Atrial fibrillation (AF) is the most persistent arrhythmia today, with its prevalence increasing exponentially with the rising age of the population. Particularly at elevated heart rates, a functional abnormality known as cardiac alternans can occur prior to the onset of lethal arrhythmias. Cardiac alternans are a beat-to-beat oscillation of electrical activity and the force of cardiac muscle contraction. Extensive evidence has demonstrated that microvolt T-wave alternans can predict ventricular fibrillation vulnerability and the risk of sudden cardiac death. The majority of our knowledge of the mechanisms of alternans stems from studies of ventricular electrophysiology, although recent studies offer promising evidence of the potential of atrial alternans in predicting the risk of AF. Exciting preclinical and clinical studies have demonstrated a link between atrial alternans and the onset of atrial tachyarrhythmias. Here, we provide a comprehensive review of the clinical utility of atrial alternans in identifying the risk and guiding treatment of AF.

The measurement of physiologic pressure helps diagnose and prevent associated health complications. From typical conventional methods to more complicated modalities, such as the estimation of intracranial pressures, numerous invasive and noninvasive tools that provide us with insight into daily physiology and aid in understanding pathology are within our grasp. Currently, our standards for estimating vital pressures, including continuous BP measurements, pulmonary capillary wedge pressures, and hepatic portal gradients, involve the use of invasive modalities. As an emerging field in medical technology, artificial intelligence (AI) has been incorporated into analyzing and predicting patterns of physiologic pressures. AI has been used to construct models that have clinical applicability both in hospital settings and at-home settings for ease of use for patients. Studies applying AI to each of these compartmental pressures were searched and shortlisted for thorough assessment and review. There are several AI-based innovations in noninvasive blood pressure estimation based on imaging, auscultation, oscillometry and wearable technology employing biosignals. The purpose of this review is to provide an in-depth assessment of the involved physiologies, prevailing methodologies and emerging technologies incorporating AI in clinical practice for each type of compartmental pressure measurement. We also bring to the forefront AI-based noninvasive estimation techniques for physiologic pressure based on microwave systems that have promising potential for clinical practice.

Figure 1. A) Kaplan Meier curve showing 30 days readmission of hospitalized rural vs urban gastroparesis population. B) Trends of 30-day readmission of gastroparesis hospitalized patient from 2010 to 2017.Table 1. Baseline characteristics of gastroparesis indexed admissions from 2010-2017 Variables n5number of patients Total gastroparesis patients (n52,384,095) Rural population (n 5330,292) Urban population (n52,053,840) P-value Age 53.0 6 16.7 53.5 6 16.5 52.9 6 16.7 , 0.001

Introduction: Peptic ulcer bleeding (PUB), a life-threatening complication of peptic ulcer disease, has been regarded as a leading cause of upper gastrointestinal bleeding globally. Studies have reported higher rates of PUB in patients with end-stage renal disease (ESRD) secondary to a cluster of complex pathophysiological mechanisms. In this study, we aimed to assess the influence of ESRD on PUB hospitalizations in the United States (US). Methods: We utilized the National Inpatient Sample to identify all adult hospitalizations of PUB in the US between 2007-2014. The study population was subdivided based on the presence or absence of ESRD. Hospitalization characteristics and outcomes were compared. Predictors of inpatient mortality were also identified. P-values #0.05 were statistically significant. Results: Between 2007-2014, there were 351,965 and 2,037,037 PUB hospitalizations with and without ESRD, respectively, in the US (Table ). PUB hospitalizations with ESRD had a higher mean age (71.6 vs 63.6 years, P, 0.001), and proportion of males (55.5 vs 44.2%, P, 0.001) compared to non-ESRD PUB hospitalizations. Additionally, PUB hospitalization with ESRD had a higher proportion of ethnic minorities such as Blacks (20.2 vs 12.4%, P, 0.001), Hispanics (9.2 vs 8.5%, P, 0.001), and Asians (4.5 vs 3.3%, P, 0.001) compared to the non-ESRD PUB cohort. However, non-ESRD PUB hospitalizations had a higher proportion of Whites (72.2 vs 63.2%, P, 0.001) compared to the ESRD cohort. Interestingly, rates of Helicobacter pylori infection were lower (3.8 vs 5.7%, P, 0.001) for PUB hospitalization with ESRD compared to the non-ESRD PUB cohort. Furthermore, we noted higher inpatient mortality (5.4% vs 2.6%, P, 0.001), mean length of stay [LOS] (8.2 vs 6 days, P, 0.001), and rates of esophagogastroduodenoscopy (EGD) (20.9 vs 19.1%, P, 0.001) for PUB hospitalizations with ESRD compared to the non-ESRD PUB cohort. After multivariate logistic regression analysis, whites with ESRD had higher odds of inpatient mortality from PUB compared to other races. To our surprise, the odds of inpatient mortality from PUB decreased by 0.6% for every one-year increase in age for patients with ESRD. Compared to the 2011-2014 study period, the 2007-2010 period had 43.7% higher odds of inpatient mortality for PUB hospitalizations with ESRD. Conclusion: Despite accounting for only 1.7% of all PUB hospitalizations in the US, PUB hospitalizations with ESRD had higher inpatient mortality, mean LOS, and EGD utilization compared to the non-ESRD PUB cohort.