Electrocardiographic Characteristics in 438 Neonates with Atrial Septal Defects.

Arrhythmias and electrocardiographic (ECG) abnormalities are common among patients with atrial septal defects (ASDs). We studied a large cohort of neonates with ASDs to investigate whether ECG abnormalities are present at this early stage or develop later, secondary to hemodynamic changes. We analyzed the echocardiograms and ECGs from the Copenhagen Baby Heart Study, a population-based cohort study. We compared ECG characteristics of 438 neonates with secundum ASDs to 1314 matched controls. In subgroup analyses, we investigated whether electrocardiographic characteristics were associated with age at examination. Neonates with ASDs (median age, 11 days; males, 51%) had longer P-wave durations (58 vs. 56 ms, p < 0.001), PR intervals (100 vs. 96 ms, p < 0.001), and a more rightward-shifted QRS axis (116 vs. 114 degrees, p = 0.032) compared to controls (median age, 10 days; males, 51%). There were no differences between cases and controls in the P-wave area, amplitude, or axis. Subgroup analyses showed that the differences in P-wave duration and PR interval were present in neonates examined in the first week after birth. The difference in the QRS axis was not found in neonates examined this early but was found in neonates examined at age two to four weeks. In conclusion, ASDs are associated with ECG changes from the neonatal phase. The P-wave duration and PR interval are longer in neonates with ASDs when compared to controls as early as the first week after birth, indicating that these changes are not purely secondary, but that neonates with an ASD have altered cardiac electrical activity.ClinicalTrials.gov Identifier NCT02753348 (April 27, 2016).

The Wolff-Parkinson-White pattern in neonates: results from a large population-based cohort study.

AIMS: Wolff-Parkinson-White (WPW) syndrome is a conduction disorder characterized by an accessory electrical pathway between the atria and ventricles, which may predispose to supraventricular tachycardia (SVT) and sudden cardiac death. It can be seen as an isolated finding or associated with structural heart disease. Our aims were to determine the prevalence of a WPW pattern in a large and unselected cohort of neonates and to describe the electro- and echocardiographic characteristics as well as the natural history during early childhood. METHODS AND RESULTS: Electrocardiograms and echocardiograms of neonates (aged 0-30 days) from a large, prospective, population-based cohort study were included. Neonates with a WPW pattern were identified and matched 1:4 to controls. Localization of the accessory pathway was assessed by different algorithms. Among 17 489 neonates, we identified 17 (76% boys) with a WPW pattern consistent with a prevalence of 0.1%. One neonate had moderate mitral regurgitation while other echocardiographic parameters were similar between cases and controls (all P > 0.05). The accessory pathways were primarily predicted to be left-sided. At follow-up (available in 14/17 children; mean age 3.2 years) the pre-excitation pattern persisted in only four of the children and none of the children had experienced any episodes of SVT. CONCLUSION: The prevalence of a WPW pattern in our cohort of unselected neonates was 0.1%. The WPW pattern was more frequent in boys and generally not associated with structural heart disease, and the accessory pathways were primarily left-sided. At follow-up, the WPW pattern had disappeared in most of the children suggesting either an intermittent nature or that normalization occurs. CLINICAL TRIAL REGISTRATION: Copenhagen Baby Heart, NCT02753348.

Atrial Septal Defect: Larger Right Ventricular Dimensions and Atrial Volumes as Early as in the First Month After Birth-a Case-Control Study Including 716 Neonates.

Atrial septal defect (ASD) is characterized by a left-to-right shunt causing dilatation of the right atrium and right ventricle as well as pulmonary hyperperfusion. The detection of ASDs often occurs late in childhood or adulthood. Little is known about cardiac structure and function in neonates with ASD.We analyzed neonatal echocardiograms from the Copenhagen Baby Heart Study, a multicenter, population-based cohort study of 27,595 neonates. We included 716 neonates with secundum-type ASDs and matched them 1:1 on sex and age at examination with neonates without ASD from the same birth cohort. Neonates with an ASD (median age 11 days, 52% female) had larger right ventricular (RV) dimensions than matched controls (RV longitudinal dimension end-diastole: 27.7 mm vs. 26.7 mm, p < 0.001; RV basal dimension end-diastole: 14.9 mm vs. 13.8 mm, p < 0.001; and RV outflow tract diameter 13.6 mm vs. 12.4 mm, p < 0.001). Atrial volumes were larger in neonates with ASD compared to controls (right atrial end-systolic volume: 2.9 ml vs. 2.1 ml, p < 0.001; and left atrial end-systolic volume 2.0 ml vs. 1.8 ml, p < 0.001). Tricuspid annular plane systolic excursion was larger in neonates with ASD than in controls (10.2 mm vs. 9.6 mm, p < 0.001). Left ventricular dimensions and function did not differ between neonates with ASD and controls. In conclusion, ASDs were associated with altered cardiac dimensions already in the neonatal period, with larger right ventricular dimensions and larger atrial volumes at echocardiography within the first 30 days after birth.ClinicalTrials.gov Identifier: NCT02753348 (April 27, 2016).

Cardiac findings in newborn twins.

AIMS: To evaluate cardiac findings in newborn twins from the general population and investigate if newborn twins may require systematic evaluation of cardiac parameters. METHODS: Prospective cohort study of newborns with cardiac evaluation performed during the first month of life. Cardiac findings were compared 1:3 with matched singletons. RESULTS: We included 412 newborn twins (16% monochorionic; 50% boys) and 1236 singletons. Comparing cardiac findings showed twins had an increased prevalence of non-severe structural heart disease (most common: ventricular septal defects in both groups), thinner left ventricular posterior wall in diastole (LVPWd; 1.82 vs. 1.87 mm, p = 0.02), smaller diameter of the left atrium (10.6 vs. 11.1 mm, p = 0.04), higher heart rate (148 vs. 144 bpm, p = 0.04), more left-shifted QRS axis (106 vs. 111°, p < 0.001), and lower maximum R-wave amplitude in V1 (927 vs. 1015 µV, p = 0.02) compared to singletons. After multifactorial adjustment for potential confounders, the effect of twinning on cardiac parameters persisted only for LVPWd (p < 0.05). CONCLUSION: Despite contemporary surveillance, we found an increased prevalence of non-severe structural heart disease in a population-based cohort of newborn twins. However, the effect of twinning on cardiac parameters was modest and generally did not persist after correction for likely confounding factors.

A novel algorithm for classification of interatrial communications within the oval fossa in the newborn.

BACKGROUND: An interatrial communication is present in most neonates. The majority are considered the "normal" patency of the oval foramen, while a minority are abnormal atrial septal defects. Differentiation between the two with transthoracic echocardiography may be challenging, and no generally accepted method of classification is presently available. We aimed to develop and determine the reliability of a new classification of interatrial communications in newborns. METHODS AND RESULTS: An algorithm was developed based on echocardiographic criteria from 495 newborns (median age 11[8;13] days, 51.5% females). The algorithm defines three main categories: patency of the oval foramen, atrial septal defect, and no interatrial communication as well as several subtypes. We found an interatrial communication in 414 (83.6%) newborns. Of these, 386 (93.2%) were categorised as patency of the oval foramen and 28 (6.8%) as atrial septal defects.Echocardiograms from another 50 newborns (median age 11[8;13] days, 36.0% female), reviewed by eight experts in paediatric echocardiography, were used to assess the inter- and intraobserver variation of classification of interatrial communications into patency of the oval foramen and atrial septal defect, with and without the use of the algorithm. Review with the algorithm gave a substantial interobserver agreement (kappa = 0.66), and an almost perfect intraobserver agreement (kappa = 0.82). Without the use of the algorithm, the interobserver agreement between experienced paediatric cardiologists was low (kappa = 0.20). CONCLUSION: A new algorithm for echocardiographic classification of interatrial communications in newborns produced almost perfect intraobserver and substantial interobserver agreement. The algorithm may prove useful in both research and clinical practice.

Repeatability and Reproducibility of Neonatal Echocardiography: The Copenhagen Baby Heart Study.

BACKGROUND: The Copenhagen Baby Heart Study (CBHS) is a population-based cohort study of neonates (N = 25,000), including echocardiography. Echocardiography in neonates is mainly focused on congenital heart disease (CHD), whereas general aspects of cardiac dimensions and function in neonates without CHD remain to be further addressed. PURPOSE: This study was conducted to assess the reliability of neonatal echocardiography and validity of echocardiographic methods used in the CBHS. METHODS: Reliability and agreement were tested for two-dimensional (2D), M-mode, spectral Doppler, and tissue velocity echocardiography for the following. (1) Measurements: seven sonographers independently performed two measurement rounds: (a) measurement of the same 50 echocardiograms (n = 350 echocardiograms measured) and (b) repeated measurement of 25 of the 50 echocardiograms (n = 175 echocardiograms measured). (2) Acquisition: four sonographers independently performed two rounds of echocardiographic acquisition and subsequent measurement of the same 22 neonates (n = 176 acquisitions and measures). Intra- and interobserver variabilities were assessed by determinations of coefficient of variation (CV), intraclass correlation coefficient (ICC), Bland-Altman plot, and 95% limits of agreement. RESULTS: (1) Measurements: we found intra- and interobserver ICC ≥ 0.67 for 2D parameters, except for left ventricular (LV) wall thicknesses and LV diameter (interobserver); ICC ≥ 0.84 for tricuspid annular plane systolic excursion (TAPSE); ICC ≥ 0.93 for pulsed-wave Doppler (PW); ICC ≥ 0.84 for continuous-wave Doppler; and ICC ≥ 0.87 for tissue velocity parameters. We found CV < 15% for all parameters except LV wall thicknesses. (2) Acquisition: we found intra- and interobserver ICC ≥ 0.69 for 2D parameters, except for LV wall thicknesses, aortic valve annulus (interobserver), and LV end-systolic diameter (interobserver); ICC = 0.45-0.49 for TAPSE; ICC = 0.48-0.64 for PW; and ICC ≥ 0.70 for continuous wave. We found CV < 15% for all parameters. CONCLUSIONS: Reliability of echocardiographic measurements and acquisition of cardiac dimensions and function were good for most parameters but lower for TAPSE (acquisition) and PW Doppler (acquisition) and poor for LV wall thicknesses. In general, echocardiography of cardiac dimensions and function in the neonate is reliable.