Systemic ventricular function in patients with transposition of the great arteries after atrial repair: a tissue Doppler and conductance catheter study

Multi-modality imaging of the systemic right ventricle in congenital heart disease

A comprehensive and structured imaging approach in the evaluation of the systemic right ventricle (sRV) in patients with complete transposition of the great arteries (TGA) after atrial switch procedure and congenitally corrected transposition of the great arteries (ccTGA) is a key for their optimal lifelong surveillance. Despite the improvements in cardiovascular imaging of adults with congenital heart disease (ACHD), the imaging of sRV remains an ongoing challenge due to its complex morphology and the difficulty in applying the existing knowledge for the systemic left ventricle. While cardiac magnetic resonance (CMR) is considered the gold standard imaging method, echocardiographic evaluation is primarily preferred in everyday clinical setting. Although qualitative assessment of its systolic function is primarily used, the introduction of advanced echocardiographic techniques, such as speckle tracking echocardiography (STE) and three-dimensional echocardiography (3DE), has provided new insights into the optimal assessment of the sRV. Standardized quantitative parameters remain to be elucidated, and morphometric and mechanistic studies are warranted to validate reference ranges for the sRV. This review highlights the challenges in the optimal evaluation of sRV and summarizes the available imaging tools. HIGHLIGHTS: CMR is the gold standard imaging method of sRV. Qualitative assessment of the systolic function of sRV is primarily used. Advanced echocardiographic techniques (STE and 3DE) provide optimal sRV assessment. Reference ranges for the sRV indices are warranted to be validated.

15-Year follow-up of regional right and left ventricular function after the Senning operation: a Colour-Doppler myocardial imaging study

INTRODUCTION

Despite right ventricular (RV) dysfunction being a major concern in Senning patients, long-term follow-up data is lacking. This study aimed (1) at evaluating regional (base-mid-apex) RV and left ventricular (LV) function using Colour-Doppler myocardial imaging over a 15-year follow-up period and (2) at comparing results with matched controls.

METHODS

For the longitudinal analysis (2004-2019), we compared systolic and diastolic function in 10 Senning patients. For the cross-sectional analysis, we compared the subaortic RV (sRV) of Senning patients with the RV and LV of matched controls and the subpulmonary LV (spLV) of Senning patients with the LV of matched controls.

RESULTS

The longitudinal analysis of sRV function showed a significant decrease in apical peak systolic strain (-17 ± 7% vs -12 ± 4%; p = 0.025) and apical peak systolic strain rate (-1.1 ± 0.3s^-1 vs -0.8 ± 0.4s^-1; p = 0.012). spLV function showed a significant decrease in peak systolic velocity (mid; p = 0.013 and apex; p = 0.011) and peak systolic strain rate (mid; p = 0.048). The cross-sectional analysis revealed significant lower values for basal, mid and apical peak systolic velocity, peak systolic strain rate, peak systolic strain of the sRV of Senning patients when compared to both LV and RV of matched controls (all p < 0.05).

CONCLUSION

Our study showed that systolic and diastolic sRV function did not change over a 15-year follow-up period, except in the apical region. There was a decline in spLV systolic function, which may be of clinical value. On the other hand, when compared to age- and gender-matched controls, the sRV of Senning patients exhibits significantly decreased measurements of longitudinal systolic function.

A Comprehensive Functional Analysis in Patients after Atrial Switch Surgery

Background  Long-term course after atrial switch operation is determined by increasing right ventricular (RV) insufficiency. The aim of our study was to investigate subtle functional parameters by invasive measurements with conductance technique and noninvasive examinations with cardiac magnetic resonance imaging (CMR).

Methods  We used invasive (pressure–volume loops under baseline conditions and dobutamine) and noninvasive techniques (CMR with feature tracking [FT] method) to evaluate RV function. All patients had cardiopulmonary exercise testing (CPET).

Results  From 2011 to 2013, 16 patients aged 28.2 ± 7.3 (22–50) years after atrial switch surgery (87.5% Senning and 12.5% Mustard) were enrolled in this prospective study. All patients were in New York Heart Association (NYHA) class I to II and presented mean peak oxygen consumption of 30.1 ± 5.7 (22.7–45.5) mL/kg/min. CMR-derived end-diastolic volume was 110 ± 22 (78–156) mL/m ² and RV ejection fraction 41 ± 8% (25–52%). CMR-FT revealed lower global systolic longitudinal, radial, and circumferential strain for the systemic RV compared with the subpulmonary left ventricle. End-systolic elastance (Ees) was overall reduced (compared with data from the literature) and showed significant increase under dobutamine (0.80 ± 0.44 to 1.89 ± 0.72 mm Hg/mL, p ≤ 0.001), whereas end-diastolic elastance (Eed) was not significantly influenced (0.11 ± 0.70 to 0.13 ± 0.15 mm Hg/mL, p  = 0.454). We found no relevant relationship between load-independent conductance indices and strain or CPET parameters. Conductance analysis revealed significant mechanical dyssynchrony, higher during diastole (mean 30 ± 4% baseline, 24 ± 6% dobutamine) than during systole (mean 17 ± 6% baseline, 19 ± 7% dobutamine).

Conclusions  Functional assessment of a deteriorating systemic RV remains demanding. Conductance indices as well as the CMR-derived strain parameters showed overall reduced values, but a significant relationship was not present (including CPET). Our conductance analysis revealed intraventricular and predominantly diastolic RV dyssynchrony.

Advanced Imaging to Phenotype Patients With a Systemic Right Ventricle

Background

Reduced ventricular function and decreased exercise capacity are widespread in adults with complete transposition of the great arteries after atrial switch (TGA‐Mustard/Senning) and congenitally corrected TGA (ccTGA). Advanced imaging techniques may help to better phenotype these patients and evaluate exercise cardiac response.

Methods and Results

Thirty‐three adults with a systemic right ventricle (70% TGA‐Mustard/Senning, 37±9 years of age, 24% female, 94% New York Heart Association class I‐II) underwent echocardiogram, cardiopulmonary exercise testing, and cardiovascular magnetic resonance imaging at rest and during a 4‐stage free‐breathing bicycle test. They were compared with 12 healthy controls (39±10 years of age, 25% female, all New York Heart Association class I). TGA‐Mustard/Senning patients had a higher global circumferential strain (−15.8±3.6 versus −11.2±5.2%, P=0.008) when compared with ccTGA, whereas global longitudinal strain and systemic right ventricle contractility during exercise were similar in both groups. Septal extracellular volume (ECV) in ccTGA was significantly higher than in TGA‐Mustard/Senning (30.2±2.0 versus 27.1±2.7%, P=0.005). During exercise, TGA‐Mustard/Senning had a fall in end‐diastolic volume and stroke volume (11% and 8%, respectively; both P≤0.002), whereas ccTGA could increase their stroke volume in the same way as healthy controls. Because of a greater heart rate reserve in TGA‐Mustard/Senning (P for interaction=0.010), cardiac index and peak oxygen uptake were similar between both patient groups.

Conclusions

Caution should be exercised when evaluating pooled analyses of systemic right ventricle patients, given the differences in myocardial contraction pattern, septal extracellular volume, and the exercise response of TGA‐Mustard/Senning versus ccTGA patients. Longitudinal follow‐up will determine whether abnormal exercise cardiac response is a marker of earlier failure.

The effects of adenotonsillar hypertrophy corrective surgery on left ventricular functions and pulmonary artery pressure in children

OBJECTIVE

Comparison of left ventricular functions in preoperative and postoperative periods of children with adenotonsillar hypertrophy (ATH) who have findings of upper airway obstruction (UAO), using echocardiographic parameters.

METHODS

Thirty children who were diagnosed with UAO due to ATH, and who have undergone adenoidectomy/adenotonsillectomy and 30 healthy children, between 2 and 11 years of age, were included in the study. Patient group was evaluated by the pulsed wave tissue Doppler echocardiography, as well as with conventional echocardiography, before and 6 months after the operation.

RESULTS

Of 30 children in study group, 18 (60%) had adenotonsillectomy and 12 (40%) had adenoidectomy. The differences between groups regarding myocardial performance index (MPI) was not statistically significant (p = 0.847). There was not any statistically significant difference between groups in terms of mitral isovolemic acceleration (MIVA) (2.28 ± 0.67, 2.24 ± 0.55, 2.23 ± 0.49; p = 0.943, respectively). Interventricular septum diameter (IVSD) was significantly higher in preoperative group than postoperative and control groups (3.68 ± 0.52, 3.50 ± 0.40, 3.38 ± 0.60; p = 0.028, respectively). Pulmonary acceleration time (PAcT) was found to be significantly lower in preoperative group compared to postoperative and control groups (107.64 ± 16.60, 119.52 ± 15.95, 120.47 ± 16.19; p = 0.004, respectively). Mean pulmonary arterial pressure (mPAP) was significantly higher in preoperative group than postoperative and control groups (30.58 ± 8.11, 25.23 ± 9.07, 25.00 ± 6.52; p = 0.002, respectively). In postoperative group mPAP was found to be similar to the control group.

CONCLUSIONS

Clinical or subclinical left ventricle (LV) dysfunction in children with ATH who have findings of UAO was not determined while mean pulmonary arterial pressure was significantly higher compared with the control cases. Besides early adenotonsillectomy is a beneficial treatment option for these patients.

Stress Echocardiographic Evaluation for D-Transposition of the Great Arteries after Atrial Redirection: Unmasking Early Signs of Myocardial Dysfunction and Baffle Stenosis

BACKGROUND

The authors used semisupine cycle ergometry stress echocardiography to assess cardiac function and unmask baffle stenosis in patients with d-transposition of the great arteries after atrial redirection surgery.

METHODS

This was a retrospective review of semisupine cycle ergometry stress echocardiography performed in 53 patients (64% male; mean age, 24.0 years; 90% Mustard procedure) and 56 healthy control subjects. Incremental exercise to volitional fatigue was performed. Hemodynamic data, echocardiographic cardiac dimensions, area change, tissue Doppler velocities, strain, ventricular synchronization, and superior vena cava flow velocities before and immediately after exercise are reported.

RESULTS

Patients had lower exercise capacity (870 vs 1,854 J/kg, P < .001) and peak heart rates (132 vs 167 beats/min, P < .001). Stroke volume index did not increase with exercise (45 vs 47 mL/m², P = .400). Cardiac index increased in both groups with exercise (3.0 vs 6.1 and 2.9 vs 7.0 L/min/m², P < .001) and was higher in control subjects (P = .006). Right ventricular diastolic and systolic areas decreased significantly with exercise in both the short-axis and four-chamber views. Right and left ventricular contraction time shortened with exercise (405 vs 247 and 338 vs 217 msec, P < .001) and remained synchronous (ratio of right ventricular to left ventricular contraction time = 0.080). Doppler velocities in patients with baffle obstruction were higher in the lower superior vena cava with exercise compared with nonobstructed patients (1.87 vs 1.46 m/sec, P = .020) and normalized after catheter intervention (1.49 vs 1.46 m/sec, P = .800).

CONCLUSIONS

Patients with d-transposition of the great arteries have lower exercise capacity and peak heart rates. The systemic right ventricle presents a lesser but qualitatively normal systolic response and decreased diastolic filling. Semisupine cycle ergometry stress echocardiography unmasked SVC obstruction.

Noninvasive Imaging in Adult Congenital Heart Disease

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

Limited Ventricular Preload is the Main Reason for Reduced Stress Reserve After Atrial Baffle Repair

The atrial baffle repair (ABR) significantly improved the fate of patients with transposition of the great arteries (TGA). However, these patients show impaired exercise tolerance and some present severe decline of systemic ventricular function. Intrinsic myocardial weakness, low heart rate response to exercise and diastolic filling impairment are discussed to be causative. Forty-nine long-term survivors with TGA (median age 23.7 year) after ABR were catheterized with measured oxygen consumption in four conditions (baseline, volume, atrial pacing, dobutamine) and the results were compared to 10 normal controls. Median cardiac output was significantly lower in the ABR group (2.2 vs. 2.6 l/min/m²; p = 0.015), and systemic resistance was significantly elevated (28.9 vs. 22.2 U m²; p = 0.04) in comparison with normals. While stroke volume rose by 27% in the control group, it dropped by 7% in patients after ABR at atrial pacing (80/min). Stroke volume increase after dobutamine was significantly lower after ABR in comparison with normal controls (34 vs. 106%; p = 0.001). Higher NYHA class (p = 0.043), degree of tricuspid regurgitation (p = 0.009) and ventricular function (p = 0.028) were associated with lower stroke volume increase. Limited exercise capability of patients after ABR for TGA is primarily due to limited diastolic filling of the ventricles due to stiff non-compliant atrial pathways. Elevated systemic resistance may lead to severe myocardial hypertrophy with possible ischemia and contribute to the multifactorial decline of ventricular function in some patients.

Assessment of right heart function in preeclampsia by echocardiography

BACKGROUND

Preeclampsia (PE) is a multisystemic disorder characterized by hypertension and proteinuria that is specific to pregnancy and associated with maternal and fetal morbidity-mortality.

AIM

To assess right heart structure and function in PE by echocardiography using conventional and tissue Doppler techniques.

METHODS

In total, 67 women with untreated PE and 46 matched healthy pregnant women were included. PE was defined according to the ACOG (2002) criteria. Right and left heart functions were evaluated using transthoracic two-dimensional (2D) echocardiography with color Doppler and tissue Doppler imaging techniques.

RESULTS

Right ventricular basal and outflow tract diameters and free wall thickness, right atrial end-systolic maximum diameter, and area were significantly higher in the PE group than the control group (p<0.05). Tricuspid annular plane systolic excursion, isovolumic acceleration time, tissue Doppler-derived tricuspid lateral annular systolic velocity (S'), right ventricle fractional area change, and myocardial performance index (Tei) were significantly lower in the PE group than the controls (p<0.05).

CONCLUSIONS

PE does not only affect the left side of the heart but also the right side. This finding may open new scenarios, because right ventricular dysfunction may also be responsible for PE-related morbidity.

Quantification of systemic right ventricle by echocardiography

Improvements in cardiac imaging have recently focused a great interest on the right ventricle (RV). In patients with congenital heart disease, the right ventricle (RV) may support the systemic circulation (systemic RV). There are 2 different anatomic conditions providing such physiology: the congenitally corrected transposition of the great arteries (ccTGA) and the TGA surgically corrected by atrial switch. During the last decades, evidence is accumulating that progressive systemic RV failure develops leading to considerable morbidity and mortality. Various imaging modalities have been used to evaluate the systemic RV, but echocardiography is still predominantly used in clinical practice, allowing an anatomic and functional approach of the systemic RV function and the potential associated anomalies. The goal of this review is to offer a clinical perspective of the non-invasive evaluation of the systemic RV by echocardiography.

HeartWare Ventricular Assist Device Placement in a Patient With Corrected Dextro-Transposition of Great Arteries: A Case Report and Its Clinical Challenges

Given the improved survival in patients with corrected dextro-transposition of great arteries (D-TGA), it has evolved into an adult congenital heart defect. It is important to understand the management and complications observed in this population that eventually progresses to systemic ventricular failure requiring cardiac transplantation. Our case focuses on the rapid right ventricle (RV) deterioration of a patient with corrected D-TGA following a surgical procedure requiring systemic support. With such patients awaiting heart transplantation, there are limited assist devices available for RV support and no right ventricular assist device is approved for destination therapy yet. Current indications for implantation of the HeartWare ventricular assist device (HVAD) are limited by the Food and Drug Administration (FDA) to the left ventricle support as a bridge to transplantation. However, its use in the United States for right-sided support has rarely been described for adult congenital defects. In this case, a HeartWare assist device was used to provide systemic support as a bridge to cardiac transplant. The size and implantation design of the HVAD makes it a promising option for patients with this challenging patient population and RV failure as a late complication.

Assessment of pulmonary artery pressure and right ventricular function in children with adenotonsillar hypertrophy using different parameters

OBJECTIVE

Our aim was comparison of preoperative and postoperative right ventricular functions of children with adenotonsillar hypertrophy (ATH) who have findings of upper airway obstruction, using new echocardiographic parameters.

METHODS

Forty-one children who have admitted to our hospital with symptoms suggestive of upper airway obstruction, whose history and physical examination findings suggest upper airway obstruction and who have undergone adenoidectomy/adenotonsillectomy and 40 healthy children, all of whom between 2 and 12 years of age, were included in the study. Patient group was evaluated by pulsed wave tissue Doppler echocardiography as well as with conventional echocardiography before the operation and 6 months after the operation.

RESULTS

Of 41 children in study group, 26 (63.4%) had adenotonsillectomy and 15 (36.6%) had adenoidectomy. Tricuspid annular plane systolic excursion (TAPSE) was significantly lower in preoperative group compared to control group (18.46±1.67, 19.77±1.62; p=0.000, respectively). Myocardial performance index (MPI) was significantly higher in preoperative group than postoperative and control group (0.40±0.07, 0.36±0.06, 0.35±0.07; p=0.032, respectively). Tricuspid isovolumic acceleration (TIVA) was significantly lower in preoperative group than preoperative and control group (2.97±0.8, 3.43±0.7, 3.43±0.9; p=0.020, respectively). Disappearance of this difference was found between postoperative and control groups (p=0.984). Pulmonary acceleration time (PAcT) was found to be significantly lower in preoperative group compared to postoperative and control group (109.68±18.03, 118.93±17.46, 120.0±14.07; p=0.010, respectively). Mean pulmonary artery pressure (mPAP) was significantly higher in preoperative group than control group (29.64±8.11, 24.95±6.33; p=0.010, respectively). In postoperative group mPAP was found to be similar to control group (25.48±7.85, 24.95±6.33; p=0.740, respectively).

CONCLUSIONS

TAPSE, PAcT, MPI and TIVA are useful markers for evaluation of preoperative and postoperative ventricular function in children with ATH who have findings of upper airway obstruction. We think that using these practical and easy-to perform parameters may be relevant for evaluation and postoperative follow-up of patients with ATH who have findings of upper airway obstruction. Besides adenotonsillectomy is a beneficial treatment option for these patients.

The value of isovolumic acceleration for the assessment of right ventricular function in acute pulmonary embolism

AIM

The aim of this study was to assess the value of tricuspid annulus myocardial isovolumic acceleration (IVA) in the assessment of right ventricular function in patients with acute pulmonary embolism (PE).

METHODS

Fifteen patients (mean age 60.6±11.3 years) with acute PE were enrolled and a control group was formed of 15 patients with a similar mean age (60.3±11.5). Patients who were diagnosed with acute PE by thoracic computed tomography angiography underwent transthoracic echocardiography at the time of diagnosis and at one month after diagnosis.

RESULTS

In the control group IVA was 2.8±0.2 m/s(2), while in the acute PE group, it was 2.0±0.1 m/s(2) at the time of diagnosis and 2.9±0.1 m/s(2) at the end of the first month. When IVA values of acute PE patients at the end of the first month were compared with their initial values and those of the control group, they had normalized (control and acute PE p<0.0001; control and PE at one-month follow-up p=0.983).

CONCLUSION

In our study, IVA was shown to be a reliable marker of right ventricular systolic function in patients with acute PE.

Comparison of pressure-volume loop and echocardiographic measures of diastolic function in patients with a single-ventricle physiology

Echocardiographic measurements of diastolic function have not been validated against invasive pressure-volume loop (PVL) analysis in the single-ventricle population. The authors hypothesized that echocardiographic measures of diastolic function would correlate with PVL indices of diastolic function in patients with a single-ventricle physiology. The conductance-derived PVL measures of diastolic function included the isovolumic relaxation time constant (τ), the maximum rate of ventricular pressure decline (peak -dP/dt), and a measure of passive diastolic stiffness (μ). The echocardiographic measures included Doppler inflow patterns of the dominant atrioventricular valve (DAVV), tissue Doppler velocities (TDI) at the lateral (ventricular free wall) component of the DAVV annulus, and the TDI-derived isovolumic relaxation time (IVRT'). The correlation between PVL and echocardiographic measures was examined. The study enrolled 13 patients at various stages of surgical palliation. The median age of the patients was 3 years (range 3 months to 19 years). τ correlated well with Doppler E:A (r = 0.832; p = 0.005), lateral E:E' (r = 0.747; p = 0.033), and IVRT' (r = 0.831; p = 0.001). Peak -dP/dt also was correlated with IVRT' (r = 0.609; p = 0.036), and μ also was correlated with IVRT' (r = 0.884; p = 0.001). This study represents the first-ever comparison of diastolic echocardiographic and PVL indices in a single-ventricle population. The findings show that Doppler E:A, lateral E:E', and IVRT' correlate well with PVL measures of diastolic function. This study supports further validation of echocardiographic measures of diastolic function versus PVL measures of diastolic function in the single-ventricle population.

Low cardiac output due to acute right ventricular dysfunction and cardiopulmonary interactions in congenital heart disease (2013 Grover Conference series)

The importance of right ventricular dysfunction, as a driver of symptoms and outcomes in the normal biventricular circulation, is increasingly recognized. However, the pathophysiologic mechanisms underlying the role of the right ventricle in acute and chronic hemodynamic deterioration are less well understood. This review aims to clarify the impact of acute right ventricular dysfunction on biventricular interactions and, in turn, to discuss the role of cardiopulmonary interactions in the normal circulation and when modified by the presence of associated structural malformations. Such interactions may be adverse or beneficial, and a more complete understanding of their importance may result in novel therapeutic strategies and improved outcomes.

Functional assessment for congenital heart disease

Significant improvement in survival of children with congenital cardiac malformations has resulted in an increasing population of adolescent and adult patients with congenital heart disease. Of the long-term cardiac problems, ventricular dysfunction remains an important issue of concern. Despite corrective or palliative repair of congenital heart lesions, the right ventricle, which may be the subpulmonary or systemic ventricular chamber, and the functional single ventricle are particularly vulnerable to functional impairment. Regular assessment of cardiac function constitutes an important aspect in the long-term follow up of patients with congenital heart disease. Echocardiography remains the most useful imaging modality for longitudinal monitoring of cardiac function. Conventional echocardiographic assessment has focused primarily on quantification of changes in ventricular size and blood flow velocities during the cardiac cycles. Advances in echocardiographic technologies including tissue Doppler imaging and speckle tracking echocardiography have enabled direct interrogation of myocardial deformation. In this review, the issues of ventricular dysfunction in congenital heart disease, conventional echocardiographic and novel myocardial deformation imaging techniques, and clinical applications of these techniques in the functional assessment of congenital heart disease are discussed.

Evaluation of right ventricular function in patients with tetralogy of Fallot using the myocardial performance index and isovolumic acceleration: a comparison with cardiac magnetic resonance imaging

BACKGROUND

Assessment of right ventricular function is a key point in the follow-up of operated patients with tetralogy of Fallot. Cardiac magnetic resonance assessment of right ventricular function is considered the gold standard. However, this technique is expensive, has limited availability, and requires significant expertise to acquire and interpret the images. Myocardial performance index and isovolumic acceleration have recently been studied for the assessment of right ventricular function and are shown to be simple yet powerful tools for assessing patients with right ventricular dysfunction of various origins.

METHODS

In this study, the integrity of myocardial performance index and isovolumic acceleration obtained by tissue Doppler imaging echocardiography to quantify right ventricular function was assessed in 31 patients operated for tetralogy of Fallot. Myocardial performance index and isovolumic acceleration measurements were compared with the parameters derived by cardiac magnetic resonance imaging.

RESULTS

In this study, a significant correlation has not been detected between cardiac magnetic resonance-originated right ventricular ejection fraction, pulmonary regurgitation fraction and myocardial performance index, isovolumic acceleration obtained by tissue Doppler imaging echocardiography from the lateral tricuspid annulus of the right ventricle.

CONCLUSION

We have concluded that when evaluated separately, myocardial performance index and isovolumic acceleration obtained from tissue Doppler imaging echocardiography can be used in the long-term follow-up of patients who have been operated for tetralogy of Fallot, but that they do not show correlation with cardiac magnetic resonance-originated right ventricle ejection fraction and pulmonary regurgitation fraction.

Isovolumic contraction acceleration before and after percutaneous closure of atrial septal defects

Aim

To compare systemic right ventricular function by isovolumic myocardial acceleration before and 6 months after the percutaneous closure of atrial septal defects (ASD).

Material and methods

Patients admitted to our tertiary center for the percutaneous closure of atrial septal defects between January 2010 and August 2012 constituted the study group. Right ventricular function of patients was assessed by tissue Doppler echocardiography before and after surgery. Echocardiographic data in patients were compared to age-matched controls without any cardiac pathology and studied in identical fashion mentioned below.

Results

A total of 44 patients (24 males, 20 females) and 44 age-matched controls (25 males, 19 females) met the eligibility criteria for the study. Right ventricular end-diastolic and end-systolic volume, right ventricular end-diastolic diameter measurements on echocardiogram, and pulmonary artery pressures in both pre- and post-ASD groups were significantly higher than in controls. Tricuspid annular plane systolic excursion and isovolumic myocardial acceleration measurements significantly increased after the percutaneous closure of the defect; however, post-ASD measurements were still significantly lower than the controls.

Conclusions

Atrial septal defect device closure resulted in a significant increase of isovolumic myocardial acceleration measurements. Tissue Doppler analysis of regional myocardial function offers new insight into myocardial compensatory mechanisms for acute and chronic volume overload of both ventricles.

Echocardiography in pediatric pulmonary hypertension

Pediatric pulmonary hypertension is a complicated disease with multiple etiologies and high mortality. Echocardiography is at the forefront of evaluation as a noninvasive, portable imaging modality that can yield diagnostic and prognostic information regarding this disease. Echocardiography is known for its ability to give an anatomic assessment of the heart and proximal blood vessels. With the additional use of Doppler echocardiography and myocardial motion assessment, the effects of elevated pulmonary pressures on the heart can be evaluated. This can allow for estimation of pulmonary artery pressures and resistances and assessment of ventricular systolic and diastolic functions. However despite its advantages, echocardiography is still an indirect assessment of pulmonary hypertension and not a substitute for cardiac catheterization. The purpose of this review is to discuss common techniques for the assessment of pulmonary hypertension by echocardiography as well as their limitations.

Myocardial tissue Doppler velocities in fetuses with hypoplastic left heart syndrome

BACKGROUND

Tissue Doppler Imaging (TDI) is a sensitive index of myocardial function. Its role in the fetus has not been extensively evaluated.

OBJECTIVE

To compare myocardial tissue Doppler velocities in fetuses with hypoplastic left heart syndrome (HLHS) to those of normal fetuses (matched for gestational age.)

METHODS

Cross-sectional retrospective study conducted at 2 large perinatal centers (2003-2007). Fetuses with HLHS (n = 13) were compared with normal fetuses (n = 207) in 5 gestational age groups. TDI data included peak systolic (s'), peak early (e'), and late diastolic velocities (a'). Linear regression was used to compare TDI parameters in fetuses with HLHS to normal fetuses matched for gestational age.

RESULTS

Fetuses with HLHS had significantly reduced lateral tricuspid annular e' as compared to normal fetuses. Both normal fetuses and those with HLHS had linear increase in TDI velocities with advancing gestational age.

CONCLUSIONS

TDI velocities are abnormal in fetuses with HLHS. TDI can be useful in serial follow-up of cardiac function in fetuses with HLHS.

Novel methods for assessment of right heart structure and function in pulmonary hypertension

Long-term increases in pulmonary vascular resistance and pulmonary arterial pressure resulting from structural alterations and abnormal vasoreactivity of the pulmonary vasculature may lead to right ventricular (RV) remodeling. Conventional methods of assessment of RV structure and function do not provide sensitive markers of RV remodeling for prognostic information. Advances in cardiac imaging have provided the capability to obtain quantitative information on the RV structure and function. This article reviews the clinical conditions that result in PH and discusses the novel and emerging methods for the assessment of right heart structure and function in PH in infants and children.

Transthoracic echocardiography in children and young adults with congenital heart disease

Transthoracic echocardiography (TTE) is the first-line tool for diagnosis and followup of pediatric and young adult patients with congenital heart disease (CHD). Appropriate use of TTE can reduce the need for more invasive modalities, such as cardiac catheterization and cardiac magnetic resonance imaging. New echocardiographic techniques have emerged more recently: tissue Doppler imaging, tissue tracking (strain and strain rate), vector velocity imaging (VVI), myocardial performance index, myocardial acceleration during isovolumic acceleration (IVA), the ratio of systolic to diastolic duration (S/D ratio), and two dimensional measurements of systolic right ventricular (RV) function (e.g., tricuspid annular plane systolic excursion, TAPSE). These may become valuable indicators of ventricular performance, compliance, and disease progression. In addition, three-dimensional (3D) echocardiography when performed for the assessment of valvular function, device position, and ventricular volumes is being integrated into routine clinical care. In this paper, the potential use and limitations of these new echocardiographic techniques in patients with CHD are discussed. A particular focus is on the echocardiographic assessment of right ventricular (RV) function in conditions associated with increased right ventricular volume (e.g., pulmonary regurgitation after tetralogy of Fallot repair) or pressure (e.g., pulmonary hypertension) in children and young adults.

Tissue Doppler-derived measurement of isovolumic myocardial contraction in the pediatric population

Multiple echocardiographic techniques have been utilized to quantify systolic function. The shortening and ejection fraction remain the most commonly used and accepted methods. However, these measures are affected by altered loading conditions, and are not applicable when ventricular geometry differs from the prolate ellipsoid typical of a left ventricle. Mitral valve annular acceleration during isovolumic contraction (IVA) has been proposed as a load independent index of left ventricular contractility. However, published values for IVA demonstrating normal function vary. In addition, the value of IVA which may discern impaired systolic function has not been established. The purpose of this study is to determine a threshold IVA value for abnormal left ventricular function in the pediatric population. Structurally/functionally normal control (n = 90) and dilated cardiomyopathy (study = 64) patients were compared for differences in left ventricular: wall stress (WS), velocity of circumferential fiber shortening (VCFc), ejection fraction (EF), ejection force, and pulsed wave-derived medial and lateral wall IVA. No difference in body surface area (p = 0.61) or gender (p = 0.53) was noted. Left ventricular ejection fraction, ejection force, VCFc, and IVA were significantly lower and WS was significantly higher in the study group (p < 0.01). The medial IVA was 1.71 ± 0.89 m/s(2) for an EF <40%, 1.74 ± 0.70 m/s(2) for an EF = 40-50%, 2.46 ± 0.89 m/s(2) for an EF >50%. The lateral IVA was 1.81 ± 1.03 m/s(2) for an EF <40%, 2.07 ± 0.78 m/s(2) for an EF = 40-50%, 2.54 ± 0.99 m/s(2) for an EF >50%. ROC analysis demonstrated a medial IVA of 1.97 m/s(2) as the cut-off for predicting an EF <50% with a 77% sensitivity of and specificity of 66% (AUC = 0.75, CI = 0.67-0.83, p < 0.01). ROC analysis demonstrated a lateral IVA of 2.31 m/s(2) as the cut-off for predicting an EF <50% with a 73% sensitivity of and specificity of 63% (AUC = 0.72, CI = 0.63-0.82, p < 0.01). IVA lateral of 1.93 m/s(2) or less was associated with heart transplant and death. ICC analysis demonstrated some interobserver variability in IVA measurement (0.57-0.65). The normal IVA of the medial and lateral mitral valve annulus measure over 1.97 m/s(2) and 2.31 m/s(2), respectively; values less than this cut-off are associated with EF <50%. Despite some problems with reproducibility IVA remains a promising method of screening for diminished ventricular contractility in the setting of abnormal geometry.

β(3)-Adrenoceptor Antagonist SR59230A Attenuates the Imbalance of Systemic and Myocardial Oxygen Transport Induced by Dopamine in Newborn Lambs

Background

In neonates, the increase in O₂-delivery (DO₂) by dopamine is offset by a greater increase in O₂-consumption (VO₂). This has been attributed to β₃-adrenergic receptors in neonatal brown fat tissue. β₃ receptors in the heart have negative inotropic properties. We evaluated the effects of SR59230A, a β₃-antagonist, on the balance of systemic and myocardial O₂-transport in newborn lambs treated with dopamine.

Methods

Lambs (2–5 days old, n = 12) were anesthetized and mechanically ventilated. Heart rate (HR) and rectal temperature were monitored. VO₂ was measured by respiratory mass spectrometry and cardiac output (CO) by a pulmonary artery transonic flowmeter. Arterial, jugular bulb venous and coronary sinus blood gases and lactate were measured to calculate DO₂, O₂ extraction ratio (ERO₂), myocardial O₂ and lactate extraction ratios (mERO₂, mERlac). After baseline measurements, lambs were randomized to receive SR59230A at 5 mg/kg iv (SRG) or placebo. Both groups received incremental doses of a dopamine infusion (0–5–10–15–20 mcg/kg/min) every 15 min. Measurements were repeated at the end of each dose.

Results

After SR59230A infusion, CO and HR trended to decrease (P = 0.06), but no significant changes occurred in other parameters. Over the incremental doses of dopamine, temperature increased in both groups (P < 0.0001) but to a lesser degree in SRG (P = 0.004). CO and HR increased (P = 0.005 and 0.04) and similarly in both groups (P > 0.1). DO₂ trended to a small increase (P = 0.08). VO₂ increased in both groups (P < 0.0001) but to a lesser degree in SRG (P < 0.0001). As a result, ERO₂ increased in both groups (P < 0.0001), but to a lesser degree in SRG (P < 0.0001). mERO₂ was lower in SRG (P = 0.01) with a faster increase (P < 0.0001). mERlac was higher in SRG (P = 0.06) with a faster decrease (P = 0.04).

Conclusion

Although SR59230A tends to induce an initial drop in CO, it significantly attenuates the rise in VO₂ and hence the imbalance of systemic and myocardial O₂ transport induced by dopamine at higher doses. Studies are warranted to examine the effect of SR59230A in cases of cardiac dysfunction and increased VO₂, observed after cardiac surgery.

The Right Heart in Congenital Heart Disease, Mechanisms and Recent Advances

In patients with congenital heart disease, the right heart may support the pulmonary or the systemic circulation. Several congenital heart diseases primarily affect the right heart including Tetralogy of Fallot, transposition of great arteries, septal defects leading to pulmonary vascular disease, Ebstein anomaly and arrhythmogenic right ventricular cardiomyopathy. In these patients, right ventricular dysfunction leads to considerable morbidity and mortality. In this paper, our objective is to review the mechanisms and management of right heart failure associated with congenital heart disease. We will outline pearls and pitfalls in the management of congenital heart disease affecting the right heart and highlight recent advances in the field.

Non-Invasive Imaging for Congenital Heart Disease: Recent Innovations in Transthoracic Echocardiography

Transthoracic echocardiography (TTE) is an important tool for diagnosis and follow-up of patients with congenital heart disease (CHD). Appropriate use of TTE can reduce the need for more invasive and complex modalities, such as cardiac catheterization and cardiac magnetic resonance imaging. New echocardiographic techniques have emerged for the assessment of ventricular systolic and diastolic function: Tissue Doppler imaging, tissue tracking, strain and strain rate imaging, vector velocity imaging (VVI), myocardial performance index, myocardial acceleration during isovolumic contraction (IVA), the ratio of systolic to diastolic duration (S/D ratio), and other measurements of systolic right ventricular (RV) function like tricuspid annular plane systolic excursion (TAPSE). These modalities may become valuable indicators of ventricular performance, compliance and disease progression, with the caveat of preload-dependency of the variables measured. In addition, three-dimensional (3D) echocardiography for the assessment of cardiac anatomy, valvular function, device position, ventricular volumes and ejection fraction is integrated into routine clinical care. In this review, we discuss the potential use and limitations of these new echocardiographic techniques in patients with CHD. A particular focus is on the echocardiographic assessment of right ventricular (RV) function by means of tissue Doppler imaging, tissue tracking, and three-dimensional imaging, in conditions associated with increased right ventricular volume or pressure load.

Right ventricular function with standard and speckle-tracking echocardiography and clinical events in adults with D-transposition of the great arteries post atrial switch

BACKGROUND

The prognostic value of deformation parameters of the systemic right ventricle in adults with D-transposition of the great arteries and prior atrial switch has not been reported.

METHODS

Sixty-four adults with D-transposition of the great arteries and prior atrial switch (mean age, 29 ± 6 years; 22 women; mean right ventricular [RV] fractional area change, 22.9 ± 7.5%; 31 with pacemakers at baseline) and no histories of heart failure or ventricular tachycardia were prospectively evaluated. Global longitudinal strain (GS), global systolic strain rate (GSRs), and global early diastolic strain rate (GSRe) of the right ventricle were measured using speckle tracking from apical views and compared with standard parameters of RV function (fractional area change, tricuspid annular plane systolic excursion, tissue Doppler velocities, and isovolumic acceleration) for association with and potential prediction of clinical events, defined as incident stage C heart failure or ventricular tachycardia.

RESULTS

Baseline RV GS, GSRs, and GSRe were -12.5 ± 3.0%, -0.59 ± 0.14 sec(-1), and 0.68 ± 0.22 sec(-1), respectively. After a median of 2.4 years (interquartile range, 1.5-4.1 years), 12 patients (19%) presented with clinical events (heart failure in 11 patients, ventricular tachycardia in one patient). In Cox models, RV GS had the strongest association with clinical events (hazard ratio [HR] per 1%, 1.35; 95% confidence interval [CI], 1.14-1.58; P < .001), followed by GSRs (HR per 0.01 sec(-1), 1.06; 95% CI, 1.02-1.11; P = .006), GSRe (HR per -0.01 sec(-1), 1.04; 95% CI, 1.00-1.07; P = .031), and fractional area change (HR per -1%, 1.08; 95% CI, 1.00-1.17; P = .047). Other measures of RV function were not significantly associated with risk for events. In receiver operating characteristic analysis, RV GS ≥ -10% optimally predicted future events (C = 0.83; 95% CI, 0.71-0.91; P < .001).

CONCLUSIONS

Reduced longitudinal GS of the systemic right ventricle is associated with increased risk for clinical events among patients with D-transposition of the great arteries and prior atrial switch.

Echocardiography as a hemodynamic monitor in critically ill children

Echocardiography is a widely used modality to assess myocardial structure and function in pediatric intensive care settings. While the use of echocardiography for diagnostic purposes remains important, its use as a hemodynamic monitoring tool has not been well established. The benefits of echocardiography are in its widespread availability, relative ease of use, and importance in diagnosing structural disease and simple changes in myocardial function. However, echocardiography in pediatric critical care is limited in its use because it requires the acquisition of quality images and the accurate interpretation of the study. To date, the literature on echocardiography in pediatric critical care is limited. The purpose of this review is to examine the scientific evidence for the usefulness of echocardiography as a hemodynamic monitoring tool in pediatric critical care.

Imaging the right ventricle--current state of the art

The right ventricle has long been the 'forgotten ventricle', as it is difficult to image owing to its complex morphology, its thin wall with coarse trabeculations, and its anterior position within the chest. Developments in cardiac magnetic resonance imaging (CMR) and echocardiography have provided new insights into right ventricular (RV) structure and function. RV performance seems to be an important determinant of clinical status and long-term outcome in patients with pulmonary hypertension, cardiomyopathies, and, especially, in patients with congenital heart disease. A variety of different parameters can be measured to assess RV function, but a lot of uncertainty remains on how to assess RV performance in daily clinical practice and which measurements to use in clinical decision-making. CMR is currently considered the reference technique for RV volumetry and calculation of ejection fraction. Various echocardiographic techniques can provide reliable information on RV dimensions and RV systolic and diastolic function that can be used in clinical follow-up. The introduction of newer echocardiographic techniques, such as three-dimensional echocardiography, tissue Doppler ultrasonography, and ultrasound strain imaging, challenge the leading role of CMR in RV functional assessment, but further validation and accumulation of data are required before these techniques can play a key part in clinical decision-making.

Do we have two hearts? New insights in right ventricular function supported by myocardial imaging echocardiography

RV performance is difficult to evaluate, given its geometry, interrelationship with the left ventricle, and sensitivity to alterations in pulmonary pressure. This article focuses on some of the challenges related to the assessment of RV function in the setting of the RV's unique anatomic, physiologic, conventional and newer echocardiographic aspects, and therapeutic implications. The majority of proposed methods of echocardiographic assessment of RV function are based on volumetric approximations of the RV. Such approaches have inherent limitations, first as volume-related measures such as EF are load dependent, second because of the complex geometry of the RV. The issue of RV geometry is usually overcome using geometry-independent parameters such as tricuspid annular excursion and the Tei index. The recent introduction of real-time three-dimensional echocardiography and myocardial imaging echocardiography (tissue Doppler imaging, 1D-strain and 2D-strain echocardiography) implied a great progress in echocardiography. Tissue Doppler imaging allows the quantitative assessment of RV systolic and diastolic function by means of measurement of myocardial velocities. Strain measurements have been shown to correlate well with sonomicrometry segment length measurements both in the inflow and outflow tract of the RV and under different loading conditions. Other findings have been reported in chronic and acute clinical settings. Standard and novel echocardiographic methods of assessment of RV size and performance can help clinicians in the treatment of acute and chronic RV failure and contribute to a better understanding of the peculiar chamber-related functional mechanisms in the context of ventricular interdependent independency.