Displaying all 11 publications

Abstract:
Sort:
  1. Evaluation of functional severity of coronary artery disease and fluid dynamics' influence on hemodynamic parameters: A review
    Govindaraju K, Badruddin IA, Viswanathan GN, Ramesh SV, Badarudin A
    Phys Med, 2013 May;29(3):225-32.
    PMID: 22704601 DOI: 10.1016/j.ejmp.2012.03.008
    Coronary Artery Disease (CAD) is responsible for most of the deaths in patients with cardiovascular diseases. Diagnostic coronary angiography analysis offers an anatomical knowledge of the severity of the stenosis. The functional or physiological significance is more valuable than the anatomical significance of CAD. Clinicians assess the functional severity of the stenosis by resorting to an invasive measurement of the pressure drop and flow. Hemodynamic parameters, such as pressure wire assessment fractional flow reserve (FFR) or Doppler wire assessment coronary flow reserve (CFR) are well-proven techniques to evaluate the physiological significance of the coronary artery stenosis in the cardiac catheterization laboratory. Between the two techniques mentioned above, the FFR is seen as a very useful index. The presence of guide wire reduces the coronary flow which causes the underestimation of pressure drop across the stenosis which leads to dilemma for the clinicians in the assessment of moderate stenosis. In such condition, the fundamental fluid mechanics is useful in the development of new functional severity parameters such as pressure drop coefficient and lesion flow coefficient. Since the flow takes place in a narrowed artery, the blood behaves as a non-Newtonian fluid. Computational fluid dynamics (CFD) allows a complete coronary flow simulation to study the relationship between the pressure and flow. This paper aims at explaining (i) diagnostic modalities for the evaluation of the CAD and valuable insights regarding FFR in the evaluation of the functional severity of the CAD (ii) the role of fluid dynamics in measuring the severity of CAD.
  2. Effect of porous media of the stenosed artery wall to the coronary physiological diagnostic parameter: a computational fluid dynamic analysis
    Govindaraju K, Kamangar S, Badruddin IA, Viswanathan GN, Badarudin A, Salman Ahmed NJ
    Atherosclerosis, 2014 Apr;233(2):630-635.
    PMID: 24549189 DOI: 10.1016/j.atherosclerosis.2014.01.043
    Functional assessment of a coronary artery stenosis severity is generally assessed by fractional flow reserve (FFR), which is calculated from pressure measurements across the stenosis. The purpose of this study is to investigate the effect of porous media of the stenosed arterial wall on this diagnostic parameter. To understand the role of porous media on the diagnostic parameter FFR, a 3D computational simulations of the blood flow in rigid and porous stenotic artery wall models are carried out under steady state and transient conditions for three different percentage area stenoses (AS) corresponding to 70% (moderate), 80% (intermediate), and 90% (severe). Blood was modeled as a non Newtonian fluid. The variations of pressure drop across the stenosis and diagnostic parameter were studied in both models. The FFR decreased in proportion to the increase in the severity of the stenosis. The relationship between the percentage AS and the FFR was non linear and inversely related in both the models. The cut-off value of 0.75 for FFR was observed at 81.89% AS for the rigid artery model whereas 83.61% AS for the porous artery wall model. This study demonstrates that the porous media consideration on the stenotic arterial wall plays a substantial role in defining the cut-off value of FFR. We conclude that the effect of porous media on FFR, could lead to misinterpretation of the functional severity of the stenosis in the region of 81.89 %-83.61% AS.
  3. The influence of artery wall curvature on the anatomical assessment of stenosis severity derived from fractional flow reserve: a computational fluid dynamics study
    Govindaraju K, Viswanathan GN, Badruddin IA, Kamangar S, Salman Ahmed NJ, Al-Rashed AA
    Comput Methods Biomech Biomed Engin, 2016 Nov;19(14):1541-9.
    PMID: 27052093 DOI: 10.1080/10255842.2016.1170119
    This study aims to investigate the influence of artery wall curvature on the anatomical assessment of stenosis severity and to identify a region of misinterpretation in the assessment of per cent area stenosis (AS) for functionally significant stenosis using fractional flow reserve (FFR) as standard. Five artery models of different per cent AS severity (70, 75, 80, 85 and 90%) were considered. For each per cent AS severity, the angle of curvature of the arterial wall varied from straight to an increasingly curved model (0°, 30°, 60°, 90° and 120°). Computational fluid dynamics was performed under transient physiologic hyperemic flow conditions to investigate the influence of artery wall curvature on the pressure drop and the FFR. The findings in this study may be useful in in vitro anatomical assessment of functionally significant stenosis. The FFR decreased with increasing stenosis severity for a given curvature of the artery wall. Moreover, a significant decrease in FFR was found between straight and curved models discussed for a given severity condition. These findings indicate that the curvature effect was included in the FFR assessment in contrast to minimum lumen area (MLA) or per cent AS assessment. The MLA or per cent AS assessment may lead to underestimation of stenosis severity. From this numerical study, an uncertainty region could be evaluated using the clinical FFR cutoff value of 0.8. This value was observed at 81.98 and 79.10% AS for arteries with curvature angles of 0° and 120° respectively. In conclusion, the curvature of the artery should not be neglected in in vitro anatomical assessment.
  4. Patient-specific 3D hemodynamics modelling of left coronary artery under hyperemic conditions
    Kamangar S, Badruddin IA, Govindaraju K, Nik-Ghazali N, Badarudin A, Viswanathan GN, et al.
    Med Biol Eng Comput, 2017 Aug;55(8):1451-1461.
    PMID: 28004229 DOI: 10.1007/s11517-016-1604-8
    The purpose of this study is to investigate the effect of various degrees of percentage stenosis on hemodynamic parameters during the hyperemic flow condition. 3D patient-specific coronary artery models were generated based on the CT scan data using MIMICS-18. Numerical simulation was performed for normal and stenosed coronary artery models of 70, 80 and 90% AS (area stenosis). Pressure, velocity, wall shear stress and fractional flow reserve (FFR) were measured and compared with the normal coronary artery model during the cardiac cycle. The results show that, as the percentage AS increase, the pressure drop increases as compared with the normal coronary artery model. Considerable elevation of velocity was observed as the percentage AS increases. The results also demonstrate a recirculation zone immediate after the stenosis which could lead to further progression of stenosis in the flow-disturbed area. Highest wall shear stress was observed for 90% AS as compared to other models that could result in the rupture of coronary artery. The FFR of 90% AS is found to be considerably low.
  5. Influence of stenosis on hemodynamic parameters in the realistic left coronary artery under hyperemic conditions
    Kamangar S, Badruddin IA, Badarudin A, Nik-Ghazali N, Govindaraju K, Salman Ahmed NJ, et al.
    Comput Methods Biomech Biomed Engin, 2017 Mar;20(4):365-372.
    PMID: 27612619 DOI: 10.1080/10255842.2016.1233402
    The current study investigates the hyperemic flow effects on heamodynamics parameters such as velocity, wall shear stress in 3D coronary artery models with and without stenosis. The hyperemic flow is used to evaluate the functional significance of stenosis in the current era. Patients CT scan data of having healthy and coronary artery disease was chosen for the reconstruction of 3D coronary artery models. The diseased 3D models of coronary artery shows a narrowing of >50% lumen area. Computational fluid dynamics was performed to simulate the hyperemic flow condition. The results showed that the recirculation zone was observed immediate to the stenosis and highest wall shear stress was observed across the stenosis. The decrease in pressure was found downstream to the stenosis as compared to the coronary artery without stenosis. Our analysis provides an insight into the distribution of wall shear stress and pressure drop, thus improving our understanding of hyperemic flow effect under both conditions.
  6. Fulltext Evidence-based traditional Siddha formulations for prophylaxis and management of respiratory symptoms in COVID-19 pandemic-a review
    Prakash P, Meena R, Stanley Abraham L, Sunkar S, Govindaraju K, Pully D, et al.
    Biocatal Agric Biotechnol, 2021 Aug;35:102056.
    PMID: 34122672 DOI: 10.1016/j.bcab.2021.102056
    The recent outbreak of COVID-19 is attributed to Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). This viral disease is rapidly spreading across the globe, including India. The mainstay in managing the disease is supportive care, nutrition, and preventing further progression in the absence of proven antiviral drugs. Currently two vaccines Covishield and Covaxin are administered in India. Long-term plans of developing most reliable mRNA-based vaccines are also underway for the future method of prophylaxis. The Siddha system of medicine's holistic approach emphasizes lifestyle modification, prophylactic interventions, and dietary management to boost the host immunity and treatment with herbal medicines and higher-order medicines as the case may be. In this review, a brief outline of the disease COVID-19, Coronavirus, evidence-based traditional Siddha interventions for respiratory ailments and immune boosters highlighting the relevant published research on individual herbs are dealt, which pave way for further research on drug repurposing for COVID-19. Historical evidence on the prevention and treatment of infections especially antivirals in Siddha classics is studied.
  7. Practice and knowledge of dietary supplement consumption among Indonesian adults post-delta wave of the COVID-19 pandemic
    d'Arqom A, Nasution MZ, Kadir SZSA, Yusof J, Govindaraju K
    F1000Res, 2023;12:3.
    PMID: 37469719 DOI: 10.12688/f1000research.129045.2
    Background: Increasing dietary supplement (DS) consumption was observed during the COVID-19 pandemic, including during the post-Delta wave period. This study aimed to measure the practice of DS consumption and respondents' knowledge of DS. Methods: An internet-based survey was distributed from October-December 2021 and obtained 541 valid and completed responses. Descriptive analysis was performed to present the practice of DS consumption, including frequency, duration, aim, preferable dosage form etc. Level of knowledge on DS principles, side effects and regulation were also measured. Inferential analyses were conducted to determine the predictors of the respondents' DS practice and level of knowledge. Results: Data from 541 valid responses showed that 77.63% of respondents consumed DS in the last 3 months, with only 59.52% reporting also consuming DS before the COVID-19 pandemic. One half of the respondents had good knowledge about DS; however, some knowledge regarding side effects and possible drug-supplement interaction needed improvement. Their DS consumption practice was affected by their economic status and history of contracting COVID-19. Nevertheless, the level of knowledge was not affected by the sociodemographic factors and DS supplement experience. Conclusions: Taken together, the practice of self-consumption of DS in Indonesia is increasing; hence, knowledge of DS is necessary to avoid detrimental effects that might occur in the future. Increasing access to information on better labelling and educating consumers about DS are important actions to consider.
  8. Mesenchymal stem cell-derived extracellular vesicles for metabolic syndrome therapy: Assessing efficacy with nuclear magnetic resonance spectroscopy
    Ling MTM, Govindaraju K, Lokanathan Y, Abidin AZ, Ibrahim B
    Cell Biochem Funct, 2023 Dec;41(8):1044-1059.
    PMID: 37933415 DOI: 10.1002/cbf.3881
    Metabolic syndrome (MetS) represents a cluster of metabolic abnormalities. The prevalence of MetS has surged, transforming it into a pressing public health concern that could potentially affect around 20%-25% of the global population. As MetS continues its ascent, diverse interventions, pharmacological, nonpharmacological and combined have been deployed. Yet, a comprehensive remedy that fully eradicates MetS symptoms remains elusive, compounded by the risks of polypharmacy's emergence. Acknowledging the imperative to grasp MetS's intricate pathologies, deeper insights for future research and therapy optimisation become paramount. Conventional treatments often target specific syndrome elements. However, a novel approach emerges in mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) therapy, promising a holistic shift. MSC-EVs, tiny membranous vesicles secreted by mesenchymal stem cells, have garnered immense attention for their multifaceted bioactivity and regenerative potential. Their ability to modulate inflammation, enhance tissue repair and regulate metabolic pathways has prompted researchers to explore their therapeutic application in MetS. This review primarily aims to provide an overview of how MSC-EVs therapy can improve metabolic parameters in subjects with MetS disease and also introduce the usefulness of NMR spectroscopy in assessing the efficacy of MSC-EVs therapy for treating MetS.
  9. Patient specific 3-d modeling of blood flow in a multi-stenosed left coronary artery
    Kamangar S, Badruddin IA, Ameer Ahamad N, Soudagar MEM, Govindaraju K, Nik-Ghazali N, et al.
    Biomed Mater Eng, 2017;28(3):257-266.
    PMID: 28527189 DOI: 10.3233/BME-171672
    The current study investigates the effect of multi stenosis on the hemodynamic parameters such as wall pressure, velocity and wall shear stress in the realistic left coronary artery. Patients CT scan image data of normal and diseased left coronary artery was chosen for the reconstruction of 3D coronary artery models. The diseased 3D model of left coronary artery shows a narrowing of more than 70% and 80% of area stenosis (AS) at the left main stem (LMS) and left circumflex (LCX) respectively. The results show that the decrease in pressure was found downstream to the stenosis as compared to the coronary artery without stenosis. The maximum pressure drop was noted across the 80% AS at the left circumflex branch. The recirculation zone was also observed immediate to the stenosis and highest wall shear stress was found across the 80% area stenosis. Our analysis provides an insight into the distribution of wall shear stress and pressure drop, thus improving our understanding on the hemodynamics in realistic coronary artery.
  10. Fulltext Exploring the rise of telehealth services in Malaysia: A retrospective study
    Loo JS, Yow HY, Ten YY, Govindaraju K, Megat Mohd Zubairi MH, Oui HC, et al.
    Digit Health, 2023;9:20552076231216275.
    PMID: 38025110 DOI: 10.1177/20552076231216275
    BACKGROUND: Telehealth services have gained popularity in Malaysia, providing convenient consultations during the COVID-19 pandemic. However, there is limited research on their usage, user demographics and prescribed medications. This study aims to fill that gap by investigating telehealth service utilisation in community pharmacies and identifying trends in common diagnoses and medications prescribed.

    METHODS: A retrospective observational study was conducted using a telehealth services database in Malaysian community pharmacies. Consultation records from January 2019 to December 2021 were extracted using a data collection form. The study identified the service usage over time, demographic profiles of users and the most common diagnoses and prescribed medications. Diagnoses were classified using the International Classification of Disease, 10th Revision (ICD-10), and medications were classified using the Anatomical Therapeutic Chemical (ATC) system.

    RESULTS: The study included 835,826 telehealth service records, with 88.8% being assisted consultations with e-prescriptions and 11.2% direct consultations. The user population consisted of primarily Malaysians (96.9%), with a mean age of 50 ± 21 years. Both telehealth services saw an increase in unique users over the 3-year study period. There was a moderate correlation between active COVID-19 cases and monthly user count. Assisted consultations were more widely used than direct consultations.

    CONCLUSION: This study found an increased usage of telehealth services and its potential to remain as a healthcare system feature in community pharmacies. Further investigation into the impact on medication safety, quality and healthcare delivery is warranted.

  11. Fulltext Ethnic disparities and its association between epicardial adipose tissue thickness and cardiometabolic parameters
    Mohamed W, Ishak KN, Baharum N, Zainudin N, Lim HY, Noh M, et al.
    Adipocyte, 2024 Dec;13(1):2314032.
    PMID: 38373876 DOI: 10.1080/21623945.2024.2314032
    Excessive deposit of epicardial adipose tissue (EAT) were recently shown to be positively correlated with cardiovascular disease (CVD). This study aims to investigate the thickness of EAT and its association with the components of metabolic syndrome among multi-ethnic Malaysians with and without acute coronary syndrome (ACS). A total of 213 patients were recruited, with the thickness of EAT were quantified non-invasively using standard two-dimensional echocardiography. EAT thickness among the Malaysian population was prompted by several demographic factors and medical comorbidities, particularly T2DM and dyslipidaemia. ACS patients have significantly thicker EAT compared to those without ACS (4.1 mm vs 3.7 mm, p = 0.035). Interestingly, among all the races, Chinese had the thickest EAT distribution (4.6 mm vs 3.8 mm), with age (p = 0.04 vs p 
Related Terms
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links