Open Field Exercise Testing in Pediatric Congenital Heart Disease Patients: A Subsumption of Cardiovascular Parameters.

Heart failure is a common phenomenon in congenital heart disease patients. Cardiopulmonary exercise testing is used for a reliable assessment of heart failure but is still challenging, especially for young children. Implementing mobile cardiopulmonary exercise testing (CPET) can close that diagnostic gap. While average values for healthy children have already been published, this study aims to describe typical ranges of cardiovascular performance parameters of young children with congenital heart disease performing an 8-min running cardiopulmonary exercise test. Children aged 4-8 years with common congenital heart defects after corrective surgery (Tetralogy of Fallot; transposition of the great arteries and univentricular hearts after palliation) were included. The outdoor running protocol consisted of slow walking, slow jogging, fast jogging, and maximum speed running. Each exercise was performed for 2 min, except the last, in which children were instructed to keep up maximal speed as long as possible. A total of 78 children (45 male/33 female, mean age 6,24) with congenital heart disease participated in the study, of which 97% completed the CPET successfully. A detailed description of participating patients, including data on cardiac function and subjective fitness levels, is given to help physicians use this method to classify their patients. This study presents a typical range for cardiovascular performance parameters in a population of 4-8-year-old children with congenital heart disease tested in a newly developed outdoor running protocol for CPET.

Accuracy of the Apple Watch Oxygen Saturation Measurement in Adults and Children with Congenital Heart Disease.

As new customer health devices have been spread throughout the consumer market in recent years, it now needs to be evaluated if they also fulfill the requirements of clinical use. The Apple Watch Series 6 provides a new health feature with its oxygen saturation measurement. The aim of this prospective, investigator-initiated, single-arm study was to compare transcutaneous oxygen saturation measurements using the Apple Watch 6 with the conventional method of pulse oximetry in patients with congenital heart disease. Patients of any age presenting at the Leipzig Heart Center, Department for pediatric cardiology, were included. After obtaining informed consent, the routine oxygen saturation measurement with the pulse oximeter was taken and simultaneously three measurements with the Apple Watch. A total of 508 patients were enrolled. Comparing children and adults in terms of measurement success shows a statistically significant difference with a higher proportion of unsuccessful measurements in children, but no difference concerning correct versus incorrect Apple Watch measurements. Noticeable, strapping on the watch properly around the patient's wrists significantly improved the measurements compared to a watch only laid on. The study demonstrated that oxygen saturation measurement with the Apple Watch 6 is not yet up to the medical standard of pulse oximetry, too large a proportion of the measurements remain either unsuccessful or incorrect. While a high proportion of unsuccessful measurements in children can be attributed to movement, the cause in adults usually remains unclear. Further influencing factors on a correct, or successful measurement could not be found.

Accuracy of the Apple Watch iECG in Children With and Without Congenital Heart Disease.

The development of smart technologies paves the way for new diagnostic modalities. The Apple Watch provides an FDA approved iECG function for users from 22 years of age. Yet, there are currently no data on the accuracy of the Apple Watch iECG in children. While arrhythmias are a frequent phenomenon in children, especially those with congenital heart disease, the increasing spread of smart watches provides the possibility to use a smart watch as mobile event recorder in case of suspected arrhythmia. This may help to provide valuable information to the treating physician, without having the patient to come to the hospital. Necessary treatment adjustments might be provided without timely delay. The aim of this study was therefore to evaluate the agreement of measured values of rate, interval, and amplitude with those obtained by a diagnostic quality ECG recording to an Apple Watch iECG in children with and without congenital heart disease. In this prospective, single-arm study, consecutive patients aged 0-16 years presenting to the Heart Center Leipzig, Department for pediatric cardiology were included. After obtaining informed consent from participants' parents, a 12-lead ECG and an iECG using an Apple Watch were performed. Cardiac rhythm was classified, amplitudes and timing intervals were measured and analyzed in iECG and 12-lead ECG for comparability. These measurements were performed blinded to the patients' history by two experienced pediatric cardiologists. Patient demographic data, medical and cardiac history were assessed. 215 children between 0 and 16 years were enrolled. Comparison of amplitudes and timing intervals between ECG and iECG showed excellent correlation (K > 0.7, p < 0.01) in all parameters except for the p-waves. Automatic rhythm classification was inferior to manual interpretation of ECG / iECG, while iECG interpretation was reliable in 94.86% of cases. The study demonstrates equal quality of the Apple Watch derived iECG compared to a lead I in 12-lead ECG in children of all age groups and independent from cardiac anatomy.