Use of Flow Restrictors in Congenital Heart Disease.

The surgical pulmonary artery band was first introduced in 1952 and, to this day, can produce challenges in regard to the ideal amount of restriction and the need for reoperations. A transcatheter option may be the ideal solution as it allows for a less-invasive approach for a better hemodynamic assessment and easier re-intervention. To date, multiple approaches have been developed with device modifications to create restrictions to flow, each with advantages and limitations. Continued experience is still necessary to determine the ideal device to use to create an adequate and modifiable level of restriction.

PDA Stent Placement *6: High-Impact Limitations of Angiography to Delineate a Complex PDA.

This is a case of an infant with duct-dependent pulmonary circulation, who required 6 stents delivered over three procedures to fully stent the arterial duct, which originated in a very unusual fashion. The attainable angiographic projections were unable to profile its origin, and only a CT scan was ultimately able to delineate the (stenotic) ductal origin from the aorta.

Prognostic value of longitudinal vasoreactivity in pediatric pulmonary hypertension.

Upon diagnosis of pulmonary hypertension in pediatrics, standard practice often involves acute vasoreactivity testing (AVT) in the cardiac catheterization laboratory. However, the importance of repeated AVT testing in a given patient thereafter remains unclear. This study sought to describe serial AVT results in pediatric patients and understand the prognostic significance of longitudinal AVT results in pediatric pulmonary hypertension. A retrospective chart review was performed for pediatric pulmonary hypertension patients diagnosed between 2008 and 2021. Patients were included if they had two or more catheterizations with AVT. The study cohorts were patients who were AVT negative upon initial catheterization then AVT positive at any subsequent catheterization (AVT-/+) compared to those were AVT negative upon initial and all subsequent catheterizations (AVT-/-). A positive AVT was defined by Sitbon criteria. The analyzed outcome was event-free survival. The relationship between study cohorts and event-free survival was analyzed by log-rank Kaplan-Meier survival as well as Cox proportional hazard regression to control for confounders. There were 35 patients who met inclusion criteria in this time period. Patients who were AVT(-/+) had statistically significantly better event-free survival than AVT(-/-) (p = 0.002). In univariate and multivariate Cox regressions, a subsequent AVT positive result amongst those who were initially AVT negative was a positive prognostic factor, hazard ratio 0.03 (95% confidence interval: 0.02-0.35). For patients with negative AVT upon initial cardiac catheterization, this data supports that continuing AVT should be performed as any subsequent AVT positive result may indicate improved expectations for event-free survival.

Arterial Baroreceptor Physiology: Differences Between Normal Subjects and Pediatric Patients with Postural Tachycardia and Neurocardiogenic Syncope.

The arterial baroreceptor reflex in children and adolescents has not been well studied in the current literature with a lack of agreed upon normal values, particularly in postural orthostatic tachycardia syndrome (POTS) or neurocardiogenic syncope (NCS). We used the sequence method and head-up tilt test (HUTT) to evaluate baroreceptor function in 3 phases: baseline supine position for 10 min, head-up position at 70° for 30 min or until syncope, and post-tilt supine reposition for 10 min. We measured the number of baroreceptor events, baroreceptor effectiveness index (BEI), and the magnitude of sensitivity of the events at each phase of HUTT. We studied 198 individuals (49 normal subjects, 67 POTS, 82 NCS) with age ranges from 8 to 21 years. The data show a statistically significant decrease in slope and BEI in patients with POTS and NCS during the head-up phase, with an increase in activity in the lag 1 and 2 portions of all phases in patients with POTS. This study provides terminology to describe baroreceptor function and identifies the slope and BEI portions of the baroreceptor reflex as the most useful objective measures to differentiate pediatric patients with POTS and NCS from normal subjects.

Hemodynamic Impact of Atrial Pacing in Patients with Fontan Physiology and Junctional Rhythm: A Cardiac Catheterization Study.

Sinus node dysfunction is a common problem and adversely impacts patients who have undergone the Fontan operation. In Fontan patients with an adequate junctional escape rhythm, the benefit of atrial pacing to restore atrioventricular synchrony remains unclear. Data were collected retrospectively on all Fontan patients with junctional rhythm who underwent atrial pacing during cardiac catheterization. Hemodynamics were obtained at baseline and after atrial pacing for 5-10 min. Seven patients, mean age 10 years (3-21) were studied. The type of Fontan was extracardiac in 6 and lateral tunnel in one. Patients were paced at 10 bpm faster than their junctional rate. With pacing, there was a significant decrease in left atrial pressure from (mean ± SEM) 8.8 ± 2.6 to 5.5 ± 2.9 mmHg (p = 0.02), a significant increase in cardiac index from 2.7 ± 0.8 to 3.5 ± 1 L/min/m2 (p = 0.01) and pulmonary blood flow from 2.1 ± 0.6 to 2.7 ± 0.7 L/min/m2 (p = 0.001), and no significant change in pulmonary artery pressure, from 13.4 ± 2.8 to 12.4 mmHg ± 3.6 (p = 0.06) or pulmonary vascular resistance from 2.1 ± 0.86 to 3.25 ± 1.9 WU × M2 (p = 0.1). In Fontan patients with junctional rhythm, atrial pacing decreased the left atrial pressure, increased cardiac output and did not significantly change the pulmonary artery pressure. Our study supports further investigation into the utility of prophylactic atrial pacemaker implantation in Fontan patients with significant durations of JR on ambulatory monitoring.

Heart Rate Induced Dynamic Coronary Ischemia Secondary to Aortic Valve Insufficiency from a Diminutive Aortic Valve Leaflet: Diagnosis and Repair.

Hemodynamically significant congenital obstruction of the coronary arteries is a rare phenomenon. The potential etiology of these obstructions is variable including coronary os stenosis, occlusive fibrous webs, or a dysplastic aortic valve leaflet resulting in obstruction. In infants, diagnosis of these coronary lesions is often difficult due to the small anatomic size and limitations of imaging modalities in the setting of the underlying rapid heart rates. We present a case of an infant presenting in heart failure secondary to dynamic coronary artery insufficiency from a diminutive aortic valve leaflet and aortic sinus and variable levels of aortic valve insufficiency based on heart rate.

Baroreceptor activity and sensitivity: normal values in children and young adults using the head up tilt test.

BACKGROUND: Baroreceptor function in children and adolescents has not been well studied in the current literature, with a lack of agreed upon normal values. The authors hypothesize that there is a significant increase in the baroreceptor activity with a decrease in the sensitivity during the upright phase in comparison to the supine phases of the head upright tilt test (HUTT) protocol. METHODS: Baroreceptor evaluation was performed using the sequence method in 49 subjects ages 8-21 years, during the 3 phases of HUTT: supine, head up, and post-tilt supine positions. Baroreceptor Effectiveness Index (BEI) and the number and slope of baroreceptor events were recorded. RESULTS: On study of the events and slope values, there was a significant difference between the three phases of the HUTT with regard to the baroreceptor activity and sensitivity. No significant difference was found in BEI. CONCLUSIONS: Our study presents normal values of baroreceptor activity, sensitivity, and BEI in pediatric patients under controlled supine and head up position. We also present new data regarding delayed heart rate responses to pressure changes in the Lag 1 and Lag 2 parameters, which may be beneficial in diagnosis and management of pediatric patients with orthostatic intolerance.

Timing and Pattern of Recurrence after Gastrectomy for Adenocarcinoma.

Gastric adenocarcinoma has a high recurrence rate. The goal of this study was to determine the timing and pattern of recurrence after gastrectomy. A retrospective review was performed of patients with gastric adenocarcinoma having curative partial or total gastrectomy with R0/D2 lymph node resection from 1999 to 2013. Follow-up included CT scans of the chest, abdomen, and pelvis at 3-month intervals for the first three years, at 6-month intervals for the next two years, and annually thereafter. There were 62 patients, 38 males and 24 females, with a median age of 65 years. Median follow-up was 29 months and recurrence was identified in 21 per cent of patients. Median time to recurrence was 12 months and 92 per cent of recurrences occurred within two years. The last recurrence was identified at 34 months. Abdominal CT scan identified all patients with recurrence, although some patients had disease elsewhere in addition to the abdominal disease. There were no extra-abdominal isolated recurrences. In conclusion, recurrence after complete resection for gastric adenocarcinoma typically occurs within the first two years, and can be found by abdominal CT scan. Close cancer follow-up appears unnecessary after three years because all recurrences were identified within 34 months of resection.

O6-methylguanine-DNA methyltransferase activity is associated with response to alkylating agent therapy and with MGMT promoter methylation in glioblastoma and anaplastic glioma.

BACKGROUND: CpG methylation in the O6-methylguanine-DNA methyltransferase (MGMT) promoter is associated with better outcome following alkylating agent chemotherapy in glioblastoma (GBM) and anaplastic glioma (AG). To what extent improved response reflects low or absent MGMT activity in glioma tissue has not been unequivocally assessed. This information is central to developing anti-resistance therapies. METHODS: We examined the relationship of MGMT activity in 91 GBMs and 84 AGs with progression-free survival (PFS) following alkylator therapy and with promoter methylation status determined by methylation-specific PCR (MSP). RESULTS: Cox regression analysis revealed that GBMs with high activity had a significantly greater risk for progression in dichotomous (P ≤ 0.001) and continuous (P ≤ 0.003) models, an association observed for different alkylator regimens, including concurrent chemo-radiation with temozolomide. Analysis of MGMT promoter methylation status in 47 of the GBMs revealed that methylated tumors had significantly lower activity (P ≤ 0.005) and longer PFS (P ≤ 0.036) compared to unmethylated tumors, despite overlapping activities. PFS was also significantly greater in methylated vs. unmethylated GBMs with comparable activity (P ≤ 0.005), and among unmethylated tumors with less than median activity (P ≤ 0.026), suggesting that mechanisms in addition to MGMT promote alkylator resistance. Similar associations of MGMT activity with PFS and promoter methylation status were observed for AGs. CONCLUSIONS: Our results provide strong support for the hypotheses that MGMT activity promotes alkylator resistance and reflects promoter methylation status in malignant gliomas. GENERAL SIGNIFICANCE: MGMT activity is an attractive target for anti-resistance therapy regardless of methylation status.