Downside risk-return volatilities during Covid 19 outbreak: a comparison across developed and emerging markets.

This research study evaluates the impact of the Covid 19 pandemics on the downside risk-return volatilities across the four stock markets of the USA, UK, China, and Pakistan. The pandemic results in severe economic and financial consequences both at micro and macro levels as well as across the stock markets of various countries. The selected stock markets of the USA, UK, Pakistan, and China are significantly affected in terms of both investor risk and return during the pandemic time. The entire period distribution of the risk exhibited the downside risk behavior of both markets and investors' serious concern regarding their investment strategies. Using high-frequency data from January 2020 to April 2021, the findings of the study reveal more of the downside abnormal returns across both markets. The impact is larger and high in developed markets of USA and UK compared to the emerging markets of China and Pakistan. The outcomes of the various value-at-risk models disclose the higher downside risk implications for all markets, larger for developed countries. Similarly, the three stock markets of the USA, UK, and China were found to be significantly connected during a pandemic. Investors' reactions were positive and high in case of positive news outbreaks and dwindling in case of negative news and downside impact. The outcomes of the study are useful for investors, portfolio managers, investment advisors, and others to understand the dynamics of the pandemic situation and devise effective strategies to overcome the severities of downside risk.

Utility of preprocedure checklists in the congenital cardiac catheterization laboratory.

OBJECTIVE: Preprocedure meetings have become more commonplace in medicine but are not performed routinely in the cardiac catheterization laboratory. We sought to create, implement, and evaluate a preprocedural meeting in the form of a checklist for the cardiac catheterization laboratory. Staff attitudes and perceptions toward safety and sense of teamwork were also analyzed. DESIGN: All procedures performed in the cardiac catheterization laboratory on patients with structural heart disease from January 2010 to February 2012 were retrospectively reviewed for demographics, procedural details, and reported complications. A checklist was introduced to the preprocedure protocol at the halfway point, and patients were divided into pre- and postchecklist cohorts. Anesthesia and cardiac catheterization laboratory staff were surveyed at the beginning and end of the study period regarding attitude toward safety, team climate, and the impact of errors. RESULTS: Total number of procedures (prechecklist, n = 371; postchecklist, n = 370) and demographics were similar among groups. Complication rates were equivalent pre- and postchecklist, but there was a greater proportion of interventional cases and higher median complication level in the postchecklist group. Cardiac catheterization laboratory staff reported improved awareness of being briefed with the checklist. Anesthesia differed from cardiac catheterization staff in perception of communication as well as team and safety climate. CONCLUSIONS: A preprocedure checklist for congenital cardiac catheterization cases is easy to perform and serves to update cardiac catheterization laboratory staff. Anesthesia and cardiac catheterization staff had different perceptions of safety and teamwork climate. Further studies are needed to determine if this briefing could lead to better communication among services and ultimately reduce complications.

Magnetic resonance angiography in paced complex heterotaxy syndrome with Fontan conduit obstruction and venovenous collateral decompression.

Imaging of complex congenital heart diseases (CHDs) in children is challenging. This article reviews the complementary role of high temporal and high spatial resolution magnetic resonance (MR) angiographic imaging techniques in evaluation of a patient with complex congenital cardiovascular disease and related postsurgical complications. A 4-year-old female patient with complex CHD and multiple previous palliative surgical procedures underwent MR angiography to evaluate the cause of refractory hypoxia. High-resolution MR angiography demonstrated the complex postsurgical cardiovascular anatomy and also assisted in the evaluation of cavopulmonary shunt patency and secondary venovenous shunt formation. Time-resolved MR angiography evaluated pulmonary perfusion and demonstrated a significant pulmonary arteriovenous malformation. This information guided physicians in planning further managements, which resulted in a satisfactory clinical outcome.

Occlusion of Sano conduit with the Amplatzer vascular plug: a reliable method for staged elimination of accessory pulmonary blood flow in single ventricle palliation.

BACKGROUND: Staged palliative surgery is often required to regulate pulmonary and systemic blood flow in children with complex congenital heart disease. Accessory sources of pulmonary blood flow have been utilized to provide satisfactory pulmonary blood flow after Glenn anastomosis in select patients. Prolonged exposure to increased flow can lead to elevated pulmonary arterial pressures and volume loading of the ventricle, potentially limiting candidacy for Fontan completion. OBJECTIVE: To review the feasibility, technique, and outcome of transcatheter closure of the Sano conduit utilizing the Amplatzer Vascular Plug (AVP). METHODS: All patients who underwent device closure of the Sano conduit with an AVP were reviewed retrospectively. Patient demographics, indications, procedural details, and patient outcomes were reviewed. Hemodynamic changes before and after occlusion of the Sano conduit were compared. A P value < 0.05 was considered significant. RESULTS: Between 2005 and 2009, 11 male patients underwent Sano occlusion with an AVP. Average weight was 8.8 ± 2.2 kg. The Sano was occluded from both antegrade (n = 6) and retrograde (n = 5) approaches. Arterial saturation and mean pulmonary artery pressure both decreased significantly after Sano occlusion [86.9 ± 4.9% to 82.6 ± 4.9% (P < 0.001) and 14.1 ± 5 mm Hg to 12.8 ± 4 mm Hg (P < 0.05), respectively]. Conduit diameter averaged 3.6 mm (range 3.1-4.4) 13 months after Stage I palliation. The conduit was closed using a 6 mm AVP in nine patients and a 4 mm AVP in the other two. The ratio of AVP size to conduit diameter was 1.5 ± 0.27. There were no procedural complications and all patients at least 2 years of age have undergone Fontan completion. CONCLUSIONS: The Sano conduit can be left open in select patients who do not tolerate closure after Glenn anastomosis. It can be closed safely and effectively using the AVP. © 2010 Wiley-Liss, Inc.

QTc interval in infants receiving cisapride.

OBJECTIVE: To examine the effect of cisapride on the corrected QT (QTc) interval in infants over a 14-day period. STUDY DESIGN: A prospective cohort study of infants receiving cisapride (0.8 mg/kg per day). Twelve-lead electrocardiograms were obtained before and 3, 5, 7, and 14 days after cisapride initiation. RESULTS: Fifty infants completed the study; none had arrhythmias. Fifteen of 50 infants (30%) developed QTc interval > or =450 msec; QTc interval normalized in 13 of 15 infants. Infants with QTc interval on day 3 > or =2 standard deviations above the mean baseline QTc interval (401+40 msec) were more likely to develop prolonged QTc interval (p<0.0001). CONCLUSION: QTc interval prolongation was noted in 30% of infants. Subsequently, the majority of those infants had QTc interval normalization by day 14 of cisapride therapy. QTc interval 3 days following cisapride initiation may identify infants at risk for transient QTc interval prolongation. With appropriate monitoring, hospitalized infants receiving cisapride may have improved gastrointestinal motility without cardiac morbidity.