A 70-year-old man was admitted to the hospital for planned chemotherapy for recently diagnosed CNS lymphoma. His medical history included follicular lymphoma (achieved remission 1 year prior with chemotherapy) and tonic-clonic seizure 1 month prior to admission, which led to his eventual biopsy-confirmed diagnosis of CNS lymphoma. Physical examination revealed temperature 36.4 °C, heart rate of 60 beats/min, BP of 160/81 mm Hg, and 98% oxygen saturation on room air. Neurologic condition, including mental status examination, was normal. His cardiac examination revealed regular rate and rhythm with normal first and second heart sounds without murmurs, rubs, or gallops. The remainder of the examination was unremarkable. Review of systems noted progressive and intermittent confusion prior to his seizure. He denied any shortness of breath, dyspnea on exertion, orthopnea, lower extremity edema, palpitations, or syncope. Laboratory data were unremarkable.

Background

Atrial fibrillation (AF) has been reported to occur with coronavirus disease 2019 (COVID-19), but whether it is related to myocarditis or lung injury is unclear.

Objectives

The purpose of this study was to compare incident AF in patients with pneumonia/adult respiratory distress syndrome (ARDS) with and without COVID.

Methods

This retrospective multicenter cohort study from 17 hospitals (March 2020 to December 2021) utilizing the University of California COVID Research Data Set (CORDS) included patients aged ≥18 years with primary diagnosis of pneumonia or ARDS during hospitalization. Patients with a history of AF were excluded. All subjects had documented COVID test results. Cohorts were compared using the χ² test for categorical variables and the Wilcoxon rank test for continuous variables. Multivariable logistic regression models were used to investigate the association between COVID and development of new AF.

Results

Of the 39,415 subjects, 12.2% had COVID. The COVID+ cohort consisted predominantly of younger males with more comorbidities. Incident AF was lower in the COVID+ group than in the non-COVID group (523 [10.85%] vs 4899 [14.16%]; odds ratio [OR] 0.74; P <.001), which remained significant after adjustment for demographics and comorbidities (OR 0.71; P <.001). Patients had normal cardiac troponin levels. AF was related to intensive care unit care, pressor support, and mechanical ventilation, and was associated with higher mortality (26.2% vs 10.21%; P <.001) and longer hospitalization (22.5 vs 15.1 days; P <.001) in the COVID+ group compared to the controls.

Conclusion

Incident AF is lower in COVID+ compared to non-COVID pneumonia/ARDS patients and seems to be related to severity of illness rather cardiac injury. AF was associated with higher mortality and prolonged hospitalization.

Stereotactic body radiation therapy is a novel treatment option for refractory ventricular tachycardia. We present a case of ventricular tachycardia, with epicardial origin located in large inferior infarct scar, that recurred despite treatment with multiple antiarrhythmic drugs, catheter ablation, and cardiac sympathetic denervation. Stereotactic body radiation therapy safely and effectively terminated the arrhythmia. (Level of Difficulty: Advanced.).

Areas of low voltage electrograms (<0.5 mV) (LVA) are known to correlate with areas of atrial fibrosis and are related to clinical outcomes after ablation. We hypothesized that delay in seeking invasive treatment is linked to larger LVA.

Synapses and receptive fields of the cerebral cortex are plastic. However, changes to specific inputs must be coordinated within neural networks to ensure that excitability and feature selectivity are appropriately configured for perception of the sensory environment. We induced long-lasting enhancements and decrements to excitatory synaptic strength in rat primary auditory cortex by pairing acoustic stimuli with activation of the nucleus basalis neuromodulatory system. Here we report that these synaptic modifications were approximately balanced across individual receptive fields, conserving mean excitation while reducing overall response variability. Decreased response variability should increase detection and recognition of near-threshold or previously imperceptible stimuli. We confirmed both of these hypotheses in behaving animals. Thus, modification of cortical inputs leads to wide-scale synaptic changes, which are related to improved sensory perception and enhanced behavioral performance.