Manifold-based denoising for Ferumoxytol-enhanced 3D cardiac cine MRI.

The two-dimensional (2D) cine cardiovascular magnetic resonance (CMR) technique is the reference standard for assessing cardiac function. However, one challenge with 2D cine is that the acquisition time for the whole cine stack is long and requires multiple breath holds, which may not be feasible for pediatric or ill patients. Though single breath-hold multi-slice cine may address the issue, it can only acquire low-resolution images, and hence, affect the accuracy of cardiac function assessment. To address these challenges, a Ferumoxytol-enhanced, free breathing, isotropic high-resolution 3D cine technique was developed. The method produces high-contrast cine images with short acquisition times by using compressed sensing together with a manifold-based method for image denoising. This study included fifteen patients (9.1 $ \pm $ 5.6 yrs.) who were referred for clinical cardiovascular magnetic resonance imaging (MRI) with Ferumoxytol contrast and were prescribed the 3D cine sequence. The data was acquired on a 1.5T scanner. Statistical analysis shows that the manifold-based denoised 3D cine can accurately measure ventricular function with no significant differences when compared to the conventional 2D breath-hold (BH) cine. The multiplanar reconstructed images of the proposed 3D cine method are visually comparable to the golden standard 2D BH cine method in terms of clarity, contrast, and anatomical precision. The proposed method eliminated the need for breath holds, reduced scan times, enabled multiplanar reconstruction within an isotropic data set, and has the potential to be used as an effective tool to access cardiovascular conditions.

Dobutamine Stress Cardiovascular Magnetic Resonance Derived 2-Dimension Feature Tracking Strain Analysis in Pediatric Population with Anomalous Aortic Origin of Right Coronary Artery.

Anomalous aortic origin of right coronary artery (AAORCA) is associated with myocardial ischemia and sudden cardiac arrest/death. Risk stratification remains challenging and relies upon provocative test results. This study describes the utility of dobutamine stress cardiovascular magnetic resonance (DSCMR) and potential benefit of strain analysis in children with AAORCA. All patients less than 21 years of age with AAORCA who underwent DSCMR between July 2018 and December 2022 were included. Visual wall motion abnormalities (VWMA) at rest and during protocolized increments of dobutamine infusion were assessed. Regional and global left ventricular circumferential (GCS) and radial (GRS) strain using 2-dimension Feature tracking (2D-FT) analysis (cvi42, Circle Cardiovascular Imaging Inc.) were calculated at rest and peak response. Of the total 54 DSCMR studies performed in 51 children with median age (IQR) of 13.5 (11-15) years, FT analysis was reliably performed in 52 (96%) studies. None had VWMA. The absolute change in GCS and GRS from rest to peak dobutamine stress was 4% (1-6%) and 11% (4-18%), respectively. There was no significant difference in GCS and GRS in patients with exertional symptoms vs no/non-exertional symptoms as well as between those considered to be high-risk vs low-risk anatomical features. DSCMR-derived 2D-FT strain analysis is feasible to assess myocardial deformation in children with AAORCA and may enhance this method of provocative testing. Although there were no statically significant differences in GCS and GRS values between high and low-risk subgroups, the absolute change in GCS between rest and peak stress is diminished when compared to normal adult reports.

Echocardiography evaluation of neonatal vein of Galen aneurysmal malformation.

BACKGROUND: In neonatal vein of Galen aneurysmal malformation, vein of Galen aneurysmal malformation echocardiography remains the mainstay for early detection and explains various haemodynamic changes occurring due to a large systemic arterio-venous shunt. However, there is limited evidence of echocardiography in risk stratifying neonatal vein of Galen aneurysmal malformation vein of Galen aneurysmal malformation. The objective of this study was to identify echocardiographic parameters that could be associated with major outcomes and guide timing of neuro-intervention. METHODS: In this retrospective chart review, infants < 28 days of age with the diagnosis of vein of Galen aneurysmal malformation vein of Galen aneurysmal malformation were included. Demographic, clinical, and echocardiographic parameters were compared in neonates who survived or died with neonatal presentation. A risk algorithm model based on key echocardiographic parameters was developed to determine those who are at risk of early death. RESULTS: Of the 19 neonates included, with median birth weight 3.1 kg (IQR 2.58-3.36), nine (47%) neonates died at median age of 5 days (IQR 4-17). All neonates showed retrograde diastolic flow at the level of descending aorta by colour Doppler on the first post-natal echocardiogram at median age of 2 days (IQR 1-5.5). An aortic antegrade-to-retrograde velocity time integral ratio of < 1.5 and supra-systemic pulmonary artery pressure had 100% positive predictive value of death (p = 0.029), whereas aortic antegrade-to-retrograde velocity time integral ratio of > 1.5 and sub-systemic pulmonary artery pressure had 100% positive predictive value of survival (p = 0.029). CONCLUSION: Combination of aorta antegrade-to-retrograde velocity time integral ratio and degree of pulmonary hypertension on the first post-natal echocardiogram may help stratify the severity of disease and guide optimal timing for neuro-intervention for neonatal vein of Galen aneurysmal malformation.

Tolerability and efficacy of a reduced dose adenosine stress cardiac magnetic resonance protocol under general anesthesia in infants and children.

BACKGROUND: Intravenous adenosine induces pharmacological stress by causing vasodilatation and thus carries the risk of severe hypotension when combined with vasodilatory effects of anesthetic agents. OBJECTIVE: This study describes our experience with a reduced dose adenosine cardiac magnetic resonance imaging (MRI) protocol in young children under general anesthesia (GA). MATERIALS AND METHODS: This is a retrospective report of all patients from birth to 18 years who underwent adenosine stress cardiac MRI under GA between August 2018 and November 2022. Based on our anecdotal experience of severe adverse effects in patients receiving adenosine infusion under GA and in discussion with the pediatric anesthesia team, we developed a modified protocol starting at a dose of 110 mcg/kg/min with incremental escalation to a full dose of 140 mcg/kg/min to achieve desired hemodynamic effect. RESULTS: Twenty-two children (mean age 6.5 years, mean weight 28 kg) satisfied the inclusion criteria. The diagnoses included Kawasaki disease (7), anomalous aortic origin of left coronary artery (3), anomalous aortic origin of right coronary artery (2), coronary fistula (3), repaired d-transposition of great arteries (2), repaired anomalous left coronary artery from pulmonary artery (2), repaired truncus arteriosus with left coronary artery occlusion (1), extracardiac-Fontan with left coronary artery myocardial bridge (1), and post heart transplantation (1). Nine patients needed dose escalation beyond 110 mcg/kg/min. Two patients had transient hypotension during testing (systemic blood pressure drop > 25 mmHg). No patient developed significant heart block or bronchospasm. Six patients (repeat study in one) demonstrated inducible perfusion defects (27%) on stress perfusion sequences-5 of whom had confirmed significant coronary abnormalities on angiography or direct surgical inspection. CONCLUSION: A reduced/incremental dose adenosine stress cardiac MRI protocol under GA in children is safe and feasible. This avoids severe hypotension which is both unsafe and may result in inaccurate data.

Ivabradine Overdose in a Newborn: Precautions of Dispensing in Infants.

Ivabradine is currently approved to reduce heart rate in children with chronic heart failure and dilated cardiomyopathy. Ivabradine has also been used off-label in children to treat automatic tachyarrhythmias such as ectopic atrial tachycardia and junctional ectopic tachycardia. Adverse effects of ivabradine at physiological doses as well as its toxicity at supra-physiological doses have rarely been reported in adults. In children, weight-based dosing requires dilution of commercially available ivabradine oral solution for accuracy. We describe a case of ivabradine overdose in a newborn (treated for ectopic atrial tachycardia) secondary to inaccurate dosing leading to the infant receiving 10 times more drug than prescribed. This case highlights potential pitfalls of ivabradine prescription and preparation in children.

Role of sildenafil in a neonate with double outlet left ventricle and pulmonary hypertension.

Double outlet left ventricle (DOLV) is a rare congenital heart defect where the aorta and the pulmonary trunk arise predominantly from the morphologic left ventricle. The clinical manifestations depend upon the location of the ventricular septal defect in relation to the great arteries, degree of pulmonary and aortic outflow tract obstruction, and other associated cardiac defects. We describe a neonate with DOLV, sub-aortic ventricular septal defect, and side-by-side great vessels who continued to require oxygen for desaturation to 60% in the neonatal period. His clinical symptoms were suggestive of persistent pulmonary hypertension, with 5-8% higher saturations in the leg compared to arm. He was started on oral sildenafil and his oxygen requirement decreased from 2 L/min to 0.1 L/min within 24 hours of initiating sildenafil. .

Device-detected nonsustained ventricular tachycardia in adult congenital heart disease without tetralogy of fallot.

OBJECTIVES: To evaluate any association between non-sustained ventricular tachycardia (NSVT) detected by intra-cardiac device and clinical outcomes in repaired adult congenital heart disease (ACHD) without tetralogy of Fallot (TOF). BACKGROUND: NSVT portends a higher risk of serious ventricular tachyarrhythmia in TOF. However its clinical significance when incidentally detected by implantable cardiac device is not well elucidated in non-TOF ACHD cohort. METHODS: We performed a single center, retrospective, longitudinal follow-up study in repaired ACHD (≥18 years) patients without TOF who hosted a pacemaker or automatic implantable cardiac defibrillator (AICD). The cohort was divided based on presence/absence of device detected NSVT. The primary end-point was a composite of sustained ventricular tachycardia (VT), ventricular fibrillation (VF), or sudden cardiac death (SCD). RESULTS: One hundred fifty eight patients (male 56.3%, median [IQR] age of 35 [28-43] years at last follow-up] with longitudinal post-implant follow-up duration of 8 (5-12) years were included. NSVT was detected in 52 (33%) patients. The primary composite end-point was more frequent in NSVT group [11.5% vs. 2.8%; p = .04]. Patients with NSVT were (i) older at the time of initial implant (age 25 vs. 18 years, p = .011) and more frequently demonstrated (ii) systemic ventricular dysfunction (44% vs. 26%; p = .015), as well as (iii) history of ventriculotomy (38% vs. 21%; p = .017). CONCLUSIONS: In our repaired ACHD cohort, we noted a significant association between device-detected-NSVT and the primary composite end-point of sustained VT/VF or SCD. Systemic ventricular dysfunction and history of ventriculotomy were more frequent in the NSVT group and likely constituted the clinical milieu.

Is there an association of near-infrared spectroscopy with low cardiac output and adverse outcomes in single-ventricle patients after stage 1 palliation?

Objective: Our primary objective study was to evaluate the association between near-infrared spectroscopy (NIRS) and low cardiac output (LCO) in patients with single-ventricle physiology after stage 1 palliation. Methods: In this retrospective study, infants ≤6 months of age with single-ventricle physiology who underwent stage 1 palliation were included. Cerebral and renal NIRS values at various time intervals after surgery were compared between patients with low and normal cardiac output. LCO within the first 48 after surgery was defined as per the pediatric cardiac critical care consortium database. NIRS values were also compared with other adverse outcomes such as cardiac arrest, need for extracorporeal membrane oxygenation and mortality. The receiver operative characteristic curve was generated to determine an optimal cut-off NIRS value for detecting LCO. Results: Ninety-one patients with median (Interquartile range) age of 10 days (6-26) and weight of 3.3 kg (3-3.5) were included in the study. Cerebral NIRS at 1 h (41.2 vs. 49.5; P = 0.002), 6 h (44 vs. 52.2; P = 0.001), and 12 h (51.8 vs. 56; P = 0.025) was significantly lower in the grouP with LCO compared to no LCO. Cerebral NIRS at 6 h was independently associated with LCO (P = 0.018), and cerebral NIRS at 6 h ≤57% had 91% sensitivity and 72% specificity to detect LCO. Conclusions: Cerebral NIRS ≤57% at 6 h after surgery detected LCO after stage 1 palliation in single-ventricle patients. Cerebral or renal NIRS was not associated with adverse outcomes and therefore, may not be useful in predicting adverse outcomes in this population.

Changes in Clinical Care of the Newborn During COVID-19 Pandemic: From the Womb to First Newborn Visit.

COVID-19 has afflicted the health of children and women across all age groups. Since the outbreak of the pandemic in December 2019, various epidemiologic, immunologic, clinical, and pharmaceutical studies have been conducted to understand its infectious characteristics, pathogenesis, and clinical profile. COVID-19 affects pregnant women more seriously than nonpregnant women, endangering the health of the newborn. Changes have been implemented to guidelines for antenatal care of pregnant women, delivery, and newborn care. We highlight the current trends of clinical care in pregnant women and newborns during the COVID-19 pandemic.

Does Premature Ventricular Contractions Affect Exercise Capacity in Teenagers with Normal Hearts?

Premature ventricular contractions (PVCs) are common in teenagers even in the absence of structural heart disease or channelopathy. The suppression of PVCs with exercise is a favorable prognostic indicator. There is a paucity of data regarding the relationship between exercise capacity and PVC burden in this population. Our objective was to evaluate the association between various exercise stress parameters and PVC burden ascertained with a 24 h Holter in children without structural heart disease and/or channelopathy. In this retrospective study, 447 patient's charts with a diagnosis of PVC were reviewed at a single tertiary center. The study cohort consisted of ninety one patients with no structural heart disease or channelopathy who underwent an echocardiogram, maximal stress test, and 24 h Holter monitor. The cohort was divided into two groups based on PVC burden by 24-h Holter monitoring: < 10% and ≥ 10%. Peak oxygen uptake (VO2 in ml/kg/min), an indicator of maximal aerobic capacity, was collected. Other exercise parameters included a) percentage of predicted VO2 (%VO2) based on age, weight, height, and gender b) percent oxygen pulse, c) Anaerobic threshold (AT), and d) Metabolic equivalents. Demographic and exercise stress test-derived parameters were compared between the two groups using student t test and a p value < 0.05 was considered significant. In our cohort of 91 patients, the mean (SD) age at exercise was 14.5 (3.2) years with 56 (62%) males. Left ventricle shortening fraction (LVFS) was ≥ 28% in all enrolled patients. PVCs were monomorphic in 72(80%) patients. The mean (SD) PVC burden was 14.43% (12.3) ranging from 0.1 to 49.8%. PVC burden was ≥ 10% in 48 (53%) patients. Eighty eight (97%) patients in the study cohort had suppression of PVCs with exercise. There were no significant differences between the two groups (< 10% vs. ≥ 10% PVC burden) with respect to demographic or exercise test-derived parameters. Univariate regression between PVC burden and %VO2 did not show significant correlation (r = - 0.04, p = 0.75). Children even with ≥ 10% PVC burden did not demonstrate any objective decrease in their exercise capacity. A plausible reason for no difference in exercise capacity in our cohort may be due to lower PVC load or shorter duration of PVCs compared to adults.

Rapid progression of mitral valve disease in a child with Noonan syndrome.

Noonan syndrome is the second most common genetic syndrome associated with congenital heart disease after Trisomy 21. The two most common cardiac lesions associated with Noonan syndrome are pulmonary stenosis and hypertrophic cardiomyopathy. Although the incidence of mitral valve disease in Noonan syndrome ranges between 2 and 6%, rapid progression of mitral valve dysplasia causing severe mitral valve regurgitation and left atrial dilatation is seldom seen. Most cases of mitral valve disease have been diagnosed either on routine echocardiographic surveillance or when presented with heart failure symptoms. We describe an 18-month-old boy with Noonan syndrome presenting in atrial flutter due to a massively enlarged left atrium caused by severe mitral valve regurgitation which developed and progressed in less than 17 months.

Wrist Deformity in Children and Adolescents with b-thalassemia on Oral Iron Chelation Therapy.

OBJECTIVE: To describe a novel wrist deformity in b-thalassemia major patients, and their radiographic and magnetic resonance imaging findings. METHODS: 30 patients with b-thalassemia major who were noticed to have ulnar deviation at wrist joint were evaluated for previous history of medications, serum ferritin levels, presence of pain and swelling at the wrist joint, and the duration of iron chelation therapy. Radiographs of wrist and limited magnetic resonance imaging (MRI) sequences were obtained in 30 and 15 patients, respectively. RESULTS: Radiographs revealed varying severity of distal ulnar shortening, distal radial slanting and presence of soft tissue distal to the ulna. MRI showed similar deformities along with abnormal marrow signal at distal ulnar ends; in 8 patients, a soft tissue distal to the distal end of ulna was noted. CONCLUSIONS: Varying severity of radiological abnormalities, predominantly affecting the distal ulna, are present in children and adolescents with b-thalassemia receiving oral chelation therapy.

Bilateral Phrenic Nerve Palsy in a Diabetic Causing Respiratory Failure.

Neuropathy is one of the major reasons of morbidity in diabetes mellitus (DM). We presented a 64-year-old male who was a case of type 2 DM for >6 years. He presented with orthopnea and respiratory failure secondary to bilateral phrenic neuropathy and resultant diaphragmatic palsy. Clinical examination, ultrasound, and nerve conduction studies confirmed the bilateral involvement of the phrenic nerves. Phrenic neuropathy may be an important, albeit a rare complication of diabetes, and hence, diaphragmatic dysfunction associated with diabetic phrenic neuropathy should be considered in any patient with unexplained breathlessness, orthopnea, and respiratory failure.

Intracranial Hematopoiesis in Beta Thalassemia: A Case Series.

Extramedullary hematopoiesis (EMH) is a normal response to failure of hematopoiesis at its normal site i.e., bone marrow. It is a manifestation of many congenital hemolytic anemias and marrow failure secondary to myelodysplastic syndromes. Usually, extramedullary myeloid proliferation occurs in liver, spleen and lymph nodes. However, there are many unusual sites where EMH can occur. The authors report two cases of intracranial extramedullary hematopoiesis in beta thalassemia. In one of these patients, epidural soft tissue was detected along frontal and parietal convexities causing compression of brain parenchyma leading to raised intracranial tension and sagging of brain stem, corpus callosum and herniation of cerebellar tonsils. The other case had a similar but unilateral epidural soft tissue. Expansion of diploic spaces of skull was seen in both these cases. As myeloid proliferation is slow, it presents with subtle symptoms of headache and gradually progressive lower limb weakness. A high index of clinical suspicion coupled with imaging findings is the only way to confirm the diagnosis.