Electrophysiological phenotyping of left ventricular noncompaction cardiomyopathy in pediatric populations: A systematic review.

Left ventricular noncompaction cardiomyopathy (LVNC) is a structural heart defect that has been associated with generation of arrhythmias in the population and is a cause of sudden cardiac death with severe systolic dysfunction and fatal arrhythmias. LVNC has gained increasing acknowledgment with increased prevalence. We conducted a systematic review of reported electrocardiogram (ECG) results for pediatric LVNC patients. EMBASE database query was performed, yielding 4531 articles related to LVNC between 1990 and December 2023. Patient age ranged from prenatal to 18 years of age. Qualitative analyses were performed to characterize individual arrhythmias, and summative interpretation of ECG evaluations was gathered for the entire cohort. Systematic review of 57 LVNC cases and ECG presentation revealed many waveform consistencies, including abnormal left ventricular, atrioventricular node, and interventricular septal patterns, and specifically a high incidence of Mobitz type II and Wolff-Parkinson-White waveforms. This review of ECG analysis reinforces the clinical and etiologic significance of pediatric LVNC. While LVNC in pediatric populations may not always present as acute clinical cases, further investigation into the electrophysiology of the disease supports the need for further evaluation and risk stratification for patients with suspected LVNC and/or ventricular arrhythmia.

18-Month-Old with Lethargy and Accelerated Idioventricular Rhythm in Prehospital Setting: A Case Report.

INTRODUCTION: We report a case of accelerated idioventricular rhythm (AIVR) identified by Emergency Medical Services (EMS) monitoring of an infant presenting with lethargy and respiratory distress. Accelerated idioventricular rhythms are rare ventricular rhythms originating from the His-Purkinje system or ventricular myocytes, consisting of >3 monomorphic beats with gradual onset and termination.1 An AIVR is usually well-tolerated and does not require treatment, though sustained arrythmia may induce syncope, and the rhythm has been seen in newborn infants with congenital heart diseases.1 Monitoring ill children with ECG can identify such dysrhythmias in the prehospital setting. CASE REPORT: An 18-month-old male presented to their pediatrician with lethargy and respiratory distress, prompting activation of EMS. The patient was placed on a 4-lead ECG initially revealing monomorphic QRS complexes at a rate of 170 beats per minute (BPM). A 12-lead ECG was interpreted as sinus tachycardia by the paramedics who noted the QRS complexes were "getting taller and shorter" with a stable rapid heart rate. The clinician then noted a consistently wide tachycardia which spontaneously converted to a narrow complex tachycardia. The QRS pattern remained variable, with notation of variable R-wave height. After arrival to the emergency department, pediatric cardiology was consulted and interpreted the prehospital ECG findings as accelerated idioventricular rhythm. The patient experienced multiple occurrences of accelerated idioventricular rhythm during hospitalization without associated hypoxia or decreased perfusion. DISCUSSION: Accelerated idioventricular rhythm is relatively rare entity without underlying cardiac disease and most cases are asymptomatic or benign. In the pediatric population, AIVR is generally related to congenital heart defects, cardiac tumors, and cardiomyopathies. In the prehospital setting, continuous ECG monitoring should be a part of care by Advanced Life Support personnel in children with altered mental status, respiratory distress, unexplained syncope, or suspected arrhythmias and 12 lead ECG should be considered if there is any abnormality noted. While this patient did not experience persisting morbidity from AIVR, the potentially hazardous rhythm would not have been recognized without the astute observation, clinical management and persistent follow up of the prehospital clinicians.

Early Surgical Resection of Left Atrial Myxoma After Thromboembolic Stroke.

We present a case report of a five-year-old male with acute ischemic stroke who underwent successful mechanical endovascular thrombectomy and early surgical resection of left atrial myxoma two days after onset of stroke symptoms without additional neurological sequelae.

Medium-Term Outcomes in Pediatric Patients Undergoing Cardiac Catheterization Early After Congenital Cardiac Surgery.

Safety and acute outcomes for patients who need catheterization shortly after congenital cardiac surgery has been established; literature on mid-term outcomes is lacking. We sought to evaluate the mid-term outcomes of patients who undergo early postoperative cardiac catheterization. This is a retrospective cohort study of patients who underwent cardiac catheterization within 6 weeks of congenital cardiac surgery with longitudinal follow-up and assessment of mid-term outcomes. Multivariable analysis was utilized to relate variables of interest to outcomes. 99 patients underwent cardiac catheterizations within 6 weeks of cardiac surgery between January 2008 and September 2016. Forty-six (45.5%) interventional procedures were performed at a median age of 41 days (IQR 21-192) and a median weight of 3.9 kg (3.3-6.6). During a median follow-up duration of 4.24 years (1.6-5.6) in study survivors, 61% of patients remained free from the primary endpoint (death and/or transplant). Sixty-nine patients (69.7%) underwent an unplanned surgical or catheter procedure. Renal failure at catheterization (OR 280.5, p 0.0199), inotropic medication at catheterization (OR 14.8, p 0.002), and younger age were all significantly associated with meeting the primary endpoint. Patients requiring surgical intervention as an initial additional intervention underwent more unplanned re-interventions, while patients who survived to hospital discharge demonstrated favorable mortality, though with frequent need for re-intervention. In patients requiring early postoperative cardiac catheterization, renal failure, younger age, and need for inotropic support at catheterization are significantly associated with meeting the primary endpoint.

Hypertension in the Neonatal Intensive Care Unit (NICU): A Case of Mid-Aortic Syndrome.

A term baby was born with findings of edema, harsh murmur, and hypertension. Pregnancy course was complicated by hydrops fetalis. Upon birth, blood work did not reveal any abnormalities, but an echocardiogram showed patient in high-output heart failure. A computed tomography (CT) chest, abdomen, and pelvis revealed narrowing of aorta in the thoracic region to distal iliac and renal arteries, consistent with mid-aortic syndrome. Mid-aortic syndrome, which results in the narrowing of thoracic or abdominal aorta, is a rare cause of hypertension, especially in newborns. This case elucidates the importance of maintaining a broad differential when encountering an uncommon problem in a newborn.

Multiple QRS Morphologies: Findings on an Initial Newborn ECG.

Regular wide complex tachycardia carries with it a standard array of differential diagnoses. This electrocardiogram demonstrates wide complex tachycardia and multiple QRS configurations in a neonate without structural heart disease with an uncommon suspected underlying diagnosis. (Level of Difficulty: Advanced.).

Baseline intracardiac echocardiography predicts haemodynamic changes and Doppler velocity patterns during follow-up after percutaneous pulmonary valve implantation.

BACKGROUND: Intracardiac echocardiography Doppler-derived gradients have previously been shown to correlate with post-procedure echocardiographic evaluations when compared with invasive gradients measured during percutaneous pulmonary valve implantation, suggesting that intracardiac echocardiography could offer an accurate and predictable starting point to estimate valve function after percutaneous pulmonary valve implantation. METHODS: We performed a retrospective chart review of 51 patients who underwent percutaneous pulmonary valve implantation between September 2018 and December 2019 in whom intracardiac echocardiography was performed immediately after valve implantation. We evaluated the correlation between intracardiac echocardiography gradients and post-procedural Doppler-derived gradients. Among the parameters assessed, those which demonstrated the strongest correlation were used to create a predictive model of expected echo-derived gradients after percutaneous pulmonary valve implantation. The equation was validated on the same sample data along with a subsequent cohort of 25 consecutive patients collected between January 2020 and July 2020. RESULTS: All the assessed correlation models between intracardiac echocardiography evaluation and post-procedure transthoracic echocardiographic assessments were statistically significant, presenting moderate to strong correlations. The strongest relationship was found between intracardiac echocardiography mean gradients and post-procedural transthoracic echocardiographic mean gradients. Therefore, an equation was created based on the intracardiac echocardiography-derived mean gradient, to allow prediction of the post-procedural and follow-up transthoracic echocardiographic-derived mean gradients within a range of ±5 mmHg from the observed value in more than 80% of cases. CONCLUSIONS: There is a strong correlation between intracardiac echocardiography and post-procedure transthoracic echocardiographic. This allowed us to derive a predictive equation that defines the expected transthoracic echocardiographic Doppler-derived gradient following the procedure and at out-patient follow-up after percutaneous pulmonary valve implantation.

Upper-Extremity Venous Access for Children and Adults in Pediatric Cardiac Catheterization Laboratory.

BACKGROUND: Traditional approaches to pediatric cardiac catheterization have relied on femoral venous access. Upper- extremity venous access may enable cardiac catheterization procedures to be performed safely for diagnostic and interventional catheterizations. The objective of this multicenter study was to demonstrate the feasibility and safety of upper-extremity venous access in a pediatric cardiac catheterization laboratory. METHODS: A retrospective chart review of all patients who underwent cardiac catheterization via upper-extremity vascular access was performed. RESULTS: Eighty-two cardiac catheterizations were attempted via upper-extremity vein on 72 patients. Successful access was obtained in 75 catheterizations (91%) in 67 patients. Median age at catheterization was 18.79 years (interquartile range [IQR], 13.02-32.75 years; n = 75) with a median weight of 59.4 kg (IQR, 43.3-76.5 kg; n = 75). The youngest patient was 4.1 months old, weighing 4.3 kg. Local anesthesia or light sedation was utilized in 46 procedures (61%). Diagnostic right heart catheterization was the most common procedure (n = 65; 87%), with intervention performed via the upper extremity in 8 cases (11%). Median fluoroscopy time was 10.02 min (IQR, 2.87-36.26 min; n = 75), with dose area product/kg of 3.765 µGy•m²/kg (IQR, 0.74-34.12 µGy•m²/kg; n = 64). Median sheath duration time was 48 min (IQR, 19.5-147 min; n = 57) and median total procedure time was 116 min (IQR, 80.5-299 min; n = 65). Median length of stay for outpatient procedures was 5.37 hr (IQR, 4.25-6.92 hr; n = 27). There were no procedural complications. CONCLUSION: Upper-extremity venous access is a useful, feasible, and safe modality for cardiac catheterization in the pediatric cardiac catheterization laboratory.

Novel direct approach for placement of permanent transvenous pacing leads after Fontan procedure.

The need for transvenous pacing (patients who have exhausted epicardial options) after a Fontan-type operation has been recognized. Many novel strategies have been proposed, but currently, all of them require additional maneuvers or rerouting of the leads to the pacemaker pocket. In this report, we describe a novel direct approach to transvenous pacing after a Fontan-type operation from a standard, prepectoral approach.

Carotid body size measured by computed tomographic angiography in individuals born prematurely.

PURPOSE: We tested the hypothesis that the carotid bodies would be smaller in individuals born prematurely or exposed to perinatal oxygen therapy when compared individuals born full term that did not receive oxygen therapy. METHODS: A retrospective chart review was conducted on patients who underwent head/neck computed tomography angiography (CTA) at the Mayo Clinic between 10 and 40 years of age (n = 2503). Patients were identified as premature ( < 38 weeks) or receiving perinatal oxygen therapy by physician completion or billing codes (n = 16 premature and n = 7 receiving oxygen). Widest axial measurements of the carotid body images captured during the CTA were performed. RESULTS: Carotid body visualization was possible in 43% of patients and 52% of age, sex, and body mass index (BMI)-matched controls but only 17% of juvenile preterm subjects (p = .07). Of the carotid bodies that could be visualized, widest axial measurements of the carotid bodies in individuals born prematurely (n = 7, 34 ±â€¯4 weeks gestation, birth weight: 2460 ±â€¯454 g; average size: 2.5 ±â€¯0.2 cm) or individuals exposed to perinatal oxygen therapy (n = 3, 38 ±â€¯2 weeks gestation, Average size: 2.2 ±â€¯0.1 cm) were not different when compared to controls (2.3 ±â€¯0.2 cm and 2.3 ±â€¯0.2 cm, respectively, p > 0.05). CONCLUSIONS: Carotid body size, as measured using CTA, is not smaller in adults born prematurely or exposed to perinatal oxygen therapy when compared to sex, age, and BMI-matched controls. However, carotid body visualization was lower in juvenile premature patients. The decreased ability to visualize the carotid bodies in these individuals may be a result of their prematurity.