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Atrial fibrillation (AFib) is the most common tachyarrhythmia of the heart in adults and is associated with an increased risk for stroke and heart failure. It can be described as irregularly irregular, foci in the atrium that set up chaotic atrial circuits and irregular rapid contraction of the atrium with loss of consistent atrio-ventricular synchrony due to decremental conduction at the atrio-ventricular node. The challenge was to identify predictive features of ECG signals with variable time and spatial components. These features were extracted from 8528 single lead ECG recordings and then input to a gradient boosting classifier. The trained model could classify AFib with an F1 score of 0.83. Present in the dataset were three other rhythm classes; Normal Sinus Rhythm, Other, and Noisy. The F1 scores achieved for these classes were 0.91, 0.77, and 0.66 respectively.

ObjectivesWe sought to identify risk factors for mortality and morbidity during the Norwood hospitalization in newborn infants with hypoplastic left heart syndrome and other single right ventricle anomalies enrolled in the Single Ventricle Reconstruction trial.MethodsPotential predictors for outcome included patient- and procedure-related variables and center volume and surgeon volume. Outcome variables occurring during the Norwood procedure and before hospital discharge or stage II procedure included mortality, end-organ complications, length of ventilation, and hospital length of stay. Univariate and multivariable Cox regression analyses were performed with bootstrapping to estimate reliability for mortality.ResultsAnalysis included 549 subjects prospectively enrolled from 15 centers; 30-day and hospital mortality were 11.5% (63/549) and 16.0% (88/549), respectively. Independent risk factors for both 30-day and hospital mortality included lower birth weight, genetic abnormality, extracorporeal membrane oxygenation (ECMO) and open sternum on the day of the Norwood procedure. In addition, longer duration of deep hypothermic circulatory arrest was a risk factor for 30-day mortality. Shunt type at the end of the Norwood procedure was not a significant risk factor for 30-day or hospital mortality. Independent risk factors for postoperative renal failure (n=46), sepsis (n=93), increased length of ventilation, and hospital length of stay among survivors included genetic abnormality, lower center/surgeon volume, open sternum, and post-Norwood operations.ConclusionsInnate patient factors, ECMO, open sternum, and lower center/surgeon volume are important risk factors for postoperative mortality and/or morbidity during the Norwood hospitalization.