The superior QRS axis in ostium primum ASD: a proposed mechanism

Congenital heart disease detection by pediatric electrocardiogram based deep learning integrated with human concepts

Early detection is critical to achieving improved treatment outcomes for child patients with congenital heart diseases (CHDs). Therefore, developing effective CHD detection techniques using low-cost and non-invasive pediatric electrocardiogram are highly desirable. We propose a deep learning approach for CHD detection, CHDdECG, which automatically extracts features from pediatric electrocardiogram and wavelet transformation characteristics, and integrates them with key human-concept features. Developed on 65,869 cases, CHDdECG achieved ROC-AUC of 0.915 and specificity of 0.881 on a real-world test set covering 12,000 cases. Additionally, on two external test sets with 7137 and 8121 cases, the overall ROC-AUC were 0.917 and 0.907 while specificities were 0.937 and 0.907. Notably, CHDdECG surpassed cardiologists in CHD detection performance comparison, and feature importance scores suggested greater influence of automatically extracted electrocardiogram features on CHD detection compared with human-concept features, implying that CHDdECG may grasp some knowledge beyond human cognition. Our study directly impacts CHD detection with pediatric electrocardiogram and demonstrates the potential of pediatric electrocardiogram for broader benefits.

Arrhythmias in adult congenital heart disease

Recent advances in pediatric cardiology and cardiac surgery have allowed a rapidly expanding population of patients with congenital heart disease to thrive well into their adult years. Often after prolonged uneventful clinical courses as children and adolescents, arrhythmias may surface later in life. These arrhythmias are a major source of morbidity. In addition, sudden death is the leading cause of mortality in adult patients with congenital heart disease. This review highlights the various types of brady- and tachyarrhythmias encountered in the more common forms of adult congenital heart disease and explores prognostic implications and therapeutic options.

Electrophysiologic and anatomical relationships studied in primum atrioventricular septal defect

Anatomy and pattern of electrical activation predict the function and contraction pattern of the heart. Patients with primum atrioventricular septal defect (primum AVSD) present with abnormality of both anatomical arrangements and electric activation and serve therefore as an interesting population for studying electro-anatomic relationships in the heart. Understanding the relationships between anatomic and electrophysiologic abnormality is appropriate not only for diagnosis, therapy, and prognosis in patients with primum AVSD but also for understanding the developmental relationship between the conduction system and heart structures, in general. This article presents a review of the anatomical and electrophysiologic characteristics of patients with primum AVSD and provides recent knowledge of electroanatomical relationships of the heart.

A combination of physical examination and ECG detects the majority of hemodynamically significant heart defects in neonates with Down syndrome

Echocardiography has become the method of choice in the diagnosis of a congenital heart defect (CHD) in neonates with Down syndrome. The most compelling argument for diagnosis of CHD in the neonatal period is the need for early surgical intervention (ideally prior to 6 months of age) in those with a complete atrioventricular (AV) canal. We evaluated the efficacy of a combined approach of physical examination (PE) and electrocardiography (ECG) in the detection of CHD in 49 neonates with Down syndrome. Our findings indicate that most hemodynamically significant defects (78%), especially a complete AV canal, can be detected by this approach. Hemodynamically insignificant minor defects, such as a small patent ductus arteriosus (PDA) and a small atrial septal defect (ASD), may be missed. Thus, echocardiography remains the most sensitive way to diagnose CHD. However, given that the combination of PE and ECG detects the majority of complete AV canal defects, it can be used as an alternative approach when echocardiography is not easily accessible, due to geographic or economic constraints. Follow-up after a few weeks of those with normal PE and ECG findings should enable detection of new symptoms and signs and evolving ECG findings that may have been missed in the immediate newborn period. Patients who are judged by PE and ECG to have CHD will need echocardiographic confirmation.

Neonatal ECG screening for congenital heart disease in Down syndrome

We studied the value of routine neonatal electrocardiography (ECG) in the 1st 48 hours of life to diagnose congenital heart disease in 37 neonates with Down syndrome. Twenty-four infants had no clinical evidence of congenital heart disease, had normal ECGs and normal cardiac anatomy on echocardiography. Thirteen children (35.2%) had congenital heart disease. The ECG was normal in seven infants with congenital heart disease: four with atrial septal defect (ASD), two with tetralogy of Fallot (TOF) and one with ventricular septal defect (VSD). A left QRS axis deviation was found in six infants: five with complete atrioventricular septal defect (AVSD) and one with VSD and mitral valve prolapse. However, only the five infants with complete AVSD had a superior QRS axis. Although neonatal ECG detected the presence of complete AVSD in neonates with Down syndrome, it missed an equal number with other heart defects. Echocardiography remains the way reliably to diagnose or exclude congenital heart disease in these infants.

Electrophysiologic cardiac function before and after surgery in children with atrioventricular canal

Thirty-two children with atrioventricular (AV) canal underwent electrophysiologic studies: 18 underwent preoperative studies at a median age of 3 years (range 6 months to 16 years); 14 underwent postoperative studies at a median age of 4 years (range 2 to 19); and 2 underwent both preoperative and postoperative matched studies. In the preoperative group the following abnormalities were observed: first-degree AV block in 5 patients (due to internodal conduction delay in 1, AV nodal conduction delay in 2 and normal intracardiac intervals in 2); internodal conduction delay but normal PR interval in 4; and disease of the sinus node in only 1. In the postoperative group the following abnormalities were observed: first-degree AV block in 9 (due to AV nodal conduction delay in 2, His-Purkinje system conduction delay in 1, upper normal intracardiac intervals in 3 and unidentified in 3); prolongation of the right ventricular apical activation time in 11 of 13 with right bundle branch block; abnormal sinus node function in 3; and abnormal AV nodal function in 4 (1 of whom had associated sinus node disease). Atrial and ventricular functions were normal in all preoperative and postoperative patients. Electrophysiologic dysfunction is rare in preoperative patients with AV canal; in postoperative patients electrophysiologic abnormalities occur in 38% and involve the sinus and AV nodes in 19 and 25%, respectively.

Left axis deviation: a reassessment

This report deals with the ramifications of the concept of left axis deviation. In early life, the leftward shift of the frontal plane QRS axis is determined chiefly, if not solely, by the relative weights of the ventricles. Once adult ventricular weight ratios are reached, there is a long period of axis stability, then a gradual leftward drift of the QRS, governed principally by left anterior fascicular conduction. Thus, the normal QRS axis is age-dependent, and left axis deviation must be considered accordingly.