Comparison of Left Ventricular Hypertrophy by Electrocardiography and Echocardiography in Children Using Analytics Tool

Modified torso vs distal limb electrode placement for performing ECGs in children: A method comparison study

BACKGROUND

The electrocardiogram (ECG) is routinely performed in children with the limb electrodes positioned on the torso, but few studies have investigated the effects of this modification on the pediatric ECG. Our objective was to assess the agreement between the standard limb lead configuration and a modified torso electrode configuration in normal, healthy children, and to assess the effect of height on that agreement.

METHODS

185 children aged 5-18 years underwent two consecutive 12‑lead ECGs, one with standard distal limb lead placement and one with the limb leads placed on the torso. Agreement was assessed for 17 ECG parameters (intervals, axes, and amplitudes) using Bland-Altman plots, height-dependent mean error, and false positive rates.

RESULTS

The torso configuration systematically biased the QRS and P wave axes rightwards (towards aVF). Adequate agreement was observed for PR interval and QRS duration, but QTc limits of agreement (±40 ms) were wide. The torso configuration overestimated left-precordial Q, R, and S wave amplitudes and underestimated right-precordial R and S wave amplitudes compared to the distal limb placement. Mean measurement errors increased with the magnitude of the ECG parameter. Mean and variance of measurement errors were more pronounced in shorter children. False positive rates did not differ between the torso and distal limb configurations.

CONCLUSION

Modified placement of the limb electrodes onto the torso resulted in multiple differences in the pediatric ECG signals. This may lead to misclassification of electrocardiographic abnormalities, particularly in children with measurement values at the upper limits of normal.

Limited Relationship Between Echocardiographic Measures and Electrocardiographic Markers of Left Ventricular Size in Healthy Children

Pediatric ECG standards have been defined without echocardiographic confirmation of normal anatomy. The Pediatric Heart Network Normal Echocardiogram Z-score Project provides a racially diverse group of healthy children with normal echocardiograms. We hypothesized that ECG and echocardiographic measures of left ventricular (LV) dimensions are sufficiently correlated in healthy children to imply a clinically meaningful relationship. This was a secondary analysis of a previously described cohort including 2170 digital ECGs. The relationship between 6 ECG measures associated with LV size were analyzed with LV Mass (LVMass-z) and left ventricular end-diastolic volume (LVEDV-z) along with 11 additional parameters. Pearson or Spearman correlations were calculated for the 78 ECG-echocardiographic pairs with regression analyses assessing the variance in ECG measures explained by variation in LV dimensions and demographic variables. ECG/echocardiographic measurement correlations were significant and concordant in 41/78 (53%), though many were significant and discordant (13/78). Of the 6 ECG parameters, 5 correlated in the clinically predicted direction for LV Mass-z and LVEDV-z. Even when statistically significant, correlations were weak (0.05-0.24). R2 was higher for demographic variables than for echocardiographic measures or body surface area in all pairs, but remained weak (R2 ≤ 0.17). In a large cohort of healthy children, there was a positive association between echocardiographic measures of LV size and ECG measures of LVH. These correlations were weak and dependent on factors other than echocardiographic or patient derived variables. Thus, our data support deemphasizing the use of solitary, traditional measurement-based ECG markers traditionally thought to be characteristic of LVH as standalone indications for further cardiac evaluation of LVH in children and adolescents.

The Neonatal QRS Complex and Its Association with Left Ventricular Mass

To evaluate QRS complex features during the first month of life and the association with echocardiographic measurements of left ventricular mass in neonates. Prospective cohort study of neonates with electrocardiography (ECG) and echocardiography performed during the first month of life. Left ventricular mass index (LVMI) was determined by echocardiography and the correlation with electrocardiographic markers of LVMI outliers (≥ 98th percentile) were analyzed. We included 17,450 neonates (52% boys; median age at examination 11 days) and found an increase in median QRS duration and LVMI during the first month of life (54 vs. 56 ms and 24.7 vs. 28.6 g/m2 at days 0-4 and 25-30, respectively; both p < 0.001). All investigated ECG features (QRS duration, QRS area in V1/V6, maximum amplitudes of S-V1/R-V6, and the Sokolow-Lyon voltage product) showed no to low correlation with LVMI, resulting in low sensitivities (0-9.0%), but high specificities (97.2-98.1%), and area under the curve values close to the identity line (0.49-0.61) for identifying LVMI outliers. Adjustment of outlier definition for LVMI and threshold for QRS features had no significant effect on sensitivity. We present reference values for QRS complex features and their association with LVMI in neonates from a large, unselected, population-based cohort. The QRS complex gradually evolved during the first month of life but had a low correlation with LVMI. Our results indicate a poor diagnostic value of using ECG features to identify LVMI outliers in neonates.Trial Registry Copenhagen Baby Heart, NCT02753348, https://clinicaltri-als.gov/ct2/show/NCT02753348?cond=Copenhagen+Baby+Heart&draw=2&rank=1 , deidentified individual participant data will not be made available.

Right and left ventricular mass development in early infancy: Correlation of electrocardiographic changes with echocardiographic measurements

BACKGROUND

Right ventricular mass indexed to body surface area (RVMI) decreases and left ventricular mass index (LVMI) increases rapidly and substantially during early infancy. The relationship between these sizeable mass transformations and simultaneous electrocardiographic changes have not been previously delineated.

METHODS

Normal term infants (#45 initially enrolled) were prospectively evaluated at 2 days and at 2-week, 2-month, and 4-month clinic visits. Ventricular masses were estimated with 2D echocardiographic methods. QRS voltages were measured in leads V1, V6, I and aVF.

RESULTS

Mean QRS axis shifted from 135 (95%CI 124, 146) to 65 degrees (95%CI 49, 81) and correlated with both RVMI decrease and LVMI increase (R = 0.46⁎ vs. 0.25†, respectively. *p < 0.01, †p < 0.05). As RVMI decreased from mean 28.1 (95%CI 27.1, 29.1) to 23.3 g/m2 (95%CI 21.4, 25.2) so did V1R and V6S voltages. RVMI changes correlated with V1R, V6S, and V1R + V6S voltages (R = 0.29*, 0.23† and 0.35*, respectively. *p < 0.01, †p < 0.05) but not with V1R/S ratio. As LVMI increased from 44.6 (95%CI 42.9, 46.3) to 55.4 g/m2 (95%CI 52.3, 58.5) V6R and V6Q increased but V1S voltage did not. LVMI changes correlated with V6R, V6R-S, and V6(Q + R)-S voltages (R = 0.31*, 0.34*, and 0.38* respectively. *p < 0.01) but not with V1S or V6R/S (R = 0.01 and 0.18 respectively, p = NS).

CONCLUSIONS

During early infancy the RVMI decrease correlates best with the QRS axis shift and V1R + V6S voltage, and the LVMI increase correlates best with V6R-S and V6(Q + R)-S voltages.

Effects of blood pressure percentile, body mass index, and race on left ventricular mass in children

OBJECTIVE

To evaluate the association of systolic blood pressure percentile, race, and body mass index with left ventricular hypertrophy on electrocardiogram and echocardiogram to define populations at risk.

STUDY DESIGN

This is a retrospective cross-sectional study design utilising a data analytics tool (Tableau) combining electrocardiogram and echocardiogram databases from 2003 to 2020. Customized queries identified patients aged 2-18 years who had an outpatient electrocardiogram and echocardiogram on the same date with available systolic blood pressure and body measurements. Cases with CHD, cardiomyopathy, or arrhythmia diagnoses were excluded. Echocardiograms with left ventricle mass (indexed to height^2.7) were included. The main outcome was left ventricular hypertrophy on echocardiogram defined as Left ventricle mass index greater than the 95th percentile for age.

RESULTS

In a cohort of 13,539 patients, 6.7% of studies had left ventricular hypertrophy on echocardiogram. Systolic blood pressure percentile >90% has a sensitivity of 35% and specificity of 82% for left ventricular hypertrophy on echocardiogram. Left ventricular hypertrophy on electrocardiogram was a poor predictor of left ventricular hypertrophy on echocardiogram (9% sensitivity and 92% specificity). African American race (OR 1.31, 95% CI = 1.10, 1.56, p = 0.002), systolic blood pressure percentile >95% (OR = 1.60, 95% CI = 1.34, 1.93, p < 0.001), and higher body mass index (OR = 7.22, 95% CI = 6.23, 8.36, p < 0.001) were independently associated with left ventricular hypertrophy on echocardiogram.

CONCLUSIONS

African American race, obesity, and hypertension on outpatient blood pressure measurements are independent risk factors for left ventricular hypertrophy in children. Electrocardiogram has little utility in the screening for left ventricular hypertrophy.

Safety, Tolerability, and Immunogenicity of Plasmodium falciparum Sporozoite Vaccine Administered by Direct Venous Inoculation to Infants and Young Children: Findings From an Age De-escalation, Dose-Escalation, Double-blind, Randomized Controlled Study in Western Kenya

BACKGROUND

The whole Plasmodium falciparum sporozoite (PfSPZ) vaccine is being evaluated for malaria prevention. The vaccine is administered intravenously for maximal efficacy. Direct venous inoculation (DVI) with PfSPZ vaccine has been safe, tolerable, and feasible in adults, but safety data for children and infants are limited.

METHODS

We conducted an age de-escalation, dose-escalation randomized controlled trial in Siaya County, western Kenya. Children and infants (aged 5-9 years, 13-59 months, and 5-12 months) were enrolled into 13 age-dose cohorts of 12 participants and randomized 2:1 to vaccine or normal saline placebo in escalating doses: 1.35 × 105, 2.7 × 105, 4.5 × 105, 9.0 × 105, and 1.8 × 106 PfSPZ, with the 2 highest doses given twice, 8 weeks apart. Solicited adverse events (AEs) were monitored for 8 days after vaccination, unsolicited AEs for 29 days, and serious AEs throughout the study. Blood taken prevaccination and 1 week postvaccination was tested for immunoglobulin G antibodies to P. falciparum circumsporozoite protein (PfCSP) using enzyme-linked immunosorbent assay.

RESULTS

Rates of AEs were similar in vaccinees and controls for solicited (35.7% vs 41.5%) and unsolicited (83.9% vs 92.5%) AEs, respectively. No related grade 3 AEs, serious AEs, or grade 3 laboratory abnormalities occurred. Most (79.0%) vaccinations were administered by a single DVI. Among those in the 9.0 × 105 and 1.8 × 106 PfSPZ groups, 36 of 45 (80.0%) vaccinees and 4 of 21 (19.0%) placebo controls developed antibodies to PfCSP (P < .001).

CONCLUSIONS

PfSPZ vaccine in doses as high as 1.8 × 106 can be administered to infants and children by DVI, and was safe, well tolerated, and immunogenic.

CLINICAL TRIALS REGISTRATION

NCT02687373.

Identified themes of interactive visualizations overlayed onto EHR data: an example of improving birth center operating room efficiency

OBJECTIVE

While electronic health record (EHR) systems store copious amounts of patient data, aggregating those data across patients can be challenging. Visual analytic tools that integrate with EHR systems allow clinicians to gain better insight and understanding into clinical care and management. We report on our experience building Tableau-based visualizations and integrating them into our EHR system.

MATERIALS AND METHODS

Visual analytic tools were created as part of 12 clinician-initiated quality improvement projects. We built the visual analytic tools in Tableau and linked it within our EPIC environment. We identified 5 visual themes that spanned the various projects. To illustrate these themes, we choose 1 exemplary project which aimed to improve obstetric operating room efficiency.

RESULTS

Across our 12 projects, we identified 5 visual themes that are integral to project success: scheduling & optimization (in 11/12 projects); provider assessment (10/12); executive assessment (8/12); patient outcomes (7/12); and control and goal charts (2/12).

DISCUSSION

Many visualizations share common themes. Identification of these themes has allowed our internal team to be more efficient and directed in developing visualizations for future projects.

CONCLUSION

Organizing visual analytics into themes can allow informatics teams to more efficiently provide visual products to clinical collaborators.

Prediction of outcome in fetal autoimmune complete heart block

Assessing cardiac function and risk stratification in a fetal anti-Sjögren syndrome type A (SSA) or anti-Sjögren syndrome type B (SSB) complete atrioventricular block (CAVB) is challenging. We aimed to evaluate the cardiovascular profile score (CVP) and its components in surveillance of fetuses with autoimmune CAVB.

METHODS

Retrospective cohort review of CAVB pregnancies, excluding fetuses with significant cardiac anomalies.

RESULTS

CAVBs are in 17 fetuses, diagnosed at mean gestational age of 23 ± 5 weeks. Overall mortality is 18%: 1 termination, 1 fetal demise (intrauterine fetal demise [IUFD]), and 1 postnatal death. Both mortalities had intrauterine growth restriction; IUFD had placental infarction. Presenting CVP 8.7 ± 1. No fetus had CVP <7; the score correlated with increased risk of perinatal death. The 2 mortalities had initial CVP scores of 8 and 9; both increased to 10 on subsequent exams. 30% of fetuses had low middle cerebral artery pulsatility (MCA-PI) on the last study. All had high umbilical artery pulsatility (UA-PI) throughout gestation. The 2 deaths had the lowest MCA-PI.

CONCLUSION

Despite low heart rates, high CVP scores in our cohort remained high and were not predictive of mortality. Abnormalities in MCA flow reflects fetal cerebral vasodilation that may indicate altered hemodynamics and be predictive of outcomes, but data is limited. Abnormal umbilical artery (UA) flow suggests that perinatal mortality may also be related to placental disease.