The Role of Cardiovascular Magnetic Resonance in Congenital Heart Disease

The increasing prevalence of congenital heart disease (CHD) can be attributed to major improvements in diagnosis and treatment. Although echocardiography is the most commonly used imaging modality for diagnosis and follow up of subjects with CHD, the evolution of both cardiovascular magnetic resonance (MR) imaging and computed tomography (CT) does offer new ways to visualize the heart and the great vessels. The development of cardiovascular MR techniques such as spinecho and gradient-echo imaging, velocity-encoded phase contrast MR and gadolinium-enhanced MR angiography allow comprehensive assessment of cardiac anatomy and function. This provides information about the long-term sequelae of the underlying complex anatomy, hemodynamic assessment of residual post-operative lesions and complications of surgery. As much of the functional data in CHD patients is usually acquired with invasive X-ray angiography, non-invasive alternatives such as cardiovascular MR and CT are desirable. This review evaluates the role of both these modalities in the management of subjects with CHD, particularly detailing recent developments in imaging techniques as they relate to the various CHD diagnoses we commonly encounter in our practice

ANALYTICAL METHOD DEVELOPMENT AND VALIDATION OF DABIGATRAN ETEXILATE RELATED SUBSTANCE IN PHARMACEUTICAL DOSAGE FORM BY REVERSE‑PHASE – HIGH‑PERFORMANCE LIQUID CHROMATOGRAPHY

Objective: The objective of the study was to develop and validate new, simple, and selective reverse-phase–high-performance liquid chromatography (RP-HPLC) method for the quantitative determination of Dabigatran Etexilate (DE) and its impurities in pharmaceutical dosage form as per the International Conference on Harmonization guidelines.Method: Chromatographic analysis was performed on Princeton SPHER-l00 C18 (250 × 4.6 mm, 5 μm) HPLC column, maintained at 50°C column temperatures, 6°C sample tray temperature, and detection monitored at 225 nm. The mobile phase consisted of acetonitrile:phosphate buffer (pH 2.5) (33:67 V/V). The flow rate was maintained at 1.0 ml/min.Results: The system suitability results indicate good performance of the system. Specificity study indicates that there is no interference of placebo and blank. The percentage relative standard deviation (RSD) of six preparations for known and unknown impurity in the sample solution is found below 10%; hence, the method is precise. The calibration curve for DE (unknown impurity), Impurity A was linear from 0.38 to 4.5 μg/ml (correlation coefficients [r2] for unknown Impurity [DE] and Impurity A are 0.996 and 0.999, respectively). The calibration curve for Impurity B and Impurity E was linear from 0.38 to 9.00 μg/ml (r2 for Impurity B and Impurity E are 0.999 and 0.999, respectively); hence, the method is linear. Accuracy for DE (unknown Impurity), Impurity A, Impurity B, and Impurity E are found within 80%–120%; hence, the method is accurate. The percentage RSD for a standard solution is found below 5% up to 24 h, and percentage impurity change in the sample solution is found below 0.1% up to 18 h; hence, standard solution is stable up to 24 h, and sample solution is stable up to 18 h.Conclusion: The developed method is new, simple, adequate, specific, precise, linear, and accurate for the determination of DE and its impurities in pharmaceutical dosage forms

Long term CMR follow up of patients with right ventricular abnormality and clinically suspected arrhythmogenic right ventricular cardiomyopathy (ARVC)

Background: The Task Force Criteria (TFC) for arrhythmogenic right ventricular cardiomyopathy (ARVC) was updated in 2010 to improve specificity. There was concern however that the revised cardiovascular magnetic resonance (CMR) criteria was too restrictive and not sensitive enough to detect early forms of the condition. We previously described patients with clinically suspected ARVC who satisfied criteria from non-imaging TFC categories and fulfilled parameters from the original but not the revised CMR criteria; as a result, these patients were not confirmed as definite ARVC but may represent an early phenotype. Methods: Patients scanned between 2008 and 2015 who had either right ventricular (RV) dilatation or regional dyskinesia satisfying at least minor imaging parameters from the original criteria and without contra-indication underwent serial CMR scanning using a 1.5 T scanner. The aims were to assess the risk of progressive RV abnormalities, evaluate the accuracy of the revised CMR criteria and the need for guideline directed CMR surveillance in at-risk individuals. Results: Overall, 48 patients were re-scanned; 24 had a first-degree relative diagnosed with ARVC using the revised TFC or a first-degree relative with premature sudden death from suspected ARVC and 24 patients had either left bundle branch morphology ventricular tachycardia or > 500 ventricular extra-systoles in 24-h. Mean follow up was 69+/- 25 months. The indexed RV end-diastolic, end-systolic volumes and ejection fraction were calculated for both scans. There was significant reduction in RV volumes and improvement in RV ejection fraction (EF) irrespective of changes to body surface area; - 11.7+/- 15.2 mls/m2, - 6.4+/- 10.5 mls/m2 and + 3.3 +/- 7.9% (p = 0.01, 0.01 and 0.04). Applying the RV parameters to the revised CMR criteria, two patients from the family history group (one with confirmed ARVC and one with a premature death) had progressive RV abnormalities satisfying major criteria. The remaining patients (n = 46) did not satisfy the criteria and either had normal RV parameters with regression of structural abnormalities (27,56.3%) or stable abnormalities (19,43.7%). Conclusion: The revised CMR criteria represents a robust tool in the evaluation of patients with clinical suspicion of ARVC, especially for those with ventricular arrhythmias without a family history for ARVC. For patients with RV abnormalities that do not fulfill the revised criteria but have a family history of ARVC or an ARVC associated gene mutation, a surveillance CMR scan should be considered as part of the clinical follow up protocol

ECG-based Cardiac Screening Programs: Legal, Ethical and Logistical Considerations

Screening asymptomatic people with a resting electrocardiogram (ECG) has been theorised to detect latent cardiovascular disease. However, resting ECG screening is not recommended for numerous populations, such as asymptomatic middle-aged (sedentary) people, as it is not sufficiently sensitive to detect coronary artery disease. While the issues raised in this article are largely common to all screening programs, this review focuses on two distinct programs: (1) screening elite athletes for conditions associated with sudden cardiac death (SCD); and (2) screening people aged ?65 years for atrial fibrillation (AF). These two settings have recently gained attention for their promise and concerns regarding prevention of SCD and stroke, respectively. If screening is done, it must be done well. Organisations conducting screening must consider a range of legal, ethical and logistical responsibilities which arise from the beginning to end of the process. This includes consideration of who to screen, timing of screening, whether it is mandatory, consent issues, and auditing systems to ensure quality control. Good infrastructure for interpretation of ECG results according to expert guidelines, and follow-up testing for abnormal screening results, including a pathway to treatment, are essential. Finally, there may be significant implications for those diagnosed with cardiac disease, including insurance, employment, the ability to play sport and mental health issues. There are several legal risks, and the best protective measures are good communication systems, thorough clinical records, careful handling of eligibility questions for those diagnosed, and reference to expert guidelines as the standard of ca

Utilization of Community as a Resource for Depolluting Cities

There exists an intimate relationship between a city, its community and pollution. Most of the pollution can be attributed to the anthropogenic manipulation of city's resources, done to service the community. This pollution, in turn, creates conditions that challenge the well-being of the community as well as that of the city's natural resources. In recent times, urbanization has surpassed the rate of development of pollution mitigation strategies. As municipal corporations struggle to treat and dispose the ever increasing wastes and control various forms of environmental contamination, the pollution load of developing cities is steadily on the rise. This paper suggests ways to utilize community as a tool for mitigation of pollution. First, it is suggested that the city be divided into zones based on pollution load (spatial and annual occurrence) with the help of environmental testing and monitoring techniques. This creates a clear picture of the nature and extent of pollution in various parts of the city. Training activities and pollution prevention programs can be conducted for the communities residing in these parts, focusing on the nature of pollution load that they contribute towards. Such zoning would also optimize decisions regarding regulations, policies and fund allocation. Another concept explored in this paper deals with identification of pollution causing and pollution reducing agents. Various activities and objects, like open dumping of wastes, vehicular pollution, open discharge of sewage, etc. can be labelled as pollution causing agents. Similarly, scavengers such as crows (that feed on wastes), community initiatives such as waste segregation at source or reuse of waste, etc. can be classified under pollution reducing agents. This categorization enables planners to develop community development initiatives that generate awareness regarding activities and aspects that cause pollution and help in integrating trends that cause lesser or no pollution. Policy development with sensitivity towards the existing social strata is also touched upon. Thusly, this paper attempts to explore strategies to aid de-pollution of cities by conditioning its community and human resource

Unveiling the Potential of Infrared Thermography in Quantitative Investigation of Potential-Induced Degradation in Crystalline Silicon PV Module

Potential-induced degradation-shunting (PID-s) is a severe degradation mechanism in photovoltaic (PV) cells that significantly impacts module performance. Regular monitoring and quantitative assessment of PID-s are crucial for ensuring long-term reliability of PV systems. Current-voltage (I-V) characteristics and electroluminescence (EL) imaging are commonly used for quantitative performance evaluation of PID-s affected PV modules. However, conducting I-V measurements is time-consuming when performed across large PV installations, while EL imaging has limitations for severely PID-s affected cells with no EL emission. This article proposes the use of inverse infrared (IRINV) thermography as an alternative investigation technique for PID-s in a PV module. IRINV imaging is fast and also effectively maps the severely PID-s affected cells in a PV module. This article unveils the potential of IRINV thermography in quantitative investigation of PID-s in crystalline silicon PV modules. The module level investigations present insights into the correlations between cell temperature and power output under different imaging conditions using Pearson correlation. Results indicate that steady-state operation with medium input current provides the most suitable condition for quantitative PID-s investigation. Furthermore, cell level analysis of temperature distribution and its variation with PID-s progression has been investigated using histogram and kernel density estimation (KDE) statistical tools, revealing distinct patterns as PID-s progresses. A PID-s severity index is proposed based on KDE, providing a quantitative measure of PID-s severity in cells within a PV module. This work provides valuable insights into the use of IRINV thermography as an alternative technique for assessment of PID-s in PV module inspection

Estimate of etched tracks by optical method and spark counting

Solid State Nuclear Track Detectors (SSNTD) are commonly used for long term measurements of radon, thoron and progeny concentrations. In the present study, we compared the optical counting method and the spark counting technique for counting the alpha tracks on LR 115 track detector films. The paper discusses the various parameters that are innate in the process. More than 300 films were counted by both optical microscope and spark counter and the results are compared. The overall results show that the tracks obtained by spark counting are marginally less compared to the optical measurement. A linear fit of the data gives a slope less that one, which indicates that both the methods are almost in good agreement for counting the tracks when the track density is low. At higher track densities the spark counter gives an underestimation with respect to actual number of tracks formed, which could be corrected using a relation obtained between the tracks measured by optical method and spark counting.Estimate of etched tracks by optical method and spark counting Rajesh Kumar, K P Eappen*, A K Shukla, R M Tripathi and V D Puranik Environmental Assessment Division, Bhabha Atomic Research Centre, Mumbai-400 085, India E-mail : [email protected] Assessment Division, Bhabha Atomic Research Centre, Mumbai-400 085, Indi

Systematic review : impact of the new task force criteria in the diagnosis of arrhythmogenic right ventricular cardiomyopathy

Background Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited disorder of cardiac desmosomes associated with ventricular arrhythmias and sudden cardiac death. The clinical diagnosis is problematic and relies on a complex criteria composed of clinical and non-clinical parameters. In 2010, the original 1994 Task Force Criteria (TFC) was revised with particular attention given to the imaging parameters. Methods Five retrospective studies compared the diagnostic concordance between the 1994 and 2010 TFC. Three studies used cardiac magnetic resonance (CMR) and compared major and minor CMR criteria and three studies compared definite ARVC cases; one study assessed both. Results Three studies with 1435 patients compared the 1994 imaging and the 2010 CMR criteria. Using the 1994 criteria, 123 (8.6%) and 419 (29.2%) patients satisfied major and minor criteria compared to only 52 (3.6%) and 28 (1.9%) using the 2010 criteria; 57.7% and 94.3% reduction in major and minor criteria (p value, 0.0001 and 0.0001). Three studies with 611 patients assessed for definite ARVC. Using the 1994 and 2010 criteria, 207 (33.9%) and 243 (39.8%) patients satisfied the parameters respectively. This resulted in a statistically significant 17.4% (p value, 0.0379) increase in ARVC cases driven largely by two sub-groups. Conclusions The 2010 revised TFC have resulted in a significant reduction in the number of patients that satisfy CMR criteria particularly those that satisfied minor imaging abnormalities using the 1994 criteria. In addition, in certain groups the revised criteria have significantly increased the number of patients diagnosed with definite ARVC