations induced by high-intensity exercise are attenuated in middle-aged relative to young individuals. Further study is warranted to determine whether acute exercise-induced cardiac perturbations alter the adaptive myocardial remodeling response.NEW & NOTEWORTHY High-intensity endurance exercise elicits acute cardiac imbalances that may be an important stimulus for adaptive cardiac remodeling. This study highlights that following a bout of high-intensity exercise that is typical of routine day-to-day cycling training, exercise-induced autonomic, biochemical, and functional cardiac imbalances are attenuated in middle-aged relative to young well-trained cyclists. These findings suggest that aging may alter exercise-induced stress stimulus response that initiates cardiac remodeling in athlete's heart.

Impact of Graded Passive Cycling on Hemodynamics, Cerebral Blood Flow, and Cardiac Function in Septic ICU Patients

Background: In-bed passive cycling is considered a safe and feasible early mobilization technique in intensive care unit (ICU) patients who are unable to exercise actively. However, the impact of varying intensity of passive cycling on perfusion and function of ischemia-prone organs is unknown. In this study, we assessed the impact of a graded passive cycling protocol on hemodynamics, cerebral blood flow, and cardiac function in a cohort of septic ICU patients. Methods: In consecutive patients presenting with sepsis, we measured global hemodynamic indices, middle cerebral artery velocity (MCAv), and cardiac function in response to a graded increase in passive cycling cadence. Using 5-min stages, we increased cadence from 5 to 55 RPM in increments of 10 RPM, preceded and followed by 5 min baseline and recovery periods at 0 RPM. The mean values obtained during the last 2 min of each stage were compared within and between subjects for all metrics using repeated-measures ANOVA. Results: Ten septic patients (six males) completed the protocol. Across patients, there was a 5.2% reduction in MCAv from baseline at cycling cadences of 25-45 RPM with a dose-dependent decrease of MCAv of > 10% in four of the 10 patients enrolled. There was a 16% increase in total peripheral resistance from baseline at peak cadence of 55 RPMs and no changes in any other measured hemodynamic parameters. Patient responses to passive cycling varied between patients in terms of magnitude, direction of change, and the cycling cadence at which these changes occurred. Conclusions: In septic patients, graded passive cycling is associated with dose-dependent decreases in cerebral blood flow, increases in total peripheral resistance, and either improvement or worsening of left ventricular function. The magnitude and cadence threshold of these responses vary between patients. Future studies should establish whether these changes are associated with clinical outcomes, including cognitive impairment, vasopressor use, and functional outcomes.

Detection of Tissue Fibrosis using Natural Mechanical Wave Velocity Estimation: Feasibility Study

In the feasibility study described here, we developed and tested a novel method for mechanical wave velocity estimation for tissue fibrosis detection in the myocardium. High-frame-rate ultrasound imaging and a novel signal processing method called clutter filter wave imaging was used. A mechanical wave propagating through the left ventricle shortly after the atrial contraction was measured in the three different apical acquisition planes, for 20 infarct patients and 10 healthy controls. The results obtained were correlated with fibrosis locations from magnetic resonance imaging, and a sensitivity ≥60% was achieved for all infarcts larger than 10% of the left ventricle. The stability of the wave through several heart cycles was assessed and found to be of high quality. This method therefore has potential for non-invasive fibrosis detection in the myocardium, but further validation in a larger group of subjects is needed.

Early postnatal cardiac follow-up of survivors of twin-twin transfusion syndrome treated with fetoscopic laser coagulation

OBJECTIVE

To assess the cardiac function and prevalence of congenital heart defects (CHD) in twin-twin transfusion syndrome (TTTS) survivors.

STUDY DESIGN

Prospective follow-up of TTTS pregnancies treated with laser surgery (2015-2018). Echocardiography was performed 1 day and 1 month after birth (corrected for prematurity). Results were compared with a control group of age-matched uncomplicated monochorionic twin-pairs at 1 month.

RESULT

Eighty-nine TTTS (168 neonates) and nine control pregnancies (18 neonates) were enrolled. CHD birth prevalence was 9.2% (8/87) in recipients and 13.6% (11/81) in donors (p = 0.37). Four of 19 (21%) were detected prenatally, all pulmonary stenosis. Donors had lower aortic peak velocities compared with recipients at day 1 (0.66 ± 0.15 m/s vs 0.71 ± 0.19 m/s, p = 0.04) and 1 month (1.04 ± 0.21 m/s vs 1.11 ± 0.18 m/s, p = 0.02), but not compared with controls.

CONCLUSION

CHD prevalence in TTTS survivors is high, with a low prenatal detection of minor abnormalities. Follow-up fetal echocardiograms and a postnatal echocardiogram should be offered.

Feasibility and agreement of a novel combined echocardiographic method to measure global longitudinal strain and strain rate compared to speckle tracking and tissue Doppler imaging

Background: Currently, two echocardiographic techniques are used to measure deformation: tissue Doppler imaging (TDI) and speckle tracking echocardiography (STE). Recently, a technique combining STE and TDI (on TDI overlay images) has become available, allowing derivation of STE/TDI results from a single acquisition/reading (combined-STE/combined-TDI). We tested the feasibility and agreement of this novel technique to measure left ventricular deformation in the general population compared to STE and TDI.Methods: We examined a subsample of 106 consecutive subjects of the Asklepios Study, a population-based random sample of male/female volunteers without overt clinical disease (mean age: 55.9 years). Left ventricular deformation measurements were assessed with transthoracic echocardiography using the combined method, STE and TDI.Results: Almost all deformation parameters significantly differed between all methods. Global systolic longitudinal strain (GS) and strain rate (GSRs) values measured by combined-TDI were significantly higher (GS -17.2% ± 3.0, GSRs -0.9 s^-1 ± 0.2) compared to TDI (GS -21.1% ± 2.2, GSRs -1.3 s^-1 ± 0.2). Measurements by combined-STE were significantly lower (GS -19.1% ± 2.9, GSRs -1.0 s^-1 ± 0.2) compared to STE (GS -18.2% ± 3.0, GSRs -0.9 s^-1 ± 0.1). Overall, the smallest differences and highest agreement were observed between STE and combined-STE (GS r = 0.84, p < .001; GSRs r = 0.70, p < .001).Conclusions: The comparison of methods showed different values and poor agreement between the echocardiographic modalities. Regrettably, the combined method does not make it possible to obtain in a single image/measurement results that are comparable to STE and TDI data in the general population.