A Case of Persistent Junctional Reciprocating Tachycardia Coincident With Cor Triatriatum Sinister.

Persistent junctional reciprocating tachycardia is a rare form of refractory atrioventricular reentrant tachycardia that accounts for <1% of supraventricular tachycardia in pediatrics. The accessory pathways are generally isolated with few reported underlying structural heart defects. We present a case of a five-month-old male with refractory tachyarrhythmia found to have cor triatriatum sinister, which to our knowledge, is the first reported case of these two rare anomalies coexisting.

Double outlet right ventricle.

This review article addresses the history, morphology, anatomy, medical management, and different surgical options for patients with double outlet right ventricle.

Case report: Use of therapeutic drug monitoring and pharmacogenetic testing as opportunities to individualize care in a case of flecainide toxicity after fetal supraventricular tachycardia.

Flecainide is a class IC antiarrhythmic utilized in prophylaxis of refractory paroxysmal supraventricular tachycardias in pediatric populations. Despite being a highly effective agent, its narrow therapeutic index increases the risk of toxicity and proarrhythmic events, including wide-complex tachycardia. In the absence of direct plasma sampling in the fetus to quantitate flecainide systemic concentrations, clinicians typically make drug dosing decisions from maternal plasma concentrations and QRS duration on maternal ECGs. There remains a paucity of standard guidelines and data to inform the timing and frequency of the aforementioned test in pregnancy and timing of flecainide discontinuation prior to childbirth. Flecainide primarily undergoes metabolism via cytochrome P450 (CYP). Given the variance of CYP-mediated metabolism at the level of the individual patient, pharmacogenomics can be considered in patients who present with flecainide toxicity to determine the maternal vs. fetal factors as an etiology for the event. Finally, pharmacogenetic testing can be utilized as an adjunct to guide flecainide dosing decisions, but must be done with caution in neonates <2 weeks of age. This case report highlights utilization of pharmacogenomic testing and therapeutic drug monitoring as adjuncts to guide therapy for a newborn with refractory supraventricular tachycardia, who experienced flecainide toxicity immediately post-partum and was trialed unsuccessfully on multiple alternative antiarrhythmics without rhythm control.

The Use of Automated Atrial CMR Measures and a Novel Atrioventricular Coupling Index for Predicting Risk in Repaired Tetralogy of Fallot.

Atrial size and function have been recognized as markers of diastolic function, and diastolic dysfunction has been identified as a predictor of adverse outcomes in repaired tetralogy of Fallot (rTOF). This was a retrospective single-center study with the objective of investigating the use of atrial measurements obtained via CMR for predicting outcomes in rTOF patients. Automated contours of the left and right atria (LA and RA) were performed. A novel parameter, termed the Right Atrioventricular Coupling Index (RACI), was defined as the ratio of RA end-diastolic volume to right ventricle (RV) end-diastolic volume. Patients were risk-stratified using a previously validated Importance Factor Score for the prediction of life-threatening arrhythmias in rTOF. Patients with a high-risk Importance Factor Score (>2) had a significantly larger minimum RA volume (p = 0.04) and RACI (p = 0.03) compared to those with scores ≤2. ROC analysis demonstrated RACI to be the best overall predictor of a high-risk Importance Factor Score (AUC 0.73, p = 0.03). Older age at the time of repair and a diagnosis of pulmonary atresia were associated with a larger RACI. Automated atrial CMR measurements are easily obtained from standard CMRs and have the potential to serve as noninvasive predictors of adverse outcomes in rTOF.

Electrocardiographic changes in non-hospitalised children with COVID-19.

OBJECTIVES: Many children diagnosed with COVID-19 infections did not require hospitalisation. Our objective was to analyse electrocardiographic changes in children with asymptomatic, mild or moderate COVID-19 who did not require hospitalisation. METHODS: All children are seen in a paediatric cardiology clinic who had asymptomatic, mild or moderate COVID-19 that did not require hospitalisation and had at least one electrocardiogram after their diagnosis were included in this retrospective analysis. Records were reviewed to determine COVID-19 disease severity and presence of Long COVID. Rhythm assessment, atrial enlargement, ventricular hypertrophy, PR/QRS/QT interval duration and ST-T wave abnormalities were analysed by a paediatric electrophysiologist. Clinically ordered echocardiograms were reviewed for signs of myopericarditis (left ventricular ejection fraction and pericardial effusion) on any subject with an electrocardiographic abnormality. RESULTS: Of the 82 children meeting inclusion criteria (14.4 years, range 1-18 years, 57% male), 17 patients (21%) demonstrated electrocardiographic changes. Ten patients (12%) had electrocardiogram of borderline significance, which included isolated mild PR prolongation or mild repolarisation abnormalities. The other seven patients (9%) had concerning electrocardiographic findings consisting of more significant repolarisation abnormalities. None of the patients with an abnormal electrocardiogram revealed any echocardiographic abnormality. All abnormal electrocardiograms normalised over time except in two cases. Across the entire cohort, greater COVID-19 disease severity and long COVID were not associated with electrocardiographic abnormalities. CONCLUSIONS: Electrocardiographic abnormalities are present in a minority of children with an asymptomatic, mild or moderate COVID-19 infection. Many of these changes resolved over time and no evidence of myopericarditis was present on echocardiography.

Guidewire pacing during transcatheter aortic valve implantation in a patient with complex congenital heart disease.

We present a case of temporary guidewire pacing in a patient with Fontan anatomy during transcatheter aortic valve implantation. Temporary pacing was successfully achieved utilizing this method without complications. There is an increasing population of patients with complex congenital heart disease and expanding variety of transcatheter interventions. Due to limitations in vascular access and surgical anatomies, guidewire pacing may have a wide array of potential applications in pediatrics and the congenital heart disease population.

Utility and safety of adenosine challenge for subtle ventricular pre-excitation in the pediatric population.

INTRODUCTION: Adenosine challenge (AC) can be used to evaluate possible Wolff-Parkinson-White (WPW) pattern on an electrocardiogram (ECG). Despite the use of this technique, there is a paucity of studies in the pediatric population evaluating the efficacy, safety, and outcomes of this testing modality. METHODS AND RESULTS: All ACs performed from January 2009 to June 2017 were retrospectively reviewed. Patient demographics, adenosine dosing, results, adverse effects, and outcomes including results of electrophysiology studies (EPS) were reviewed. Analysis was conducted between AC positive and negative cohorts. ECG criteria of shortest PR interval, longest QRS duration, and the number of suspected pre-excited leads were evaluated for inter-rater reliability and correlation to positive AC. Fifty-six AC (n = 51) were performed (median age, 13.8; range, 0.3-20 years). Forty-one AC were pre-EPS and 15 post-EPS due to concern for recurrent WPW. Thirty-one (76%) pre-EPS AC were negative, 9 (22%) positive, and 1 (2%) equivocal. EPS was performed following seven positive AC revealing 5 (71%) left posterior and 2 (29%) right posteroseptal AP. The 15 post-EPS AC were all found to be negative. Mean effective adenosine dose was 0.2 ± 0.11 mg/kg. No adverse events were reported. Mean follow up duration after AC was 314 ± 482 days with no documented arrhythmias. CONCLUSION: Adenosine challenge is an effective and safe testing modality for subtle WPW in the pediatric population. In our population, there were no adverse events or documented arrhythmias in patients following a negative study.

Marked First-Degree Atrioventricular Block and Pseudo-Pacemaker Syndrome in a Pediatric Patient.

We describe a 17-year-old female who presented with 3 weeks of abdominal pain, exercise intolerance, and an episode of altered mental status found to have marked first-degree atrioventricular block. Exercise stress test and cardiac catheterization demonstrated pseudo-pacemaker syndrome, and a permanent pacemaker was placed. Following placement, she has resolution of symptoms and markedly improved exercise tolerance.

Automated QT analysis on Holter monitors in pediatric patients can differentiate long QT syndrome from controls.

BACKGROUND: Borderline QTc is a common referral to the pediatric cardiology clinic. Evaluation is challenging due to significant overlap of normal and abnormal QTc ranges. We hypothesized that automated QT analysis on Holter could differentiate between patients with long QT syndrome (LQTS) and healthy controls. METHODS: We conducted a retrospective review of 39 patients with known genotype-positive, phenotype-positive LQTS who underwent Holter monitoring between January 2010 and January 2016. They were compared 2:1 to age- and sex-matched controls. Automated QT analysis data were analyzed. RESULTS: Significant differences were found in all automated QT and QTc fields, except minimum QTc interval (P = 0.57). Mean QTc interval (LQTS 479 ± 28 ms vs controls 429 ± 16 ms; P ≤ 0.001) and percent QTc intervals (%QTc) >450 ms (LQTS 80 ± 28% vs controls 14 ± 16%; P ≤ 0.001) were selected for further analysis. A receiver operating characteristic curve was generated for each variable demonstrating high area under the curve values of 0.9494 and 0.9540, respectively. Threshold values of ≥461 ms for mean QTc (sensitivity 79.49%, specificity 98.72%) and ≥65% of %QTc >450 ms (sensitivity 79.49%, specificity 98.72%) allowed highly specific discrimination between cohorts (false positive rate 1.09%). Similarly, thresholds of <434 ms (sensitivity 97.44, specificity 61.54) for mean QTc and <32% (sensitivity 89.74, specificity 87.18) for %QTc >450 ms resulted in highly sensitive discrimination (false negative rates 2.17% and 8.7%). CONCLUSION: Holter monitor testing with automated QT analysis may be a useful tool to differentiate LQTS and control patients.

Adenosine-sensitive Wolff-Parkinson-White: Longer time across the atrioventricular groove.

BACKGROUND: Successful ablation sites in Wolff-Parkinson-White syndrome (WPW) are characterized by short atrioventricular (AV) intervals. Approximately 15% of patients with WPW have adenosine-sensitive accessory pathways (APs). We sought to determine if local AV intervals of adenosine-sensitive APs are different from those of adenosine-insensitive APs in patients with WPW. METHODS: Patients ≤21 years with WPW and adenosine-sensitive APs who underwent successful ablation over a 9-year period were included. Patients with WPW and adenosine-insensitive APs were matched by age and weight in a 1:2 case-control design. AP location, antegrade and retrograde conduction properties, supraventricular tachycardia (SVT) inducibility, local AV interval, interval from delta wave onset to local ventricular activation (del-V), and time to loss of preexcitation were reviewed. RESULTS: Fourteen patients with adenosine-sensitive APs and 28 with adenosine-insensitive APs were included. Patients with adenosine-sensitive APs had minimum 1:1 antegrade AP conduction at a longer median paced cycle length (380, interquartile range [IQR] 295 to 585 ms vs 290, IQR 250 to 330 ms, P = 0.046), were less likely to have inducible SVT (35.7% vs 75.0%, P = 0.035), and had a longer median local AV interval (40.5, IQR 30.8 to 58.3 ms vs 32.0, IQR 29.3 to 37.8 ms, P = 0.029) when compared to those with adenosine-insensitive APs. CONCLUSION: Patients with WPW and adenosine-sensitive APs have 1:1 antegrade AP conduction at longer cycle lengths, lower likelihood of SVT induction, and longer local AV intervals when compared to those with adenosine-insensitive APs. In patients with WPW, it may be important to consider adenosine response when selecting appropriate ablation targets.

Embedding patient simulation in a pediatric cardiology rotation: a unique opportunity for improving resident education.

OBJECTIVE: High-fidelity patient simulation (HFPS) has been used in medical education to bridge gaps in medical knowledge and clinical skills. Few studies have analyzed the impact of HFPS in subspecialty rotations for pediatric residents. We hypothesized that pediatric residents exposed to HFPS with a structured content curriculum would perform better on a case quiz than residents without exposure to HFPS. DESIGN: Prospective randomized controlled SETTING: Tertiary-care free standing children's hospital INTERVENTIONS: During a cardiology rotation, senior pediatric residents completed an online pediatric cardiology curriculum and a cardiology quiz. After randomization into two groups, the study group participated in a fully debriefed HFPS session. The control group had no HFPS. OUTCOME MEASURE: Both groups completed a case quiz. Confidence surveys pre- and postsimulation were completed. RESULTS: From October 2010 through March 2013, 55 residents who rotated through the pediatric cardiology rotation were used in the final analysis (30 control, 25 in the study group). There was no significant difference between groups on the initial cardiology quiz. The study group scored higher on the case quiz compared with the control group (P = .024). Based on pre- and postsimulation questionnaires, residents' confidence in approaching a pediatric cardiology patient improved from an average Likert score of 5.1 to 7.5 (on scale of 0-10) (P < .001). CONCLUSIONS: Incorporation of HFPS into a preexisting pediatric cardiology rotation was feasible and well received. Our study suggests that simulation promotes increased confidence and may modestly improve clinical reasoning compared to traditional educational techniques. Targeted simulation sessions may readily be incorporated into pediatric subspecialty rotations.

Combining Thrombolysis in Myocardial Infarction risk score and clear-cut alternative diagnosis for chest pain risk stratification.

OBJECTIVE: The Thrombolysis in Myocardial Infarction (TIMI) risk score is a validated risk stratification tool useful in patients with definite and potential acute coronary syndromes (ACS) but does not identify patients safe for discharge from the emergency department (ED). Likewise, the use of a clear-cut alternative noncardiac diagnosis risk stratifies patients but does not identify a group safe for discharge. We hypothesized that the presence of an alternative diagnosis in patients with a TIMI risk score less than 2 might identify a cohort of patients safe for ED discharge. METHODS: In prospective cohort study, we enrolled ED patients with potential ACS. Data included demographics, medical history, components of the TIMI risk score, and whether the treating physician ascribed the condition to an alternative noncardiac diagnosis. Investigators followed the patients through the hospital course, and 30-day follow-up was done. The main outcome was 30-day death, myocardial infarction, or revascularization. RESULTS: A total of 3169 patients were enrolled (mean age, 53.6+/-14 years; 45% men; 67% black). There were 991 patients (31%) with an alternative diagnosis, 980 patients with a TIMI risk score of 0, and 828 with a TIMI score of 1. At low levels of TIMI risk (<3), adding in a clinical impression of an alternative diagnosis did not reduce risk; at higher levels of TIMI risk, it did. The incidence of 30-day death, myocardial infarction, or revascularization for patients with a clinical impression of an alternative diagnosis and a TIMI score of 0 was 2.9% (95% confidence interval, 1.6%-5.0%). CONCLUSIONS: The TIMI risk score stratifies patients with and without an alternative diagnosis. Unfortunately, patients with both a low TIMI risk score and a clinical impression of an alternative noncardiac diagnosis still have a risk of 30-day adverse events that is not low enough to allow safe discharge from the ED.

Effect of household children on adult ED smokers' motivation to quit.

OBJECTIVE: We hypothesized adult parenting smokers in the emergency department (ED) have a higher interest in quitting and may be more amenable to tobacco cessation counseling than smokers without children. STUDY DESIGN: Cross-sectional survey study of adult smokers in 8 US academic EDs. RESULTS: One thousand one hundred sixty-eight smokers enrolled, 441 (37.8%) with household children (total of 973 exposed children). Compared to smokers without household children, smokers with children were younger (mean age, 37.4 vs 42.8 years), more female (60.3% vs 40.3%), and nonwhite (57.5% vs 44.5%) (all P < .006). Groups did not differ in nicotine addiction (median Fagerstrom score, 4 vs 4; P = .31). Parenting smokers were more interested in quitting (mean Ladder of Contemplation score, 4.8 vs 5.1 [P = .02]), felt it more important to quit (median score, 9 vs 8 [P = .01]), and more confident to quit (7 vs 6 [P = .004]) than nonparenting smokers. Smoking inside the home was banned by 45% of smokers with children vs 30% without household children (P < .001). CONCLUSIONS: Adult ED parenting smokers are interested in quitting and taking steps to limit their children's secondhand smoke exposure. Asking adult ED smokers about household children may enhance motivation to quit.

TIMI risk score: does it work equally well in both males and females?

OBJECTIVE: The TIMI (Thrombolysis In Myocardial Infarction) risk score is a seven item risk stratification tool derived from trials of patients with non-ST segment elevation acute coronary syndromes (ACS) that has been validated in emergency department (ED) patients with potential ACS. We hypothesised that it might have different prognostic abilities in male and female patients. METHODS: This was a prospective cohort study of ED patients with potential ACS. Data included demographics, medical and cardiac history, and components of the TIMI risk score. Investigators followed the hospital course daily. The main outcome was death, acute myocardial infarction (AMI), or revascularisation within 30 days as stratified by TIMI risk score and compared between genders using chi2 tests. RESULTS: There were 2022 patients enrolled: 1204 (60%) females and 818 (40%) males. The incidence of 30 day death, AMI, revascularisation (n = 168) according to TIMI score is as follows (female vs male): TIMI 0 (n = 670), 1.6% vs 2.0%, p = 0.2; TIMI 1 (n = 525), 4.6% vs 8.5%, p = 0.02; TIMI 2 (n = 378), 6.3% vs 10.4%, p = 0.05; TIMI 3 (n = 234), 6.5% vs 24.6%, p<0.001; TIMI 4 (n = 157), 22.7% vs 24.4%, p = 0.15; TIMI 5 (n = 52), 35.5% vs 39.1%, p = 0. 2; TIMI 6 or 7 (n = 6), 33.3% vs 66.7%, p = 1.0. The relationship between TIMI score and outcome was highly significant (p<0.001) for each gender; however, males tended to have worse outcomes at lower TIMI risk scores. CONCLUSIONS: The TIMI risk score successfully risk stratifies both males and females with potential ACS at the time of ED presentation; however, males have worse outcomes at lower TIMI scores than females.