Jimmy C. Lu

Relation of Right Ventricular Dilation, Age of Repair, and Restrictive Right Ventricular Physiology With Patient-Reported Quality of Life in Adolescents and Adults With Repaired Tetralogy of Fallot

The present study aimed to determine the predictors of patient-reported quality of life and restrictive right ventricular (RV) physiology in adolescents and adults with repaired tetralogy of Fallot. A total of 62 patients (median age 28.5 years, range 14 to 69) undergoing cardiovascular magnetic resonance imaging completed the Short Form 36-item questionnaire, version 2, a validated quality of life assessment. RV inflow curves were generated from the sum of tricuspid inflow and pulmonary insufficiency. The patient-reported quality of life was comparable to population norms. Patients repaired after 1 year of age showed a strong trend toward a greater likelihood of physical component summary age-adjusted z-score ≤-1 (odds ratio 7.50, 95% confidence interval 0.90 to 62.3, p = 0.06). Patients with a RV ejection fraction of <45% reported decreased physical component summary (p = 0.02) and physical functioning (p = 0.02) scores. The RV end-diastolic volume, pulmonary regurgitation, and diastolic indexes did not predict the quality of life. The indexed RV end-diastolic volume was related to diastolic abnormalities, correlating with a greater peak early filling rate (r = 0.71, p <0.0001), ratio of peak early to atrial filling rates (r = 0.45, p = 0.006), and showing a strong trend with the end-diastolic forward flow in the pulmonary trunk (odds ratio 2.67 for moderate dilation and 3.50 for severe dilation, p = 0.06). Patients who underwent repair before 1 year old were more likely to have end-diastolic forward flow (15 of 17 vs 25 of 42, p = 0.03). In conclusion, the RV ejection fraction and age of repair were the best predictors of quality of life in this population, in whom end-diastolic forward flow and associated diastolic parameters appeared to reflect an overdistended ventricle, which might suggest a role for early pulmonary valve replacement.

The utility of handheld echocardiography for early rheumatic heart disease diagnosis: A field study

AIMS The World Heart Federation (WHF) guidelines for rheumatic heart disease (RHD) are designed for a standard portable echocardiography (STAND) machine. A recent study in a tertiary care centre demonstrated that they also had good sensitivity and specificity when modified for use with handheld echocardiography (HAND). Our study aimed to evaluate the performance of HAND for early RHD diagnosis in the setting of a large-scale field screening. METHODS AND RESULTS STAND was performed in 4773 children in Gulu, Uganda, with 10% randomly assigned to also undergo HAND. Additionally, any child with mitral or aortic regurgitation also underwent HAND. Studies were performed by experienced echocardiographers and blindly reviewed by cardiologists using 2012 WHF criteria, which were modified slightly for HAND--due to the lack of spectral Doppler capability. Paired echocardiograms were performed in 1420 children (mean age 10.8 and 53% female), resulting in 1234 children who were normal, 133 who met criteria for borderline RHD, 47 who met criteria for definite RHD, and 6 who had other diagnoses. HAND had good sensitivity and specificity for RHD detection (78.9 and 87.2%, respectively), but was most sensitive for definite RHD (97.9%). Inter- and intra-reviewer agreement ranged between 66-83 and 71.4-94.1%, respectively. CONCLUSIONS HAND has good sensitivity and specificity for diagnosis of early RHD, performing best for definite RHD. Protocols for RHD detection utilizing HAND will need to include confirmation by STAND to avoid over-diagnosis. Strategies that evaluate simplified screening protocols and training of non-physicians hold promise for more wide spread deployment of HAND-based protocols.

Handheld echocardiographic screening for rheumatic heart disease by non-experts

Objectives Handheld echocardiography (HAND) has good sensitivity and specificity for rheumatic heart disease (RHD) when performed by cardiologists. However, physician shortages in RHD-endemic areas demand less-skilled users to make RHD screening practical. We examine nurse performance and interpretation of HAND using a simplified approach for RHD screening. Methods Two nurses received training on HAND and a simplified screening approach. Consented students at two schools in Uganda were eligible for participation. A simplified approach (HAND performed and interpreted by a non-expert) was compared with the reference standard (standard portable echocardiography, performed and interpreted by experts according to the 2012 World Heart Federation guidelines). Reasons for false-positive and false-negative HAND studies were identified. Results A total of 1002 children were consented, with 956 (11.1 years, 41.8% male) having complete data for review. Diagnoses included: 913 (95.5%) children were classified normal, 32 (3.3%) borderline RHD and 11 (1.2%) definite RHD. The simplified approach had a sensitivity of 74.4% (58.8% to 86.5%) and a specificity of 78.8% (76.0% to 81.4%) for any RHD (borderline and definite). Sensitivity improved to 90.9% (58.7% to 98.5%) for definite RHD. Identification and measurement of erroneous colour jets was the most common reason for false-positive studies (n=164/194), while missed mitral regurgitation and shorter regurgitant jet lengths with HAND were the most common reasons for false-negative studies (n=10/11). Conclusions Non-expert-led HAND screening programmes offer a potential solution to financial and workforce barriers that limit widespread RHD screening. Nurses trained on HAND using a simplified approach had reasonable sensitivity and specificity for RHD screening. Information on reasons for false-negative and false-positive screening studies should be used to inform future training protocols, which could lead to improved screening performance.

Non-invasive pulsed cavitational ultrasound for fetal tissue ablation: feasibility study in a fetal sheep model

Currently available fetal intervention techniques rely on invasive procedures that carry inherent risks. A non‐invasive technique for fetal intervention could potentially reduce the risk of fetal and obstetric complications. Pulsed cavitational ultrasound therapy (histotripsy) is an ablation technique that mechanically fractionates tissue at the focal region using extracorporeal ultrasound. In this study, we investigated the feasibility of using histotripsy as a non‐invasive approach to fetal intervention in a sheep model.

Handheld echocardiography versus auscultation for detection of rheumatic heart disease

BACKGROUND: Rheumatic heart disease (RHD) remains a major public health concern in developing countries, and routine screening has the potential to improve outcomes. Standard portable echocardiography (STAND) is far more sensitive than auscultation for the detection of RHD but remains cost-prohibitive in resource-limited settings. Handheld echocardiography (HAND) is a lower-cost alternative. The purpose of this study was to assess the incremental value of HAND over auscultation to identify RHD. METHODS: RHD screening was completed for schoolchildren in Gulu, Uganda, by using STAND performed by experienced echocardiographers. Any child with mitral or aortic regurgitation or stenosis plus a randomly selected group of children with normal STAND findings underwent HAND and auscultation. STAND and HAND studies were interpreted by 6 experienced cardiologists using the 2012 World Heart Federation criteria. Sensitivity and specificity of HAND and auscultation for the detection of RHD and pathologic mitral or aortic regurgitation were calculated by using STAND as the gold standard. RESULTS: Of 4773 children who underwent screening with STAND, a subgroup of 1317 children underwent HAND and auscultation. Auscultation had uniformly poor sensitivity for the detection of RHD or valve disease. Sensitivity was significantly improved by using HAND compared with auscultation for the detection of definite RHD (97.8% vs 22.2%), borderline or definite RHD (78.4% vs 16.4%), and pathologic aortic insufficiency (81.8% vs 13.6%). CONCLUSIONS: Auscultation alone is a poor screening test for RHD. HAND significantly improves detection of RHD and may be a cost-effective screening strategy for RHD in resource-limited settings.

Simplified Rheumatic Heart Disease Screening Criteria for Handheld Echocardiography

BACKGROUND Using 2012 World Heart Federation criteria, standard portable echocardiography (STAND) reveals a high burden of rheumatic heart disease (RHD) in resource-poor settings, but widespread screening is limited by cost and physician availability. Handheld echocardiography (HAND) may decrease costs, but World Heart Federation criteria are complicated for rapid field screening, particularly for nonphysician screeners. The aim of this study was to determine the best simplified screening strategy for RHD detection using HAND. METHODS In this prospective study, STAND (GE Vivid q or i or Philips CX-50) was performed in five schools in Gulu, Uganda; a random subset plus all children with detectable mitral regurgitation or aortic insufficiency also underwent HAND (GE Vscan). Borderline or definite RHD cases were defined by 2012 World Heart Federation criteria on STAND images, by two experienced readers. HAND studies were reviewed by cardiologists blinded to STAND results. Single and combined HAND parameters were evaluated to determine the simplified screening strategy that maximized sensitivity and specificity for case detection. RESULTS In 1,439 children (mean age, 10.8 ± 2.6 years; 47% male) with HAND and STAND studies, morphologic criteria and the presence of any mitral regurgitation by HAND had poor specificity. The presence of aortic insufficiency was specific but not sensitive. Combined criteria of mitral regurgitation jet length ≥ 1.5 cm or any aortic insufficiency best balanced sensitivity (73.3%) and specificity (82.4%), with excellent sensitivity for definite RHD (97.9%). With a prevalence of 4% and subsequent STAND screening of positive HAND studies, this would reduce STAND studies by 80% from a STAND-based screening strategy. CONCLUSIONS In resource-limited settings, HAND with simplified criteria can detect RHD with good sensitivity and specificity and decrease the need for standard echocardiography. Further study is needed to validate screening by local practitioners and long-term outcomes.

Clinical significance of late gadolinium enhancement in patients<20 years of age with hypertrophic cardiomyopathy.

Late gadolinium enhancement (LGE) on cardiovascular magnetic resonance imaging is associated with adverse events in adults with hypertrophic cardiomyopathy (HC). However, limited data exist on the extent and clinical significance of LGE in the pediatric population. In 30 patients (aged 14.1±3.2 years) with clinically diagnosed HC who underwent cardiovascular magnetic resonance imaging from 2007 to 2012, segments with hypertrophy and LGE were identified by 2 experienced readers blinded to outcome. Radial, circumferential, and longitudinal strains were evaluated using feature tracking software. The composite outcome was defined as cardiac death, nonsustained ventricular tachycardia, ventricular fibrillation, or appropriate implantable cardioverter-defibrillator discharge. LGE was present in 17 of 30 patients (57%), all in a midmyocardial pattern, with median 3 segments per patient (interquartile range [IQR] 2 to 5). No LGE was detected in patients without phenotypic hypertrophy. Segments with LGE had decreased radial (basal segments 20.7% vs 70.9%, p=0.01), circumferential (basal segments -23.2% vs -29.3%, p=0.04), and longitudinal strains (basal segments -13.8% vs -20.9%, p=0.04). After median follow-up of 26.9 months (IQR 7.5 to 34.3), 7 patients who had an adverse outcome (5 ventricular tachycardia, 1 appropriate implantable cardioverter-defibrillator discharge, and 1 death) had more segments of LGE (median 4, IQR 2 to 7 vs 0, IQR 0 to 2, p=0.01). One patient without LGE had ventricular tachycardia on exercise test. In conclusion, LGE occurs in a similar pattern in pediatric patients with HC as in adults, associated with hypertrophy, decreased myocardial strain, and adverse clinical outcomes. Further longitudinal studies are necessary to evaluate the rate of development of LGE and relation to outcomes in a larger cohort.

Imaging of the Coronary Sinus: Normal Anatomy and Congenital Abnormalities

Knowledge of the anatomy of the coronary sinus (CS) and cardiac venous drainage is important because of its relevance in electrophysiologic procedures and cardiac surgeries. Several procedures make use of the CS, such as left ventricular pacing, mapping and ablation of arrhythmias, retrograde cardioplegia, targeted drug delivery, and stem cell therapy. As a result, it is more important for physicians interpreting the results of computed tomographic (CT) examinations dedicated to the heart or including the heart to be able to identify normal variants and congenital anomalies and to understand their clinical importance. Abnormalities of the CS range from anatomic morphologic variations to hemodynamically significant anomalies such as an unroofed CS, anomalous pulmonary venous connection to the CS, and coronary artery-CS fistula. It can be important to identify some anatomic variations, even though they are clinically occult, to ensure appropriate preprocedural planning. Both CT and magnetic resonance imaging provide excellent noninvasive depiction of the anatomy and anomalies of the CS. Supplemental material available at http://radiographics.rsna.org/lookup/suppl/doi:10.1148/rg.324105220/-/DC1.

Relation of Strain by Feature Tracking and Clinical Outcome in Children, Adolescents, and Young Adults With Hypertrophic Cardiomyopathy

Evaluation of hypertrophic cardiomyopathy (HC) in young patients is limited by lack of age-specific norms for wall thickness on cardiovascular magnetic resonance (CMR) images. Left ventricular strain may have a role in identifying and risk stratifying patients with HC, but few data exist for strain measurement on CMR images. In 30 patients (14.1 ± 3.2 years) with clinically diagnosed HC and 24 controls (15.6 ± 2.8 years), strain (radial, longitudinal, and circumferential) was evaluated by 2 experienced readers using CMR feature tracking. In patients with HC, hypertrophied segments had decreased radial (28.0 ± 5.2% vs 58.6 ± 3.9%, p = 0.0002), circumferential (-23.7 ± 1.1% vs -28.3 ± 0.8%, p = 0.004), and longitudinal (-11.2 ± 1.2% vs -21.7 ± 0.8%, p <0.0001) strains versus control segments. Hypertrophied segments had decreased longitudinal (basal segments -12.2 ± 1.9% vs -22.6 ± 1.2%, p = 0.0002), radial (basal segments 22.7 ± 10.8% vs 78.8 ± 7.2%, p = 0.0001), and circumferential (basal segments -22.4 ± 1.7% vs -30.6 ± 1%, p = 0.0004) strains versus nonhypertrophied segments in patients with HC. Longitudinal strain had the lowest intraobserver and interobserver variabilities (coefficient of variability -15.7% and -18.5%). After a median follow-up of 28.1 months (interquartile range [IQR] 4.2 to 33.1), 7 patients with HC with an adverse event outcome (5 ventricular tachycardia, 1 appropriate implantable cardioverter-defibrillator discharge, and 1 death) had reduced global radial (median 39.7%, IQR 39.6% to 46.6% vs 65.4%, IQR 46.1% to 83.4%, p = 0.01) and longitudinal strains (median -16.5%, IQR -18.7% to -15.5% vs -19.7%, IQR -23.8% to -17.5%, p = 0.046) compared with patients with HC without an event. In conclusion, CMR feature tracking detects differences in global and segmental strains and may represent a novel method to predict clinical outcome in patients with HC. Further study is necessary to evaluate longitudinal changes in this population.

Evaluation with Cardiovascular MR Imaging of Baffles and Conduits Used in Palliation or Repair of Congenital Heart Disease

A wide array of baffles and conduits are used in repair or palliation of congenital heart disease, which is the most common major birth defect, often with complex redirection of blood flow to achieve a more stable physiology. Cardiovascular magnetic resonance (CMR) imaging is an increasingly used modality for noninvasive assessment of anatomy and physiology both before and after surgical intervention, with highly reproducible measurements of ventricular size and function, quantification of valvular insufficiency and flow volumes, and excellent delineation of intracardiac and extracardiac anatomy. The authors review the indications, appearances on CMR images, and potential complications of various cardiovascular baffles and conduits: Mustard and Senning procedures, venoatrial baffles, intraventricular baffles, ventriculoarterial conduits, and baffles and conduits used in functional single-ventricle palliation. CMR imaging offers the most complete evaluation of single-ventricle anatomy and physiology, demonstrating the anatomy of venous pathways and pulmonary arteries and quantifying systemic ventricular size and systolic function, differential pulmonary blood flow, ratio of pulmonary to systemic blood flow, and aortopulmonary collateral flow. Anatomic and physiologic considerations are discussed, and suggested CMR imaging protocols and practical advice for performing and interpreting CMR studies are provided. The diversity and complexity of baffles and conduits complicates performance and interpretation of studies in this population, but a fundamental understanding of the goals of the procedure, postoperative physiology, and potential complications allows targeted imaging and precise reporting of clinically significant findings. Supplemental material available at http://radiographics.rsna.org/lookup/suppl/doi:10.1148/rg.323115096/-/DC1.