Novel Utilization of Ultrasound Enhancing Agents in Complex Congenital Heart Disease Following Superior Cavopulmonary Connection.

BACKGROUND: Children with single-ventricle congenital heart disease typically undergo a superior cavopulmonary connection (SCPC) as the second stage in their surgical palliation. Postoperatively, stenoses of the SCPC and branch pulmonary arteries can occur. If there are clinical concerns and echocardiography is insufficient for diagnosis, patients undergo invasive evaluation with exposure to radiation and anesthesia. The use of ultrasound enhancing agents (UEAs) to improve echocardiographic diagnostic capabilities has not previously been described in this population. METHODS: A single-center, retrospective case review was conducted of children who underwent echocardiography with UEA, following SCPC, from March 1, 2020, to April 15, 2022, at the Children's Hospital of Philadelphia. Twenty-two patients with hypoxemia or concern for obstruction following SCPC underwent UEA echocardiography. Extracted clinical data included patient demographics, echocardiographic images, angiography, surgical and transcatheter interventions, as well as available follow-up data. RESULTS: Six of the 22 UEA echocardiograms demonstrated stenosis or occlusion of either the SCPC or a pulmonary artery. All six patients underwent cardiac catheterization and five required intervention. Angioplasty was performed in each case with one requiring subsequent surgical revision. Sixteen of 22 UEA echocardiograms demonstrated no evidence of stenosis. Ten of these 16 patients improved, while six experienced persistent hypoxemia prompting referral for cardiac catheterization. Angiography confirmed the UEA echocardiographic findings (absence of stenosis) in four of these six patients. There were no adverse reactions related to UEA administration. CONCLUSIONS: Echocardiography with UEAs is a valuable and safe adjunctive imaging modality following SCPC, particularly when two-dimensional and color imaging is limited. This novel application of UEAs in complex patients with congenital heart disease provides an "angiogram-like" image, better delineating vessel walls and improving assessment of postoperative obstruction. As experience with UEAs increases in the congenital heart disease population, there may be opportunities to decrease invasive and costly procedures, while expediting the care of patients in need of intervention.

Stent Angioplasty for Post-Operative Coronary Artery Stenosis in Infants.

INTRODUCTION: While frequently performed in the adult population, percutaneous coronary artery stent angioplasty (CSA) in infants is rare. CSA in infants is challenging because of limited options in terms of appropriately sized (length and diameter) stents, concern about stenting vessels with significant growth potential and limited data regarding durability of benefit. We report a multicenter case series of infants who underwent CSA. METHODS: A multicenter, retrospective case series of infants who underwent percutaneous CSA to treat post-operative coronary artery stenoses was performed. RESULTS: Six infants from 3 institutions who underwent post-operative CSA were identified. The anatomic diagnoses were d-transposition of the great arteries in 3 cases, anomalous left coronary artery from the pulmonary artery in 2 and supravalvar aortic stenosis in 1. All infants were critically ill at the time of CSA. Diameters of coronary artery stents used ranged from 2.25 to 2.75 mm. There were no procedural complications. All stents were patent immediately after placement and the clinical condition improved or stabilized in all patients. Follow-up angiography was available for 3 patients at 4 to 16 months post-CSA, at which time 67% (2/3) remained patent. CONCLUSION: CSA is a feasible and effective therapy for critically ill infants with post-surgical coronary obstruction. Treatment appears to allow at least short-term reperfusion to facilitate recovery of ventricular function and potential development of collateral circulation when longer-term stent patency is not achieved. Longer-term stent patency and coronary artery health remain unanswered questions.

Sustained improvement in fellows' echocardiographic completeness through the coronavirus pandemic with a standardised imaging protocol.

First-year cardiology fellows must quickly learn basic competency in echocardiography during fellowship orientation. This educational process was disrupted in 2020 due to the coronavirus pandemic, as our hands-on echocardiography teaching transitioned from practice on paediatric volunteers to simulation-based training. We previously described an improvement in echocardiographic completeness after implementation of a standardised imaging protocol for the performance of acute assessments of ventricular function. Herein, we assessed whether this improvement could be sustained over the two subsequent years, including the fellowship year affected by the pandemic. Echocardiograms performed by first-year paediatric cardiology fellows to assess ventricular function were reviewed for completeness. The frequency with which each requested component was included was measured. A total demographic score (out of 7) and total imaging score (out of 23) were calculated. The pre-protocol years (2015-2017) were compared to the post-protocol years (2018-2020), and the pre-COVID years (2018-2019) were compared to the year affected by COVID (2020). There was a sustained improvement in completeness after protocol implementation with improvement in the demographic score (median increasing from 6 to 7, p < 0.001) and imaging score (median increasing from 13 to 16, p < 0.001). More individual components showed a statistically significant increase in frequency compared to our prior publication. The COVID pandemic resulted in very few differences in completeness. Demographic reporting improved modestly (p = 0.04); the imaging score was unchanged (p = 0.59). The only view obtained less frequently was the apical two-chamber view. A standardised imaging protocol allowed sustained improvements in echocardiographic completeness despite the disruption of fellowship orientation by COVID-19.

Impact of Transcatheter Pulmonary Artery Intervention Following Superior Cavopulmonary Connection on Pulmonary Artery Growth.

INTRODUCTION: Balloon and stent angioplasty of the pulmonary arteries (PAs) are frequently performed following superior cavopulmonary connection (SCPC), not only to normalize the caliber of the affected PA but also in hopes of maximizing downstream growth over time. There are limited data on the impact on subsequent PA growth prior to total cavopulmonary connection (TCPC). METHODS: A single-center, retrospective cohort study was performed on children who underwent transcatheter (TC) PA intervention following SCPC between January 1, 2010, and December 31, 2018. Growth of treated and contralateral PAs was measured at the lobar bifurcation (distal branch PA [DBPA]) and in the proximal lower lobe (lower lobe branch [LLB]) on serial angiograms. Growth rate was evaluated using a mixed-effect model clustered by individual patient with an interaction term for treated PA and time to evaluate for differential growth rates between treated and contralateral PAs. RESULTS: Thirty-five patients underwent TC PA intervention following SCPC, at a median of 70 days (interquartile range: 19-297 days) postoperatively. Significant growth was seen at both DBPA and LLB for raw (0.8 mm/year, 95% CI: 0.6-1.0, P < .001 for both) and body surface area (BSA) adjusted measures (8.4mm/m2/year, 95% CI: 5.6-11.2, P < .001; 7.9 mm/m2/year, 95% CI: 5.5-10.2, P < .001). The growth rate of the treated vessel was not significantly different from that of the contralateral vessel at the DBPA or LLB positions for raw (P = .71, .70) or BSA-adjusted measurements (P = .86, .64). CONCLUSION: Transcatheter PA intervention was associated with normal distal PA growth rate relative to the untreated side.

Vagal Termination of Ventricular Tachycardia in a Pediatric Patient.

Ventricular tachycardia is a rare clinical entity in pediatric patients and typically requires chemical and/or electrical intervention to convert into a sustained sinus rhythm. However, for certain forms originating from the right ventricular outflow tract, conversion with adenosine and vagal maneuvers has been demonstrated in adult patients. In this case, we suggest that pediatric patients with right ventricular outflow tract ventricular tachycardia who are hemodynamically stable may benefit from a trial of vagal maneuvers.