Alison K. Meadows

Bicuspid Aortic Valve: Four-dimensional MR Evaluation of Ascending Aortic Systolic Flow Patterns

PURPOSE To use time-resolved three-dimensional phase-contrast magnetic resonance (MR) imaging, also called four-dimensional flow MR imaging, to evaluate systolic blood flow patterns in the ascending aorta that may predispose patients with a bicuspid aortic valve (BAV) to aneurysm. MATERIALS AND METHODS The HIPAA-compliant protocol received institutional review board approval, and informed consent was obtained. Four-dimensional flow MR imaging was used to assess blood flow in the thoracic aorta of 53 individuals: 20 patients with a BAV, 25 patients with a tricuspid aortic valve (TAV), and eight healthy volunteers. The Fisher exact test was used to evaluate the significance of flow pattern differences. RESULTS Nested helical flow was seen at peak systole in the ascending aorta of 15 of 20 patients with a BAV but in none of the healthy volunteers or patients with a TAV. This flow pattern was seen both in patients with a BAV with a dilated ascending aorta (n = 6) and in those with a normal ascending aorta (n = 9), was seen in the absence of aortic stenosis (n = 5), and was associated with eccentric systolic flow jets in all cases. Fusion of right and left leaflets gave rise to right-handed helical flow and right-anterior flow jets (n = 11), whereas right and noncoronary fusion gave rise to left-handed helical flow with left-posterior flow jets (n = 4). CONCLUSION Four-dimensional flow MR imaging showed abnormal helical systolic flow in the ascending aorta of patients with a BAV, including those without aneurysm or aortic stenosis. Identification and characterization of eccentric flow jets in these patients may help identify those at risk for development of ascending aortic aneurysm.

Best Practices in Managing Transition to Adulthood for Adolescents With Congenital Heart Disease: The Transition Process and Medical and Psychosocial Issues: A Scientific Statement From the American Heart Association

Many children born with complex childhood illnesses that historically caused early death are now surviving into adulthood with the expectation of leading meaningful and productive lives. They will ultimately need to transition their care from pediatric to adult-centered care. Unfortunately, in the absence of structured programs to guide this transition, there is often delayed or inappropriate care, improper timing of the transfer of care, and undue emotional and financial stress on the patients, their families, and the healthcare system. At its worst, and as frequently happens now, patients are lost to appropriate follow-up. In fact, the number of adults with congenital heart disease (CHD) in the United States is rising exponentially and now exceeds 1 000 000.1,–,7 At least half of these patients may have complex CHD. Fewer than 30% of adults with CHD are seen by appropriate specialized providers. Fewer than 15% of these patients, who are seen in specialty adult CHD (ACHD) clinics, have CHD that is classified as severe.8 Thus, adolescents with CHD constitute a growing population of individuals for whom a well-planned and well-executed “transition process” is essential. The goals of a formal transition program are to prepare young adults for transfer of care. It should provide uninterrupted health care that is patient centered, age and developmentally appropriate, flexible, and comprehensive. It should include age-appropriate education about medical conditions and promote skills in communication, decision making, self-care, and self-advocacy.9,–,13 It should foster greater personal and medical independence and a greater sense of control over health, healthcare decisions, and psychosocial environment. The ultimate goal of a transition program is to optimize the quality of life (QOL), life expectancy, and future productivity of young patients.14 We acknowledge that the development of ideal transition programs is a …

Clinical evaluation of aortic coarctation with 4D flow MR imaging

To show that 4D Flow is a clinically viable tool for evaluation of collateral blood flow and demonstration of distorted blood flow patterns in patients with treated and untreated aortic coarctation.

Evaluation of Bicuspid Aortic Valve and Aortic Coarctation With 4D Flow Magnetic Resonance Imaging

Time-resolved, 3D, phase-contrast magnetic resonance imaging (4D flow) is an effective means of evaluating dynamic multidirectional blood flow in the thoracic aorta.1 We have used the technique for characterization of abnormal flow features in a 14-year-old boy with aortic coarctation and bicuspid aortic valve (BAV) but without evidence of aortic stenosis or regurgitation. In addition to the expected flow disturbance in the region of the juxtaductal coarctation (Figure 1), we show an unusual flow feature in the ascending aorta that has not been previously reported in this clinical setting and that may be unique to BAV: 2 discrete nested helices of midsystolic blood flow in a nonaneurysmal aorta (Figure 2). Figure 1. Fourteen-year-old boy with BAV and aortic coarctation. A, Three-dimensional contrast-enhanced magnetic resonance angiography that demonstrates a focal juxtaductal coarctation and prominent internal mammary and …

Tetralogy of Fallot: Impact of the Excursion of the Interventricular Septum on Left Ventricular Systolic Function and Fibrosis after Surgical Repair

PURPOSE To quantify the excursion of interventricular septum (IVS) in patients after repair of tetralogy of Fallot (TOF), a marker of interventricular interaction, and assess its association with left ventricular (LV) ejection fraction, LV septal wall thickening, and LV fibrosis. MATERIALS AND METHODS The HIPAA-compliant protocol received institutional board review approval. IVS excursion was measured at cardiovascular magnetic resonance (MR) imaging in 82 patients after repair of TOF and in 10 healthy volunteers. IVS excursion was correlated with LV ejection fraction, LV septal wall thickening, and LV delayed gadolinium enhancement. Independent predictors of reduced LV ejection fraction were identified, including significant univariable predictors with use of a multivariable logistic regression model. RESULTS IVS excursion was greater in patients than in healthy volunteers (5.3 mm ± 3.1 vs 1.2 mm ± 0.4, P < .01). Patients (n = 68) with abnormal excursion of the IVS had reduced LV ejection fraction (57% ± 7 vs 61% ± 4, P < .01) and reduced LV septal wall thickening (24% ± 10 vs 29% ± 5, P = .01) compared with patients with normal IVS excursion. Maximal IVS excursion (odds ratio = 1.27 per millimeter, P = .03) and right ventricular (RV) ejection fraction (odds ratio = 0.92 per percentage, P = .031) were independent predictors of reduced LV ejection fraction (<55%). Among the 44 patients with delayed enhancement images, those with abnormal excursion of the IVS had higher LV delayed enhancement scores (median, 1.5 [interquartile range, 0-2] vs 0 [interquartile range, 0-0]; P < .01] than patients with normal IVS excursion. Notably, in all but one patient the delayed enhancement was located at the RV-LV hinge points. CONCLUSION Abnormal IVS excursion after repair of TOF is associated with reduced global and septal LV systolic function and LV fibrosis at the RV-LV hinge points, suggesting a mechanism of adverse interventricular interaction.

Impaired regional left ventricular strain after repair of tetralogy of Fallot.

To test the potential of magnetic resonance imaging (MRI) in early detection of left ventricular (LV) dysfunction in patients with pulmonary regurgitation and normal LV ejection fraction after repair of tetralogy of Fallot.

Magnetic Resonance Imaging in the Adult with Congenital Heart Disease

Given relatively recent advances in pediatric cardiovascular surgery, catheter-based interventional therapies, intensive care, and medical management, many children with complex congenital heart disease (CHD) are surviving into adulthood. As such, adults with CHD constitute a rapidly growing population. The majority of these adults have complex residual disease requiring serial imaging and often further intervention. There are a number of imaging modalities available to the clinician and radiologist when it comes to these evaluations. Magnetic resonance imaging (MRI) holds a unique and growing position among these. Echocardiography has been a mainstay of imaging in congenital heart disease. Despite its importance in rapid diagnosis and follow-up, it has limitations in the evaluation of the adult with CHD. The presence of postoperative scar, chest wall deformities, overlying lung tissue, and large body size often results in suboptimal transthoracic echocardiographic windows. Transesophageal echocardiography, while providing improved acoustic windows, is limited by its small fieldof-view and more invasive nature, often requiring deep sedation or general anesthesia. Cardiac catheterization, employing X-ray fluoroscopy and contrast angiography, has an expanding role in minimally invasive interventions, but its role as a diagnostic procedure is rapidly diminishing. This is in part due to its limitation as a 2D projection imaging technique with poor soft-tissue contrast and the substantial ionizing radiation exposure involved, and in part because both diagnostic and functional analysis are often better performed with noninvasive imaging techniques. Computed tomography (CT) has been useful in evaluating vascular anatomy, and with the advent of high-resolution CT and cardiac gating, has emerged as a useful tool for assessing intracardiacanatomyandmyocardialfunction.Nevertheless, the temporal resolution of cardiac CT remains limited and advances in CT imaging technology have often come with increases in exposure to ionizing radiation. MRI has emerged over the past few decades as an alternative, complementary, and frequently superior imaging modality for the investigation of anatomy and function in the adult with CHD. It has many advantages over other imaging modalities. It does not require the use of iodinated contrast agents and does not involve exposure to ionizing radiation. This is particularly important in a population of patients who have been, and continue to be, exposed to large doses of contrast agent and radiation during hemodynamic and interventional catheterization. Major advances in MRI hardware and software, including advanced coil design, faster gradients, new pulse sequences, and faster image reconstruction techniques, allow rapid, high-resolution imaging of complex anatomy and accurate, quantitative assessment of physiology and function. This review highlights the MRI techniques frequently employed to evaluate the anatomy and physiology of the adult with CHD. It provides information about the general application of cardiac MRI in this patient population, as well as sample protocols and guidelines for its use in the more commonly encountered lesions referred for MRI.

Best Practices in Managing Transition to Adulthood for Adolescents With Congenital Heart Disease: The Transition Process and Medical and Psychosocial Issues

Many children born with complex childhood illnesses that historically caused early death are now surviving into adulthood with the expectation of leading meaningful and productive lives. They will ultimately need to transition their care from pediatric to adult-centered care. Unfortunately, in the absence of structured programs to guide this transition, there is often delayed or inappropriate care, improper timing of the transfer of care, and undue emotional and financial stress on the patients, their families, and the healthcare system. At its worst, and as frequently happens now, patients are lost to appropriate follow-up. In fact, the number of adults with congenital heart disease (CHD) in the United States is rising exponentially and now exceeds 1 000 000.1,–,7 At least half of these patients may have complex CHD. Fewer than 30% of adults with CHD are seen by appropriate specialized providers. Fewer than 15% of these patients, who are seen in specialty adult CHD (ACHD) clinics, have CHD that is classified as severe.8 Thus, adolescents with CHD constitute a growing population of individuals for whom a well-planned and well-executed “transition process” is essential. The goals of a formal transition program are to prepare young adults for transfer of care. It should provide uninterrupted health care that is patient centered, age and developmentally appropriate, flexible, and comprehensive. It should include age-appropriate education about medical conditions and promote skills in communication, decision making, self-care, and self-advocacy.9,–,13 It should foster greater personal and medical independence and a greater sense of control over health, healthcare decisions, and psychosocial environment. The ultimate goal of a transition program is to optimize the quality of life (QOL), life expectancy, and future productivity of young patients.14 We acknowledge that the development of ideal transition programs is a …

Diagnostic value of the flow profile in the distal descending aorta by phase‐contrast magnetic resonance for predicting severe coarctation of the aorta

To compare aortic flow profiles at the level of the proximal descending (PDAo) and distal descending aorta (DDAo) in patients investigated for coarctation of the aorta (CoA), and compare their respective diagnostic value for predicting severe CoA. Diastolic flow decay in the PDAo predicts severe CoA, but flow measurements at this level are limited by flow turbulence, aliasing, and stent‐related artifacts.

Prediction of Hemodynamic Severity of Coarctation by Magnetic Resonance Imaging

A published formula containing minimal aortic cross-sectional area and the flow deceleration pattern in the descending aorta obtained by cardiovascular magnetic resonance predicts significant coarctation of the aorta (CoA). However, the existing formula is complicated to use in clinical practice and has not been externally validated. Consequently, its clinical utility has been limited. The aim of this study was to derive a simple and clinically practical algorithm to predict severe CoA from data obtained by cardiovascular magnetic resonance. Seventy-nine consecutive patients who underwent cardiovascular magnetic resonance and cardiac catheterization for the evaluation of native or recurrent CoA at Childrens Hospital Boston (n = 30) and the University of California, San Francisco (n = 49), were retrospectively reviewed. The published formula derived from data obtained at Childrens Hospital Boston was first validated from data obtained at the University of California, San Francisco. Next, pooled data from the 2 institutions were analyzed, and a refined model was created using logistic regression methods. Finally, recursive partitioning was used to develop a clinically practical prediction tree to predict transcatheter systolic pressure gradient ≥ 20 mm Hg. Severe CoA was present in 48 patients (61%). Indexed minimal aortic cross-sectional area and heart rate-corrected flow deceleration time in the descending aorta were independent predictors of CoA gradient ≥ 20 mm Hg (p <0.01 for both). A prediction tree combining these variables reached a sensitivity and specificity of 90% and 76%, respectively. In conclusion, the presented prediction tree on the basis of cutoff values is easy to use and may help guide the management of patients investigated for CoA.