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Shariat M, Mertens L, Seed M, Grosse-Wortmann L, Golding F, Mercer-Rosa L, Harris M, Whitehead KK, Li C, Fogel MA, Yoo SJ. Utility of feed-and-sleep cardiovascular magnetic resonance in young infants with complex cardiovascular disease. Pediatr Cardiol 2015; 36:809-12. [PMID: 25527227 DOI: 10.1007/s00246-014-1084-2] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/07/2014] [Accepted: 12/11/2014] [Indexed: 11/27/2022]
Abstract
Utilization of cardiovascular magnetic resonance (CMR) is limited in young children because of the need for sedation or general anesthesia (GA). It has been previously shown that CMR can be performed without sedation or GA in young infants who are prone to fall asleep after being fed and swaddled. The purpose of this study was to prospectively prove the feasibility of the feed-and-sleep CMR technique in larger cohorts in the two institutions where the technique was initially developed. This was a prospective dual-center cohort study over a two-year period. All infants younger than 6 months old with complex congenital cardiovascular anomaly who required CMR were recruited for this study. The exclusion criteria included mechanical ventilation, oxygen dependence, feeding difficulties, and any contraindication to CMR. The feed-and-sleep study was performed by fasting the infant for a period of 4 h prior to the scan, placing the infant in a vacuum immobilizer, and feeding the infant just prior to the CMR. The CMR sequences were prioritized to target the area of most importance first. A study was considered complete and diagnostic if the clinical question was answered. A total of 60 infants (39 from center A and 21 from center B) were recruited for this study, 32 male and 28 female, ages ranging from 1 to 177 days (50 ± 54). The CMR studies were diagnostic and answered the clinical questions in all patients. All infants tolerated the procedure well, and no complications were noted in any of the patients. The CMR duration ranged between 4-132 minutes (45 ± 21). The feed-and-sleep approach in selected patients obviates the need of sedation or GA for CMR in infants younger than 6 months old. Therefore, CMR can be utilized whenever echocardiography fails to provide the complete information required for the patients' management.
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Khiabani RH, Whitehead KK, Han D, Restrepo M, Tang E, Bethel J, Paridon SM, Fogel MA, Yoganathan AP. Does TCPC power loss really affect exercise capacity? Heart 2015; 101:575-6. [DOI: 10.1136/heartjnl-2015-307484] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
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Haggerty CM, Whitehead KK, Bethel J, Fogel MA, Yoganathan AP. Relationship of single ventricle filling and preload to total cavopulmonary connection hemodynamics. Ann Thorac Surg 2015; 99:911-7. [PMID: 25620596 DOI: 10.1016/j.athoracsur.2014.10.043] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Revised: 10/14/2014] [Accepted: 10/21/2014] [Indexed: 11/17/2022]
Abstract
BACKGROUND Single ventricle lesions are associated with gradual attrition after surgical palliation with the total cavopulmonary connection (TCPC). Ventricular dysfunction is frequently noted, particularly impaired diastolic performance. This study seeks to relate TCPC hemodynamic energy losses to single ventricle volumes and filling characteristics. METHODS Cardiac magnetic resonance (CMR) data were retrospectively analyzed for 30 single ventricle patients at an average age of 12.7 ± 4.8 years. Cine ventricular short-axis scans were semiautomatically segmented for all cardiac phases. Ventricular volumes, ejection fraction, peak filling rate, peak ejection rate, and time to peak filling were calculated. Corresponding patient-specific TCPC geometry was acquired from a stack of transverse CMR images; relevant flow rates were segmented from through-plane phase contrast CMR data at TCPC inlets and outlets. The TCPC indexed power loss was calculated from computational fluid dynamics simulations using a validated custom solver. Time-averaged flow conditions and rigid vessel walls were assumed in all cases. Pearson correlations were used to detect relationships between variables, with p less than 0.05 considered significant. RESULTS Ventricular end-diastolic (R = -0.48) and stroke volumes (R = -0.37) had significant negative correlations with the natural logarithm of a flow-independent measure of power loss. This power loss measure also had a significant positive relationship to time to peak filling rate (normalized to cycle time; R = 0.67). CONCLUSIONS Flow-independent TCPC power loss is inversely related with ventricular end-diastolic and stroke volumes. Elevated power losses may contribute to impaired diastolic filling and limited preload reserve in single ventricle patients.
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Mercer-Rosa L, Paridon SM, Fogel MA, Rychik J, Tanel RE, Zhao H, Zhang X, Yang W, Shults J, Goldmuntz E. 22q11.2 deletion status and disease burden in children and adolescents with tetralogy of Fallot. ACTA ACUST UNITED AC 2015; 8:74-81. [PMID: 25561045 DOI: 10.1161/circgenetics.114.000819] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
BACKGROUND Patients with repaired tetralogy of Fallot experience variable outcomes for reasons that are incompletely understood. We hypothesize that genetic variants contribute to this variability. We sought to investigate the association of 22q11.2 deletion status with clinical outcome in patients with repaired tetralogy of Fallot. METHODS AND RESULTS We performed a cross-sectional study of tetralogy of Fallot subjects who were tested for 22q11.2 deletion, and underwent cardiac magnetic resonance, exercise stress test, and review of medical history. We studied 165 subjects (12.3±3.1 years), of which 30 (18%) had 22q11.2 deletion syndrome (22q11.2DS). Overall, by cardiac magnetic resonance the right ventricular ejection fraction was 60±8%, pulmonary regurgitant fraction was 34±17%, and right ventricular end-diastolic volume was 114±39 cc/m(2). On exercise stress test, maximum oxygen consumption was 76±16% predicted. Despite comparable right ventricular function and pulmonary regurgitant fraction, on exercise stress test the 22q11.2DS had significantly lower percent predicted: forced vital capacity (61.5±16 versus 80.5±14; P<0.0001), maximum oxygen consumption (61±17 versus 80±12; P<0.0001), and work (64±18 versus 86±22, P=0.0002). Similarly, the 22q11.2DS experienced more hospitalizations (6.5 [5-10] versus 3 [2-5]; P<0.0001), saw more specialists (3.5 [2-9] versus 0 [0-12]; P<0.0001), and used ≥1 medications (67% versus 34%; P<0.001). CONCLUSIONS 22q11.2DS is associated with restrictive lung disease, worse aerobic capacity, and increased morbidity, and may explain some of the clinical variability seen in tetralogy of Fallot. These findings may provide avenues for intervention to improve outcomes, and should be re-evaluated longitudinally because these associations may become more pronounced with time.
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Fogel MA, Li C, Nicolson SC, Spray TL, Gaynor JW, Fuller S, Keller MS, Harris MA, Yoganathan AP, Whitehead KK. Comparison by magnetic resonance phase contrast imaging of pulse-wave velocity in patients with single ventricle who have reconstructed aortas versus those without. Am J Cardiol 2014; 114:1902-7. [PMID: 25432153 DOI: 10.1016/j.amjcard.2014.09.032] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2014] [Revised: 09/20/2014] [Accepted: 09/20/2014] [Indexed: 11/29/2022]
Abstract
Pulse-wave velocity (PWV), a measure of arterial stiffness, is a known independent risk factor for cardiovascular events. Patients with single ventricle who undergo aortic to pulmonary anastomosis (recon) have noncompliant patch material inserted into the neoaorta, possibly increasing vessel stiffness and afterload. The purpose of this study is to determine if PWV in patients with single ventricle differed between those who did and those who did not undergo aortic reconstruction (nonrecon). We retrospectively reviewed cardiac magnetic resonance anatomic, cine, and phase contrast evaluations in the ascending aorta and descending aorta (DAo) at the level of the diaphragm data from 126 patients with single ventricle (8.6 ± 8.0 years) from January 2012 to May 2013. Significance = p <0.05. Seventy-five patients underwent recon and 51 did not. PWV in recon was significantly higher than in nonrecon (3.9 ± 0.9 m/s vs 3.2 ± 1.0 m/s, p = 0.008); in recon, patients >13 years old had a higher PWV than those <7 years (4.5 ± 0.6 vs 3.5 ± 0.7 m/s, p = 0.004). Whether <7 or >13 years old, PWV of those with recon was higher than nonrecon DAo distensibility was similar between both groups. There was no difference in age, body surface area, or cardiac index between recon and nonrecon. No correlations between various hemodynamic and ventricular function parameters with PWV were noted. In conclusion, PWV in recon is higher than in nonrecon with similar DAo distensibility implicating the aortic reconstruction as a possible cause of increased afterload; older recon patients have stiffer aortas than younger ones, possibly imposing an additional cardiovascular risk in the future. Other biomaterials may potentially moderate PWV if clinical outcome is adversely affected.
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Fogel MA, Pawlowski T, Schwab PJ, Nicolson SC, Montenegro LM, Berenstein LD, Spray TL, Gaynor JW, Fuller S, Keller MS, Harris MA, Whitehead KK, Vossough A, Licht DJ. Brain magnetic resonance immediately before surgery in single ventricles and surgical postponement. Ann Thorac Surg 2014; 98:1693-8. [PMID: 25149046 DOI: 10.1016/j.athoracsur.2014.05.079] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2014] [Revised: 05/14/2014] [Accepted: 05/27/2014] [Indexed: 12/31/2022]
Abstract
BACKGROUND Single-ventricle patients undergoing surgical reconstruction experience a high rate of brain injury. Incidental findings on preoperative brain scans may result in safety considerations involving hemorrhage extension during cardiopulmonary bypass that result in surgical postponement. METHODS Single-ventricle patients were studied with brain scans immediately preoperatively, as part of a National Institutes of Health study, and were reviewed by neuroradiology immediately before cardiopulmonary bypass. RESULTS Of 144 consecutive patients recruited into the project, 33 were studied before stage I (3.7±1.8 days), 34 before bidirectional Glenn (5.8±0.5 months), and 67 before Fontan (3.3±1.1 years) operations. Six operations (4.5%), 2 before stage I, 3 before bidirectional Glenn, and 1 before Fontan, were postponed because of concerning findings on brain magnetic resonance imaging. Five were due to unexpected incidental findings of acute intracranial hemorrhage, and 1 was due to diffuse cerebellar cytotoxic edema; none who proceeded to operation had these lesions. Prematurity and genetic syndromes were not present in any patients with a postponed operation. Four of 4 before bidirectional Glenn/Fontan with surgical delays had hypoplastic left heart syndrome compared with 44 of 97 who did not (p=0.048). After observation and follow-up, all eventually had successful operations with bypass. CONCLUSIONS Preoperative brain magnetic resonance imaging performed in children with single ventricles disclosed injuries in 4.5% leading to surgical delay; hemorrhagic lesions were most common and raised concerns for extension during the operation. The true risk of progression and need for delay of the operation due to heparinization associated with these lesions remains uncertain.
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Abu Hazeem AA, Dori Y, Whitehead KK, Harris MA, Fogel MA, Gillespie MJ, Rome JJ, Glatz AC. X-ray magnetic resonance fusion modality may reduce radiation exposure and contrast dose in diagnostic cardiac catheterization of congenital heart disease. Catheter Cardiovasc Interv 2014; 84:795-800. [PMID: 24619541 DOI: 10.1002/ccd.25473] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Revised: 02/25/2014] [Accepted: 03/01/2014] [Indexed: 11/05/2022]
Abstract
BACKGROUND Radiation exposure in the pediatric population may increase the risk of future malignancy. Children with congenital heart disease who often undergo repeated catheterizations are at risk. One possible strategy to reduce radiation is to use X-ray Magnetic Resonance Fusion (XMRF) to facilitate cardiac catheterization. METHODS Catheterization data of patients who underwent diagnostic XMRF procedures between January 1, 2009 and February 1, 2012 were reviewed. Cases were matched 1:1 to contemporary controls who did not undergo XMRF based on weight and diagnosis and were compared in radiation exposure, contrast dose, and procedural and anesthesia times. RESULTS Forty-four matched pairs were included. Baseline demographics were similar in both groups. Patients in the XMRF group had lower indices of radiation exposure measured by fluoroscopy time (14 vs. 16.4 vs. P = 0.047), dose-area product from fluoroscopy (513.2 vs. 589.1 µGy·m(2) , P = 0.042), total dose-area product (625.8 vs. 995.2 µGy·m(2) , P = 0.027), and total air kerma dose (94.5 vs. 153.8 mGy, P = 0.017). There was also a significant reduction in contrast dose (2 vs. 3.3 cc/kg, P <0.001). Procedural time tended to be shorter in the XMRF group but anesthesia time was significantly longer. CONCLUSION Select diagnostic cardiac catheterization cases that utilized XMRF used less radiation and contrast than similar cases where XMRF was not used. Future work is needed to determine whether similar benefits can be extended to other types of diagnostic and complex interventional procedures.
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Tang E, Restrepo M, Haggerty CM, Mirabella L, Bethel J, Whitehead KK, Fogel MA, Yoganathan AP. Geometric characterization of patient-specific total cavopulmonary connections and its relationship to hemodynamics. JACC Cardiovasc Imaging 2014; 7:215-24. [PMID: 24529885 DOI: 10.1016/j.jcmg.2013.12.010] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2013] [Revised: 11/27/2013] [Accepted: 12/03/2013] [Indexed: 11/25/2022]
Abstract
Total cavopulmonary connection (TCPC) geometries have great variability. Geometric features, such as diameter, connection angle, and distance between vessels, are hypothesized to affect the energetics and flow dynamics within the connection. This study aimed to identify important geometric characteristics that can influence TCPC hemodynamics. Anatomies from 108 consecutive patients were reconstructed from cardiac magnetic resonance (CMR) images and analyzed for their geometric features. Vessel flow rates were computed from phase contrast CMR. Computational fluid dynamics simulations were carried out to quantify the indexed power loss and hepatic flow distribution. TCPC indexed power loss correlated inversely with minimum Fontan pathway (FP), left pulmonary artery, and right pulmonary artery diameters. Cardiac index correlated with minimum FP diameter and superior vena cava (SVC) minimum/maximum diameter ratio. Hepatic flow distribution correlated with caval offset, pulmonary flow distribution, and the angle between FP and SVC. These correlations can have important implications for future connection design and patient follow-up.
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Fogel MA, Khiabani RH, Yoganathan A. Imaging for preintervention planning: pre- and post-Fontan procedures. Circ Cardiovasc Imaging 2014; 6:1092-101. [PMID: 24254479 DOI: 10.1161/circimaging.113.000335] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Restrepo M, Mirabella L, Tang E, Haggerty CM, Khiabani RH, Fynn-Thompson F, Valente AM, McElhinney DB, Fogel MA, Yoganathan AP. Fontan pathway growth: a quantitative evaluation of lateral tunnel and extracardiac cavopulmonary connections using serial cardiac magnetic resonance. Ann Thorac Surg 2014; 97:916-22. [PMID: 24444876 DOI: 10.1016/j.athoracsur.2013.11.015] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2013] [Revised: 10/31/2013] [Accepted: 11/11/2013] [Indexed: 11/16/2022]
Abstract
BACKGROUND Typically, a Fontan connection is constructed as either a lateral tunnel (LT) pathway or an extracardiac (EC) conduit. The LT is formed partially by atrial wall and is assumed to have growth potential, but the extent and nature of LT pathway growth have not been well characterized. A quantitative analysis was performed to evaluate this issue. METHODS Retrospective serial cardiac magnetic resonance data were obtained for 16 LT and 9 EC patients at 2 time points (mean time between studies, 4.2 ± 1.6 years). Patient-specific anatomies and flows were reconstructed. Geometric parameters of Fontan pathway vessels and the descending aorta were quantified, normalized to body surface area (BSA), and compared between time points and Fontan pathway types. RESULTS Absolute LT pathway mean diameters increased over time for all but 2 patients; EC pathway size did not change (2.4 ± 2.2 mm vs 0.02 ± 2.1 mm, p < 0.05). Normalized LT and EC diameters decreased, while the size of the descending aorta increased proportionally to BSA. Growth of other cavopulmonary vessels varied. The patterns and extent of LT pathway growth were heterogeneous. Absolute flows for all vessels analyzed, except for the superior vena cava, proportionally to BSA. CONCLUSIONS Fontan pathway vessel diameter changes over time were not proportional to somatic growth but increases in pathway flows were; LT pathway diameter changes were highly variable. These factors may impact Fontan pathway resistance and hemodynamic efficiency. These findings provide further understanding of the different characteristics of LT and EC Fontan connections and set the stage for further investigation.
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Anwar S, Fogel EJ, Doddasomayajula R, Davidson A, Keller MS, Harris MA, Whitehead KK, Fogel MA. Feature tracking strain is similar to harmonic phase cardiac magnetic resonance in Fontan patients: a validation study. J Cardiovasc Magn Reson 2014. [PMCID: PMC4042444 DOI: 10.1186/1532-429x-16-s1-p106] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
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Whitehead KK, Harris MA, McNeal GR, Fogel MA. Use of a 3D respiratory navigated IR-FLASH sequence after gadofosveset in the pediatric and adult congenital population. JOURNAL OF CARDIOVASCULAR MAGNETIC RESONANCE 2014. [PMCID: PMC4044303 DOI: 10.1186/1532-429x-16-s1-p109] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Khiabani RH, Whitehead KK, Losse JD, Fogel MA, Yoganathan A. Studying effect of respiration on total cavopulmonary connection flows using real-time cardiac magnetic resonance. J Cardiovasc Magn Reson 2014. [PMCID: PMC4044966 DOI: 10.1186/1532-429x-16-s1-p137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Anwar S, Doddasomayajula R, Keller MS, Harris MA, Yoganathan A, Fogel MA, Whitehead KK. Strain to evaluate ventricular function in Fontan patients undergoing exercise cardiac magnetic resonance imaging. J Cardiovasc Magn Reson 2014. [PMCID: PMC4042447 DOI: 10.1186/1532-429x-16-s1-p123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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Haggerty CM, Restrepo M, Tang E, de Zélicourt DA, Sundareswaran KS, Mirabella L, Bethel J, Whitehead KK, Fogel MA, Yoganathan AP. Fontan hemodynamics from 100 patient-specific cardiac magnetic resonance studies: a computational fluid dynamics analysis. J Thorac Cardiovasc Surg 2013; 148:1481-9. [PMID: 24507891 DOI: 10.1016/j.jtcvs.2013.11.060] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2013] [Revised: 10/27/2013] [Accepted: 11/15/2013] [Indexed: 11/28/2022]
Abstract
OBJECTIVES This study sought to quantify average hemodynamic metrics of the Fontan connection as reference for future investigations, compare connection types (intra-atrial vs extracardiac), and identify functional correlates using computational fluid dynamics in a large patient-specific cohort. Fontan hemodynamics, particularly power losses, are hypothesized to vary considerably among patients with a single ventricle and adversely affect systemic hemodynamics and ventricular function if suboptimal. METHODS Fontan connection models were created from cardiac magnetic resonance scans for 100 patients. Phase velocity cardiac magnetic resonance in the aorta, vena cavae, and pulmonary arteries was used to prescribe patient-specific time-averaged flow boundary conditions for computational fluid dynamics with a customized, validated solver. Comparison with 4-dimensional cardiac magnetic resonance velocity data from selected patients was used to provide additional verification of simulations. Indexed Fontan power loss, connection resistance, and hepatic flow distribution were quantified and correlated with systemic patient characteristics. RESULTS Indexed power loss varied by 2 orders of magnitude, whereas, on average, Fontan resistance was 15% to 20% of published values of pulmonary vascular resistance in single ventricles. A significant inverse relationship was observed between indexed power loss and both systemic venous flow and cardiac index. Comparison by connection type showed no differences between intra-atrial and extracardiac connections. Instead, the least efficient connections revealed adverse consequences from localized Fontan pathway stenosis. CONCLUSIONS Fontan power loss varies from patient to patient, and elevated levels are correlated with lower systemic flow and cardiac index. Fontan connection type does not influence hemodynamic efficiency, but an undersized or stenosed Fontan pathway or pulmonary arteries can be highly dissipative.
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Downing TE, Whitehead KK, Dori Y, Gillespie MJ, Harris MA, Fogel MA, Rome JJ, Glatz AC. Accuracy of conventional oximetry for flow estimation in patients with superior cavopulmonary connection: a comparison with phase-contrast cardiac MRI. Circ Cardiovasc Imaging 2013; 6:943-9. [PMID: 24097418 DOI: 10.1161/circimaging.113.000496] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Cardiac catheterization is routinely used as a diagnostic tool in single ventricle patients with superior cavopulmonary connection. This physiology presents inherent challenges in applying the Fick principle to estimate flow. We sought to quantitatively define the error in oximetry-derived flow parameters using phase-contrast cardiac MRI (CMR) as a reference. METHODS AND RESULTS Thirty patients with superior cavopulmonary connection who underwent combined CMR and catheterization between July 2008 and June 2012 were retrospectively analyzed. Estimates of flow and resistance calculated using the Fick equation were compared with CMR measurements. Oximetry underestimated CMR-measured pulmonary blood flow (Qp) by an average of 1.1 L/min per m(2) or 32% of the CMR value (P<0.0001). Oximetry overestimated systemic blood flow (Qs) by an average of 0.5 L/min per m(2) or 15% of the CMR value (P=0.009). There was no correlation between the Qp:Qs ratio derived by Fick and that measured by CMR (ρ(c)=0.01). The error in the Fick Qp correlated moderately with the measured systemic-to-pulmonary arterial collateral flow (r=0.39). The median total oxygen consumption calculated using combined CMR and oximetry data was 173 mL/min per m(2), higher than the assumed values used to calculate flows by the Fick equation. The upper body circulation received on average 51% of systemic blood flow while conducting only 39% of total body metabolism. CONCLUSIONS Fick-derived estimates of flow are inherently unreliable in patients with superior cavopulmonary connections. Integrating flows measured by CMR and pressures measured by catheter will provide the best characterization of superior cavopulmonary connection physiology.
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O'Byrne ML, Mercer-Rosa L, Zhao H, Zhang X, Yang W, Cassedy A, Fogel MA, Rychik J, Tanel RE, Marino BS, Paridon S, Goldmuntz E. Morbidity in children and adolescents after surgical correction of truncus arteriosus communis. Am Heart J 2013; 166:512-8. [PMID: 24016501 DOI: 10.1016/j.ahj.2013.05.023] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2013] [Accepted: 05/25/2013] [Indexed: 11/19/2022]
Abstract
BACKGROUND Studies of outcome after operative correction of truncus arteriosus communis (TA) have focused on mortality and rates of reintervention. We sought to investigate the clinical status of children and adolescents with surgically corrected TA. METHODS AND RESULTS A cross-sectional study of subjects with TA was performed. Subjects underwent concurrent genetic testing, electrocardiogram, cardiac magnetic resonance imaging, cardiopulmonary exercise testing, and completed questionnaires assessing health status and health-related quality of life. Review of their medical history provided retrospective information on cardiac reintervention and use of medical care. Twenty-five subjects with a median age of 11.8 (8.1-18.99) years were enrolled. The prevalence of 22q11.2 deletion was 32%. Incidence of hospitalization, cardiac reintervention, and noncardiac operations was highest in the first year of life. Combined catheter-based and operative reintervention rates were 52% on the conduit and 56% on the pulmonary arteries. Right ventricular ejection fraction and end-diastolic volume were normal. Moderate or greater truncal valve insufficiency was seen in 11% of subjects, and truncal valve replacement occurred in 8% of subjects. Maximal oxygen consumption (P = .0002), maximal work (P < .0001), and forced vital capacity (P < .0001) were all lower than normal for age and sex. Physical health status and health-related quality of life were both severely diminished. CONCLUSION Patients with TA demonstrate significant comorbid disease throughout childhood, significant burden of operative and catheter-based reintervention, and deficits in exercise performance, functional status, and health-related quality of life.
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Schulz-Menger J, Bluemke DA, Bremerich J, Flamm SD, Fogel MA, Friedrich MG, Kim RJ, von Knobelsdorff-Brenkenhoff F, Kramer CM, Pennell DJ, Plein S, Nagel E. Standardized image interpretation and post processing in cardiovascular magnetic resonance: Society for Cardiovascular Magnetic Resonance (SCMR) board of trustees task force on standardized post processing. J Cardiovasc Magn Reson 2013; 15:35. [PMID: 23634753 PMCID: PMC3695769 DOI: 10.1186/1532-429x-15-35] [Citation(s) in RCA: 828] [Impact Index Per Article: 75.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2013] [Accepted: 03/05/2013] [Indexed: 01/29/2023] Open
Abstract
With mounting data on its accuracy and prognostic value, cardiovascular magnetic resonance (CMR) is becoming an increasingly important diagnostic tool with growing utility in clinical routine. Given its versatility and wide range of quantitative parameters, however, agreement on specific standards for the interpretation and post-processing of CMR studies is required to ensure consistent quality and reproducibility of CMR reports. This document addresses this need by providing consensus recommendations developed by the Task Force for Post Processing of the Society for Cardiovascular MR (SCMR). The aim of the task force is to recommend requirements and standards for image interpretation and post processing enabling qualitative and quantitative evaluation of CMR images. Furthermore, pitfalls of CMR image analysis are discussed where appropriate.
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Desai K, Haggerty CM, Kanter KR, Rossignac J, Spray TL, Fogel MA, Yoganathan AP. Haemodynamic comparison of a novel flow-divider Optiflo geometry and a traditional total cavopulmonary connection. Interact Cardiovasc Thorac Surg 2013; 17:1-7. [PMID: 23563054 DOI: 10.1093/icvts/ivt099] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
OBJECTIVES The total cavopulmonary connection (TCPC), the current palliation of choice for single-ventricle heart defects, is typically created with a single cylindrical tunnel or conduit routing inferior vena caval (IVC) flow to the pulmonary arteries. Previous studies have shown the haemodynamic efficiency of the TCPC to be sub-optimal due to the collision of vena caval flow, thus placing an extra energy burden on the single ventricle. The use of a bifurcated graft as the Fontan baffle (i.e. the 'Optiflo') has previously been proposed on the basis of theoretically improved flow efficiency; however, anatomical constraints may limit its effectiveness in some patients. METHODS In this study, an alternative approach to flow bifurcation is proposed, where a triangular insert is placed at the distal end of the IVC graft. The proof of concept for this design is demonstrated in two steps: first, determining the optimal insert size at a fixed Fontan graft size through a parametric study; then, characterizing the efficiency as a function of graft size when compared with a TCPC control. TCPC power loss and IVC flow distribution were the primary metrics of interest and were evaluated under both resting and simulated exercise conditions using an in-house computational fluid dynamics solver. RESULTS Results demonstrated that there was an optimal insert size that improved efficiency compared with the TCPC. For an 18-mm Fontan baffle, TCPC power loss was 4.1 vs 3.7 mW with the optimal flow-divider. The optimal insert was then scaled up for a 20-mm graft, with a similar reduction in power loss observed. Flow distribution results were inconsistent, based on sensitivity to the placement of the insert within the baffle. CONCLUSION This study demonstrated proof of concept that the flow-divider has the potential to reduce power loss and streamline IVC flow through the TCPC. An appropriate size for the insert in proportion to the Fontan baffle size was identified that reduced losses compared with a TCPC control under both resting and simulated exercise flow conditions.
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Haggerty CM, Kanter KR, Restrepo M, de Zélicourt DA, Parks WJ, Rossignac J, Fogel MA, Yoganathan AP. Simulating hemodynamics of the Fontan Y-graft based on patient-specific in vivo connections. J Thorac Cardiovasc Surg 2013; 145:663-70. [PMID: 22560957 PMCID: PMC3517690 DOI: 10.1016/j.jtcvs.2012.03.076] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2011] [Revised: 02/05/2012] [Accepted: 03/12/2012] [Indexed: 11/23/2022]
Abstract
BACKGROUND Using a bifurcated Y-graft as the Fontan baffle is hypothesized to streamline and improve flow dynamics through the total cavopulmonary connection (TCPC). This study conducted numerical simulations to evaluate this hypothesis using postoperative data from 5 patients. METHODS Patients were imaged with cardiac magnetic resonance or computed tomography after receiving a bifurcated aorto-iliac Y-graft as their Fontan conduit. Numerical simulations were performed using in vivo flow rates, as well as 2 levels of simulated exercise. Two TCPC models were virtually created for each patient to serve as the basis for hemodynamic comparison. Comparative metrics included connection flow resistance and inferior vena caval flow distribution. RESULTS Results demonstrate good hemodynamic outcomes for the Y-graft options. The consistency of inferior vena caval flow distribution was improved over TCPC controls, whereas the connection resistances were generally no different from the TCPC values, except for 1 case in which there was a marked improvement under both resting and exercise conditions. Examination of the connection hemodynamics as they relate to surgical Y-graft implementation identified critical strategies and modifications that are needed to potentially realize the theoretical efficiency of such bifurcated connection designs. CONCLUSIONS Five consecutive patients received a Y-graft connection to complete their Fontan procedure with positive hemodynamic results. Refining the surgical technique for implementation should result in further energetic improvements that may help improve long-term outcomes.
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96
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Fogel MA, Pawlowski T, Keller M, Harris M, Paridon S, Whitehead K. LEFT CORONARY ARTERY ANGLE OF TAKEOFF IN PATIENTS WITH TRANSPOSITION OF THE GREAT ARTERIES AFTER ARTERIAL SWITCH OPERATION IS NOT RELATED TO FUNCTION BUT IS RELATED TO LEFT VENTRICULAR MASS: A CMR STUDY. J Am Coll Cardiol 2013. [DOI: 10.1016/s0735-1097(13)60470-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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97
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Anwar S, Harris MA, Keller MS, Fogel MA, Whitehead KK. Feature tracking strain is a promising functional analysis technique in single ventricle patients. J Cardiovasc Magn Reson 2013. [PMCID: PMC3559953 DOI: 10.1186/1532-429x-15-s1-p297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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98
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Dori Y, Glatz AC, Hanna BD, Gillespie MJ, Harris MA, Keller MS, Fogel MA, Rome JJ, Whitehead KK. Acute effects of embolizing systemic-to-pulmonary arterial collaterals on blood flow in patients with superior cavopulmonary connections: a pilot study. Circ Cardiovasc Interv 2013; 6:101-6. [PMID: 23322742 DOI: 10.1161/circinterventions.112.972265] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND The significance and optimal treatment of systemic-to-pulmonary arterial collateral (SPC) vessels in single ventricle patients are poorly understood. The acute efficacy of SPC embolization has not been demonstrated in a quantifiable fashion. We sought to assess the acute efficacy of SPC embolization on blood flow as quantified by phase contrast magnetic resonance imaging and hypothesized that embolization acutely decreases SPC flow and increases systemic blood flow (Q(S)). METHODS AND RESULTS Six superior cavopulmonary connection patients underwent SPC flow quantification by phase contrast magnetic resonance imaging, including quantification of superior and inferior caval, total pulmonary artery, total pulmonary vein, ascending and descending aortic flows (Q(SVC), Q(IVC), Q(PA), Q(PV), Q(Ao), and Q(Dao), respectively), both immediately before and after cardiac catheterization with coil and particle embolization of angiographically evident SPC vessels. All studies were performed under a single anesthetic. After embolization, we found a significant decrease in SPC flow of 0.9 (range, 0.6-1.3) L/(min·m(2)) (P=0.03); a median reduction of 47% (range, 32-60). There was a significant decrease in the median Q(P):Q(S) from 1.3 before to 0.8 after embolization (P=0.03), and an increase in Q(S) from a median of 3.4 to 4.4 L/(min·m(2)) (P<0.05), and Q(SVC) from a median of 1.7 to 2.3 L/(min·m(2)) (P=0.03). CONCLUSIONS We report on the acute efficacy of SPC embolization, demonstrating a significant decrease in SPC flow and Q(P):Q(S) and increase in Q(SVC) and Q(S). Further studies are needed to assess the durability of the procedure and the effect on Fontan and longer-term outcomes.
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Restrepo M, Mirabella L, Tang E, Haggerty CM, Fogel MA, Valente AM, McElhinney DB, Yoganathan AP. Growth of the inferior cavopulmonary pathway in patients with a lateral tunnel fontan connection: quantification from serial magnetic resonance images. J Cardiovasc Magn Reson 2012. [PMCID: PMC3305132 DOI: 10.1186/1532-429x-14-s1-p114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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100
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Tang E, Haggerty CM, Khiabani RH, de Zélicourt D, Kanter J, Sotiropoulos F, Fogel MA, Yoganathan AP. Numerical and experimental investigation of pulsatile hemodynamics in the total cavopulmonary connection. J Biomech 2012. [PMID: 23200904 DOI: 10.1016/j.jbiomech.2012.11.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Computational fluid dynamics (CFD) tools have been extensively applied to study the hemodynamics in the total cavopulmonary connection (TCPC) in patients with only a single functioning ventricle. Without the contraction of a sub-pulmonary ventricle, pulsatility of flow through this connection is low and variable across patients, which is usually neglected in most numerical modeling studies. Recent studies suggest that such pulsatility can be non-negligible and can be important in hemodynamic predictions. The goal of this work is to compare the results of an in-house numerical methodology for simulating pulsatile TCPC flow with experimental results. Digital particle image velocimetry (DPIV) was acquired on TCPC in vitro models to evaluate the capability of the CFD tool in predicting pulsatile TCPC flow fields. In vitro hemodynamic measurements were used to compare the numerical prediction of power loss across the connection. The results demonstrated the complexity of the pulsatile TCPC flow fields and the validity of the numerical approach in simulating pulsatile TCPC flow dynamics in both idealized and complex patient specific models.
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