O’Leary, Patrick

Solitary myofibromas are rare, benign, mesenchymal tumors typically found in the head and neck regions. We report an exceptionally rare case of a solitary cardiac myofibroma and its short-term management and outcome. A two-month-old infant was referred due to a murmur. Echocardiography revealed a 2 × 1 cm solitary mass originating from a mitral papillary muscle, causing severe regurgitation. Magnetic resonance imaging showed the mass to be homogeneous on T1, hyperintense on T2, and hypointense on first-pass perfusion imaging with no enhancement on delayed postcontrast imaging. The mass was surgically excised partially due to its involvement with the mitral valve. Postoperative recovery was uneventful, with echocardiography four months later showing no tumor recurrence and trivial mitral regurgitation. This report provides valuable imaging and pathology examples to aid in the recognition of this rare tumor and demonstrates that successful surgical excision is possible, even with significant cardiac involvement.

Background There is currently no consensus regarding the use of surveillance cross-sectional imaging in pediatric patients after bidirectional cavopulmonary connection (BDCPC). We sought to determine how computed tomography with angiography (CTA) and cardiac magnetic resonance (CMR) imaging impacted the clinical management of pediatric patients after BDCPC. Methods A single-center retrospective study including patients with single ventricle who had BDCPC between 2010 and 2019, and CTA/CMR studies obtained in these patients, at ≤5 years of age, and with Glenn physiology. Repeat studies on the same patient were included if the clinical situation had changed. The impact of CTA/CMR studies was categorized as major, minor, or none. Results Twenty-four patients (63% male) and 30 imaging studies (22 CTAs) were included. 60% were obtained in patients with hypoplastic left heart syndrome (HLHS); most common indication was Follow-up after an intervention (23%). 6 CMRs were performed on stable HLHS patients as part of a research protocol, with no clinical concerns. The overall impact of CTA/CMR studies was major in 13 cases (43.3%). CTA/CMR studies performed ≥1 year of age (62.5% vs 21.4%, P = .02) and in non-HLHS patients (66.7% vs 27.8%, P = .035) were associated with major impact. Also, 2/6 Research studies were associated with a major impact. Conclusions CTA/CMR imaging in pediatric patients with SV after BDCPC was associated with significant clinical impact in over 40% of cases, with a higher impact if obtained in patients ≥1 year of age and in non-HLHS patients. We cannot disregard the possibility of CMR as a surveillance imaging modality in this population.

Background: There is a paucity of literature regarding systemic semilunar valve (SSLV) dysfunction in patients with Fontan circulation. We sought to describe our center's 47-year experience with systemic semilunar valve replacement or repair (SSLVR) in patients with Fontan circulation. Methods: The Mayo Clinic Fontan Database is a comprehensive institutional database that stores clinical information of 1176 patients from 1973 to 2021. It was reviewed to identify patients who had a SSLV intervention at the time of or after Fontan. A cohort of 15 patients was identified and a retrospective review of their records was performed. Results: Fourteen patients had SSLV replacement (all mechanical) and one had a repair. SSLVR occurred up to 29 years following the Fontan (mean 11.3 ± 9 years, median 14 years). Thirteen of 14 with SSLVR were performed after Fontan and one was done at the time of initial Fontan. This was an older cohort and mean age at the time of Fontan was 8.7 ± 9.4 years (median 4 years). Indication for the operation was > moderate SSLV regurgitation in all patients. Six patients had decreased ventricular function (EF < 50%) prior to SSLVR and 8 had reduced function after SSLVR. Conclusion: Fortunately, the need for SSLV intervention after Fontan was rare, as evidenced by our small cohort extracted from a large single-institution database spanning a 47-year time period. Reduced preoperative and postoperative ejection fraction was common but did not seem to impact the outcome. Optimal timing for SSLV intervention after Fontan remains unclear.

Background: Echocardiographic (echo) functional assessment of single systemic right ventricle (RV) lacks a reliable parameter and does not provide a substitute of volumetric ejection fraction (EF). RV volumes by 3D-echo are challenging and not widely used. Apical RV fractional area change (FAC) has shown some relation to CMR EF, but the strength of correlation has been suboptimal. Adding additional planes to apical FAC may improve this correlation. Our objective was to assess correlation of triplane FAC (apical, short-axis, and inflow-outflow) with CMR EF and to compare the tri- and single plane methods of measuring FAC to each other. Methods: Subjects with hypoplastic left heart syndrome (after superior or total cavopulmonary anastomosis) were prospectively recruited. CMR was performed and right ventricular ejection fraction was calculated. Transthoracic echo studies were performed close to the time of the CMR scan (median interval: 1 d). FAC was measured in apical 4-chamber view, parasternal short axis view at the mid ventricular level, and para-apical right ventricular inflow-outflow view. Triplane FAC was calculated by the average of the three FAC. Comparison was made between FAC and CMR-derived ejection fraction. Results: A total of 25 subjects underwent testing. Triplane FAC could not be assessed in 5, due to lack of optimal acoustic windows. Mean age was 10 ± 8 y (range 9 m to 24 y). Out of the uniplanar methods, apical FAC had the closest relationship to CMR EF. Triplane FAC showed even better correlation coefficient and R 2 values; although in this small group the difference did not reach significance. Results are summarized in the Table. Conclusion: In patients with single systemic RV, triplane FAC offers improved correlation with CMR EF relative to single plane evaluations. This approach may be useful if 3D echo is unavailable or of suboptimal quality and warrants further study.

Background: Hypoplastic left heart syndrome (HLHS) with risk of poor outcome has been linked to MYH6 variants, implicating overlap in genetic etiologies of structural and myopathic heart disease. Methods: Whole genome sequencing was performed in 197 probands with HLHS, 43 family members, and 813 controls. Data were filtered for rare, segregating variants in 3 index families comprised of an HLHS proband and relative(s) with cardiomyopathy. Whole genome sequencing data from cases and controls were compared for rare variant burden across 56 cardiomyopathy genes utilizing a weighted burden test approach, accounting for multiple testing using a Bonferroni correction. Results: A pathogenic MYBPC3 nonsense variant was identified in the first proband who underwent cardiac transplantation for diastolic heart failure, her father with left ventricular noncompaction, and 2 fourth-degree relatives with hypertrophic cardiomyopathy. A likely pathogenic RYR2 missense variant was identified in the second proband, a second-degree relative with aortic dilation, and a fourth-degree relative with dilated cardiomyopathy. A pathogenic RYR2 exon 3 in-frame deletion was identified in the third proband diagnosed with catecholaminergic polymorphic ventricular tachycardia and his father with left ventricular noncompaction and catecholaminergic polymorphic ventricular tachycardia. To further investigate HLHS-cardiomyopathy gene associations in cases versus controls, rare variant burden testing of 56 genes revealed enrichment in MYH6 ( P =0.000068). Rare, predicted-damaging MYH6 variants were identified in 10% of probands in our cohort—4 with familial congenital heart disease, 4 with compound heterozygosity (3 with systolic ventricular dysfunction), and 4 with MYH6 – FLNC synergistic heterozygosity. Conclusions: Whole genome sequencing in multiplex families, proband-parent trios, and case-control cohorts revealed defects in cardiomyopathy-associated genes in patients with HLHS, which may portend impaired functional reserve of the single-ventricle circulation.

Hypoplastic left heart syndrome is one of the most complex congenital heart diseases and requires several cardiac surgeries for survival. The diagnosis is usually established prenatally or shortly after birth. Each stage of surgery poses a unique hemodynamic situation that requires deeper understanding to manage common pediatric problems such as dehydration and respiratory infections. Careful multidisciplinary involvement in the care of these complex patients is improving their outcome; however, morbidity and mortality are still substantial. In this review, we focus on the hemodynamic aspects of various surgical stages that a primary care provider should know to manage these challenging patients.

AbstractWe performed a retrospective review of outcomes after heart transplantation during long‐term follow‐up of a surgical cohort of 1138 Fontan patients who were followed at the Mayo Clinic. Follow‐up information was obtained from medical records and a clinical questionnaire that was mailed to patients not known to be deceased at the initiation of the study. Forty‐four of 1138 Fontan patients with initial or subsequent evaluation at Mayo had cardiac transplantation between 1988 and 2014 (mean age at transplantation was 23.2 ± 12 yr, median was 19.8 yr; mean interval between Fontan and transplantation was 13.0 ± 7.7 yr, median was 13.1 yr). Two patients had combined organ transplantation (one heart–lung, one heart–liver). Twelve of the 44 (27%) patients had PLE prior to transplantation. There was no difference in post‐bypass Fontan pressures or incidence of late reoperations for AVV repair/replacement between transplanted and non‐transplanted patients. There were 16 (36%) deaths in the transplantation cohort; seven occurred within 30 days of transplantation. Overall one, five, 10, and 15 yr post‐transplantation survival was 80%, 72%, 69%, and 55%, respectively. Although this is a challenging group of patients, intermediate‐term results suggest that cardiac transplantation remains a reasonable option for patients with a failed Fontan circulation.