Novel Technique for Cardiac Monitor Implantation in Pediatrics.

Implantable cardiac monitors (ICM) allow for symptom-rhythm correlation. Current manufacturer recommendations call for implantation of ICMs diagonally in the left anterior chest. Complications such as skin tenting and device erosion have occurred using this technique in pediatric patients. The purpose of this study was to assess the safety and efficacy of implanting ICMs via new vertical-parasternal technique (VP) compared to manufacturer-recommended diagonal technique (D) in pediatric patients. Single-center, IRB-approved retrospective study of pediatric patients that underwent ICM implantation from 01/01/2017 to 12/01/2021. All implants were performed after informed consent, under sterile conditions in the electrophysiology laboratory. Data collected included demographics, implant orientation (VP or D), complications, device type, presence of P-wave, and measurement of R-wave amplitude at implantation and follow-up. ICMs were implanted in 34 patients without congenital heart disease. Initial R-wave amplitude average for VP 1.00, D 0.99 (p = NS). Follow-up R-wave amplitude was 0.97 VP and 0.93 for D (p = NS). Median follow-up period for VP was 11 and for D was 20 months (p = NS). D cohort had only post-procedural complication due to skin tenting of the ICM in child < 2.5 years of age. No skin tenting, erosions, or complications occurred in the vertical-parasternal implant technique. Vertical-Parasternal ICM implantation is as safe and effective as the manufacturer-recommended diagonal implant. Short- and long-term data demonstrate an equivalent R-wave detection and no significant signal deterioration, even in very young children. No skin tenting, erosions, or complications occurred in the vertical parasternal implant technique.

Characteristics and Outcomes of Heart Transplantation in DiGeorge Syndrome.

DiGeorge syndrome (DGS) is commonly associated with both congenital heart disease (CHD) and immunologic abnormalities. While CHD may prompt consideration for heart transplantation (HTx), little is known about HTx management or outcomes in this group. The aim of this study was to describe the spectrum of patients with DGS who undergo HTx and report post-HTx outcomes. All pediatric HTx recipients (2002-2016) with DGS were identified using ICD codes from a linked billing and clinical registry database. Patient characteristics and outcomes were described and compared to non-DGS HTx recipients with CHD. Kaplan-Meier methods were used to assess overall survival, freedom from infection, and freedom from rejection. A total of 17 patients with DGS who underwent HTx at 12 different centers were included. Median age at HTx was 5 years (IQR 0-13 years). Steroids were used for induction in all patients in addition to thymoglobulin in 13/17 (76%) and IL2R antagonists in 3/17 (18%). Maintenance immunosuppression was a combination of tacrolimus or cyclosporine and mycophenolate or azathioprine in 16/17 (94%). Half received steroids at the time of discharge. There were six deaths (35%). The median post-HTx survival was 5.4 years with no difference in freedom from rejection, infection, or overall survival between patients with and without DGS. Patients with DGS undergoing HTx received standard immunosuppression. We found no difference in freedom from infection, rejection, or overall post-HTx survival compared to non-DGS patients, although the small size of our study resulted in limited statistical power. Given the potential for favorable outcomes, patients with DGS may be considered for HTx in the appropriate clinical setting.

Relation of Right Atrial Volume, Systemic Venous Dimensions, and Flow Patterns to Right Atrial Pressure in Infants and Children.

Echocardiographic assessment of right atrial (RA) volume, inferior vena cava (IVC) diameter, and hepatic vein flow velocity independently correlate with the RA pressure by direct catheter measurement in adults. We prospectively collected invasive RA pressure measurements and echocardiographic data in infants and young children with the goal of developing a predictive model to noninvasively determine normal RA pressure. All subjects had a central venous catheter through which RA pressure could be transduced. Specific inclusion criteria consisted of (1) biventricular heart, (2) absence of inotropes, (3) sinus rhythm, and (4) at least 24 hours from surgery. Two-dimensional echocardiography (2DE)-Doppler and 3DE-Doppler were used to measure RA volume, systemic venous diameters, and flow velocity. Regression equations of RA pressure with RA volume, systemic venous size, and flow velocity were explored. Of 46 studies, 43 (93%) had echocardiograms adequate for analysis. RA pressure did not correlate with body surface area or age (p = 0.69, p = 0.87). The mean indexed RA volume by 3DE-Doppler was significantly higher than by 2DE (p <0.005). On multivariable analysis, only IVC systolic flow velocity and systolic 2D Simpson's derived indexed RA volume demonstrated significant independent correlation with RA pressure, resulting in the equation: RA pressure (mm Hg) = 7.35 - 0.0025 × IVC systolic flow velocity (cm/s) + 0.119 × indexed RA volume by systolic 2D Simpson's (ml/m2). RA pressure did not show correlation with systemic venous diameters or systolic and diastolic flow velocities in the SVC and hepatic veins. In conclusion, regression incorporating 2DE-derived RA volume and IVC systolic flow velocity provided the best noninvasive estimate of normal RA pressure in infants and children. The model derived requires validation in an independent sample.