Treatment of Atrial Fibrillation and Atrial Flutter: Part II

Machine learning workflow for edge computed arrhythmia detection in exploration class missions

Deep-space missions require preventative care methods based on predictive models for identifying in-space pathologies. Deploying such models requires flexible edge computing, which Open Neural Network Exchange (ONNX) formats enable by optimizing inference directly on wearable edge devices. This work demonstrates an innovative approach to point-of-care machine learning model pipelines by combining this capacity with an advanced self-optimizing training scheme to classify periods of Normal Sinus Rhythm (NSR), Atrial Fibrillation (AFIB), and Atrial Flutter (AFL). 742 h of electrocardiogram (ECG) recordings were pre-processed into 30-second normalized samples where variable mode decomposition purged muscle artifacts and instrumentation noise. Seventeen heart rate variability and morphological ECG features were extracted by convoluting peak detection with Gaussian distributions and delineating QRS complexes using discrete wavelet transforms. The decision tree classifier's features, parameters, and hyperparameters were self-optimized through stratified triple nested cross-validation ranked on F1-scoring against cardiologist labeling. The selected model achieved a macro F1-score of 0.899 with 0.993 for NSR, 0.938 for AFIB, and 0.767 for AFL. The most important features included median P-wave amplitudes, PRR20, and mean heart rates. The ONNX-translated pipeline took 9.2 s/sample. This combination of our self-optimizing scheme and deployment use case of ONNX demonstrated overall accurate operational tachycardia detection.

Hypertension in the elderly

Many elderly patients have hypertension, although it is more likely to go untreated in this population. Treatment goals are the same in elderly patients as in younger patients, but elderly patients are more likely to have multiple comorbidities, which must be factored into treatment plans. This article highlights the unique challenges in treating this population.

Treating hypertension in older adults: safety considerations

This article discusses the efficacy, use and adverse effects of antihypertensive drug therapy in older adults. Numerous double-blind, randomized, placebo-controlled studies have demonstrated that antihypertensive drug therapy reduces cardiovascular events in older adults. All antihypertensive drugs may predispose older patients to the development of symptomatic orthostatic hypotension and postprandial hypotension, and syncope or falls. Adverse effects of diuretics, beta-adrenergic receptor antagonists, ACE inhibitors, angiotensin receptor antagonists, calcium channel antagonists, alpha-adrenergic receptor antagonists, centrally acting drugs and direct vasodilators are discussed. The adverse effects depend on the antihypertensive drugs used, the doses used, the co-morbidities present in older patients taking these drugs and drug-drug interactions.