Median Arcuate Ligament Syndrome in Children: A Single-Center Experience.

BACKGROUND: Data on median arcuate ligament syndrome (MALS) in children are scant. It is postulated that MALS can cause chronic abdominal pain. It is unclear what percentage of children with this condition are symptomatic and what comorbidities are associated with this syndrome. METHODS: In this retrospective study, data on consecutive patients in a single center diagnosed coincidentally with MALS during routine echocardiogram were reviewed. Symptom burden, comorbidities, and the effect of anthropometric indices on MALS were investigated. Descriptive statistics and nonparametric tests were used to describe the findings and to compare variables with normal distribution. RESULTS: Between 2013 and 2020, there were 82 children, 55 females (67%), mean age 13.9 ± 3.2 years, with MALS and complete record. Mean velocity across the stenotic area was 2.6 ± 0.4 m/s. Forty-six patients (57%) had abdominal pain. Age, gender, weight, body mass index (BMI), and Doppler velocity had no statistically significant influence on symptom occurrence. Conversely, patients with joint hypermobility and symptoms of orthostatic intolerance were more likely to have abdominal pain from MALS. Of 24 patients with joint hypermobility, 18 patients had abdominal pain (p=0.027). Thirty-eight patients with orthostatic intolerance (OI) with MALS complained of abdominal pain vs 13 patients with OI and no abdominal pain (p=<0.0001). CONCLUSION: Nearly half of patients with MALS had abdominal pain. Age, gender, weight, and the degree of stenosis had no statistically significant influence on symptom occurrence. OI, specifically postural orthostatic tachycardia syndrome (POTS), and joint hypermobility on exam predicted a higher propensity for abdominal pain in patients with MALS.

Prevalence and Risk Factors for Tube-Feeding at Discharge in Infants following Early Congenital Heart Disease Surgery: A Single-Center Cohort Study.

OBJECTIVE: Oral feeding difficulty is common in infants after congenital heart disease (CHD) surgical repair and is associated with prolonged hospital stay and increased risk for tube-feeding at discharge (TF). The current understanding of the enteropathogenesis of oral feeding difficulty in infants requiring CHD surgery is limited. To determine the prevalence and risk factors for TF following CHD surgery in early infancy. STUDY DESIGN: This was a 6-year single-center retrospective cohort study (2016-2021) of infants under 6 months who had CHD surgery. Infants required TF were compared with infants who reached independent oral feeding (IOF). RESULTS: Of the final sample of 128 infants, 24 (18.8%) infants required TF at discharge. The risk factors for TF in univariate analysis include low birth weight, low 5-minute Apgar score, admitted at birth, risk adjustment in congenital heart surgery categories IV to VI, presence of genetic diagnosis, use of Prostin, higher pre- and postsurgery respiratory support, lower weight at surgery, lower presurgery oral feeding, higher presurgery milk calory, delayed postsurgery enteral and oral feeding, higher pre- and postsurgery gastroesophageal reflux disease (GERD), need for swallow study, abnormal brain magnetic resonance imaging (p < 0.05). In the multivariate analysis, only admitted at birth, higher presurgery milk calories, and GERD were significant risk factors for TF. TF had significantly longer hospital stay (72 vs. 17 days) and lower weight gain at discharge (z-score: -3.59 vs. -1.94) compared with IOF (p < 0.05). CONCLUSION: The prevalence of TF at discharge in our study is comparable to previous studies. Infants with CHD admitted at birth, received higher presurgery milk calories, and clinical GERD are significant risk factors for TF. Mitigating the effects of identified risk factors for TF will have significant impact on the quality of life for these infants and their families and may reduce health care cost. KEY POINTS: · Oral feeding difficulty in infants after congenital heart disease surgical repair is common.. · Such infants require prolonged hospital stay and higher risk for tube-feeding at discharge.. · Identifying modifiable risk factors associated with tube-feeding can enhance clinical outcomes..

The Effect of Cardiac Mass and Venous Return in Children with Postural Orthostatic Tachycardia Syndrome: A Prospective, Observational Study.

Low left ventricular mass index (LVMI) is thought to limit exercise tolerance in adult patients with postural orthostatic tachycardia syndrome (POTS). This finding has not been studied in children. We evaluated the effect of LVMI and hemodynamics at baseline and during exercise in POTS versus controls. POTS and control subjects aged 12-18 years were prospectively enrolled. POTS patients underwent autonomic studies. An echocardiogram was performed on all patients at baseline and during exercise. LVMI, venous return from inferior vena cava (IVC-VTI), left ventricular dimension, and cardiac output were assessed at baseline and during exercise. Generalized linear modeling with mixed effects was used to perform repeated measures testing between POTS and controls. Eighteen POTS patients (14 female, aged 15.4 ± 1.4 years) and nine control subjects (six female, aged 15.0 ± 1.3 years; p = 0.44) were enrolled. At baseline, LVMI was similar in both groups. During exercise, IVC-VTI, left ventricular end-diastolic dimension and volume, and stroke volume were lower in POTS patients. Peak heart rate was higher in POTS patients, but cardiac output was similar in both groups. Exercise time was higher in the control group (11.4 ± 2.7 min vs 9.2 ± 2.1, p = 0.024). Lower venous return resulted in smaller cardiac dimension and stroke volume during exercise. Higher heart rate in POTS may compensate to achieve similar cardiac output compared with control subjects. Lower ventricular filling and earlier time to peak heart rate may explain lower exercise capacity in pediatric POTS.

Extraction of Peak Velocity Profiles from Doppler Echocardiography Using Image Processing.

The objective of this study is to extract positive and negative peak velocity profiles from Doppler echocardiographic images. These profiles are currently estimated using tedious manual approaches. Profiles can be used to establish realistic boundary conditions for computational hemodynamic studies and to estimate cardiac time intervals, which are of clinical utility. In the current study, digital image processing algorithms that rely on intensity calculations and two different thresholding methods were proposed and tested. Image intensity histograms were used to guide threshold choices, which were selected such that the resulting velocity profiles appropriately represent Doppler shift envelopes. The resulting peak velocity profiles contained artifacts in the form of sudden velocity changes and possible outliers. To reduce these artifacts, image smoothing using a moving average process was then implemented. Bland-Altman analysis suggested good agreement between the two thresholding methods. Artifacts decreased when image smoothing was performed. Results also suggested that one thresholding method tended to provide the lower limit (i.e., underestimate) of velocities, while the second tended to provide the velocity upper limit (i.e., overestimate). Combining estimates from both methods appeared to provide a smoother peak velocity profile estimate. The proposed automated approach may be useful for objective estimation of peak velocity profiles, which may be helpful for computational hemodynamic studies and may increase the efficiency of current clinical diagnostic tools.

Development of quality metrics for ambulatory pediatric cardiology: Chest pain.

OBJECTIVE: As part of the American College of Cardiology Adult Congenital and Pediatric Cardiology Section effort to develop quality metrics (QMs) for ambulatory pediatric practice, the chest pain subcommittee aimed to develop QMs for evaluation of chest pain. DESIGN: A group of 8 pediatric cardiologists formulated candidate QMs in the areas of history, physical examination, and testing. Consensus candidate QMs were submitted to an expert panel for scoring by the RAND-UCLA modified Delphi process. Recommended QMs were then available for open comments from all members. PATIENTS: These QMs are intended for use in patients 5-18 years old, referred for initial evaluation of chest pain in an ambulatory pediatric cardiology clinic, with no known history of pediatric or congenital heart disease. RESULTS: A total of 10 candidate QMs were submitted; 2 were rejected by the expert panel, and 5 were removed after the open comment period. The 3 approved QMs included: (1) documentation of family history of cardiomyopathy, early coronary artery disease or sudden death, (2) performance of electrocardiogram in all patients, and (3) performance of an echocardiogram to evaluate coronary arteries in patients with exertional chest pain. CONCLUSIONS: Despite practice variation and limited prospective data, 3 QMs were approved, with measurable data points which may be extracted from the medical record. However, further prospective studies are necessary to define practice guidelines and to develop appropriate use criteria in this population.

A Practical ECG Criterion to Unmask Left Accessory AV Connections in Patients With Subtle Preexcitation.

BACKGROUND: Accessory AV-connections capable of antegrade conduction need to be recognized because of the potential for life-threatening arrhythmias. However, the preexcited ECG pattern may be subtle, especially among left-sided AV-connections. We explored whether additional ECG criteria might help identify left-sided AV-connections. METHODS: We analyzed 156 patients who underwent an electrophysiology study (EPS) and ablation for paroxysmal supraventricular tachycardias (PSVT). Patients were divided into 2 groups: those with left-sided AV-connections (Group 1) and all other PSVT (Group 2). Various ECG parameters were compared before and after ablation in both groups. RESULTS: The EPS identified left-sided AV-connections among 43 patients (Group 1) and excluded it among 113 (Group 2). Baseline ECG in Group 1 demonstrated obvious preexcitation among 24/43 patients (55.8%), the remaining 19/43 missing obvious preexcitation. R/S ratio > 0.5 in V1 was noted in 38/43 (88.4%) patients in Group 1 before ablation (median 1.00; IQR 0.58-2.20), including 16/19 (84.2%) patients lacking obvious left-sided AVconnections. Conversely, only 10/113 (8.8%) patients in Group 2 had R/S ratios in V1 ≥ 0.5 (0.20; 0.10-0.31), P < 0.0001. After ablation, the R/S ratio decreased significantly in Group 1 (0.29; 0.17-0.45), P < 0.0001. Thus, a combined criterion of classic preexcitation or R/S ratio ≥ 0.5 on ECG identified 40/43 left-sided AV-connections (sensitivity 93.0%). The negative predictive value of this combined criterion was 103/106 (97.2%). CONCLUSIONS: In symptomatic patients, combining the R/S ratio (≥ 0.5) in lead V1 with the classic preexcitation pattern on ECG markedly improved the sensitivity to diagnose left-sided AV-connections. This ratio may be particularly useful among patients lacking obvious preexcitation.

Prolonged electrical quiescence after direct current cardioversion for atrial flutter in congenital heart disease.

Elective direct current cardioversion is considered first-line treatment in many cases of atrial flutter and fibrillation. This also is true in the pediatric population. This report describes a case of successful cardioversion that resulted in a very prolonged electrical quiescence.

Is there an association between external cardioversions and long-term mortality and morbidity? Insights from the Atrial Fibrillation Follow-up Investigation of Rhythm Management study.

BACKGROUND: Cardiac electric therapies effectively terminate tachyarrhythmias. Recent data suggest a possible increase in long-term mortality associated with implantable cardioverter-defibrillator shocks. Little is known about the association between external cardioversion episodes (ECVe) and long-term mortality. We sought to assess the safety of repeated ECVe with regard to cardiovascular mortality and morbidity. METHODS AND RESULTS: We analyzed the data of the 4060 patients from the AFFIRM (Atrial Fibrillation Follow-up Investigation of Rhythm Management) trial. In particular, associations of ECVe with all-cause mortality, cardiovascular mortality, and hospitalizations after ECVe were studied. Over an average follow-up of 3.5 years, 660 (16.3%) patients died, 331 (8.2%) from cardiovascular causes. A total of 207 (5.1%) and 1697 (41.8%) patients had low ejection fraction and nonparoxysmal atrial fibrillation, respectively; 2460 patients received no ECVe, whereas 1600 experienced ≥ 1 ECVe. Death occurred in 412 (16.7%), 196 (16.5%), 39 (13.5%), and 13 (10.4%) of patients with 0, 1, 2, and ≥ 3 ECVe, respectively. There was no significant association between ECVe and mortality within any of the 4 subgroups defined by ejection fraction and atrial fibrillation type, although myocardial infarction, coronary artery bypass graft, and digoxin were significantly associated with death (estimated hazard ratios, 1.65, 1.59, and 1.62, respectively; P < 0.0001). ECVe were associated with increased cardiac hospitalization reported at the next follow-up visit (39.3% versus 5.8%; estimated odds ratio, 1.39; P < 0.0001). CONCLUSIONS: In the AFFIRM study, there was no significant association between ECVe and long-term mortality, even though ECVe were associated with increased hospitalizations from cardiac causes. Digoxin, myocardial infarction, and coronary artery bypass graft were significantly associated with mortality.

Surgical electrocautery facilitated transseptal puncture in children.

BACKGROUND: Transseptal puncture has been performed in adults and children for decades. However, transseptal puncture can be challenging especially in pediatric patients because of an elastic septum and small atria. In adults, dedicated radiofrequency (RF) to facilitate transseptal puncture has become routine. OBJECTIVES: We wanted to assess whether RF could be used routinely in children to facilitate transseptal procedure. METHOD: The study population included all children referred to our electrophysiology lab who underwent an ablation requiring a transseptal puncture over a period of 10 months. RF was applied at the time of transseptal puncture. The source of RF was standard surgical electrocautery device with the electrosurgical pen in direct contact with the transseptal needle applied for a short period of time during transseptal puncture. RF output was set initially at 30 W in cut mode. All procedures were performed under general anesthesia. Patients were followed for possible complications. RESULTS: Thirteen patients (ages 11.6 ± 3.6 years, range 5-17 years, five boys) were included. One patient had left ventricular tachycardia, and the remainder had a supraventricular tachycardia with a left-sided accessory pathway. In all but two patients, a single attempt with an RF output of 30 W applied for less than 2 seconds was sufficient to cross the septum. In two patients, three attempts were needed with a last successful attempt using 35 W. No complications were observed either acutely or during the follow-up. CONCLUSION: Transseptal puncture facilitated by RF energy can be performed in children routinely and safely.

Inside-out access: a new method of lead placement for patients with central venous occlusions.

BACKGROUND: Physicians will increasingly encounter patients who require rhythm management devices but have venous obstructions that prevent conventional access. Alternate access options, such as thoracotomy or transiliac approaches, exist but are associated with greater cost and morbidity. OBJECTIVE: The purpose of this study is to describe a novel method of vascular access that allows prepectoral placement of conventional pacing and defibrillation leads in patients with complex central venous occlusions. METHODS: Eight patients with central venous occlusions were referred for device implantation. Inside-out central venous access (IOCVA) was obtained via a percutaneous femoral approach. A catheter-dilator system was advanced via the right atrium to the most central point of venous occlusion. The occluded vein segment was punctured with a directionally guided needle, which was advanced along intravascular or extravascular tissue planes to the subclavian region. A solid wire needle was oriented toward the skin surface and advanced through the soft tissues until it exists from the body. The wire was used to pull rigid dilators through the occluded segment. Standard transvenous leads were implanted though the newly created channel. RESULTS: All patients with total central venous occlusions (4 superior vena cava, 4 brachiocephalic and bilateral subclavian) had successful, prepectoral device implants (4 left-sided, 1 single-chamber, 4 dual-chamber, 3 biventricular). No procedure-related complications occurred. All patients had normal device function at follow-up of 485 ± 542 days. CONCLUSION: IOCVA is an effective method of pacemaker and defibrillator implantation for patients with central venous occlusions. Further clinical evaluation of this novel method is needed.

Frequent ventricular premature beats in children with a structurally normal heart: a cause for reversible left ventricular dysfunction?

Ventricular premature beats (VPBs) in a structurally normal heart generally are a benign condition. Rarely, however, reversible cardiomyopathy may develop. This study aimed to evaluate the incidence of cardiomyopathy among pediatric patients in a cohort with frequent VPBs and to examine the characteristics of the ventricular ectopic beats as well as therapeutic options. This study reviewed the charts of all pediatric patients between the ages of 1 day and 18 years seen at the University of Kentucky with the diagnosis of VPBs between 2003 and 2007. Frequent VPBs were defined as an ectopy burden of 5% or more in 24 h. Electrocardiograms, Holter monitors, and echocardiograms were reviewed. The review identified 28 patients (17 boys, age 13.3 ± 5.9 years, and 11 girls, age 13 ± 5.2 years) with frequent VPBs. The echocardiograms of four patients (2 boys, 14%) showed cardiomyopathy. Cardiac function normalized in all four patients, with spontaneous resolution of the VPBs (2 patients) or with antiarrhythmic therapy (2 patients). During a follow-up period of 2.7 ± 2.3 years, 32% of the patients without cardiomyopathy showed a marked spontaneous improvement in arrhythmia burden. Most of the patients showed VPBs with a left bundle branch block (LBBB) and inferior axis morphology. The most commonly associated symptoms were chest pain (17.8%) and dizziness and syncope (21.4%). Generally, VPBs in structurally normal hearts are considered benign. Rarely, a reversible cardiomyopathy can develop, requiring therapeutic intervention.

Pediatric nonpost-operative junctional ectopic tachycardia medical management and interventional therapies.

OBJECTIVES: To determine the outcomes of medical management, pacing, and catheter ablation for the treatment of nonpost-operative junctional ectopic tachycardia (JET) in a pediatric population. BACKGROUND: Nonpost-operative JET is a rare tachyarrhythmia that is associated with a high rate of morbidity and mortality. Most reports of clinical outcomes were published before the routine use of amiodarone or ablation therapies. METHODS: This is an international, multicenter retrospective outcome study of pediatric patients treated for nonpost-operative JET. RESULTS: A total of 94 patients with JET and 5 patients with accelerated junctional rhythm (age 0.8 year, range fetus to 16 years) from 22 institutions were identified. JET patients presenting at age < or =6 months were more likely to have incessant JET and to have faster JET rates. Antiarrhythmic medications were utilized in a majority of JET patients (89%), and of those, amiodarone was the most commonly reported effective agent (60%). Radiofrequency ablation was conducted in 17 patients and cryoablation in 27, with comparable success rates (82% radiofrequency vs. 85% cryoablation, p = 1.0). Atrioventricular junction ablation was required in 3% and pacemaker implantation in 14%. There were 4 (4%) deaths, all in patients presenting at age < or =6 months. CONCLUSIONS: Patients with nonpost-operative JET have a wide range of clinical presentations, with younger patients demonstrating higher morbidity and mortality. With current medical, ablative, and device therapies, the majority of patients have a good clinical outcome.

Successful management of acute failure of the systemic right ventricle with cardiac resynchronization therapy.

Management of systemic right ventricular (RV) failure can be challenging. Anatomical abnormality due to congenital heart disease adds to the complexity when interventions are performed. We report a patient with acute systemic RV failure who was successfully managed with cardiac resynchronization therapy.

Complete occlusion of the left circumflex coronary artery after radiofrequency catheter ablation in an infant.

Radiofrequency catheter ablation of a left lateral accessory atrioventricular pathway was performed in a 5-week-old infant with drug-refractory supraventricular tachycardia. Energy application via a 5-French mapping and ablation catheter in the temperature-controlled mode (60 degrees C, 30 W) at the atrial aspect of the mitral valve annulus repeatedly resulted in termination of the tachycardia by conduction block within the pathway. Tachycardia remained inducible subsequently. After a safety energy application during sinus rhythm, significant ST-segment elevation in the inferior, mid precordial, and left lateral leads was noted. Selective left coronary angiography revealed complete occlusion of the circumflex coronary artery. Moderate-to-severe mitral valve regurgitation developed, finally requiring mitral valve replacement.