Fluoxetine Can Cause Epileptogenesis and Aberrant Neurogenesis in Male Wild Type Mice.

Antidepressants in general, and fluoxetine in particular, increase adult hippocampal neurogenesis (AHN) in mice. Here we asked how the antidepressant fluoxetine affects behavior and AHN in a corticosterone model of depression. In three groups of adult male C57BL/6j mice we administered either vehicle (VEH), corticosterone (CORT) treatment to induce a depression-like state or corticosterone plus a standard dose of fluoxetine (CORT+FLX). Following treatment, mice performed the open field test, the novelty suppressed feeding (NSF) test and the splash test. Neurogenesis was assessed by means of immunohistochemistry using BrdU and neuronal maturation markers. Unexpectedly, 42% of the CORT+FLX-treated mice exhibited severe weight loss, seizures and sudden death. As expected, the CORT treated group had altered behaviors compared to the VEH group, but the CORT+FLX mice that survived did not show any behavioral improvement compared to the CORT group. Antidepressants generally increase neurogenesis and here we also found that compared to CORT mice, CORT+FLX mice that survived had a significantly greater density of BrdU+, BrdU+DCX+ and BrdU+NeuN+ cells, suggesting increased neurogenesis. Moreover, the density of BrdU+NeuN+ cells was increased in an aberrant location, the hilus, of CORT+FLX mice, similar to previous studies describing aberrant neurogenesis following seizures. In conclusion, fluoxetine could induce considerable adverse effects in wild type mice, including seizure-like activity. Fluoxetine-induced neurogenesis increases could be related to this activity, therefore proneurogenic effects of fluoxetine and other antidepressants, especially in the absence of any behavioral therapeutic effects, should be interpreted with caution.

Adult-born dentate granule cells promote hippocampal population sparsity.

The dentate gyrus (DG) gates neocortical information flow to the hippocampus. Intriguingly, the DG also produces adult-born dentate granule cells (abDGCs) throughout the lifespan, but their contribution to downstream firing dynamics remains unclear. Here, we show that abDGCs promote sparser hippocampal population spiking during mnemonic processing of novel stimuli. By combining triple-(DG-CA3-CA1) ensemble recordings and optogenetic interventions in behaving mice, we show that abDGCs constitute a subset of high-firing-rate neurons with enhanced activity responses to novelty and strong modulation by theta oscillations. Selectively activating abDGCs in their 4-7-week post-birth period increases sparsity of hippocampal population patterns, whereas suppressing abDGCs reduces this sparsity, increases principal cell firing rates and impairs novel object recognition with reduced dimensionality of the network firing structure, without affecting single-neuron spatial representations. We propose that adult-born granule cells transiently support sparser hippocampal population activity structure for higher-dimensional responses relevant to effective mnemonic information processing.

Use of Ambulatory Patch Monitoring Devices to Supplement Inpatient Telemetry-A Descriptive Study of a Single-center Experience During the Coronavirus Disease 2019 Pandemic.

To accommodate the surge in patients with coronavirus disease 2019 during the spring of 2020, outpatient areas in our health system were repurposed as inpatient units. These spaces often lacked the same resources as the standard inpatient unit, including telemetry equipment. We utilized mobile cardiac outpatient telemetry (MCOT) in place of traditional telemetry and suggest that MCOT is an appropriate substitution only for patients at low risk of developing arrhythmia given the prolonged time to notification of the care team regarding events and imprecise measurements of the corrected QT interval when compared to 12-lead electrocardiography.

An Approach to Standard Perioperative Transthoracic Echocardiography Practice for Anesthesiologists-Perioperative Transthoracic Echocardiography Protocols.

The use of intraoperative transesophageal echocardiography (TEE) has become the standard of care for most cardiac surgical procedures. There are guidelines established for training, practice, and quality improvement in perioperative TEE by the joint efforts of the American Society of Echocardiography and Society of Cardiovascular Anesthesiologists. Cardiac point-of-care ultrasound (POCUS) increasingly is being incorporated into anesthesiologists' training and practice. While a special "certification in Critical Care Echocardiography" was created by the National Board of Echocardiography in 2019, there currently exist no guidelines for training, certification, and practice of perioperative TTE by anesthesiologists. In this review, the authors describe the categories, indications and applications of perioperative TTE and provide a recommended sequence for performing an examination tailored to the evaluation of perioperative patients. Although the authors describe a protocol utilized at their institution, there are no standards described in the literature for PTTE. Cardiac anesthesiologists and cardiac anesthesia societies (Society of Cardiovascular Anesthesiologists, European Association of Cardiothoracic Anesthesiologists) must come forward to establish standards working in collaboration with echocardiography societies (American Society of Echocardiography, European Society of Cardiology).

Malignancy-Related Pulmonary Hypertension Presenting as a Pulmonary Veno-Occlusive-Like Syndrome: A Single-Center Case Series.

Tumoral obstruction is a small, but broadly defined, category of pulmonary hypertension that encompasses microvascular tumor emboli, tumor thrombotic microangiopathy, and macrovascular tumor obstruction within the pulmonary circulation. We present 4 patients with solid tumors, severe pre-capillary pulmonary hypertension, right ventricular failure, and pulmonary veno-occlusive-like disease. (Level of Difficulty: Advanced.).

High Peak Inspiratory Pressures After a Change of Heat and Moisture Exchangers: A Case Series.

Elevated peak inspiratory pressures (PIPs) cause harm via hypoventilation, barotrauma, and hemodynamic instability. Heat and moisture exchangers (HMEs) are used during mechanical ventilation to prevent heat loss, dehydration of airway mucosa, and accumulation of dried secretions. Multiple reports detail sudden HME occlusions causing increased PIPs. We describe 4 cases of gradually increasing PIPs from progressive HME obstruction that occurred within 6 months of an institutional change to a newer model. HME obstruction should be considered when PIPs are elevated. Alternative heat and moisture preservation strategies should be contemplated, as HMEs increase airflow resistance and add another point of possible malfunction.

Diagnostic Accuracy of Spiral Whole-Heart Quantitative Adenosine Stress Cardiovascular Magnetic Resonance With Motion Compensated L1-SPIRIT.

BACKGROUND: Variable density spiral (VDS) pulse sequences with motion compensated compressed sensing (MCCS) reconstruction allow for whole-heart quantitative assessment of myocardial perfusion but are not clinically validated. PURPOSE: Assess performance of whole-heart VDS quantitative stress perfusion with MCCS to detect obstructive coronary artery disease (CAD). STUDY TYPE: Prospective cross sectional. POPULATION: Twenty-five patients with chest pain and known or suspected CAD and nine normal subjects. FIELD STRENGTH/SEQUENCE: Segmented steady-state free precession (SSFP) sequence, segmented phase sensitive inversion recovery sequence for late gadolinium enhancement (LGE) imaging and VDS sequence at 1.5 T for rest and stress quantitative perfusion at eight short-axis locations. ASSESSMENT: Stenosis was defined as ≥50% by quantitative coronary angiography (QCA). Visual and quantitative analysis of MRI data was compared to QCA. Quantitative analysis assessed average myocardial perfusion reserve (MPR), average stress myocardial blood flow (MBF), and lowest stress MBF of two contiguous myocardial segments. Ischemic burden was measured visually and quantitatively. STATISTICAL TESTS: Student's t-test, McNemar's test, chi-square statistic, linear mixed-effects model, and area under receiver-operating characteristic curve (ROC). RESULTS: Per-patient visual analysis demonstrated a sensitivity of 84% (95% confidence interval [CI], 60%-97%) and specificity of 83% [95% CI, 36%-100%]. There was no significant difference between per-vessel visual and quantitative analysis for sensitivity (69% [95% CI, 51%-84%] vs. 77% [95% CI, 60%-90%], P = 0.39) and specificity (88% [95% CI, 73%-96%] vs. 80% [95% CI, 64%-91%], P = 0.75). Per-vessel quantitative analysis ROC showed no significant difference (P = 0.06) between average MPR (0.68 [95% CI, 0.56-0.81]), average stress MBF (0.74 [95% CI, 0.63-0.86]), and lowest stress MBF (0.79 [95% CI, 0.69-0.90]). Visual and quantitative ischemic burden measurements were comparable (P = 0.85). DATA CONCLUSION: Whole-heart VDS stress perfusion demonstrated good diagnostic accuracy and ischemic burden evaluation. No significant difference was seen between visual and quantitative diagnostic performance and ischemic burden measurements. EVIDENCE LEVEL: 2 TECHNICAL EFFICACY: Stage 2.

Vascular Access for Large Bore Access.

Recent advances in the field of interventional cardiology have allowed for more complex procedures to be performed percutaneously. Ability to obtain safe large bore vascular access is frequently the key factor to procedural success. Meticulous technique for successful vascular access incorporates the understanding of anatomic landmarks, ultrasound, fluoroscopy, and micropuncture. Adequate hemostasis at the end of the case can be achieved through careful use of commercially available vascular closure devices. Although access-related vascular complications are uncommon, early recognition is key to successful management. Arterial tortuosity and calcification can present a significant challenge to successful common femoral artery access.

Integrating new memories into the hippocampal network activity space.

By investigating the topology of neuronal co-activity, we found that mnemonic information spans multiple operational axes in the mouse hippocampus network. High-activity principal cells form the core of each memory along a first axis, segregating spatial contexts and novelty. Low-activity cells join co-activity motifs across behavioral events and enable their crosstalk along two other axes. This reveals an organizational principle for continuous integration and interaction of hippocampal memories.

Electrocardiographic left atrial abnormality in patients presenting with ischemic stroke.

BACKGROUND: P wave indices represent electrocardiographic marker of left atrial pathology. We hypothesized that P wave would be more abnormal in patients presenting with ischemic stroke than a comparable group without ischemic stroke. METHODS: We compared P wave terminal force in V1 (PTFV1) between patients admitted with ischemic stroke (case) and patients followed in cardiology clinic (control) at a single medical center. Using logistic regression models, we tested for an association between abnormal PTFV1 (> 4000 µV ms) and ischemic stroke. We also defined several optimal cut-off values of PTFV1 using a LOESS plot and estimated odds ratio of ischemic stroke when moving from one cut-point level to the next higher-level. RESULTS: A total of 297 patients (case 147, control 150) were included. PTFV1 was higher in patients with vs. those without ischemic stroke (median 4620 vs 3994 µV ms; p=0.006). PTFV1 was similar between cardioembolic/cryptogenic and other stroke subtypes. In multivariable analyses adjusting for sex, obesity, age, and hypertension, the association between abnormal PTFV1 and ischemic stroke ceased to be significant (OR 1.53 [0.95, 2.50], p=0.083). Increase to the next cutoff level of PTFV1 (900, 2000, 3000, 4000, 5000, and 6000 µV ms) was associated with 18% increase in odds of having ischemic stroke (vs. no ischemic stroke) (OR 1.18 [1.02, 1.36], p=0.026). CONCLUSION: Patients presenting with acute ischemic stroke are more likely to have abnormal PTFV1. These findings from a real-world clinical setting support the results of cohort studies that left atrial pathology manifested as abnormal PTFV1 is associated with ischemic stroke.