Assessment of Disease Progression in Patients With Repaired Tetralogy of Fallot Using Cardiac Magnetic Resonance Imaging: A Systematic Review.

AIMS: Tetralogy of Fallot (ToF) is the most common cyanotic congenital heart disease with a growing population of adult survivors. Late pulmonary outflow tract and pulmonary valve postoperative complications are frequent, leading to long-term risks such as right heart failure and sudden death secondary to arrhythmias. Cardiac magnetic resonance imaging (CMR) is the gold standard for assessment of cardiac function in patients with repaired ToF. We aimed to determine the most useful CMR predictors of disease progression and the optimal frequency of CMR. METHODS AND RESULTS: We systematically reviewed PubMed from inception until 29 April 2019 for longitudinal studies assessing the relationship between CMR features and disease progression in repaired ToF. Fourteen (14) studies were identified. Multiple studies showed that impaired right and left ventricular function predict subsequent disease progression. Right ventricular end diastolic volume, while being associated with disease progression when analysed alone, was generally not associated with disease progression on multivariate analysis. Severity of tricuspid regurgitation and pulmonary regurgitation likewise did not show a consistent association with subsequent events. A number of non-CMR factors were also identified as being associated with disease progression, in particular QRS duration and older age at repair. Restrictive right ventricular physiology was not consistently an independent predictor of events. CONCLUSION: Impaired right and left ventricular function are the most consistent independent predictors of disease progression in repaired ToF. The optimal timing of repeat cardiac imaging remains controversial. Large scale prospective studies will provide important information to guide clinical decision making in this area.

Assessment and Implications of Right Ventricular Afterload in Tetralogy of Fallot.

Patients with tetralogy of Fallot (TOF) have abnormal right ventricular (RV) afterload because of residual or recurrent outflow tract obstruction, often with abnormal pulmonary artery (PA) vascular function. The purpose of this study was to determine if RV afterload was independently associated with death and/or heart transplant in patients with TOF. This is a retrospective study of TOF patients that underwent cardiac catheterization for clinical indications at Mayo clinic between 1990 and 2015. Invasively measured RV systolic pressure (RVSP) was used to define RV afterload. To explore clinical utility for echocardiographic estimates of invasive data, correlations between invasive and Doppler-derived indices of RV afterload were examined. Among 266 patients with TOF (age 35 ± 14 years, TOF-pulmonary atresia 117 [44%]), RVSP was 72 ± 28 mm Hg, PA systolic pressure 45 ± 19 mm Hg, mean PA pressure 27 ± 10 mm Hg, pulmonary vascular resistance 4.2 ± 3.1 WU, and PA wedge pressure 14 ± 5 mm Hg. Over a mean follow up of 12.9 years, there were 35 deaths and 4 heart transplants. Invasively measured RVSP (hazard ratio 1.25, 95% confidence interval 1.12 to 1.37; p <0.001) and TOF-pulmonary atresia (hazard ratio 1.18, 95% confidence interval 1.08 to 1.41; p = 0.023) were independent risk factors for death and/or transplant. Doppler-derived RVSP was well-correlated with invasive RVSP (r = 0.92, p <0.001), and was also independently associated with the combined end point. RVSP, a composite measure of RV afterload, is independently prognostic in patients with TOF, and can be reliably assessed using Doppler echocardiography. Further study is required to test whether interventions to reduce RVSP can improve outcomes in patients with TOF.

Assessment of the Reconstructed Pulmonary Circulation With Lung Perfusion Scintigraphy After Unifocalization and Repair of Tetralogy of Fallot With Major Aortopulmonary Collaterals.

BACKGROUND: Pulmonary vascular supply in tetralogy of Fallot (TOF) with major aortopulmonary collaterals (MAPCAs) is highly variable. Our approach to surgical management of this condition emphasizes early repair including unifocalization and reconstruction of the pulmonary circulation, incorporating all lung segments and addressing stenoses both proximal to and within the lung, in addition to ventricular septal defect closure. At our institution, we have over 15 years of experience using lung perfusion scintigraphy (LPS) to assess the distribution of pulmonary blood flow after complete unifocalization and repair. METHODS: We reviewed clinical and quantitative LPS data in 310 patients who underwent complete unifocalization and repair of TOF/MAPCAs from 2003 to 2018 at our institution. Postrepair relative lung perfusion distributions were determined from LPS initially obtained at our institution within 60 days after repair and thereafter. RESULTS: Total lung perfusion to the right and left lungs was 58.0% ± 14.2% and 42.0% ± 14.2%, respectively. Perfusion was balanced in 75% of patients and unbalanced in 25%, including 11% in whom it was extremely unbalanced. On multivariable analysis, older age at repair, surgery other than a single-stage complete unifocalization, and native anatomy consisting of unilateral pulmonary blood supply through a ductus arteriosus were associated with unbalanced perfusion. CONCLUSION: We present our experience using LPS as an outcome measure after surgical repair of TOF/MAPCAs. Balanced lung perfusion was present in the majority of patients who had complete repair of TOF/MAPCAs performed at our center.

The role of echocardiography for quantitative assessment of right ventricular size and function in adults with repaired tetralogy of Fallot.

BACKGROUND: Quantitative assessment of right ventricular (RV) systolic function by echocardiography is challenging in patients with congenital heart disease because of the complex geometry of the RV and the iatrogenic structural abnormalities resulting from prior cardiac surgeries. The purpose of this study was to determine the correlation between echocardiographic indices of RV systolic function and cardiac magnetic resonance imaging (CMRI) derived RV ejection fraction (RVEF) in adults with repaired tetralogy of Fallot (TOF). METHODS: Quantitative assessment of RV function was performed with RV tissue Doppler systolic velocity (RV s'), tricuspid annular plane systolic excursion (TAPSE), and fractional area change (FAC). These echocardiographic indices were compared to RVEF from CMRI performed on the same day as echocardiogram. RESULTS: Of 209 patients, the mean RV FAC was 39 ± 9%, TAPSE was 18 ± 4 mm, RV s' was 10 ± 2 cm/s, and RVEF was 40 ± 10%. There was a good correlation between TAPSE and RVEF (r = 0.79, P < .001), good correlation between RV s' and RVEF (r = 0.71, P < .001), and modest correlation between FAC and RVEF (r = 0.66, P < .001). TAPSE < 17 mm effectively discriminated between patients with RV systolic dysfunction defined as RVEF < 47% (sensitivity 81%, specificity 79%, area under the curve [AUC] 0.805). FAC < 40% was associated with RVEF < 47% (sensitivity 72%, specificity 63%, AUC 0.719). RV s' < 11 cm was associated with RVEF < 47% (sensitivity 83%, specificity 68%, AUC 0.798). CONCLUSION: Despite the structural and functional abnormalities of the RV in patients with repaired TOF, quantitative assessment of RV systolic function by echocardiography is feasible and had good correlation with CMRI-derived RVEF.

Serial assessment of postoperative ventricular mechanics in young children with tetralogy of Fallot: Comparison of transannular patch and valve-sparing repair.

BACKGROUND: Little is known about the early time course of biventricular function and mechanics after tetralogy of Fallot (TOF) repair. We sought to evaluate and describe the evolution of the right ventricle (RV) after TOF repair in young infants and children using conventional echocardiographic parameters and global longitudinal strain (GLS). METHODS: A retrospective review was performed of all patients with TOF and pulmonary stenosis who underwent repair from January 2002 to September 2015 and had at least 3 serial postsurgical echocardiograms spanning from infancy to early childhood (<8 years). Student's t test was performed to compare patients who underwent valve sparing (VS) versus transannular patch (TAP) repair. ANOVA was used to track measures of ventricular systolic function over time. RESULTS: We analyzed 151 echocardiograms performed on 42 patients. Pulmonary regurgitation (PR, moderate or severe) and the RV to left ventricular (LV) basal dimension ratio were higher in TAP patients (P < .04 at all-time points). Along with a significant increase in RV basal diameter Z-score in the TAP group (P < .001), there was an improvement in RV and LV GLS over time in both groups (P < .001). The LV GLS at last follow-up was lower in patients who underwent reoperation than those who did not (P = .050). LV GLS at the last follow-up echocardiogram was lower in patients with significant PR than those without (P < .001). CONCLUSIONS: Ventricular function appeared improve over time from the initial postoperative period in TOF patients. TAP repair was associated with a progressively higher RV/LV ratio in young children. GLS and RV/LV basal diameter ratio may be useful when following young children after TOF repair. Further research is necessary to understand the trajectory of ventricular functional and volumetric changes in young children in order to provide the most effective lifetime management of patients with TOF.

Prevention of sudden cardiac death in patients with Tetralogy of Fallot: Risk assessment and long term outcome.

BACKGROUND: In patients with repaired Tetralogy of Fallot (ToF), implantable cardioverter defibrillators (ICD) are considered reasonable in selected adults with multiple risk factors for sudden cardiac death. PATIENTS AND METHODS: We performed a retrospective cohort study of all 174 patients with repaired ToF who are followed at the University Hospital of Muenster. We analyzed data according to the risk score previously proposed by Khairy and coworkers and patient outcome. We analyzed data separately for patients without previous sustained ventricular tachycardia (VT) (risk stratification group, n = 157) and patients with VT/secondary prevention ICD (n = 17). RESULTS: In the risk stratification group, a mean of 4 ±â€¯1 risk score parameters were available. All six risk parameters were known in 10%, five in 14%. Risk score increased with availability of parameters. 15 patients with secondary prevention ICD had a mean risk score of 6.3 ±â€¯2.2 (range 2-10). 11 patients of the risk stratification group with primary prevention ICD had a mean risk score 5.8 ±â€¯2.4 (range 3-8). During follow-up of up to 14 years, five patients died (3%): at age 58, two at 69 and two at 76 years. CONCLUSION: In the majority of patients risk score variables were incomplete, severely limiting its applicability because the true score cannot be calculated. Risk scores were not different between patients with secondary prevention ICD and patients with ICD for primary prevention based on current guidelines. Standardization of follow-up and prospective evaluation of these standards in large prospective patient cohorts is desirable to improve risk stratification in patients with ToF.

Assessment of early diastolic intraventricular pressure gradient in the left ventricle among patients with repaired tetralogy of Fallot.

Assessment of left ventricular (LV) dysfunction is vital in patients with repaired tetralogy of Fallot (rTOF). The early diastolic intraventricular pressure gradient (IVPG) in the LV plays an important role in diastolic function. IVPG is calculated as the intraventricular pressure difference divided by the LV length, which allows to account for differences in LV size and therefore calculate IVPG in children. We aimed to investigate the mechanisms of LV diastolic dysfunction by measuring mid-to-apical IVPG as an indicator of the active suction force sucking blood from the left atrium into the LV. We included 38 rTOF patients and 101 healthy controls. The study population was stratified based on age group into children (4-9 years), adolescents (10-15 years), and adults (16-40 years). IVPGs were calculated based on mitral inflow measurements obtained using color M-mode Doppler echocardiography. Although total IVPGs did not differ between rTOF patients and controls, mid-to-apical IVPGs in adolescents and adults were smaller among rTOF patients than among controls (0.15 ± 0.05 vs. 0.21 ± 0.06 mmHg/cm, p < 0.05; 0.09 ± 0.07 vs. 0.17 ± 0.05 mmHg/cm, p < 0.001; respectively). Additionally, only mid-to-apical IVPG correlated linearly with peak circumferential strain (ρ = 0.217, p = 0.011), longitudinal strain (ρ = -0.231, p = 0.006), torsion (ρ = -0.200, p = 0.018), and untwisting rate in early diastole (ρ = -0.233, p = 0.006). In rTOF, the mechanisms underlying diastolic dysfunction involve reduced active suction force, which correlates with reduced LV deformation in all directions.

Analysis of the psychosocial impact of caretaking on the parents of an infant with severe congenital heart defect.

This case report considers the psychosocial burden of caring for an infant with a severe congenital heart defect (CHD) on parents. Improved prenatal diagnostics and postnatal surgical intervention have created a new and increasing demographic of children and adults with CHDs that require lifelong medical care. For this reason, primary caregivers spend excessive amounts of time in hospitals and medical facilities, and must regularly decipher vast amounts of unfamiliar medical terminology and concepts with varying levels of assistance from medical personnel. This often leads to marked psychological morbidities in parental caregivers, such as stress, anxiety and depression. The financial cost of caring for infants with CHD, including loss of employment opportunities, is another important factor that impacts the quality of life of caregivers. Frequent and extended travel to seek specialised medical care, often at distant medical centres, represents an additional burden.

Pulmonary valve replacement and quality-of-life assessment.

BACKGROUND: Chronic pulmonary regurgitation is common after repair of tetralogy of Fallot. Despite the deleterious effects of chronic pulmonary regurgitation on right ventricular function, many patients with repaired tetralogy of Fallot remain asymptomatic. Health is defined not only by the absence of disease but also by physical, mental, and social wellbeing. We sought to examine the impact of pulmonary valve replacement on quality of life in asymptomatic patients with repaired tetralogy of Fallot and chronic pulmonary regurgitation. METHODS: From January 2009 to December 2012, 25 (18 male) asymptomatic patients (mean age 23.4 ± 7.4 years) who underwent pulmonary valve replacement for significant pulmonary regurgitation were recruited. Cardiac magnetic resonance was performed pre- and postoperatively. Quality of life was assessed using the Chinese version of the SF-36v2 evaluation tool. Demographics, clinical data, magnetic resonance findings, and quality-of-life scores were collected and calculated for comparison. RESULTS: After surgery, the indexed right ventricular end-diastolic volume (193 ± 47.3 vs. 105.6 ± 29.6 mL m(-2), p < 0.001) and indexed right ventricular end-systolic volume (108.5 ± 32.9 vs. 61.1 ± 23 mL m(-2), p < 0.001) decreased significantly. The response rates for pre- and postoperative quality-of-life assessments were 100%. Patients demonstrated improvements in all 8 domains of the SF-36v2 assessment. The physical (46.5 ± 6.6 vs. 49.9 ± 6.4, p = 0.012) and mental (43.7 ± 7.8 vs. 51.9 ± 7.6, p < 0.001) component summary scores increased after surgery. CONCLUSION: Pulmonary valve replacement can improve the quality of life in patients with chronic asymptomatic pulmonary regurgitation.

Assessment of left ventricular preload by cardiac magnetic resonance imaging predicts exercise capacity in adult operated tetralogy of Fallot: a retrospective study.

BACKGROUND: The optimal timing of pulmonary homograft valve replacement (PVR) is uncertain. Cardiopulmonary exercise testing (CPET) and cardiac magnetic resonance (CMR) are often used to guide the clinical decision for PVR in operated tetralogy of Fallot (TOF) patients with significant pulmonary regurgitation (PR). We aim to study the relationship between exercise capacity and CMR in these patients. METHODS: The study is a single-centre retrospective analysis of 36 operated TOF patients [median 21.4 (interquartile range 16.4, 26.4) years post-repair; 30 NYHA I, 6 NYHA II; median age 25.2 (interquartile range 19.5-31.7) years, 29 males] with significant PR on CMR who underwent CPET within 15 [median 2.0 (interquartile range 0.8-7.2)] months from CMR. CPET parameters were compared with 30 age- and sex-matched healthy controls [median age 27.8 (interquartile range 21.0-32.8) years; 24 males]. RESULTS: Peak systolic blood pressure (177 versus 192 mmHg, p = 0.007), Mets (7.3 versus 9.9, p < 0.001), peak oxygen consumption (VO2max) (29.2 versus 34.5 ml/kg/min, p < 0.001) and peak oxygen pulse (11.0 versus 13.7 ml/beat, p = 0.003) were significantly lower in TOF group versus control. Univariate analyses showed negative correlation between PR fraction and anaerobic threshold. There was a positive correlation between indexed left (LV) and right (RV) ventricular end-diastolic volumes, as well as indexed LV and effective RV stroke volumes, on CMR and VO2max and Mets achieved on CPET. These remained significant after adjustment for age and sex. CONCLUSIONS: TOF subjects have near normal exercise capacity but significantly lower Mets, VO2max and peak oygen pulse achieved compared to controls. Increased PR fraction in TOF subjects was associated with lower anaerobic threshold. Higher indexed effective RV stroke volume, a measure of LV preload, was associated with higher VO2max and Mets achieved, and may potentially be used as a predictor of exercise capacity.

Fetal MRI correlates with postnatal CT angiogram assessment of pulmonary anatomy in tetralogy of Fallot with absent pulmonary valve.

In tetralogy of Fallot with absent pulmonary valve, pulmonary stenosis and regurgitation results in significant pulmonary artery dilatation. Branch pulmonary artery dilatation often compresses the tracheobronchial tree, causing fluid trapping in fetal life and air trapping and/or atelectasis after birth. Prenatal diagnosis predicts poor prognosis, which depends on the degree of respiratory insufficiency from airway compromise and lung parenchymal disease after birth. Fetal magnetic resonance imaging (MRI) has been useful in evaluating the effects of congenital lung lesions on lung development and indicating severity of pulmonary hypoplasia. This report is the first demonstrating the utility of fetal MRI in tetralogy of Fallot/absent pulmonary valve patients, which predicted postnatal pulmonary artery size and visualized airway compression and lung parenchymal lesions. The distribution of lobar fluid trapping on fetal MRI correlated with air trapping on postnatal computed tomography angiogram.

Relationship between resource utilization and length of stay following tetralogy of Fallot repair.

BACKGROUND: The relationship between resource utilization and postoperative length of stay (PLOS) following congenital heart disease surgery is unknown. METHODS: We performed a retrospective cohort study using data from the Pediatric Health Information Systems database. We included subjects 1 month to 1 year of age with a PLOS of ≤ 1 month following elective, complete repair of tetralogy of Fallot (TOF) during 2004-2008 at children's hospitals that performed ≥ 10 such surgeries during the study period. We constructed three generalized linear models to assess the relationships of total costs, laboratory costs, and imaging costs during the first three postoperative days with overall PLOS. Race/ethnicity, insurance type, sex, and presence of a genetic syndrome (by ICD-9 codes) were included in the models as fixed effects; hospital of surgery was included as a random effect. RESULTS: For 1161 eligible surgical encounters at 36 children's hospitals, mean PLOS was 7.1 days (median = 6 days). Mean total, laboratory, and imaging costs for the first three postoperative days were $26,455, $2941, and $813, respectively. Most subjects were male (58.9%), did not have a genetic syndrome (88.3%), were non-Hispanic white (58.3%), and had either public or private insurance (41.0% and 39.1%, respectively). An estimated increase in total costs of $4600 or laboratory costs of $700 in the first three postoperative days was associated with a 1-day increase in PLOS. Imaging costs were not associated with PLOS. CONCLUSIONS: Increased resource utilization is not associated with a shorter PLOS following elective TOF repair, and it may be associated with longer PLOS.

Corrected tetralogy of Fallot: comparison of tissue doppler imaging and velocity-encoded MR for assessment of performance and temporal activation of right ventricle.

PURPOSE: To compare velocity-encoded (VE) magnetic resonance (MR) imaging with tissue Doppler imaging to assess right ventricular (RV) peak systolic velocities and timing of velocities in patients with corrected tetralogy of Fallot and healthy subjects. MATERIALS AND METHODS: Local institutional review board approval was obtained; patients or their parents gave informed consent. Thirty-three patients (20 male, 13 female; median age, 12 years; interquartile range [IQR], 11-15 years; age range, 8-18 years) and 19 control subjects (12 male, seven female; median age, 14 years; IQR, 12-16 years; age range, 8-18 years) underwent VE MR imaging and tissue Doppler imaging. Peak systolic velocity and time to peak systolic velocity (percentage of cardiac cycle) were assessed at the RV free wall (RVFW) and RV outflow tract (RVOT). Data were analyzed by using linear regression, paired and unpaired tests, and Bland-Altman plots. RESULTS: Good correlation and agreement between the two techniques were observed. For peak systolic velocity at RVFW, r = 0.95 (mean difference, -0.4 cm/sec, P < .01), and at RVOT, r = 0.95 (mean difference, -0.4 cm/sec, P = .02). For timing at RVFW, r = 0.94 (mean difference, -0.2%, P = .44), and at RVOT, r = 0.89 (mean difference, -0.5%, P = .01). Peak systolic velocity was reduced in patients with corrected tetralogy of Fallot (at RVFW, median was 8.2 cm/sec [IQR, 6.4-9.7 cm/sec] vs 12.4 cm/sec [IQR, 10.8-13.8 cm/sec], P < .01; at RVOT, 4.7 cm/sec [IQR, 4.1-7.2 cm/sec] vs 10.2 cm/sec [IQR, 8.7-11.2 cm/sec], P < .01). The time delay between RVFW and RVOT was observed, which was significantly shorter in patients with corrected tetralogy of Fallot (median, 5.9% [IQR, 4.9%-7.4%] vs 8.4% [IQR, 6.6%-12.4%], P < .01). CONCLUSION: VE MR imaging and tissue Doppler imaging enable assessment of RV systolic performance and timing of velocities at the RVFW and RVOT in patients with corrected tetralogy of Fallot. Both techniques can be used interchangeably to clinically assess velocities and timing of velocities of the RV.

Adult Tetralogy of Fallot: quantitative assessment of pulmonary perfusion with time-resolved three dimensional magnetic resonance angiography.

PURPOSE: To determine the potential role of dynamic temporally resolved three dimensional (3D) contrast-enhanced magnetic resonance angiography (MRA) for quantitative evaluation of pulmonary perfusion in adult patients with surgically treated Tetralogy of Fallot (ToF). MATERIALS AND METHODS: Institutional review board approval and written informed consent were obtained for this Health Insurance Portability and Accountability Act-compliant study. Thirty consecutive patients with surgically repaired ToF and 30 age-matched controls underwent breath-hold 3D time-resolved MRA (TR-MRA) and single-phase high-resolution 3D MRA of the thorax at 1.5 T. Two readers evaluated both datasets for image quality and findings. On TR-MRA datasets, regions-of-interest were placed over main pulmonary artery and lung fields obtaining signal intensity time curves. Using analytic software, time-to-peak (TTP), mean transit time (MTT), maximal signal intensity (MSI), maximum upslope of the curve (MUS), pulmonary blood volume (PBV), and pulmonary blood flow (PBF) were calculated. Pulmonary radionuclide scintigraphy was available for a subgroup of patients with ToF (n = 12). RESULTS: For ToF patients with unilateral pulmonary artery (PA) stenosis, TTP, and MTT were significantly longer, and MSI, MUS, PBV, and PBF were significantly lower in the ipsilateral lung compared with control subjects (P < 0.001 for all). There was no significant difference in TTP, MTT, MSI, MUS, PBV, and PBF between ToF patients without postsurgical stenotic residua and control subjects (P > 0.05 for all), nor between the mentioned perfusion indices for the contralateral lung in ToF patients with unilateral PA stenosis and control subjects (P > 0.05 for all). In ToF, patient with unilateral PA stenosis, analysis of contralateral-to-ipsilateral lung perfusion ratios on radionuclide scintigraphy and TR-MRA revealed significant correlation (r = 0.96). Bland-Altman plot showed a mean difference of 2.2% between the measured ratios (limits of agreement; -7.6%-12.0%). CONCLUSION: Time-resolved 3D contrast-enhanced MRA has potential for noninvasive and quantitative assessment of altered patterns of pulmonary perfusion in adult ToF, and may be a reliable technique for evaluation of postsurgical residua in these patients.

Assessment of myocardial function in pediatric patients with operated tetralogy of Fallot: preliminary results with 2D strain echocardiography.

The global myocardial function in patients after repair of tetralogy of Fallot (TOF) can be assessed by cardiovascular magnetic resonance (CMR) and measurement of B-type natriuretic peptides. Two-dimensional echocardiography-derived strain and strain rate (2D strain) facilitate the assessment of regional myocardial function. We evaluated myocardial function in 16 children with residual severe pulmonary valve regurgitation and right ventricular (RV) volume overload after TOF repair before, 1 month after, and 6 months after pulmonary valve replacement (PVR). In 2D strain echocardiography preoperatively, the longitudinal systolic RV strain was reduced (p < 0.05). One month after PVR, longitudinal systolic RV strain decreased further (p < 0.05), while systolic and early diastolic radial left ventricular strain and strain rate increased (each p < 0.05), followed by a return toward preoperative values after 6 months. Six months after PVR, preoperatively elevated RV end-diastolic volume (p < 0.01) assessed by CMR and N-terminal pro-B-type natriuretic peptide (p < 0.05) decreased. In conclusion, the impairment of the regional myocardial after TOF repair and transient changes after PVR can be subtly analyzed by 2D strain echocardiography in addition to the established assessment of myocardial function with CMR and measurement of B-type natriuretic peptides.

Noninvasive assessment of repaired tetralogy of Fallot by magnetic resonance imaging and dynamic radionuclide studies.

BACKGROUND: This study was designed to validate the diagnostic accuracy of magnetic resonance imaging (MRI) in evaluating biventricular ejection fraction and to quantify pulmonary regurgitant fraction (PRF) in patients after repair of tetralogy of Fallot. METHODS: Two hundred and eighty survivors of repaired tetralogy of Fallot aged 42 months to 40 years (mean, 142.2 +/- 85.3 months) underwent cardiac MRI, first-pass and gated radionuclide ventriculography (RNV) for the assessment of biventricular function, and PRF after 89.26 +/- 42.40 months. The receiver operating characteristic curve analysis was done to quantify the diagnostic accuracy of MRI. RESULTS: There was statistically significant agreement between MRI and RNV in evaluating right and left ventricular function. An MRI-derived right ventricular ejection fraction 47.2% or greater than normal was associated with a sensitivity of 92.3% and a specificity of 92.3%. An MRI-derived left ventricular ejection fraction 53.9% or greater than normal was associated with a sensitivity of 93.2% and a specificity of 93.3%. Area analysis indicated that 97.34% (standard error [SE] = 0.0118) and 98.56% (SE = 0.0052) of the time values of right and left ventricular ejection fraction were higher for patients with normal right and left ventricular functions, respectively, compared with abnormal. There was a strong agreement between velocity-encoded and stroke volume-derived PRF [(r = 0.886, p < 0.001; d = 2.62 +/- 1.12, p < 0.0001; r' = 0.121, p = 0.051; b = 0.96 (SE = 0.012); p < 0.0001; ICC = 0.98, p < 0.0001). Higher PRF was associated with increased indexed right ventricular dimensions and inversely correlated with biventricular ejection fractions. CONCLUSIONS: The MRI-derived ejection fraction values predictably separate patients with normal ventricular function from abnormal. Velocity-encoded MRI can accurately quantitate PRF in tetralogy of Fallot.

Cardiac MR imaging assessment following tetralogy of fallot repair.

Survivors of tetralogy of Fallot (TOF) repair constitute a large and growing population of patients. Although postsurgical outcome is generally favorable, as these patients move into adulthood, late morbidity is becoming more prevalent and the notion that TOF has been "definitively repaired" is increasingly being challenged. Recent evidence suggests that adverse long-term postsurgical outcome is related to chronic pulmonary regurgitation, right ventricular dilatation, and deteriorating ventricular function. Cardiac magnetic resonance (MR) imaging has been established as an accurate technique for quantifying ventricular size, ejection fraction, and valvular regurgitation. Cardiac MR imaging does not expose the patient to ionizing radiation and is therefore ideal for serial postsurgical follow-up. Familiarity with the anatomic basis of TOF, the surgical approaches to repair, and postrepair sequelae is essential for performing and interpreting cardiac MR imaging examinations. For example, awareness of the complications and sequelae that can occur will assist in determining when to intervene to preserve ventricular function and will improve long-term outcome. Technical facility is necessary to tailor the examination to the individual patient (eg, familiarity with non-breath-hold modifications that allow evaluation of young and less compliant patients). The radiologist can play an essential role in the treatment of patients with repaired TOF by providing noninvasive anatomic and physiologic cardiac MR imaging data. Further technologic advances in cardiac MR imaging are likely to bring about new applications, better normative data, and more examinations that are operator independent.

Cardiac MR imaging and MR angiography for assessment of complex tetralogy of Fallot and pulmonary atresia.

Breath-hold electrocardiographically gated cardiac magnetic resonance (MR) imaging and contrast material-enhanced MR angiography are emerging as ideal techniques for the evaluation of complex congenital heart disease. Tetralogy of Fallot is the most common cause of cyanotic congenital heart disease and, in its classic form, is associated with varying degrees of hypoplasia of the central and peripheral pulmonary arteries, with valvar pulmonary atresia and collateral aortopulmonary vessels occupying the extreme end of the spectrum. Accurate assessment of the size and anatomy of the pulmonary arteries is often difficult with echocardiography and conventional cineangiography. Compared with echocardiography in particular, cardiac MR imaging with three-dimensional reconstruction has distinct advantages for pre- or postoperative assessment of pulmonary anatomy in patients with tetralogy of Fallot and pulmonary atresia. MR imaging enables the clear and complete depiction of anatomy and thus can provide additional information about pulmonary artery abnormalities that are difficult to evaluate with conventional cardiac imaging techniques.