pECGreview: Assessment of a Novel Tool to Evaluate the Accuracy of Pediatric ECG Interpretation Skills.

The skill of interpretation of the electrocardiogram (ECG) remains poor despite existing educational initiatives. We sought to evaluate the validity of using a subjective scoring system to assess the accuracy of ECG interpretations submitted by pediatric cardiology fellows, trainees, and faculty to the Pediatric ECG Review (pECGreview), a web-based ECG interpretation training program. We conducted a retrospective, cross-sectional study of responses submitted to pECGreview. ECG interpretations were assessed independently by four individuals with a range of experience. Accuracy was assessed using a 3-point scale: 100% for generally correct interpretations, 50% for over- or underdiagnosis of minor ECG abnormalities, and 0% for over- or underdiagnosis of major ECG abnormalities. Inter-rater agreement was assessed using expanded Bland-Altman plots, Pearson correlation coefficients, and Intraclass Correlation Coefficients (ICC). 1460 ECG interpretations by 192 participants were analyzed. 107 participants interpreted at least five ECGs. The mean accuracy score was 76.6 ± 13.7%. Participants were correct in 66.1 ± 5.1%, had minor over- or underdiagnosis in 21.5 ± 4.6% and major over- or underdiagnosis in 12.3 ± 3.9% of interpretations. Validation of agreement between evaluators demonstrated limits of agreement of 11.3%. Inter-rater agreement exhibited consistent patterns (all correlations ≥ 0.75). Absolute agreement was 0.74 (95% CI 0.69-0.80), and average measures agreement was 0.92 (95% CI 0.89-0.94). Accuracy score analysis of as few as five ECG interpretations submitted to pECGreview yielded good inter-rater reliability for assessing and ranking ECG interpretation skills in pediatric cardiology fellows in training.

Variation in Antiarrhythmic Management of Infants Hospitalized with Supraventricular Tachycardia: A Multi-Institutional Analysis.

Supraventricular tachycardia (SVT) is the most frequent form of symptomatic tachyarrhythmia in infants. The purposes of this study were to describe practice patterns of the management of infants hospitalized with SVT and factors associated with 30-day hospital readmission. This was a multi-institutional, retrospective review of the pediatric health information system database of SVT hospitalizations from 2003 to 2013. High-volume centers (HVC) were defined as those at the upper quartile of admissions. Infants with an ICD-9 code of paroxysmal SVT were included. Antiarrhythmics investigated included amiodarone, atenolol, digoxin, esmolol, flecainide, procainamide, propafenone, propranolol, and sotalol. Frequency of antiarrhythmic use based on center volume was the primary end point. Rate of 30-day SVT readmission was the secondary end point. Analysis of factors associated with readmission was assessed by Chi-square analysis and expressed as odds ratio and 95 % confidence interval. A total of 851 patients (60 % male, 44 % neonates) were hospitalized at 43 hospitals. Propranolol, digoxin, and amiodarone were the most frequently utilized antiarrhythmics. HVCs represented 12 hospitals comprising 494 (58 %) patients. Although HVCs were more likely to utilize propranolol (OR 2.5, CI 1.5-4.1), there was no significant difference in the 30-day readmission rate between patients treated at HVCs versus non-HVCs (p = 0.9). The majority of infants with SVT are treated with a small number of antiarrhythmic medications during index hospitalization. Although hospital-to-hospital variation in antiarrhythmic choice exists, there appears to be no difference in readmission. The remaining practice variation may be related to intrinsic patient characteristics.

Risk for prolonged QT interval and associated outcomes in children with early restrictive eating patterns.

UNLABELLED: Aim This study aimed to describe the frequency of QTc prolongation in children with restrictive eating disorders early in the course of disease admitted for inpatient therapy, to determine the frequency of associated ventricular arrhythmia, and to evaluate the relationship between QTc interval and concomitant electrolyte abnormalities and rate of weight loss. METHODS: This was a retrospective cohort study of patients aged 11-25 years with early restrictive eating disorders. RESULTS: In all, 82 patients met the inclusion criteria (84% female). In total, 9.8% had prolonged QTc interval during hospitalisation. Patients with prolonged QTc had significantly higher resting heart rates (p=0.006), but there was no association with hypokalaemia (p=0.31), hypomagnesaemia (p=0.43), hypophosphataemia (p=1), or rate of weight loss (p=1). CONCLUSION: Mild QTc prolongation in patients with restrictive eating disorders is not related to electrolyte abnormalities or rate of weight loss in this population, suggesting that investigation about other potential risk factors of prolonged QTc interval may be warranted.

Relationship between echocardiographic LV mass and ECG based left ventricular voltages in an adolescent population: related or random?

BACKGROUND: In attempts to detect diseases that may place adolescents at risk for sudden death, some have advocated for population-based screening. Controversy exists over electrocardiography (ECG) screening due to the lack of specificity, cost, and detrimental effects of false positive or extraneous outcomes. OBJECTIVES: Analyze the relationship between precordial lead voltage on ECG and left ventricle (LV) mass by echocardiogram in adolescent athletes. METHODS: Retrospective cohort analysis of a prospectively obtained population of self-identified adolescent athletes during sports screening with ECG and echocardiogram. Correlation between ECG LV voltages (R wave in V6 [RV6] and S wave in lead V1 [SV1]) was compared to echocardiogram-based measurements of left ventricular mass. Potential effects on ECG voltages by body anthropometrics, including weight, body mass index (BMI), and body surface area were analyzed, and ECG voltages indexed to BMI were compared to LV mass indices to analyze for improved correlation. RESULTS: A total of 659 adolescents enrolled in this study (64% male). The mean age was 15.4 years (14-18). The correlations between LV mass and RV6, SV1, and RV6 + SV1 were all less than 0.20. The false positive rate for abnormal voltages was relatively high (5.5%) but improved if abnormal voltages in both RV6 and SV1 were mandated simultaneously (0%). Indexing ECG voltages to BMI significantly improved correlation to LV mass, though false positive findings were increased (12.9%). CONCLUSION: There is poor correlation between ECG precordial voltages and echocardiographic LV mass. This relationship is modified by BMI. This finding may contribute to the poor ECG screening characteristics.

Pediatric Cardio-Oncology Medicine: A New Approach in Cardiovascular Care.

Survival for pediatric patients diagnosed with cancer has improved significantly. This achievement has been made possible due to new treatment modalities and the incorporation of a systematic multidisciplinary approach for supportive care. Understanding the distinctive cardiovascular characteristics of children undergoing cancer therapies has set the underpinnings to provide comprehensive care before, during, and after the management of cancer. Nonetheless, we acknowledge the challenge to understand the rapid expansion of oncology disciplines. The limited guidelines in pediatric cardio-oncology have motivated us to develop risk-stratification systems to institute surveillance and therapeutic support for this patient population. Here, we describe a collaborative approach to provide wide-ranging cardiovascular care to children and young adults with oncology diseases. Promoting collaboration in pediatric cardio-oncology medicine will ultimately provide excellent quality of care for future generations of patients.

Diagnostic and Therapeutic Approach to Arrhythmias in Adult Congenital Heart Disease.

PURPOSE OF REVIEW: Adult survivors of congenital heart disease (CHD) are at increased risk of arrhythmia. The goal of this review is to outline diagnostic and therapeutic approaches to arrhythmia in adult CHD patients. RECENT FINDINGS: Macro-reentrant atrial tachyarrhythmia is the most common arrhythmia encountered in adults with CHD. Approximately 25% of hospitalizations associated with arrhythmia. The risk of ventricular arrhythmia is estimated as high as 25-100 times that for the general population and increased after two decades. Routine ambulatory monitoring is important for arrhythmia risk assessment in adults with CHD. There are limitations, potential adverse effects, and risk of recurrence with antiarrhythmic drugs, catheter ablation, and surgical approaches. Adults with CHD suffer various forms of arrhythmia, are at increased risk of sudden death, and require special consideration for medical and interventional therapy.

Learning in Cardiology Fellowship: Opportunities for Optimization.

Cardiology fellowship is filled with opportunities for learning; however, numerous obstacles must be successfully navigated to complete training with the knowledge, skills, and attitudes necessary for a successful career. To assist Cardiology fellows in prioritizing their time and energy in order to fully gain from their training, a list of recommendations with rationales has been provided.

Unexpectedly low left ventricular voltage on ECG in hypertrophic cardiomyopathy.

OBJECTIVE: While late gadolinium enhancement (LGE) in paediatric patients with hypertrophic cardiomyopathy (HCM) is reported as similar to adults, the relationship between LGE and ECG findings in paediatric patients is unknown. We sought to evaluate the relationship between LGE on cardiac MRI and LV precordial voltage on ECG. METHODS: This was a retrospective analysis of paediatric patients with HCM aged 9-21 years with cardiac MRI and ECG completed within 60 days of each other. Demographic, MRI and ECG data were compared between patients with and without LGE. Maximal diastolic septal thickness, septal to free wall ratio and LGE presence were compared with LV precordial voltage (SV1, RV6 and SV1+RV6). RESULTS: This study included 37 patients (33 male). Mean age was 15.8±2.8 years. Mean maximal LV diastolic septal thickness was 22.1±7.9 mm. Mean septal to free wall ratio was 2.4±1.6 mm. LGE was present in 18 patients, with 16 isolated to the ventricular septum. Comparing patients with and without LGE, there was no difference in age (p=0.2) or body surface area (p=0.9). However, the presence of LGE was associated with significantly increased septal thickness (p=0.03), yet decreased voltages in SV1 (p=0.005), RV6 (p=0.005) and SV1+RV6 (p=0.002) despite increased septal dimensions. CONCLUSIONS: A significant inverse relationship exists between LGE presence and LV precordial voltage in this population. Unexpectedly low LV precordial voltages in patients with HCM may serve as a clinical surrogate marker for myocardial fibrosis and potential loss of viable myocardial tissue.

Short QT Interval Prevalence and Clinical Outcomes in a Pediatric Population.

BACKGROUND: Risk associated with short QT interval has recently received recognition. European studies suggest a prevalence of 0.02% to 0.1% in the adult population, but similar studies in pediatric patients are limited. We sought to determine the prevalence of short QT interval in a pediatric population and associated clinical characteristics and outcomes. METHODS AND RESULTS: Retrospective review of an ECG database at a single pediatric institution. The database was queried for ECGs on patients ≤21 years with electronically measured QTc of 140 to 340 ms. Patients with QTc of 140 to 340 ms confirmed by a pediatric electrophysiologist were identified for chart review for associated clinical characteristics, symptoms, and outcome. Patients with and without symptoms were compared in an attempt to identify variables associated with outcome. The query included 272 504 ECGs on 99 380 unique patients. Forty-five patients (35 men, 76%) had QTc ≤340 ms, for a prevalence of 0.05%. Median age was 15 years (interquartile range, 2-17), median QT 330 ms (interquartile range, 280-360), and median QTc 323 ms (IQR, 313-332). Women had significantly shorter QTc compared with men (312 versus 323 ms; P=0.03). Two deaths were noted in chart review--one from respiratory failure and the second of unknown pathogenesis in a patient with dilated cardiomyopathy. CONCLUSIONS: Short QT interval was a rare finding in this pediatric population, with a prevalence of 0.05%. Male predominance was identified, although the median QT interval was significantly shorter in women. There seem to be no unifying clinical characteristics for this pediatric patient cohort with short QT interval.

Correlation of precordial voltages to left ventricular mass on echocardiogram in adolescent patients with hypertrophic cardiomyopathy compared with that in adolescent athletes.

Electrocardiograms continue to be part of screening programs for athletes and familial hypertrophic cardiomyopathy (HC). Whether electrocardiographic (ECG) findings of left ventricular (LV) hypertrophy can distinguish between healthy populations and those with HC remains unclear. We sought to (1) analyze the relation between ECG voltage and LV mass in patients with HC and (2) evaluate ECG characteristics of patients with phenotypical HC. Retrospective cohort of patients with HC aged 13 to 18 years. Relation between ECG voltages (RV6, SV1, and RV6 + SV1) and echocardiogram measurements of LV mass was investigated using smoothing splines to display relations and compared with those in a prospectively obtained population of adolescents. Frequency of abnormal LV voltages and nonvoltage ECG changes (Q waves, T-wave changes, and ST changes) were analyzed for association with HC. Fifty-three patients with HC (72% men) were age and gender matched to 104 control patients. Smoothing splines demonstrated that parabolic rather than linear relations existed between LV mass and SV1, RV6, and RV6 + SV1 in patients with HC and not the control cohort. LV hypertrophy by ECG voltage criteria was present in 34% of patients with HC and associated with poor sensitivity (29%). In patients with HC, 56% demonstrated nonvoltage ECG abnormalities and were associated with improved sensitivity (68%) and high specificity (94%). In conclusion, there is a parabolic relation between LV voltages and LV mass in adolescents with HC that may lead to "pseudonormalization." Voltage abnormalities were associated with poor sensitivity, whereas nonvoltage criteria were associated with improved sensitivity with high specificity.

Usefulness of ventricular premature complexes in asymptomatic patients ≤21 years as predictors of poor left ventricular function.

Although ventricular premature complexes (VPCs) have been shown to correlate with decreased cardiac function in adults, the correlation of left ventricular (LV) function to VPCs in asymptomatic children remains unclear. The aim of this study was to determine the correlation of VPC burden with LV function in asymptomatic pediatric patients with structurally normal hearts. This was a retrospective analysis of patients aged ≤21 years with echocardiograms and 24-hour Holter monitors with ≥0.5% VPCs completed within 60 days of each other. LV fractional shortening (FS) was compared with VPC burden and VPC characteristics. Normal LV function was defined as FS ≥28%. Correlation between VPC burden and LV function was determined by regression analysis. Wilcoxon's rank-sum test was used to compare LV function with VPC characteristics. This study included 123 patients (77 male [63%]). The median age was 11.6 years (interquartile range 5.8 to 14.3). The median VPC burden was 11.2% (interquartile range 4.8% to 18.9%), and median FS was 36% (interquartile range 33% to 38%). There was no significant correlation between VPC burden and LV FS (p = 0.50). The presence of uniform versus multiform VPCs (p = 0.29), ventricular couplets (p = 0.37), or runs of ventricular ectopy (p = 0.19) were not associated with a decrease in LV FS. Twenty-two patients (18%) had VPC burden >24%, none of which had decreased LV FS. In conclusion, there was no significant relation between VPC burden or VPC characteristics and LV systolic function in this pediatric population with structurally normal hearts.