The Utility of Echocardiography in Estimating Fluid Responsiveness.

Assessing the volume status in critically ill patients is the key to maintain the stability of the hemodynamics; however, it can be challenging to view the complexity of cases and the diversity of shock etiology. Multiple noninvasive means have been used to study the effectiveness of volume resuscitation, but none of them have been used as gold standard. We aim to illustrate the most used techniques: left ventricular outflow tract velocity time integral versus inferior vena cava compressibility index, and highlight their limitations and strengths. These tools are both operator-dependent and might be affected by several factors including ventilator settings.

Heart failure - An unexplored risk factor for infective endocarditis after pacemaker implantation.

BACKGROUND: With the widespread use of permanent pacemakers (PPM), and increased mortality associated with pacemaker endocarditis, it is essential to evaluate comorbidities that could potentially increase the risk of infective endocarditis (IE). Heart failure (HF), a common comorbidity, has not been well studied as an independent risk factor for development of IE in individuals with PPM. METHODS: The US National Inpatient Sample database was used to sample individuals with PPM. Patients with concomitant implantable cardioverter defibrillator, acute heart failure, history of endocarditis, intravenous drug use, prosthetic heart valves, or central venous catheter infection were excluded. Propensity matching was performed to match patients with and without HF. Pre- and post-match logistic regression was performed to assess HF as an independent risk factor for IE. A subgroup analysis was performed comparing IE rates between patients with HF with reduced (HFrEF) vs preserved (HFpEF) ejection fraction. RESULTS: Out of 333,571 patients with PPM included in the study, 121,862 (37 %) had HF. HF patients were older and had a higher prevalence of females. All comorbidities except for dental disease and cancer were more prevalent in the HF group. Patients with HF were 1.30 times more likely to develop IE [OR: 1.30 (1.16-1.47); p < 0.001]. The two cohorts were then matched for age, gender, and 20 comorbidities using a 1:1 propensity score matching algorithm. After matching, HF was still independently associated with increased risk of IE [OR: 1.62 (1.36-1.93); p < 0.001]. In our sub-group analysis, HFrEF and HFpEF patients had similar IE rates. CONCLUSION: In PPM population, HF was associated with an increased risk of IE compared to those without HF. We hypothesize that HF being a low-flow and high-inflammatory state might have contributed to this increased risk. Larger studies are required to corroborate our findings and evaluate the need for antimicrobial prophylaxis for this population.

Monitoring long-term vegetation condition dynamics in persistent semi-arid wetland communities using time series of Landsat data.

Wetlands in arid and semi-arid regions are characterized by dry- and wet-phase vegetation expression which responds to variable water resources. Monitoring condition trends in these wetlands is challenging because transitions may be rapid and short-lived, and identification of meaningful condition change requires longitudinal study. Remotely-sensed data provide cost effective, multi-decadal information with sufficient temporal and spatial scale to explore wetland condition. In this study, we used a time series of Enhanced Vegetation Index (EVI) derived from 34 years (1988-2021) of Landsat imagery, to investigate the long-term condition dynamics of six broad vegetation groups (communities) in a large floodplain wetland system, the Macquarie Marshes in Australia. These communities were persistently mapped as River Red Gum wetland, Black Box/Coolibah woodland, Lignum shrubland, Semi-permanent wetland, Terrestrial grassland and Terrestrial woodland. We used generalized additive models (GAM) to explore the response of vegetation to seasonality, river flow and climatic conditions. We found that EVI was a useful metric to monitor both wetland condition and response to climatic and hydrological drivers. Wetland communities were particularly responsive to river flow and seasonality, while terrestrial communities were responsive to climate and seasonality. Our results indicate asymptotic condition responses, and therefore evidence of hydrological thresholds, by some wetland communities to river flows. We did not observe a long-term trend of declining condition although an apparent increase in condition variability towards the end of the time series requires continued monitoring. Our remotely-sensed, landscape-scale monitoring approach merits further ground validation. We discuss how it can be used to provide a management tool which continuously assesses short and long-term wetland condition and informs conservation decisions about water management for environmental flows.

A Rare Case of High-Grade Atrioventricular Block in Granulomatosis With Polyangiitis.

Granulomatosis with polyangiitis (GPA) is an autoimmune disease that affects small and medium-sized vessels. It is classically known to present with renal and respiratory tract symptoms. However, the disease can manifest in other organ systems, especially cardiovascular involvement. Though there are multiple reports of cardiac involvement in GPA, it is not commonly evaluated and is often overlooked in patients with GPA. Heart disease in GPA has a wide range of presentations ranging from subacute and silent to severe abnormalities, which can prove fatal if not identified and treated appropriately. Identifying cardiac involvement early in patients with no apparent signs can help with prevention strategies and follow-up to avoid significant complications. Pericarditis is the most common pathology noted in GPA, followed by cardiomyopathy, coronary artery disease, valvular disease, and conduction abnormality. In our report, we present a case of GPA in a young male with asymptomatic conduction abnormality of the heart. Although it was silent at the presentation, identifying the initial electrocardiogram (ECG) changes prompted us to admit him to the telemetry floor. Continuous telemetry monitoring helped us identify the progression of the conduction abnormality, which otherwise could have been missed. This led us to correlate to his symptoms which he later developed during his admission course. His symptoms subsided after prompt treatment. If not identified early, these cardiac abnormalities can delay management, leading to increased disease burden and morbidity. Hence, essential cardiac work with at least ECG and continuous telemetry monitoring is recommended.

Lactococcus endocarditis after Bentall procedure presenting with intracranial hemorrhage.

Background: Endocarditis is more common in patients with cardiac prostheses. A Bentall procedure entails surgical replacement of the aortic valve, aortic root, and ascending aorta with re-implantation of coronary arteries into the graft. Case: 65-year-old male with history of atrial fibrillation on rivaroxaban, bicuspid aortic valve, and ascending aortic aneurysm with a history of a Bentall procedure two years prior, presented with headache and dysarthria for one day. National Institutes of Health Stroke Scale was 3 and CT head showed 2.7 cm left frontal hematoma with extension into the subarachnoid space. Andexanet alfa was given for rivaroxaban reversal followed by cerebral angiogram which showed 5 mm intracranial inferior MCA aneurysm and embolization and coil placement was done. Blood cultures grew Lactococcus garvieae and transesophageal echocardiogram revealed aortic valve thickening and vegetation on the non-coronary cusp. He was subsequently treated with six weeks of IV ceftriaxone and Gentamycin. Conclusion: With increasing use of bioprosthetic valves, the possibility of infective endocarditis with uncommon pathogens should be kept in mind. Lactococcus commonly affects native valves, however it can affect bioprosthetic valves and can present with mycotic aneurysms.

Robotic-assisted revision total knee arthroplasty: a novel surgical technique.

BACKGROUND: Revision total knee arthroplasty is a challenging procedure. The robotic-assisted system has been shown to enhance the accuracy of preoperative planning and improve reproducibility in primary arthroplasty surgeries. The aim of this paper was to describe the surgical technique for robotic-assisted revision total knee arthroplasty and the potential benefits of this technique. METHOD: This single-centre retrospective study included a total of 19 patients recruited from April 1, 2021 to April 30, 2022. Inclusion criteria were patients who had Mako™ robotic-assisted revision total knee arthroplasty done within the study period with a more than 6 months follow-up. Statistical analysis was done using Microsoft Excel 16.0. RESULTS: All 19 patients were followed up for 6 to 18 months. All patients in this study had uneventful recoveries without needing any re-revision surgery when reviewed to date. CONCLUSION: With the development of dedicated revision total knee software, robot-assisted revision TKA can be a promising technique that may improve surgical outcomes by increasing the accuracy of implant placement, and soft tissue protection and achieving a better well-balanced knee.

Human Herpes Virus 6-Associated Meningitis in an Immunocompetent Adult With a History of Plaque Psoriasis: A Case Report.

Human herpes virus-6 (HHV-6) is a common cause of viral infection in humans, recognized for causing exanthema subitem during the first two years of life. Chronic inflammatory states in different autoimmune diseases can be associated with an immunosuppressed microenvironment. We report a case of HHV-6-associated meningitis in a patient with psoriasis. A 36-year-old man with a history of psoriasis presented with worsening bifrontal headache as well as painful oral lesions on the tongue and soft palate. Computed tomographic (CT) scan of the brain was nondiagnostic. Cerebrospinal fluid (CSF) analysis was diagnostic for HHV-6 infection and was treated with intravenous ganciclovir for two weeks. This case report highlights the emergence of HHV-6 infections in people with underlying mild immune disorders, such as psoriasis. Plaque psoriasis, such as in this patient, could be related to viral infections not typically seen among adults.

Severe Tricuspid Stenosis Secondary to Permanent Pacemaker Lead.

Tricuspid stenosis (TS) is a rare valvular abnormality and generally associated with mitral stenosis in cases of rheumatic heart disease. TS is now frequently being described in the setting of permanent pacemaker leads, either with or without the presence of infective endocarditis. We describe a case of a female with TS secondary to permanent pacemaker leads in the absence of infective endocarditis being managed during the pre-conception period. She initially had a balloon valvuloplasty done for moderate to severe TS and subsequently conceived and delivered without complications. However, upon being evaluated before her second pregnancy, she was again found to have severe TS. We hypothesize that the presence of permanent pacemaker lead contributed to the development of early restenosis after the first procedure. A repeat balloon valvuloplasty was unsuccessful and she ultimately underwent successful tricuspid valve replacement with no echocardiographic or clinical signs of restenosis years later. The options for management of TS secondary to permanent pacemaker lead include medical management, balloon valvuloplasty (with or without removal of pacemaker lead), or tricuspid valve replacement. Overall, there is a scarcity of data on long-term outcomes of either option making the management challenging.

Expression analysis of notsh signaling pathway molecules in shed cultured in keratinocyte growth medium

Aim: To detect the expression of molecules associated with Notch signaling pathway in stem cells from human exfoliated deciduous teeth (SHED) cultured in specific differentiation medium, namely, keratinocyte growth medium (KGM). Methods:RNA was extracted from SHED harvested on day 1, 3 and 7. RNA was reverse-transcribed to obtain the cDNA and then proceeded with PCR using specific primers for the Notch signaling pathway molecules (Notch1, Jagged-1, Jagged-2 and, Hes1) as well as stem cell marker (Nanog). PCR products were electrophoresed on a 2% agarose gel and stained with SYBR green. Results:Notch-1 was highly expressed in SHED cultured in KGM and showed increase in density as the days progressed, while Jagged-1 showed a decrease. Jagged-2 on the other hand, showed a slight increase on day 3 followed by a decrease on day 7. However, Hes-1 was not expressed in SHED cultured in KGM. Nanog showed expression only on day 3 and gradually increased in expression on day 7. Conclusions:Notch signaling pathway associated molecules; Notch-1, Jagged-1, Jagged-2, and stem cell marker Nanog are expressed in SHED cultured in KGM which may be involved in the differentiation into epithelial-like cells in human dental pulp tissues.