Aortic Dissection in a Young Patient With Unsuspected Aortopathy.

Aortic dissection is often a fatal condition if not recognized and treated emergently. Fortunately, it is extremely rare in children and adolescents. We report a case of an adolescent boy who survived an aortic dissection due to severe aortic root dilation. A comprehensive history and physical examination, including family history, can facilitate an early diagnosis of connective tissue diseases, such as Loeys-Dietz syndrome (LDS).

Subaortic Stenosis in Adult Patients With Atrioventricular Septal Defect.

BACKGROUND: Patients with atrioventricular septal defects (AVSD) are at risk for development of subaortic stenosis throughout their lifetime. The early and midterm outcomes of adults with AVSD undergoing primary operation or reoperation for subaortic stenosis remain unknown. METHODS: All patients aged 18 years or more with partial or complete AVSD who underwent operation for subaortic stenosis at our institution from 1992 to 2020 were retrospectively reviewed. RESULTS: Nineteen patients were identified: 15 patients with partial AVSD (79%); 3 (16%) with complete AVSD; and 1 (5%) with transitional AVSD. Fifteen patients (79%) had previously corrected AVSD (median 8 years; interquartile range, 3.6-23.1) and 7 (37%) had previous repair of subaortic stenosis. The mechanism for obstruction included subaortic membrane (n = 19, 100%); septal hypertrophy (n = 11, 58%); anomalous papillary muscle, chordae, or left atrioventricular valve tissue (n = 9, 47%); and tunnel obstruction (n = 5, 26%). All patients underwent transaortic membrane resection, and septal myectomy was done in 18 patients (95%). There was no early mortality. During follow-up (median 8.3 years, maximum 28), survival was 100% at 5 years and 95% at 10 years. One patient required reintervention for subaortic stenosis 15 years after the operation at our institution. CONCLUSIONS: Surgical correction of subaortic obstruction in adult patients with AVSD can be accomplished with low morbidity and mortality. Subaortic stenosis can appear late after the initial repair of AVSD, and these patients remain at risk for recurrence after resection.

Diagnostic accuracy of the 12-lead electrocardiogram in the first 48 hours of life for newborns of a parent with congenital long QT syndrome.

BACKGROUND: Long QT syndrome (LQTS) is an autosomal dominant disorder characterized by a prolonged QT interval. Electrocardiographic (ECG) screening in the first 48 hours of life may be misleading, even in newborns with a genotype-positive LQTS parent. OBJECTIVE: The purpose of this study was to determine the ECG's diagnostic accuracy in the first 48 hours of life for neonates born to a parent with LQTS. METHODS: We conducted a retrospective review of all neonates born at Mayo Clinic to a parent with ≥1 pathogenic variant in a LQTS-causative gene who had least 1 ECG in the first 48 hours and genetic test results were available. The sensitivity and specificity of the diagnostic ECG were calculated using Bazett's heart rate-corrected QT (QTc) thresholds of 440, 450, 460, and 470 ms. RESULTS: Overall, 74 newborns (36 females [49%]) were included (mean QTc interval on the first ECG 489 ± 54 ms; 50 [68%] LQTS genotype-positive). The mean QTc interval in the first 48 hours for neonates that ultimately were genotype-positive was greater (506 ± 52 ms) than that for genotype-negative neonates (455 ± 41 ms) (P = .0004). When using a recommended threshold QTc interval of ≥440 ms, 6 of 50 genotype-positive neonates (12%) were missed (underdiagnosed) and 17 of 24 genotype-negative neonates (71%) were overdiagnosed (sensitivity 88%; specificity 29%). CONCLUSION: The newborn ECG should not be used in isolation to make the diagnosis of LQTS since it will result in many misclassifications. Genetic testing must be initiated before discharge, and proper anticipatory guidance is vital while awaiting test results.

Myocarditis Following Coronavirus Disease 2019 mRNA Vaccine: A Case Series and Incidence Rate Determination.

BACKGROUND: Myocarditis following coronavirus disease 2019 (COVID-19) mRNA vaccines (Pfizer-BioNTech and Moderna) has been increasingly reported. Incidence rates in the general population are lacking, with pericarditis rather than myocarditis diagnostic codes being used to estimate background rates. This comparison is critical for balancing the risk of vaccination with the risk of no vaccination. METHODS: A retrospective case series was performed using the Mayo Clinic COVID-19 Vaccine Registry. We measured the incidence rate ratio (IRR) for myocarditis temporally related to COVID-19 mRNA vaccination compared with myocarditis in a comparable population from 2016 through 2020. Clinical characteristics and outcomes of the affected patients were collected. A total of 21 individuals were identified, but ultimately 7 patients met the inclusion criteria for vaccine-associated myocarditis. RESULTS: The overall IRR of COVID-19-related myocarditis was 4.18 (95% confidence interval [CI], 1.63-8.98), which was entirely attributable to an increased IRR among adult males (IRR, 6.69; 95% CI, 2.35-15.52) compared with females (IRR 1.41; 95% CI, .03-8.45). All cases occurred within 2 weeks of a dose of the COVID-19 mRNA vaccine, with the majority occurring within 3 days (range, 1-13) following the second dose (6 of 7 patients, 86%). Overall, cases were mild, and all patients survived. CONCLUSIONS: Myocarditis is a rare adverse event associated with COVID-19 mRNA vaccines. It occurs in adult males with significantly higher incidence than in the background population. Recurrence of myocarditis after a subsequent mRNA vaccine dose is not known at this time.