A tale of two cities: A retrospective observational cohort study of the impact of COVID-19 on acute stroke presentation, timing, and outcomes.

Objectives: The purpose of this study was to identify the impact of COVID-19-related "shelter in place" restrictions on stroke metrics in two metropolitan Texas cities, Austin and San Antonio.

Materials And Methods: Data was derived from stroke quality metric registries and compared between two treatment periods: (1) during the state's COVID-19 "shelter in place" restriction period, and (2) the corresponding period during the previous year for Austin and San Antonio, Texas. Primary outcomes include the dichotomized process measures of time last known well (TLKW) to arrival, arrival to brain imaging initiation, and arrival to administration of thrombolytic therapy.

Decrease in Stroke Diagnoses During the COVID-19 Pandemic: Where Did All Our Stroke Patients Go?

Despite the evidence suggesting a high rate of cerebrovascular complications in patients with SARS-CoV-2, reports have indicated decreasing rates of new ischemic stroke diagnoses during the COVID-19 pandemic. The observed decrease in emergency department (ED) visits is unsurprising during this major crisis, as patients are likely to prioritize avoiding exposure to SARS-CoV-2 over addressing what they may perceive as mild symptoms of headache, lethargy, difficulty speaking, and numbness. In the central and south Texas regions where we practice, we suspect that patient admission, treatment, and discharge volumes for acute stroke treatment have decreased significantly since COVID-19-related shelter-at-home orders were issued.

Importance of atrial surface area and refractory period in sustaining atrial fibrillation: testing the critical mass hypothesis.

Objective: The critical mass hypothesis for atrial fibrillation (AF) was proposed in 1914; however, there have been few studies defining the relationship between atrial surface area and AF. This study evaluated the effect of tissue area and effective refractory period (ERP) on the probability of sustaining AF in an in vivo model.

Methods: Domestic pigs (n = 9) underwent median sternotomy.

Chronic performance of a novel radiofrequency ablation device on the beating heart: Limitations of conduction delay to assess transmurality.

Objective: The creation of consistently transmural lesions with epicardial ablation on the beating heart has represented a significant challenge for current technology. This study examined the chronic performance of the AtriCure Coolrail device (AtriCure Inc, West Chester, Ohio), an internally cooled, bipolar radiofrequency ablation device designed for off-pump epicardial ablation. The study also examined the reliability of using acute intraoperative conduction delay to evaluate lesion integrity.