Optical modeling and computational analysis of improved daylight collector geometry for a tubular skylight.

A carefully designed daylight collector for a tubular skylight is necessary to serve the occupants' illumination needs under the dynamic trajectory of the sun. This work simulated an improved configuration of a passive daylight collector comprising parabolic and conical reflectors in a modeled room using the lighting software tool TracePro. Results indicated that the lighting performance of the proposed design configuration was significantly enhanced under low altitude sun in comparison with conventional tubular skylights (with revolved parabolic and cylindrical reflectors) [Light. Res. Technol.52, 495 (2020)10.1177/1477153519872794] and hemispherical transparent dome as daylight collectors by more than ∼30%-40% and ∼110%-130%, respectively.

Mean wavelength-based Fresnel lens solar collector for eliminating the hotpot problem in daylighting systems.

In this paper, the mean-wavelength-based Fresnel lens was designed by merging the modified edge ray principle and idea of superposition. The bottom-to-top approach optimizes the design of individual prisms according to the predetermined plastic optical fiber (POF) bundle size. The simulated optical efficiency of the collector for the sun's visible spectrum (380-740 nm) light is 82.93% with a uniformity ratio of 0.434. Based on the designed collector, the daylighting system can deliver 199.38 lumens via a 10 m long POF bundle with an efficiency of 23.78%. The thermal analysis revealed that the maximum temperature on the focus plane was 49.7°C.

Premature atrial contraction induced cardiomyopathy: A case report.

This case report describes the successful management of a 45-year-old female patient with incessant premature atrial complexes (PACs) leading to left ventricular dysfunction. Despite initial treatment with beta-blockers, the patient's PACs persisted, prompting catheter ablation. Mapping in the left atrium identified the site of earliest atrial activation near the right superior pulmonary vein, and radiofrequency energy successfully terminated the PACs. Follow-up assessments showed the patient remained asymptomatic, with normalized left ventricular function. This case highlights the efficacy of catheter ablation in resolving PAC-induced cardiomyopathy and emphasizes the need for further research in this area.

Modeling a UVC irradiation standalone system for inactivating Mycobacterium tuberculosis from indoor spaces.

After the outbreak of the COVID-19 pandemic, a rise in demand has occurred for efficient designs of disinfection systems that utilize ultraviolet-C (UVC) radiation to inactivate airborne microorganisms effectively. This paper proposes what we believe to be a novel standalone system for inactivating Mycobacterium tuberculosis (which requires a higher dosage value than SARS-CoV-2) from a medium size room of 12.5f t×12.5f t×9f t. The structure consists of a UVC source at the center and a spiral pathway guiding the air around the UVC source, thus increasing the residence time of the aerosol particle. The top and bottom louvre and a hollow cylindrical cover (comprising four external cover segments) enclose the UVC source and prevent the danger of direct exposure to indoor occupants. The whole system is modeled in SolidWorks, and flux leakage was examined using the RayViz tool in SolidWorks. Optical/radiometric analysis in ray tracing software TracePro provided the UVC flux value at different locations of the standalone system. Flow simulation carried out in SolidWorks helped calculate aerosol particles' residence time at different airflow trajectories. The designed standalone system demonstrated the capability of delivering 1.87 times more dosage than is required to inactivate Mycobacterium tuberculosis from the ambient air. The standalone system achieves a ventilation rate, i.e., air changes per hour value of 10, according to guidelines from the Council of Scientific & Industrial Research, India.

Reversible Mechanical Atrioventricular Block Caused By A Steerable Introducer Sheath During Transseptal Catheterization.

A 62-year-old woman presents for pulmonary vein isolation (PVI) for paroxysmal atrial fibrillation. During transseptal catheterization (TSC) the patient sustained mechanical injury to the atrioventricular node (AVN) with consequent complete heart block (CHB). Injury to the AVN and CHB recovered after approximately forty minutes. The patient subsequently underwent a successful PVI with the remainder of the hospital stay uneventful. We present a case of reversible injury to the AVN caused by a steerable introducer sheath during TSC and discuss the mechanisms of injury as well as potential measures to avoid such a complication in the future.

Incessant palpitations in a young male.

27-year-old male with incessant palpitations and reduced ejection fraction presents for diagnostic electrophysiology study. ECG shows a long RP tachycardia. Permanent junctional reciprocating tachycardia is diagnosed on EP study with successful ablation of posteroseptal accessory pathway.

The initial experience of 2495 cases of the ulnar artery as default access for coronary diagnostic and interventional procedures at a single center: An observational study.

INTRODUCTION: Upper limb arterial access is being increasingly used for coronary diagnostic and intervention procedures. Radial artery access is associated with reduced morbidity and mortality as compared to femoral artery access. However, access to the radial artery is not always successful with reported crossover rates to other routes between 3% and 8%. Ulnar artery access is emerging an attractive option both as upfront access and rescue access in case of failure to obtain radial artery access. AIMS -: To assess and document the feasibility and safety of ulnar access as a default strategy. METHODS: 2654 patients planned for coronary diagnostic and intervention procedureswere assessed for inclusion. Inclusion criteria were, all patients planned for coronary angiography (CAG) or percutaneous coronary intervention (PCI) with palpable ulnar pulse. Exclusion criteria included reverse Barbeau test type D, previous procedure resulting in radial artery occlusion/excision, hemodialysis patients having ipsilateral AV fistula and severe forearm deformities. RESULTS: 2525 patients were found eligible, out of which 2495 (98.81%) were successfully cannulated. Procedure was completed in 2414 patients. Local site bleeding in 40 (1.6%) and acute loss of ulnar pulse noted in 33 (1.3%) out of 2495 patients. None of the patients had gangrene of access site, pseudo-aneurysm, arteriovenous fistula or neurological deficit post procedure. CONCLUSION: The Ulnar artery access as a default access is safe and feasible option for patient undergoing coronary diagnostic and interventional procedures.

Ivabradine vs metoprolol in patients with acute inferior wall myocardial infarction-"Expanding arena for ivabradine".

BACKGROUND: Atrioventricular (AV) blocks are of concern with the use of beta blockers in inferior wall myocardial infarction (MI). Ivabradine lowers heart rate with a lesser risk of AV blocks. OBJECTIVES: To compare ivabradine with metoprolol in acute inferior wall MI in terms of feasibility, tolerability, and efficacy. METHODS: It was a prospective double-blind single-center randomized controlled study. Of 1032 patients with acute inferior wall MI, 468 eligible patients were randomized in 1:1 manner to ivabradine (group A) and metoprolol (group B). Intention to treat analysis of 426 patients (group A-232 and group B-232) was performed. The primary endpoint was 30-day incidence of major adverse cardiovascular events including death, reinfarction, complete heart block (CHB), and heart failure. Secondary endpoints included 30 days incidence of recurrent angina, readmission, first- or second-degree AV block, and tachyarrhythmias. RESULTS: Both the drugs decreased the mean heart rate to 62.22±2.95 (group A) vs 62.53±3.59 (group B) beats per minute (P=0.33). Ejection fraction improved in both the groups (5.15±1.93% in group A vs 5.52±2.18% in group B, P=0.065). The two groups did not differ significantly in their primary endpoints in terms of death (group A=1.72% vs group B=1.72%, OR=1.00, 95% CI=0.25-4.05, P=1.00), reinfarction (group A=0.86% vs group B=0.86%, OR=1.00, 95% CI=0.14-7.16, P=1.00), heart failure (group A=4.31% vs group B=2.59%, OR=1.70, 95% CI=0.61-4.75, P=0.31), or CHB (0% vs 2.59%, OR=0.07, 95% CI=0.00-1.34, P=0.08). There were no significant differences in the secondary endpoints of recurrent angina, readmission, and tachyarrhythmias except for more first- and second-degree AV blocks with metoprolol (12.93% vs 2.59%, OR=5.59, 95% CI=2.28-13.72, P=0.0002). CONCLUSIONS: Ivabradine is well tolerated and equally effective as metoprolol in acute inferior wall ST elevation myocardial infarction patients for lowering the heart rate with lesser risk of AV blocks.

A pediatric echocardiographic Z-score nomogram for a developing country: Indian pediatric echocardiography study - The Z-score.

BACKGROUND: Almost all presently available pediatric echocardiography Z-score nomograms are based on Western data. They may not be a suitable reference standard for assessing the sizes of cardiac structures of children from developing countries. OBJECTIVE: This study's objective was to collect normative data of 21 commonly measured cardiovascular structures using M-mode and two-dimensional echocardiography in Indian children aged between 4 and 15 years and to derive Z-score nomograms for each. SUBJECTS AND METHODS: The study was conducted at two centers in India - Ajmer, Rajasthan, and Mohali, Punjab. We studied a community-based sample involving healthy school going children. After excluding children with cardiovascular abnormalities on the screening echocardiogram, 746 children were included in the final analysis. Echocardiographic assessment was performed using a Philips iE33 system. RESULTS AND ANALYSIS: For each parameter measured, seven models were evaluated to assess the relationship of that parameter with the body surface area and the one with the best fit was used to plot the Z-score chart for that parameter. Z score charts were thus derived. CONCLUSIONS: The Z-score nomograms derived by this study may be better alternatives to the Western nomograms for use in India and other developing countries for preprocedural decision making in the pediatric population. However, they will require validation in large-scale studies before they can become clinically applicable.

3D Xplane Echocardiographic Technique for Validation of Mitral Leaflet Separation to Assess Severity of Mitral Stenosis.

BACKGROUND: Determining the severity of mitral stenosis (MS) is important for both prognostic and therapeutic implications. Mitral valve area (MVA) calculation techniques have more limitations. Mitral leaflet separation (MLS) is a precise and operator friendly alternative to planimetry. In contrast to previous researchers, we have used a novel 3D Xplane technique to validate MLS for assessing the severity of MS. 3D Xplane is superior for validation of MLS due to simultaneous real time acquisition of MLS in parasternal long-axis view and corresponding MVA by planimetry in parsternal short-axis view. METHODS: It was a prospective observational single center study. A total of 174 patients with MS were evaluated for MVA estimation by various echocardiographic modalities. Maximum leaflet separation and corresponding planimetered MVA were measured using novel 3D Xplane technique. RESULTS: With 3D Xplane technique, there was strong positive correlation between planimetered MVA and MLS (R = 0.925, P < 0.001), irrespective of coexisting MR (R = 0.886, P < 0.001) or AF (R = 0.912, P < 0.001). Receiver operating characteristic curves of MLS demonstrated AUC for mild and severe MS to be 0.966 and 0.995, respectively. MLS less than 8.62 mm predicted severe MS with 95.5% sensitivity and 94.7% specificity and MLS more than 12.23 mm predicted mild MS with 93.2% sensitivity and 91.4% specificity. CONCLUSION: In our study, a strong correlation between planimetered MVA and MLS was found using 3D Xplane technique. 3D Xplane thus validates and standardizes MLS by excluding errors due to temporal and spatial variations which are important limitations of 2D echocardiography.

Ulnar Artery Interventions Non-Inferior to Radial Approach: AJmer Ulnar ARtery (AJULAR) Intervention Working Group Study Results.

BACKGROUND: Percutaneous coronary procedures are undergoing a paradigm shift from femoral to forearm approach due to obvious advantages in terms of patient safety and comfort, and faster time to ambulation. Transradial access (TRA) has been established as a primary forearm access site. We have tried to use ulnar artery access as an alternative to radial route and found that transulnar access (TUA) is an excellent alternative and non-inferior to TRA if performed by an experienced operator. METHODS: This was a prospective, single-center study involving 2532 patients who were randomized in a 1:1 manner to either TUA (n = 1270) or TRA (n = 1262). All cannulations were performed by operators who were experienced in radial artery (RA) cannulation and had performed a minimum of 50 ulnar artery (UA) cannulations. The primary endpoint was a composite of major adverse cardiac events during hospital stay, crossover to another arterial access route, major vascular events during hospital stay (large hematoma with hemoglobin drop of ≥3 g%) or vessel occlusion rate. To prove non-inferiority of TUA, a margin of 1.93 was derived by fixed-margin method (preserving 50% of difference of procedural failure rate [4.87%] between radial and femoral access from meta-analysis). RESULTS: The composite primary endpoint occurred in 14.6% of TUA and 14.4% of TRA patients (risk ratio, 1.01; 95% confidence interval, 0.83-1.2; P=.92 at α=0.05). All assessed parameters (except large hematoma, for which non-inferiority could not be proved conclusively) were non-inferior in TUA when compared with TRA. CONCLUSIONS: TUA is non-inferior to TRA when performed by an experienced operator. The utilization of TUA as an access site option increases the chance of success with forearm access and reduces the need for crossover to femoral route.

Sweating: A Specific Predictor of ST-Segment Elevation Myocardial Infarction Among the Symptoms of Acute Coronary Syndrome: Sweating In Myocardial Infarction (SWIMI) Study Group.

BACKGROUND: Today, cardiologists seek to minimize time from symptom onset to interventional treatment for the most favorable results. HYPOTHESIS: In the acute coronary syndrome (ACS) symptom complex, sweating can differentiate ST-segment elevation myocardial infarction (STEMI) from non-ST-segment elevation ACS (NSTE-ACS) during early hours of infarction. METHODS: This single-center, prospective, observational study compared symptoms of STEMI and NSTE-ACS patients admitted from August 2012 to July 2014. RESULTS: Of 12 913 patients, 90.56% met ACS criteria. Among these, 22.51% had STEMI. Typical angina was the most common symptom (83.82%). On stepwise multiple regression, sweating (odds ratio: 97.06, 95% confidence interval [CI]: 82.16-114.14, P < 0.0001) and typical angina (odds ratio: 2.72, 95% CI: 2.18-3.38, P < 0.001) had significant association with STEMI. For diagnosis of STEMI, positive likelihood ratio (LR) and positive predictive value (PPV) were highest for typical angina with sweating (LR: 11.17, 95% CI: 10.31-12.1; PPV: 76.09, 95% CI: 74.37-77.75), followed by sweating with atypical angina (LR: 3.6, 95% CI: 3.07-4.21; PPV: 50.61, 95% CI: 46.45-54.76), typical angina (LR: 1.05, 95% CI: 1.03-1.07; PPV: 22.97, 95% CI: 22.11-23.84), and atypical angina (LR: 0.77, 95% CI: 0.69-0.87; PPV: 18.09, 95% CI: 16.32-19.97). C statistic values of 0.859 for typical angina with sweating and 0.519 for typical angina alone reflected high discriminatory value of sweating for STEMI prediction. CONCLUSIONS: Presence of sweating with ACS symptoms predicts probability of STEMI, even before clinical confirmation. Sweating in association with typical or atypical angina is a much better predictor of STEMI than NSTE-ACS.

Palmar arch anatomy: Ajmer Working Group classification.

INTRODUCTION: Forearm arteries are frequently used as workhorse site for cardiac catheterization, bypass grafting and haemodialysis access. There is paucity of data on palmar circulation in live human being and only cadaveric data are available till date. We, therefore, made an attempt to look at the various patterns of sufficient or insufficient palmar arch circulation and various anomalies of forearm arteries, to discuss their clinical implications. METHODS AND RESULTS: We obtained the forearm and hand arteriograms of patients (n = 302) through radial (n = 200) and ulnar routes (n = 102). Modified Allen's test was normal in all of our patients. On the basis of predetermined parameters angiograms were analysed and findings were divided into three groups. These three groups were further classified as type A, type B, type C superficial palmar arch. CONCLUSION: We concluded that type A superficial palmar arch is most suitable for providing adequate collateral circulation in case of harvesting of forearm vessel, whereas type C superficial palmar arch appears to be highly susceptible for digital ischemia in case of radial or ulnar artery occlusion. Modified Allen's test alone is not justifiable for documenting good collateral circulation and it should be supplemented by other tests to document good collateral circulation before proceeding to any radical procedure.

Eptifibatide in post-infarction angina patients who refused intervention: Ajmer postmyocardial infarction angina eptifibatide research (AJMER) study: a pilot study.

BACKGROUND: Early intervention is certainly a preferred strategy over conservative management in patients with post-infarction angina (PIA). But at times, it may not be feasible to intervene, especially if patient refuses for intervention. In a pilot study, we analyzed whether the addition of eptifibatide to intensified antianginal therapy would be of added benefit, in patients with PIA not willing to undergo intervention. METHODS: A total of 461 patients with PIA who refused intervention were randomized in a 1:1 manner to receive either eptifibatide along with intensification of antianginal therapy (group A; n = 229) or intensified antianginal therapy alone (group B; n = 232). The primary endpoints were composite of all-cause death and nonfatal myocardial infarction at 30 days. RESULTS: Primary composite endpoint did not differ between the two groups (16.2% vs. 18.9% in group A and group B, odds ratio [OR], 0.82; 95% CI, 0.5-1.30; P-value = 0.43). Significant earlier relief of angina (complete relief of angina within 12 h: 76% of patients in group A vs. 40.5% in group B; P-value <0.0001) was achieved in group A compared to group B. Although on Bleeding Academic Research Consortium (BARC) scale, type 1 and 2 bleeding was higher in group A (OR, 3.18; 95% CI, 1.76-5.74; P-value = 0.0001), the more serious (composite of type 3 and 5) bleeds did not show any difference (OR, 1.73; 95% CI, 0.7-4.08; P-value = 0.21). CONCLUSION: In patients with PIA who refused intervention, eptifibatide infusion resulted in earlier relief of angina albeit at the cost of increased non-life-threatening bleeding. Further, this effect was achieved in significantly higher number of patients receiving eptifibatide infusion when compared to patients not receiving it. Primary composite endpoints, however, did not differ in two groups, but being a pilot study, this needs to be confirmed by larger study of adequate sample size.

Feasibility of ulnar artery for cardiac catheterization: AJmer ULnar ARtery (AJULAR) catheterization study.

BACKGROUND: The ulnar artery is rarely selected for cardiac catheterization despite the expanding use of the transradial access (TRA). We tried to compare default transulnar access (TUA) with TRA in terms of feasibility and safety. MATERIALS AND METHODS: This was a prospective, open label, single center, observational study. We analyzed a total of 410 patients with normal Allen's test, who were then scheduled for coronary angiography through TUA with ad hoc PCI if necessary. Procedures were performed by a single operator who had an adequate transradial experience (≥150 transradial coronary procedures per year) but not trained in transulnar procedures. We analyzed observed findings with a retrospective cohort of patients undergoing TRA angiography under a previous study done at our center. We also performed selective ulnar arteriography of 200 patients, through radial route, to predict the bottlenecks of TUA. OBSERVATIONS: There is no statistically significant difference among the number of attempts made till the successful puncture, the total procedure time and the total fluoroscopy time for either radial or ulnar access angiography by an experienced operator (P > 0.05). However, the time taken in arterial access is statistically significant in the initial learning curve for the same (P < 0.05). On the contrary, the arterial access time, the total procedure time, and the total fluoroscopy time, all are statistically significant for the inexperienced operator (P < 0.05). There is a negligible incidence of nonmaneuverable anatomic obstruction in the real-world scenario in TUA, and so fear of the same should not impede the use of this route. Vasospasm in the use of this route is also not different from the radial route, with the experience of the operator. CONCLUSIONS: For an experienced operator, TUA is a safe and also an effective alternative to TRA in terms of feasibility and safety.

Prevalence of congenital heart disease in patients undergoing surgery for major gastrointestinal malformations: an Indian study.

BACKGROUND: The association of congenital heart disease (CHD) with malformations of the gastrointestinal (GI) tract/abdominal wall is known. The rates of cardiac malformations reported in previous studies of these anomalies are highly variable. OBJECTIVE: To find the prevalence and pattern of CHD in patients with major gastrointestinal malformations (anorectal malformations, oesophageal atresia/tracheo-oesophageal fistula, and omphalocoele) undergoing surgery at a tertiary care hospital in India. METHODS: From July 2012 to December 2013, 43 patients (34 (79%) male, 9 (21%) female) were evaluated by clinical examination, ECG, chest radiography, and colour Doppler echocardiography. RESULTS: Of the 43 patients, 26 (60.46%) had CHD. The most common GI malformation was anorectal malformation: 32 cases (74.41%), of whom 16 (50%) had CHD. The second most common malformation was oesophageal atresia/tracheo-oesophageal fistula: 5 cases (11.62%), all (100%) with CHD. The third group comprised patients with omphalocoele: 4 cases (9.3%), 3 of whom (75%) had CHD. The fourth group comprised patients with VACTERAL (vertebral anomalies, anal atresia, cardiovascular malformations, tracheo-oesophageal fistula, renal and limb anomalies) association-2 cases (4.6%), all (100%) with CHD. The most common CHD was isolated atrial septal defect (ASD) (73%), followed by ASD + ventricular septal defect (VSD) + patent ductus arteriosus (PDA) (7.6%), ASD + VSD (3.8%), ASD + PDA (3.8%), VSD (3.8%), PDA (3.8%), and coarctation of the aorta (3.8%). CONCLUSIONS: We found the frequency of CHD in patients with GI malformations was very high, the most common presentation being ASD. Our study indicates the need for larger scale studies to determine the prevalence of CHD in patients with GI malformations in the Indian population.

Warning leak of intracranial aneurysm masquerading as sinus node dysfunction: A case report.

We describe the successful endovascular repair of an intracranial aneurysm causing subarachnoid hemorrhage in a 62-year-old man, who was initially diagnosed and treated as a case of symptomatic sinus bradycardia. The aim of this report and following discussion is to discuss the subtle warning signs of intracranial aneurysm that may masquerade as sinus node dysfunction.