Value of Speckle Tracking for the Assessment of Right Ventricular Function in Patients Operated on for Tetralogy of Fallot. Comparison with Magnetic Resonance Imaging

Evaluation of right ventricular functions in patients with ischemic cardiomyopathy by speckle-tracking echocardiography

BACKGROUND

It is widely recognized that the right ventricle plays a significant role in the prognosis of numerous diseases. However, the assessment of right ventricular function (RV) has not been given much attention until recently. This study used speckle-tracking echocardiography (STE) to assess RV functions in ischemic cardiomyopathy (ICM) patients.

RESULTS

This study included 74 patients diagnosed with ischemic cardiomyopathy (ICM) and an ejection fraction (EF) of less than 50%. Although all the selected patients had normal RV systolic function by tricuspid annular plane systolic excursion (TAPSE), a considerable percentage of them had subtle RV systolic dysfunction, which could be identified by right ventricular free wall longitudinal strain (RV FWLS) (36.5%) and right ventricular global longitudinal strain (RV GLS) (55.4%). Moreover, the mean RV FWLS was significantly higher than RV GLS (- 20.4 ± 5.08% vs. - 17.5 ± 6.89%), respectively. Advanced left ventricle (LV) adverse remodeling was associated with subtle RV dysfunction. Using multivariate regression analysis, increased E/e' (p = 0.016, CI 1.135-3.423) and RV myocardial performance index (MPI) (p = 0.007, CI 0.000-0.007) were identified as independent factors of impaired RV FWLS with the greatest effectiveness.

CONCLUSION

When standard RV measures are normal in patients with ICM, RV systolic strain analysis offers an incremental utility to detect subtle abnormalities in RV function, especially in resource-constrained settings where cardiac magnetic resonance (CMR) is not practical.

Right Ventricular Strain in Patients With Ductal-Dependent Tetralogy of Fallot

BACKGROUND

Right ventricular (RV) dysfunction is an independent predictor of poor outcomes in patients with tetralogy of Fallot (TOF), and global longitudinal strain (GLS) is a well-validated echocardiographic technique to measure RV function. Although trends in RV GLS have been examined in patients with TOF, they have not been studied specifically in those with ductal-dependent TOF, a group in which there is not a clear consensus on the best surgical strategy. The aim of this study was to assess the midterm trajectory of RV GLS in patients with ductal-dependent TOF, drivers of this trajectory, and differences in RV GLS between repair strategies.

METHODS

This was a retrospective two-center cohort study of patients with ductal-dependent TOF who underwent repair. Ductal dependence was defined as being initiated on prostaglandin therapy and/or undergoing surgical intervention on or before 30 days of life. RV GLS was measured on echocardiography preoperatively, early after complete repair, and at 1 and 2 years of age. RV GLS was trended over time and compared between surgical strategies and with control subjects. Mixed-effects linear regression models were used to evaluate the factors associated with changes in RV GLS over time.

RESULTS

Forty-four patients with ductal-dependent TOF were included in the study, of whom 33 (75%) underwent primary complete repair and 11 (25%) underwent staged repair. Complete TOF repair was performed at a median of 7 days in the primary-repair group and 178 days in the staged-repair group. RV GLS improved over time from post-complete repair echocardiography through 2 years of age (-17.4% [interquartile range, -15.5% to -18.9%] vs -21.5% [interquartile range, -18.0% to -23.3%], P < .001). However, compared with age-matched control subjects, patients had worse RV GLS at all time points. There was no difference in RV GLS between the staged and primary complete repair groups at 2-year follow-up. Shorter intensive care unit length of stay after complete repair was independently associated with improvement in RV GLS over time. Strain improved by 0.07% (95% CI, 0.01 to 0.12) for each fewer day in the intensive care unit (P = .03).

CONCLUSIONS

RV GLS improves over time among patients with ductal-dependent TOF, though it is consistently reduced compared with control subjects, suggesting an altered deformation pattern in patients with ductal-dependent TOF. There was no difference in RV GLS between the primary- and staged-repair groups at midterm follow-up, suggesting that repair strategy is not a risk factor for worse RV strain in the mid postoperative period. A shorter complete-repair intensive care unit length of stay is associated with an improved trajectory of RV GLS.

The Interplay between Myocardial Fibrosis, Strain Imaging and Collagen Biomarkers in Adults with Repaired Tetralogy of Fallot

Background: We sought to assess the interplay between right ventricle (RV) fibrosis, biventricular dysfunction based on global longitudinal strain (GLS) analysis, and biomarkers such as Galectin-3 (Gal-3), procollagen type III (PCIII), and NTproBNP. Methods: We studied 35 adult patients with rToF. All patients underwent a cardiac magnetic resonance (CMR) scan including feature tracking for deformation imaging. Blood biomarkers were measured. Results: LGE RV was detected in all patients, mainly at surgical sites. Patients with the highest RV LGE scoring had greater RV dilatation and dysfunction whereas left ventricular (LV) function was preserved. LV GLS correlated with RV total fibrosis score (p = 0.007). A LV GLS value of −15.9% predicted LGE RV score > 8 (AUC 0.754 (p = 0.02)). Neither RV GLS nor biomarker levels were correlated with the extent of RV fibrosis. A cut-off value for NTproBNP of 145.25 pg/mL predicted LGE RV score > 8 points (AUC 0.729, (p = 0.03)). A cut-off value for Gal-3 of 7.42 ng/mL predicted PR Fraction > 20% [AUC 0.704, (p = 0.05)]. Conclusions: A significant extent of RV fibrosis was mainly detected at surgical sites of RV, affecting RV performance. CMR-FT reveals subtle LV dysfunction in rToF patients, due to decreased performance of the fibrotic RV. Impaired LV function and elevated NTproBNP in rToF reflect a dysfunctional fibrotic RV.

Right ventricular regional deformation analysis in patients operated for tetralogy of Fallot

PURPOSE

We aimed to compare the findings of a segmental speckle-tracking strain of right ventricle with those of cardiac magnetic resonance imaging in this setting.

METHODS

In 26 patients with operated tetralogy of Fallot (mean age, 15.35 ± 2.3 years; range 11-18 years), right ventricular segmental speckle-straining (the basal, mid, apical segments of right ventricular septum and lateral free wall, and right ventricular apex) were determined using two-dimensional echocardiography. The echocardiographic findings were compared to right ventricular ejection fraction, right ventricular indexed end-diastolic volume, indexed end-systolic volume and pulmonary regurgitation fraction at cardiac magnetic resonance.

RESULTS

Right ventricular global speckle strain was -18.6 ± 3.7and lateral free wall strain was -17.8 ± 4.9. Indexed right ventricular end diastolic volume was 171.7 ± 23.3 ml/m², indexed right ventricular end systolic volume was 95.1 ± 35.0 ml/m² and right ventricular ejection fraction was 44.76 ± 9.39%. Basal inferior septum is correlated with indexed right ventricular end-diastolic volume (RVEDV; r = -0.521, p = 0.015) and pulmonary regurgitation fraction (r = -0.584, p = 0.015). Cardiac magnetic resonance (CMR)-derived RVEDV is correlated with lateral free wall (r = -0.465, p = 0.034) and Global RV (r = 0.442, p = 0.045).

CONCLUSION

Right ventricular basal inferior septal and apical longitudinal strain correlates with the measures of right ventricular performance on CMR. These parameters would be useful to monitor right ventricular performance in patients after tetralogy of Fallot repair.

Intervendor Agreement for Right Ventricular Global Longitudinal Strain in Children

BACKGROUND

Right ventricular global longitudinal strain (RVGLS) has emerged as an important technique for clinical evaluation of (RV) function. The routine application of RVGLS in pediatrics remains limited by a lack of data on agreement between vendors. The aim of this study was to investigate intervendor agreement for RVGLS between the two commonly used analysis vendors in pediatrics, hypothesizing that RVGLS has good intervendor agreement, although it is likely lower than intravendor agreement (inter- and intraobserver reproducibility).

METHODS

Seventy infants and children with normal cardiac anatomy and varying ventricular function were included after prospectively obtaining RV-focused four-chamber apical images on the GE Vivid E95. Images were analyzed for RVGLS at acquired frame rates in EchoPAC (GE) and TomTec (TT) and in the compressed Digital Imaging and Communications in Medicine format in TT. Intraclass correlation coefficients and Bland-Altman plots were used to test intervendor agreement and intravendor reproducibility.

RESULTS

RVGLS measurements were equally feasible using TT and EchoPAC analysis (92%). There was good to excellent agreement for RVGLS between TT and EchoPAC analysis, with a relatively higher intraclass correlation coefficient between GE and TT at the acquired frame rate (0.85) than between GE and TT at the compressed frame rate (0.75) and significantly higher agreement in patients with abnormal RV function (0.7-0.9) than those with normal function (0.4-0.6). Intra- andinterobserver reproducibility for RVGLS was excellent (intraclass correlation coefficient = 0.74-0.96). Heart rate ≥ 100 beats/min and acquisition frame rate/heart rate ≤ 0.7 were associated with diminished agreement, especially when compressed data were involved.

CONCLUSIONS

RVGLS analyzed using EchoPAC and TT show good agreement, especially when analyzed at acquisition frame rates and in the setting of abnormal RV function. Otherwise, RVGLS should ideally be analyzed using the same vendor, and intervendor comparisons should be undertaken with caution, particularly if data are in a compressed format.

Assessing right ventricular systolic function using ultrasonic speckle-tracking imaging in repaired Tetralogy of Fallot with different pulmonary artery branch angles

OBJECTIVE

This study assessed whether ultrasonic speckle-tracking imaging (STI) could help evaluate right ventricular systolic function in repaired Tetralogy of Fallot (TOF) with different pulmonary artery branch angles.

METHODS

We retrospectively evaluated 64 patients who underwent surgery for TOF and 60 normal children. The angle between the left pulmonary artery and main pulmonary artery was measured using echocardiography and computed tomography angiography (CTA). Furthermore, STI was used to record the global longitudinal strain of the four-chamber view (GLS4), the global longitudinal strain of the two-chamber view (GLS2), and the global longitudinal strain of the right ventricle (RVGLS).

RESULTS

The GLS4, GLS2, and RVGLS values in the TOF groups with different pulmonary artery branch angles were significantly lower than those in the control group. Furthermore, the GLS2 and RVGLS values were significantly lower for angles of 90-100° and <90° (vs >100°). Multivariate linear regression analyses revealed that pulmonary regurgitation and the angle between the left and main pulmonary arteries were two important factors affecting RVGLS. The Bland-Altman consistency test revealed good agreement regarding the pulmonary artery branch angles measured using echocardiography and CTA.

CONCLUSION

In patients with TOF, the RVGLS was lower for acute left pulmonary artery angulation than for round and blunt left pulmonary artery angulation. The angle of the pulmonary artery branches was an important factor affecting RVGLS. Echocardiography can be used to measure the angle of the pulmonary artery branches, which provides valuable information for surgical correction of pulmonary artery morphology.

Ventricular Myocardial Deformation Imaging of Patients with Repaired Tetralogy of Fallot

In patients with repaired tetralogy of Fallot (TOF), dysfunction of the right and left ventricles remains an important issue. Adverse right ventricular (RV) remodeling has been related to RV dilation secondary to pulmonary regurgitation, electromechanical dyssynchrony, and myocardial fibrosis. Left ventricular (LV) dysfunction is attributed among other factors to altered ventricular-ventricular interaction. Advancements in echocardiography and cardiac magnetic resonance imaging have enabled direct interrogation of myocardial deformation of both ventricles in terms of myocardial strain and strain rate. Emerging evidence suggests that myocardial deformation imaging may provide incremental information for clinical use. In children and adults with repaired TOF, there is a growing body of literature on the use of myocardial deformation imaging in the assessment of ventricular mechanics and its clinical and prognostic values. The present review aims to provide an overview of impairment in RV and LV mechanics, associations between RV and LV deformation, changes in ventricular deformation after pulmonary valve replacement, and associations between measures of RV and LV deformation and outcomes and to highlight the clinical translational potential of myocardial deformation imaging in patients with repaired TOF.

The evaluation of right ventricular systolic function in patients with repaired Tetralogy of Fallot by conventional echocardiographic methods and speckle tracking echocardiography: Compared with the gold standard cardiac mangenetic resonance

BACKGROUND

Right ventricular (RV) function is one of the important prognostic factors in patients with repaired Tetralogy of Fallot (TOF). We aimed to assess RV function by conventional echocardiography and two-dimensional speckle tracking echocardiography (2D-STE) in patients with repaired TOF.

METHODS

Twenty-seven (male 17) adolescents and young adult patients (mean age 22.7 ± 6.7 years) operated on for TOF and age- and gender-matched healthy controls were included. RV systolic function in both groups were evaluated by fractional area change (FAC), tricuspid annular plane systolic excursion (TAPSE), RV myocardial performance index (RVMPI) and tricuspid annular peak systolic velocity by pulsed tissue Doppler (tricuspid S'), and also RV global longitudinal strain (RV GLS) obtained from STE. These results were compared with RV ejection fraction (RVEF) measured by cardiac magnetic resonance imaging (CMRI) performed within 3 months in patient group.

RESULTS

Systolic RVGLS values were significantly lower in patients compared to controls (-17.4 ± 3.1% vs -25.6 ± 3%). Among the echocardiographic parameters, RVGLS had the best correlation with RV EF derived from CMRI (r: -.6). By receiver operating characteristics analysis (ROC), an RV GLS cutoff value of -17.4% had 75% sensitivity and 68.4% specificity in identifying RVEF <45% with an area under curve 0.743 (P < .05). The intra- and inter-observer agreement for RV GLS was excellent.

CONCLUSION

RVGLS is an easy, effective, feasible, and reproducible tool in the evaluation of RV systolic function. So, RVGLS measurement by STE may be one of the routine echocardiographic parameters in the evaluation of RV systolic function in patients with repaired TOF.

Right Ventricular Contractile Reserve Is Impaired in Children and Adolescents With Repaired Tetralogy of Fallot: An Exercise Strain Imaging Study

BACKGROUND

Pulmonary insufficiency (PI) and right ventricular (RV) dysfunction are long-term complications in patients with repaired tetralogy of Fallot (rTOF). The aim of this study was to investigate RV contractile reserve and changes in PI that occur during exercise in patients with rTOF and the associations of these changes with exercise performance using stress echocardiography.

METHODS

Subjects with rTOF (n = 32) and healthy control subjects (n = 10) were prospectively enrolled and underwent rest and peak exercise echocardiography during standard cardiopulmonary exercise test protocol on a cycle ergometer or treadmill. RV contractile reserve was defined as the change in RV global longitudinal strain from rest to peak exercise. PI was assessed with the diastolic-to-systolic time-velocity integral ratio and diastolic/systolic velocity ratio from pulmonary artery Doppler interrogation. Exercise measures included heart rate reserve, percentage predicted maximum oxygen consumption, percentage predicted maximum work, and oxygen pulse.

RESULTS

RV contractile reserve was impaired in patients with rTOF compared with control subjects, with a significant drop in the absolute value of RV global longitudinal strain from 17% (range, 8%-27%) at rest to 13% (range, 5%-28%) at peak exercise. Similarly, PI decreased at peak exercise, with decreases in diastolic-to-systolic time-velocity integral and diastolic/systolic velocity ratios. Reduction in PI was directly associated with percentage predicted maximum oxygen consumption, percentage predicted maximum work, and greater oxygen pulse. Heart rate reserve was directly associated with percentage predicted maximum oxygen consumption and percentage predicted maximum work. RV contractile reserve was not associated with any exercise parameters.

CONCLUSIONS

Patients with rTOF have an abnormal myocardial response to exercise with impaired RV contractile reserve compared with control subjects. Heart rate reserve and reduction in PI at peak exercise are associated with better exercise performance and appear to be significant contributors to exercise performance in rTOF. Measures to improve chronotropic health in rTOF should be explored.

Longitudinal Changes in Right Ventricular Function in Tetralogy of Fallot in the Initial Years after Surgical Repair

BACKGROUND

Right ventricular (RV) dysfunction is associated with adverse long-term outcomes in patients with tetralogy of Fallot. Little is known about RV function in the first years after surgical repair. The aim of this study was to investigate perioperative changes in myocardial deformation using global longitudinal strain.

METHODS

A retrospective analysis of patients with surgically repaired tetralogy of Fallot was performed. Global longitudinal peak systolic RV strain was measured on early postoperative echocardiograms, two subsequent postoperative echocardiograms through 2 years postoperatively, and preoperative echocardiograms, when available. Preoperative and late follow-up strain was compared with strain in 0- to 8-month-old and 1- to 4-year-old control subjects, respectively.

RESULTS

Forty-seven patients were included. Compared with postoperative strain (7 ± 7 days postoperatively), strain at follow-up 1 (8.3 ± 4 months postoperatively) was significantly improved (-12.3 ± 3.3% vs -18.8 ± 2.5%, P < .001), with no additional improvement 23.2 ± 6 months postoperatively (-18.8 ± 2.5% vs -19.8 ± 3.1%, P = .12). Postoperative strain was worse than preoperative strain (n = 25, -12.5 ± 3.6% vs -18.4 ± 2.9%, P < .001). Compared with control subjects, preoperative strain was similar (-19.3 ± 3.8% vs -18.4 ± 2.9%, P = .30), though late follow-up strain was significantly worse (-27.7 ± 2.8% vs -19.8 ± 3.1%, P < .001).

CONCLUSIONS

RV global longitudinal strain worsens in the early postoperative period following surgical repair of tetralogy of Fallot but recovers through 2 postoperative years. Despite recovery to preoperative values, the presence of RV dysfunction compared with control subjects suggests that long-term dysfunction may begin early. The trajectory of RV dysfunction through the later years needs further study.

The value of right ventricular longitudinal strain in the evaluation of adult patients with repaired tetralogy of Fallot: a new tool for a contemporary challenge

OBJECTIVE

The role of right ventricular longitudinal strain for assessing patients with repaired tetralogy of Fallot is not fully understood. In this study, we aimed to evaluate its relation with other structural and functional parameters in these patients.

METHODS

Patients followed-up in a grown-up CHD unit, assessed by transthoracic echocardiography, cardiac MRI, and treadmill exercise testing, were retrospectively evaluated. Right ventricular size and function and pulmonary regurgitation severity were assessed by echocardiography and MRI. Right ventricular longitudinal strain was evaluated in the four-chamber view using the standard semiautomatic method.

RESULTS

In total, 42 patients were included (61% male, 32±8 years). The mean right ventricular longitudinal strain was -16.2±3.7%, and the right ventricular ejection fraction, measured by MRI, was 42.9±7.2%. Longitudinal strain showed linear correlation with tricuspid annular systolic excursion (r=-0.40) and right ventricular ejection fraction (r=-0.45) (all p<0.05), which in turn showed linear correlation with right ventricular fractional area change (r=0.50), pulmonary regurgitation colour length (r=0.35), right ventricular end-systolic volume (r=-0.60), and left ventricular ejection fraction (r=0.36) (all p<0.05). Longitudinal strain (β=-0.72, 95% confidence interval -1.41, -0.15) and left ventricular ejection fraction (β=0.39, 95% confidence interval 0.11, 0.67) were independently associated with right ventricular ejection fraction. The best threshold of longitudinal strain for predicting a right ventricular ejection fraction of <40% was -17.0%.

CONCLUSIONS

Right ventricular longitudinal strain is a powerful method for evaluating patients with tetralogy of Fallot. It correlated with echocardiographic right ventricular function parameters and was independently associated with right ventricular ejection fraction derived by MRI.

Early changes in right ventricular longitudinal function in chronic asymptomatic alcoholics revealed by two-dimensional speckle tracking echocardiography

BACKGROUND

Heart ventricular dysfunction has been characterized as reduced longitudinal function of the right ventricle (RV), and is associated with chronic alcohol abuse. This study investigated the use of two-dimensional speckle tracking echocardiography (2DSTE) to assess the longitudinal systolic and diastolic RV function of patients with alcoholic myocardial damage.

METHODS

We stratified 92 asymptomatic alcoholic men into three groups of increasing alcohol intake, Groups A-C. Thirty age-matched normal adult men served as the control group. Conventional echocardiography and tricuspid annulus peak systolic excursion (TAPSE) parameters were obtained. 2DSTE parameters were recorded from an apical 4-chamber view of the RV free wall. LV peak global longitudinal systolic strain was calculated from segmental averaging of the three apical long-axis views.

RESULTS

In Group C, the RV end diastolic diameter (RVEDD) was dramatically higher than that of Groups A, B and the control, while TAPSE was significantly lower in Group C compared with the other experimental groups. In Group B, the longitudinal early diastolic strain rate (SRe) and late diastolic strain rate (SRa) of the RV free wall, and LV longitudinal strain were significantly lower than that of Group A or the control. In Group C, all the 2DSTE parameters were significantly lower than that of the other groups. A significant negative linear correlation was noted between global RV systolic parameters systolic strain peak (S), peak systolic strain rate (SRs) and TAPSE (r1=-0.84, r2=-0.72, respectively, P <0.05).

CONCLUSIONS

Two-dimensional STE provided an effective and non-invasive method to assess the RV longitudinal function of patients with alcoholic myocardial damage. This methodology may be useful for diagnosing, directing treatment, and judging prognosis of alcoholic cardiac damage.

How best to assess right ventricular function by echocardiography

Right ventricular function is a crucial determinant of long-term outcomes of children with heart disease. Quantification of right ventricular systolic and diastolic performance by echocardiography is of paramount importance, given the prevalence of children with heart disease, particularly those with involvement of the right heart, such as single or systemic right ventricles, tetralogy of Fallot, and pulmonary arterial hypertension. Identification of poor right ventricular performance can provide an opportunity to intervene. In this review, we will go through the different systolic and diastolic indices, as well as their application in practice. Quantification of right ventricular function is possible and should be routinely performed using a combination of different measures, taking into account each disease state. Quantification is extremely useful for individual patient follow-up. Laboratories should continue to strive to optimise reproducibility through quality improvement and quality assurance efforts in addition to investing in technology and training for new, promising techniques, such as three-dimensional echocardiography.

Multimodality Evaluation of the Right Ventricle: An Updated Review

The assessment of the volumes, function, and mechanics of the right ventricle (RV) is very challenging because of the anatomical complexity of the RV. Because RV structure, function, and deformation are very important predictors of cardiovascular morbidity and mortality in patients with heart failure, pulmonary hypertension, congenital heart disease, or arrhythmogenic RV cardiomyopathy, it is of great importance to use an appropriate imaging modality that will provide all necessary information. In everyday clinical practice, 2-dimensional echocardiography (2DE) represents a method of first choice in RV evaluation. However, cardiac magnetic resonance (CMR) remained the gold standard for RV assessment. The development of new imaging tools, such as 3-dimensional echocardiography (3DE), provided reliable data, comparable with CMR, and opened a completely new era in RV imaging. So far, 3DE has shown good results in determination of RV volumes and systolic function, and there are indications that it will also provide valuable data about 3-dimensional RV mechanics, similar to CMR. Two-dimensional echocardiography-derived strain is currently widely used for the assessment of RV deformation, which has been proven to be a more significant predictor of functional capacity and survival than CMR-derived RV ejection fraction. The purpose of this review is to summarize currently available data about RV structure, function, and mechanics obtained by different imaging modalities, primarily 2DE and 3DE, and their comparison with CMR and cardiac computed tomography.

Preliminary Assessment of Tricuspid Valve Annular Velocity Parameters by Cardiac Magnetic Resonance Imaging in Adults with a Volume-Overloaded Right Ventricle: Comparison of Unrepaired Atrial Septal Defect and Repaired Tetralogy of Fallot

The aim is to compare tricuspid valve (TV) atrioventricular junction (AVJ) annular motion parameters in unrepaired atrial septal defect (ASD) and repaired Tetralogy of Fallot (TOF) by cardiac magnetic resonance (CMR) imaging. We retrospectively reviewed CMR studies performed between November 2007 and November 2013 in patients 16-45 years of age with unrepaired ASD (with or without partial anomalous pulmonary venous return) and with repaired TOF, who had previous infundibulotomy, but have not undergone pulmonary valve replacement. Longitudinal motion of lateral TV in four-chamber view cine image was tracked through the cardiac cycle with custom software. Twenty TOF patients and 12 ASD patients were included, and values were compared with 80 controls. Right ventricular end-diastolic volume index and right ventricular end-systolic volume index were similar in the ASD and TOF groups and were significantly higher in both groups than in controls. Maximum displacement of the TV in systole, velocity at half-maximal displacement during systole, and velocity at half-maximal displacement during early diastole were all significantly lower in the TOF group than the ASD group [1.39 ± 0.47 vs. 2.21 ± 0.46 (cm, p < 0.01), 5.9 ± 2.1 vs. 10.1 ± 2.3 (cm/s, p < 0.01), and 7.7 ± 2.6 vs. 10.9 ± 3.1 (cm/s, p < 0.05)]. TOF patients have diminished early diastolic TV AVJ velocity compared to patients with an unrepaired ASD, despite similar RV volumes. This observation could suggest diastolic dysfunction or cardiac mechanics unique to the postoperative, volume-overloaded right ventricle in patients with repaired TOF.

The effect of right ventricular myocardial remodeling on ventricular function as assessed by two-dimensional speckle tracking echocardiography in patients with tetralogy of Fallot: a single center experience from China

BACKGROUND

Published correlations between histological abnormalities and right ventricular (RV) function, as evaluated by speckle tracking echocardiography (STE), are scarce in patients with tetralogy of Fallot (TOF). The purpose of the study is to assess age-associated differences in the effect of RV myocardial remodeling on ventricular function in patients with TOF.

METHODS

Operatively resected crista supraventricularis muscle from 30 patients (median age 12months) undergoing intracardiac repair of TOF were studied by light microscopy. The patients were divided into younger (age at surgery ≤12months) and older (age at surgery >12months) subgroups. The RV global longitudinal peak systolic strain (GLS), strain rate (GLSRs) and early diastolic strain rate (GLSRe) were measured by two-dimensional STE before and 6months after repair.

RESULTS

The histopathological data revealed hypertrophy of the cardiomyocytes, a thickened endocardium, and increased interstitial and perivascular collagen in RV, which were associated with older age at the time of repair. The RV global systolic and diastolic functions in patients with repaired TOF were increased compared with the preoperative values. The RV cardiomyocyte diameter and collagen volume fraction (CVF) correlated with the preoperative GLS, GLSRs and GLSRe, respectively, in the younger patients (r1=-0.566, P1=0.018; r2=-0.493, P2=0.004; r3=-0.504, P3=0.039). The RV cardiomyocyte diameter and CVF correlated with preoperative GLS, GLSRs and GLSRe, respectively, in the older patients (r1=-737, P1=0.004; r2=-0.588, P2=0.035; r3=-0.812, P3=0.001). The correlation of the RV cardiomyocyte diameter with the postoperative GLS and GLSRe (r1=-665, P1=0.036; r2=-0.787, P2=0.007) and the CVF with the postoperative GLSRs and GLSRe (r1=-762, P1=0.002; r2=-0.713, P2=0.004) were identified only in the older patients. Multivariate analysis indicated that the age at repair was an independent predictor of postoperative GLSRs and GLSRe in all of the patients (β=-0.449, P=0.041; β=-0.607, P=0.004).

CONCLUSIONS

The effect of RV myocardial remodeling on preoperative RV function was more pronounced in the older patients with TOF than in the younger ones. Preoperative myocardial remodeling affected the postoperative RV function in the older but not in the younger patients. The age at the time of surgical repair was the independent determinant of the postoperative RV myocardial function.

Right ventricular function assessment using tissue Doppler imaging and speckle tracking echocardiography

Modern echocardiographic techniques, i.e. tissue Doppler imaging and speckle tracking echocardiography, allow for an assessment of global and regional right ventricular function. The right ventricular myocardial performance index and tricuspid annulus motion are used in the assessment of global right ventricular function, whereas duration of the cardiac cycle phases and myocardial velocities are used in the assessment of regional function. Strain and strain rate allow for an evaluation of both regional and global myocardial function. Literature reports provide data on the usefulness of these methods in patients with pressure and volume overload as well as with direct myocardial damage involving the right ventricle. In pulmonary hypertension, S' wave assessment may be used for therapeutic efficacy evaluation. Longitudinal strain reduction indicates an increased risk of vascular events, while an increased value of myocardial performance index is a predictor for a survival in pulmonary hypertension. A decreased S' wave velocity is associated with limited pulmonary vascular flow in patients with pulmonary embolism. In patients after atrial baffle repair for transposition of the great arteries, decreased longitudinal strain was an independent predictor for heart failure. A statistically significant decrease in both the S' wave as well as acceleration during isovolumic contraction were observed in arrhythmogenic right ventricular cardiomyopathy. S' wave and global right ventricular longitudinal strain values were lower in patients in the acute phase of myocardial infarction involving the right ventricle compared to the corresponding parameters in healthy individuals. In the case of tetralogy of Fallot correction, the evaluation of S' wave velocity may prove useful in identifying patients with reduced cardiac systolic reserve; a good correlation was also found between the global right ventricular longitudinal strain and right ventricular ejection fraction in MRI.

Associations between N-terminal pro-B-type natriuretic peptide and cardiac function in adults with corrected tetralogy of Fallot

BACKGROUND

Amino-terminal B-type natriuretic peptide (NT-proBNP) may detect early cardiac dysfunction in adults with tetralogy of Fallot (ToF) late after corrective surgery. We aimed to determine the value of NT-proBNP in adults with ToF and establish its relationship with echocardiography and exercise capacity.

METHODS AND RESULTS

NT-proBNP measurement, electrocardiography and detailed 2D-echocardiography were performed on the same day in 177 consecutive adults with ToF (mean age 34.6 ± 11.8 years, 58% male, 89% NYHA I, 29.3 ± 8.5 years after surgical correction). Thirty-eight percent of the patients also underwent a cardiopulmonary-exercise test. Median NT-proBNP was 16 [IQR 6.7-33.6] pmol/L, and was elevated in 55%. NT-proBNP correlated with right ventricular (RV) dilatation (r = 0.271, p < 0.001) and RV systolic dysfunction (r = -0.195, p = 0.022), but more strongly with LV systolic dysfunction (r=-0.367, p<0.001), which was present in 69 patients (39%). Moderate or severe pulmonary regurgitation was not associated with higher NT-proBNP. Tricuspid and pulmonary regurgitation peak velocities correlated with NT-proBNP (r = 0.305, p < 0.001 and r = 0.186, p = 0.045, respectively). LV twist was measured with speckle-tracking echocardiography in 71 patients. An abnormal LV twist (20 patients, 28%) was associated with elevated NT-proBNP (p = 0.030). No relationship between NT-proBNP and exercise capacity was found.

CONCLUSIONS

NT-proBNP levels are elevated in more than 50% of adults with corrected ToF, while they are in stable clinical condition. Higher NT-proBNP is most strongly associated with elevated pulmonary pressures, and with LV dysfunction rather than RV dysfunction. NT-proBNP has the potential to become routine examination in patients with ToF to monitor ventricular function and may be used for timely detection of clinical deterioration.