A Novel Patent Ductus Arteriosus Severity Score to Predict Clinical Outcomes in Premature Neonates.

Background: Patent Ductus Arteriosus (PDA) in premature neonates has been associated with comorbidities including chronic lung disease (CLD), and death. However, the treatment of PDA remains controversial. There have been several echocardiographic variables previously used to determine the hemodynamic significance of PDA but their utility in early prediction of clinical outcomes is not well studied. Objective: The objective of our study was to evaluate the use of a severity scoring system incorporating markers of systemic under perfusion, pulmonary over perfusion and left ventricular (LV) function in predicting clinical outcomes in premature neonates. Methods: It is a single center prospective observational study involving newborns < 32 weeks' gestation. An echocardiogram was done within seven days of life to measure variables previously known to predict severity of shunting in PDA including pulmonary perfusion index (PPI). Predictors of CLD/death were identified using multivariate logistic regression. A severity score was derived and its ability to predict clinical outcomes was tested using a receiver operating characteristic curve. Results: We studied 98 infants with a mean (SD) gestation of 28.9 ± 1.91 weeks and birth weight of 1228.06 ± 318.94 g, respectively. We identified five echocardiographic variables along with gestational age that was independently associated with the outcome variable (PPI, LV output, Superior Mesenteric Artery [SMA] Velocity Time Integral [VTI], Peak diastolic flow velocity in Pulmonary Vein [PV Vd], and reversal of flow in diastole in descending aorta [DFR]). The range of severity score was 0 (low risk) to 12 (high risk). A higher score was associated with the primary outcome variable of CLD/death (7.5 [1.2] vs. 3.6 [1.5], p < 0.001). Our severity score had an area under the curve of 0.97 (95% CI 0.93−0.99, p < 0.001) for predicting CLD/death. Conclusion: Our new PDA severity score of 5.5 has a sensitivity and specificity of 94% and 93%, and positive and negative predictive values of 94% and 93%, respectively.

Steroid-associated bradycardia in a newly diagnosed B precursor acute lymphoblastic leukemia patient with Holt-Oram syndrome.

Holt-Oram syndrome (HOS) (OMIM#142900) is a rare condition with upper extremity malformations as well as structural and conduction cardiac anomalies. There are sparse reports in the literature documenting malignancy in association with HOS. We report a pediatric patient clinically diagnosed with HOS (missing thumbs bilaterally, atrial septal defect, ventricular septal defect, and first-degree heart block), who also developed B precursor acute lymphoblastic leukemia. During induction of chemotherapy with steroids, she developed profound bradycardia without clinical symptoms. The bradycardia resolved without intervention, but this case highlights the challenges of managing chemotherapy side effects in a patient with congenital heart disease. A literature review pertinent to the associated findings in the case is also presented.

Complicated ventricular arrhythmia and hematologic myeloproliferative disorder in RIT1-associated Noonan syndrome: Expanding the phenotype and review of the literature.

BACKGROUND: Noonan syndrome is an autosomal dominant disorder secondary to RASopathies, which are caused by germ-line mutations in genes encoding components of the RAS mitogen-activated protein kinase pathway. RIT1 (OMIM *609591) was recently reported as a disease gene for Noonan syndrome. METHODS AND RESULTS: We present a patient with RIT1-associated Noonan syndrome, who in addition to the congenital heart defect, had monocytosis, myeloproliferative disorder, and accelerated idioventricular rhythm that was associated with severe hemodynamic instability. Noonan syndrome was suspected given the severe pulmonary stenosis, persistent monocytosis, and "left-shifted" complete blood counts without any evidence of an infectious process. Genetic testing revealed that the patient had a heterozygous c.221 C>G (pAla74Gly) mutation in the RIT1. CONCLUSION: We report a case of neonatal Noonan syndrome associated with RIT1 mutation. The clinical suspicion for Noonan syndrome was based only on the congenital heart defect, persistent monocytosis, and myeloproliferative process as the child lacked all other hallmarks characteristics of Noonan syndrome. However, the patient had an unusually malignant ventricular dysrhythmia that lead to his demise. The case highlights the fact that despite its heterogeneous presentation, RIT1-associated Noonan syndrome can be extremely severe with poor outcome.

Determination of the Frequency of Right and Left Internal Mammary Artery Embolization in Single Ventricle Patients: A Two-Center Study.

Embolization of systemic to pulmonary artery collaterals to regulate pulmonary arterial flow or pressure of the cavopulmonary circulation in patients with single ventricle is a common practice. The relative incidence and impact of this practice on future interventions like coronary artery bypass grafting is poorly understood. This study aims to evaluate the frequency and implications of internal mammary artery (IMA) embolization in the single ventricle (SV) population. A retrospective chart review was performed of SV patients who underwent cardiac catheterization before and after Fontan procedure between February 2007 and 2017. Data were collected from two tertiary care centers in the Midwest. Of the 304 SV patients, 62 (20.4%) underwent embolization of one or more IMAs, whereas 242 (79.6%) did not. The rate of embolization of IMA was 40.5% in one center and 14.5% in the second center. Among patients who received IMA embolization, left internal mammary artery (LIMA) embolization was seen in 6 (9.7%) patients. Majority of patients underwent either right internal mammary artery (RIMA) embolization (n = 25; 40.3%) or RIMA and LIMA embolization (n = 27; 43.5%). IMA embolization in SV patients is common. Embolizing IMAs early in life will likely eliminate a valuable graft option for coronary artery bypass grafting should it be required in the future care of these patients. Multi-center, prospective, nation-wide studies are warranted to examine coronary artery disease in the SV population and true frequency of IMA embolization. Delineation of which IMAs were embolized is a necessary in surgical and cardiac intervention national data, such as Society of Thoracic Surgeons (STS) database. All measures should be taken to preserve IMAs patency, if deemed feasible and safe.

Acute Pediatric Colchicine Toxicity is Associated with Marked Bradydysrhythmias.

BACKGROUND: Colchicine ingestion is rare but highly lethal. Patients usually die of multiorgan failure and cardiogenic shock. Colchicine is not only associated with depressed myocardial function but also with fatal heart rhythm disturbances, such as complete heart block, ventricular tachycardia, and asystole. While histologic changes of myocytes are well known, the mechanism by which colchicine affects cardiac impulse generation and conduction is not fully understood. CASE REPORT: We present a case of colchicine ingestion with sinus bradycardia, marked sinus arrhythmia, and first- and second-degree heart block. A 10-year-old previously healthy boy was brought to the emergency department for the sudden onset of dizziness, abdominal pain, and vomiting after ingesting his grandfather's colchicine and furosemide. His symptoms improved with ondansetron and intravenous normal saline. However, because of the colchicine ingestion, he was admitted to the pediatric intensive care unit for observation. He first developed PR prolongation (∼4-30 h postingestion) followed by marked sinus bradycardia and sinus arrhythmia along with second-degree heart block (∼48-60 hours postingestion). The minimum heart rate was 40 beats/min. Marked sinus arrhythmia was observed, suggesting an increase in parasympathetic activity. His heart rhythm improved initially with less sinus arrhythmia followed by resolution of heart block. He was discharged home without any sequelae. Holter monitoring 1 week after discharge showed normal heart rate variability for age. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: This case provides novel insights into how colchicine may affect the heart's electrophysiology. Colchicine may increase the parasympathetic tone enough to cause sinus bradycardia and different degrees of heart block.

Medium-term CT evaluation of stent geometry, integrity, and valve function of the Edwards SAPIEN transcatheter heart valve in the pulmonary position.

OBJECTIVE: Distortion of transcatheter heart valve (THV) stent shape and morphology has been shown to impact on THV function. This study sought to evaluate the relationship between geometrical CT follow-up data and consequent valve function in patients undergoing transcatheter pulmonary valve replacement with the Edwards SAPIEN THV. METHODS: All patients were enrolled in the COMPASSION trial. Multidetector computed tomography (MDCT) was performed as part of the study protocol at 6 months and yearly thereafter following valve implantation. Prosthesis eccentricity indices, circularity ratios, and expansion ratios (ER) were calculated. Valve function and reintervention rates were correlated with MDCT findings. RESULTS: Twenty consecutive patients undergoing 58 CT scans were included. Maximum Doppler gradients across the right ventricular outflow tract (RVOT) were significantly reduced following valve implantation (P < 0.001). Geometrical indices and maximum RVOT gradients were compared between the reintervention group (n = 4) and the nonreintervention group (n = 16). Although there was no difference in eccentricity index between the groups, ER [6 months: 90 +/- 12% vs. 69 ± 9%; P = 0.014; at 12 months: 89 ± 14 vs. 69 ± 10%; P = 0.018; at 24 months: 87 ± 14% vs. 70 ± 11%; P = 0.056] and valve area [6 months: 3.98 ± 0.54 vs. 2.86 ± 0.38 P = 0.005; at 12 months: 3.93 ± 0.56 vs. 2.86 ± 0.39 P = 0.006; 24 months: 3.78 ± 0.50 vs. 2.90 ± 0.45 P = 0.019] were lower in the reintervention group compared with the nonreintervention group at all time periods. CONCLUSION: Geometrical THV measurements as assessed by CT may predict the need for reintervention in patients undergoing transcatheter pulmonary valve replacement with the SAPIEN valve. Valve symmetry is maintained, however under-expansion and smaller valve area are strongly associated with the need for reintervention.