Validity of electrocardiographic criteria for left ventricular hypertrophy in children with pressure- or volume-loaded ventricles: comparison with echocardiographic left ventricular muscle mass

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.

Precordial ECG Amplitudes in the Days After Birth: Electrocardiographic Changes During Transition from Fetal to Neonatal Circulation

During the first month of life, the relation between right and left ventricular function is markedly altered. We aimed at describing the electrocardiographic transition from fetal to neonatal circulation by investigating changes in R- and S-wave amplitudes in V1 and V6 during the first 4 weeks of life. This study is part of the prospective, population-based Copenhagen Baby Heart Study offering cardiac evaluation to newborns within 28 days from birth. ECGs were obtained and analyzed using a computerized algorithm. A total of 14,577 newborns (52% boys), median age of 11.0 days, were included. All had normal echocardiograms. Within 28 days from birth, the amplitudes in V1 decreased: R-V1 (1262 µV day0; 947 µV day28, p < 0.001) and S-V1 (1240 µV day0; 473 µV day28, p < 0.001). An increase was observed for R-V6 (825 µV day0; 1196 µV day28, p = 0.002), while S-V6 decreased (830 µV day0; 634 µV day28, p = 0.003). For all amplitudes, interindividual variation was large (up to 20 times). The amplitudes were not affected by sex (p > 0.05), but R-V1, R-V6, and S-V6 positively correlated with newborn weight (p < 0.01). R-V1 and S-V6 showed positive correlation with gestational age (p < 0.05). In conclusion, systematic analyses of ECGs from healthy newborns showed significant decreases in R-V1, S-V1, and S-V6 amplitudes, while R-V6 increased. Interindividual variation was large, making ECGs unlikely as a sensitive tool for diagnosing congenital heart diseases. Our data may serve as updated, digitalized reference values in newborns.

Variability of Myocardial Repolarization in Pediatric Patients with a Ventricular Septal Defect

In patients with a ventricular septal defect, left-to-right shunting increases the left ventricular preload. This pathological change affects myocardial depolarization and repolarization and has the potential to evoke arrhythmogenic substrates. We examined the effect of ventricular septal defects on myocardial repolarization by investigating the variability in the repolarization interval. This retrospective study included 19 patients (mean age, 1.8 ± 2.1 years) who underwent surgical closure (mean left-to-right shunt ratio, 2.60 ± 0.55) and 26 age-matched healthy controls from 2008 to 2015. Using preoperative electrocardiograms, we studied two electrocardiographic parameters (heart rate-corrected repolarization and variability of repolarization) and four repolarization intervals (QT, JT, J point to T peak [JTp], and T peak to T end [Tp-e] intervals). The variability index (VI) was calculated from the logarithm of the ratio of the repolarization parameter variance to heart rate variance. The various measures were compared between the patients and controls, and significant differences were found in the corrected QT, JTp, and Tp-e intervals (p < 0.05). The VI of the four intervals also showed significant differences (patients vs.

CONTROLS

QTVI, -0.55 ± 0.61 vs. -1.10 ± 0.53; JTVI, -0.33 ± 0.60 vs. -0.86 ± 0.57; JTpVI, -0.15 ± 0.78 vs. -0.73 ± 0.56; Tp-eVI, 0.75 ± 0.70 vs. 0.11 ± 0.73, respectively; p < 0.05). No correlation was found between the QTVI and corrected QT interval using linear regression analysis. These repolarization characteristics provide not only electrophysiological indices but also a new index with which to assess the pathophysiology of congenital heart disease.

ECG is an inefficient screening-tool for left ventricular hypertrophy in normotensive African children population

Background

Left ventricular hypertrophy (LVH) is a marker of pediatric hypertension and predicts development of cardiovascular events. Electrocardiography (ECG) screening is used in pediatrics to detect LVH thanks to major accessibility, reproducibility and easy to use compared to transthoracic echocardiography (TTE), that remains the standard technique. Several diseases were previously investigated, but no data exists regarding our study population. The aim of our study was to evaluate the relationship between electrocardiographic and echocardiographic criteria of LVH in normotensive African children.

Methods

We studied 313 children (mean age 7,8 ± 3 yo), in north-Madagascar. They underwent ECG and TTE. Sokolow-Lyon index was calculated to identify ECG-LVH (>35 mm). Left ventricle mass (LVM) with TTE was calculated and indexed by height^2.7 (LVMI^2.7) and weight (LVMI^w). We report the prevalence of TTE-LVH using three methods: (1) calculating percentiles age- and sex- specific with values >95th percentile identifying LVH; (2) LVMI^2.7 >51 g/m^2.7; (3) LVMI^w >3.4 g/weight.

Results

40 (13%) children showed LVMI values >95th percentile, 24 children (8%) an LVMI^2.7 >51 g/m^2.7 while 19 children (6%) an LVMI^w >3.4 g/kg. LVH-ECG by Sokolow-Lyon index was present in five, three and three children respectively, with poor values of sensitivity (ranging from 13 to 16%), positive predictive value (from 11 to 18%) and high values of specificity (up to 92%). The effects of anthropometrics parameters on Sokolow-Lyon were analyzed and showed poor correlation.

Conclusion

ECG is a poor screening test for detecting LVH in children. In clinical practice, TTE remains the only tool to be used to exclude LVH.

Novel electrocardiographic screening criterion for hypertrophic cardiomyopathy in children

Electrocardiography is often advocated as a screening tool in children for hypertrophic cardiomyopathy (HC). We sought to establish an electrocardiographic screening tool to identify children with HC. We hypothesized that a pediatric-specific electrocardiographic criterion would perform better than the popular criteria used for screening children for left ventricular hypertrophy and HC. The earliest available electrocardiogram for children (n=108) with HC (ages 7 to 21 yrs) was reviewed. We sought to compare the diagnostic accuracy of 4 screening algorithms: (1) Sokolow-Lyon criterion (SV1+RV5/RV6>35 mm), (2) Cornell criterion (RaVL+SV3>28 mm in men, 20 mm in women), (3) total 12-lead voltage criterion (R wave to the nadir of Q/S wave>175 mm), and (4) pediatric-specific criterion (RaVL+SV2>23 mm). The same criteria were applied to a cohort of age-matched and gender-matched controls without cardiac disease. Statistically significant correlations were found between children with HC and positive screen using all 4 criteria. However, comparison of receiver operating characteristic demonstrated an area under the curve of 0.67 for Sokolow-Lyon criterion, 0.70 for Cornell criterion, 0.83 for total 12-lead criterion, and 0.82 for pediatric-specific criterion. Pediatric-specific criterion had superior sensitivity in gene-positive children and superior overall specificity than total 12-lead criterion. In conclusion, our study demonstrates that the pediatric-specific criterion employing leads RaVL+SV2 is more accurate in identifying children with HC in comparison with other popular screening criteria.

Electrocardiographic predictors of left ventricular hypertrophy in pediatric hypertension

OBJECTIVE

To determine the efficacy of electrocardiography (ECG) in detecting left ventricular hypertrophy (LVH) in pediatric hypertension (HT).

STUDY DESIGN

Concomitant echocardiograms and electrocardiograms in 108 children with HT were reviewed. Left ventricular mass (LVM), assessed by echocardiography, was used as a basis for a diagnosis of LVH (echo LVH) using accepted pediatric criteria. Using Wilcoxon's rank-sum test, 14 ECG variables were compared between subjects with and without echo LVH. Spearman correlations were used to examine the linear association between echo LVH and these ECG variables. The sensitivity and specificity of ECG in diagnosing LVH were computed.

RESULTS

Of the 108 subjects studied, 35 (32%) met the pediatric criteria for LVH; of these, 8 (7.4%) also met the adult criteria (>51 g/m(2.7)) for LVH. Mean values for only 5 ECG criteria differed significantly among the groups: RI, SaVR, RaVL, RI+SIII, and SVI+RV6 (P < .05). Significant correlations were found for several ECG criteria and at least 1 measure of LVM, but the magnitudes were modest. Standard ECG criteria predicted LVH with high specificity (>90%) but low sensitivity (<35%). RI >10 mm was identified as demonstrating a modestly improved positive likelihood ratio of approximately 3.

CONCLUSIONS

ECG is not an adequate predictor of LVH for clinical use in HT.

Electrocardiographic criteria for left ventricular hypertrophy in children

Previous studies to determine the sensitivity of the electrocardiogram (ECG) for left ventricular hypertrophy (LVH) in children had their imperfections: they were not done on an unselected hospital population, several criteria used in adults were not applied to children, and obsolete limits of normal for the ECG parameters were used. Furthermore, left ventricular mass (LVM) was taken as the reference standard for LVH, with no regard for other clinical evidence. The study population consisted of 832 children from whom a 12-lead ECG and an M-mode echocardiogram were taken on the same day. The validity of the ECG criteria was judged on the basis of an abnormal LVM index, either alone or in combination with other clinical evidence. The ECG criteria were based on recently established age-dependent normal limits. At 95% specificity, the ECG criteria have low sensitivities (<25%) when an elevated LVM index is taken as the reference for LVH. When clinical evidence is also taken into account, the sensitivity improved considerably (<43%). Sensitivities could be further improved when ECG parameters were combined. The sensitivity of the pediatric ECG in detecting LVH is low but depends strongly on the definition of the reference used for validation.

Usefulness of the pediatric electrocardiogram in detecting left ventricular hypertrophy: results from the Prospective Pediatric Pulmonary and Cardiovascular Complications of Vertically Transmitted HIV Infection (P2C2 HIV) multicenter study

BACKGROUND

A shortcoming of the pediatric electrocardiogram (ECG) appears to be its inability to accurately detect left ventricular hypertrophy (LVH). This study prospectively assesses the usefulness of the pediatric ECG as a screening modality for LVH.

METHODS

Concomitant echocardiograms and ECGs from a large cohort of children who were exposed to the human immunodeficiency virus (HIV; uninfected) and children who were infected with HIV were compared. By use of the values of Davignon et al, qualitative determination of LVH and quantitative criteria for LVH (RV6, SV1, RV6+SV1, QV6, and Q(III) >98% for age, R/SV1 <98% for age, and [-]TV6) were compared to body surface area adjusted for left ventricular (LV) mass z score. Results were then stratified according to weight and weight-for-height z scores. New age-adjusted predicted values were then constructed from children of a mixed race who were HIV-uninfected, < or =6 years old, and similarly assessed.

RESULTS

The sensitivity rate was <20% for detecting increased LV mass, irrespective of HIV status; the specificity rate was 88% to 92%. The sensitivity rate of the individual criteria ranged from 0 to 35%; the specificity rate was 76% to 99%. Test sensitivities remained low when stratified by weight and weight-for-height z scores. Areas under the receiver operator characteristic curves were between 0.59 and 0.70, also suggesting poor accuracy of the ECG criteria. By use of new age-adjusted predicted values, the sensitivity rate decreased to <17%, and the specificity rate increased to 94% to 100%.

CONCLUSION

The ECG is a poor screening tool for identifying LVH in children. Sensitivity is not improved with revision of current criteria.

Clinical and basic laboratory assessment of children for possible congenital heart disease

Accurate and cost-effective detection of congenital heart disease is a priority for the primary care physician, but there are many diagnostic modalities and strategies available. Within the past year, investigators have reported factors that contribute to the failure to diagnose congenital heart disease before autopsy. Recent research also highlights the strengths and weaknesses of the clinical evaluation by the primary care physician. An examination by a pediatric cardiologist is a more specific discriminator between heart disease and innocent murmur and can, in many instances, eliminate the expense of relying on echocardiography for diagnosis. Current reports document substantial limitations of diagnostic utility of electrocardiography and chest roentgenography. Suspicions that echocardiography can be misleading when performed in laboratories without expertise in congenital heart disease are confirmed in recent organized comparisons of accuracy. High-quality, well-designed tele-echocardiography programs are shown to be effective solutions when maldistribution of pediatric cardiology services hampers diagnostic efficiency.