Displaying publications 401 - 420 of 977 in total

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  1. Ahmad S, Valli H, Edling CE, Grace AA, Jeevaratnam K, Huang CL
    Pflugers Arch, 2017 Dec;469(12):1579-1590.
    PMID: 28821956 DOI: 10.1007/s00424-017-2054-3
    A range of chronic clinical conditions accompany cardiomyocyte energetic dysfunction and constitute independent risk factors for cardiac arrhythmia. We investigated pro-arrhythmic and arrhythmic phenotypes in energetically deficient C57BL mice with genetic ablation of the mitochondrial promoter peroxisome proliferator-activated receptor-γ coactivator-1β (Pgc-1β), a known model of ventricular arrhythmia. Pro-arrhythmic and cellular action potential (AP) characteristics were compared in intact Langendorff-perfused hearts from young (12-16 week) and aged (> 52 week), wild-type (WT) and Pgc-1β -/- mice. Simultaneous electrocardiographic and intracellular microelectrode recordings were made through successive trains of 100 regular stimuli at progressively incremented heart rates. Aged Pgc-1β -/- hearts displayed an increased incidence of arrhythmia compared to other groups. Young and aged Pgc-1β -/- hearts showed higher incidences of alternans in both AP activation (maximum AP upshoot velocity (dV/dt)max and latency), recovery (action potential duration (APD90) and resting membrane potential (RMP) characteristics compared to WT hearts. This was particularly apparent at lower pacing frequencies. These findings accompanied reduced (dV/dt)max and increased AP latency values in the Pgc-1β -/- hearts. APs observed prior to termination of the protocol showed lower (dV/dt)max and longer AP latencies, but indistinguishable APD90 and RMPs in arrhythmic compared to those in non-arrhythmic hearts. APD restitution analysis showed that Pgc-1β -/- and WT hearts showed similar limiting gradients. However, Pgc-1β -/- hearts had shortened plateau AP wavelengths, particularly in aged Pgc-1β -/- hearts. Pgc-1β -/- hearts therefore show pro-arrhythmic instabilities attributable to altered AP conduction and activation rather than recovery characteristics.
    Matched MeSH terms: Heart Ventricles/metabolism*; Heart Ventricles/physiopathology
  2. Suhaida SS, Engkasan JP
    Med J Malaysia, 2012 Dec;67(6):616-7.
    PMID: 23770957 MyJurnal
    A 48-year-old male with complete tetraplegia C6 presented with sweating and flushing of the right half of the face and neck that recurred when lying in supine and left lateral positions. The symptoms subsided immediately upon sitting upright or lying in a right lateral position. The symptoms were associated with occasional mild head discomfort rather than headache and were accompanied by marked elevation of blood pressure, which was 190-200/120-130 mmHg compared to his previous baseline blood pressure of 80-90/50-70 mmHg, and he had a heart rate of 60-70 beats per minute. We believe that post-traumatic syringomyelia, found upon further investigation, was the cause of the Autonomic dysreflexia (AD) in this patient. He was advised to avoid the positions causing the symptoms and the progression of symptoms was monitored regularly. AD might not have been diagnosed in this patient because of the atypical and unusual presentations. Therefore, knowledge and a heightened level of awareness of this possible complication are important when treating individuals with spinal cord injury (SCI).
    Matched MeSH terms: Heart Rate
  3. Chia PL, Loh SY, Foo D
    Med J Malaysia, 2012 Dec;67(6):582-4.
    PMID: 23770949
    INTRODUCTION: Ventricular tachycardia (VT) storm is an uncommon but life-threatening condition. We describe the incidence, causes and management of VT storm among patients admitted to the coronary care unit of a large tertiary hospital.

    MATERIALS AND METHODS: Between 1 November 2009 and 30 April 2010, 198 patients were admitted to the coronary care unit and 7 (3.5%) presented with VT storm. A retrospective review of their records was conducted. The mean follow-up period was 268 (196 to 345) days.

    RESULTS: The mean age was 67 years and 4 patients were male. One patient had a previous myocardial infarction. All had abnormal left ventricular ejection fraction, median of 30%. Acute myocardial infarction (4 patients) was the most common trigger, followed by decompensated heart failure (1), systemic inflammatory response syndrome on a background of non-ischemic dilated cardiomyopathy (1) and bradycardia-induced polymorphic VT (1). Three patients had polymorphic VT and the rest had monomorphic VT. Intravenous amiodarone, lignocaine, overdrive pacing and intra-aortic balloon pump counterpulsation were useful in arrhythmia control. Three patients underwent coronary revascularization, 3 patients received implantable cardioverter-defibrillators, 1 had a permanent cardiac pacemaker, 1 died during the acute episode. Five out of the 6 survivors were prescribed oral beta-blockers upon discharge. On follow-up, none of the patients had a recurrence of the tachyarrhythmia.

    CONCLUSION: Acute myocardial infarction was the main trigger of VT storm in our patients. Intravenous amiodarone, lignocaine, overdrive pacing and intra-aortic balloon pump counterpulsation were useful at suppressing VT storm.
    Matched MeSH terms: Heart Failure
  4. Raheem IA, Saaid R, Omar SZ, Tan PC
    BJOG, 2012 Jan;119(1):78-85.
    PMID: 21985500 DOI: 10.1111/j.1471-0528.2011.03151.x
    To compare oral nifedipine with intravenous labetalol in their rapidity to control hypertensive emergencies of pregnancy.
    Matched MeSH terms: Heart Rate/drug effects; Heart Rate, Fetal/drug effects
  5. Ahmad WA, Khanom M, Yaakob ZH
    Int J Clin Pract, 2011 Aug;65(8):848-51.
    PMID: 21762308 DOI: 10.1111/j.1742-1241.2011.02714.x
    The treatment of heart failure in pregnant women is more difficult than in non-pregnant women, and should always involve a multidisciplinary team approach. Knowledge required includes hemodynamic changes in pregnancy and the resultant effect on women with pre-existing or pregnancy-related cardiovascular disease, cardiovascular drugs in pregnancy, ethical issues and challenges regarding saving mother and baby. In addition, women having high risk cardiac lesions should be counselled strongly against pregnancy and followed up regularly. Pregnancy with heart failure is an important issue, demanding more comprehensive studies.
    Matched MeSH terms: Heart Failure/diagnosis; Heart Failure/physiopathology; Heart Failure/therapy*
  6. Chew F Z A W M N KS, Mohd Hashairi F, Ida Zarina Z, Shaik Farid AW, Abu Yazid MN, Nik Hisamuddin NA
    Med J Malaysia, 2011 Mar;66(1):56-9.
    PMID: 23765145 MyJurnal
    Junior doctors are often the "first line" doctors called to attend to patients in cardiac arrest. We performed an anonymous questionnaire study from October 2008 to December 2008 to assess the knowledge, attitude and skill of cardiopulmonary resuscitation among junior doctors in Hospital Universiti Sains Malaysia and Hospital Raja Perempuan Zainab II. Out of the 100 questionnaire forms sent out, 70 were returned completed. The majority (85.8%) stated that they were not confident of managing a resuscitation case. There was a statistically significant (p<0.001) association between duration of clinical practice and confidence level. Up to 77.1% said that BLS should be re-certified every two years.
    Matched MeSH terms: Heart Arrest
  7. Tan G, Abdullah B, Kunanayagam S
    Biomed Imaging Interv J, 2006 Apr;2(2):e13.
    PMID: 21614225 MyJurnal DOI: 10.2349/biij.2.2.e13
    Acquired intra-abdominal arteriovenous fistulas (AVFs) are a rare disorder where the communication most commonly occurs between abdominal aorta and inferior vena cava. Ilio-iliac AVF has been reported previously, but is exceedingly rare. We present a case of spontaneous ilio-iliac AVF in an elderly woman who presented with symptoms of right heart failure where the diagnosis was not considered. The computed tomographic (CT) and angiographic features are described. The current status of management as well as a review of the literature is also presented.
    Matched MeSH terms: Heart Failure
  8. Narasimman S, Nallusamy M, Hassan S
    Med J Malaysia, 2013;68(1):48-51.
    PMID: 23466767 MyJurnal
    Oesophageal atresia (EA) and tracheoesophageal fistula (TEF) is one of the congenital anomaly occurring in the newborns with the incidence of 1 in 2500 births seen worldwide. A retrospective review of newborns admitted to Hospital Sultanah Bahiyah (HSB) from 1st January 2000 to 31st December 2009 was done. The objective was to look at the influence of birth weight, time of surgical intervention, presence of other congenital anomaly and presence of preoperative pneumonia to the immediate outcome (mortality) of the surgery. There were 47 patients with oesophageal atresia, out of which 26 (55%) were males and 21 (45%) females. The distribution of patients by race were 34 Malays (72%), 9 Chinese (19%) and 4 Indians (9%). The birth weight of the babies range from 0.8 kg to 4.0 kg and there was a significant association with the outcome of the surgery (p< 0.05). Most of the babies (20) were operated within 24 hours of presentation but there was no significant association to the outcome. 23 (49%) of them were born with congenital malformation and there was a significant association with the outcome of the surgery (p<0.05). Based on the chest roentgenogram, 20 (43%) of them had pneumonia with significant association with the outcome (p<0.05). The mortality rate is 23% and the causes of death were pneumonia (36%), renal failure (18%), cardiac malformation (18%) and multiple congenital malformations (28%). The outcome of EA and TEF is determined mainly by birth weight, congenital malformations and presence of preoperative pneumonia in HSB.
    Matched MeSH terms: Heart Defects, Congenital
  9. Itagi AB, Arora D, Patil NA, Bailwad SA, Yunus GY, Goel A
    Int J Appl Basic Med Res, 2016 Jan-Mar;6(1):45-9.
    PMID: 26958522 DOI: 10.4103/2229-516X.174008
    An increase in the consumption of smokeless tobacco has been noticed among high school, college students, and adults. Despite the antiquity and popularity of chewing tobacco in India, its effects have not been investigated systematically in humans. The aim of this study was to investigate acute effects of gutkha chewing on heart rate variability (HRV) among healthy young adults.
    Matched MeSH terms: Heart Rate
  10. Khaw YS, Chan YF, Jafar FL, Othman N, Chee HY
    Front Microbiol, 2016;7:543.
    PMID: 27199901 DOI: 10.3389/fmicb.2016.00543
    Human rhinovirus-C (HRV-C) has been implicated in more severe illnesses than HRV-A and HRV-B, however, the limited number of HRV-C complete genomes (complete 5' and 3' non-coding region and open reading frame sequences) has hindered the in-depth genetic study of this virus. This study aimed to sequence seven complete HRV-C genomes from Malaysia and compare their genetic characteristics with the 18 published HRV-Cs. Seven Malaysian HRV-C complete genomes were obtained with newly redesigned primers. The seven genomes were classified as HRV-C6, C12, C22, C23, C26, C42, and pat16 based on the VP4/VP2 and VP1 pairwise distance threshold classification. Five of the seven Malaysian isolates, namely, 3430-MY-10/C22, 8713-MY-10/C23, 8097-MY-11/C26, 1570-MY-10/C42, and 7383-MY-10/pat16 are the first newly sequenced complete HRV-C genomes. All seven Malaysian isolates genomes displayed nucleotide similarity of 63-81% among themselves and 63-96% with other HRV-Cs. Malaysian HRV-Cs had similar putative immunogenic sites, putative receptor utilization and potential antiviral sites as other HRV-Cs. The genomic features of Malaysian isolates were similar to those of other HRV-Cs. Negative selections were frequently detected in HRV-Cs complete coding sequences indicating that these sequences were under functional constraint. The present study showed that HRV-Cs from Malaysia have diverse genetic sequences but share conserved genomic features with other HRV-Cs. This genetic information could provide further aid in the understanding of HRV-C infection.
    Matched MeSH terms: Heart Rate
  11. Sudarshan VK, Acharya UR, Ng EY, Tan RS, Chou SM, Ghista DN
    Comput Biol Med, 2016 Apr 1;71:231-40.
    PMID: 26898671 DOI: 10.1016/j.compbiomed.2016.01.028
    Cross-sectional view echocardiography is an efficient non-invasive diagnostic tool for characterizing Myocardial Infarction (MI) and stages of expansion leading to heart failure. An automated computer-aided technique of cross-sectional echocardiography feature assessment can aid clinicians in early and more reliable detection of MI patients before subsequent catastrophic post-MI medical conditions. Therefore, this paper proposes a novel Myocardial Infarction Index (MII) to discriminate infarcted and normal myocardium using features extracted from apical cross-sectional views of echocardiograms. The cross-sectional view of normal and MI echocardiography images are represented as textons using Maximum Responses (MR8) filter banks. Fractal Dimension (FD), Higher-Order Statistics (HOS), Hu's moments, Gabor Transform features, Fuzzy Entropy (FEnt), Energy, Local binary Pattern (LBP), Renyi's Entropy (REnt), Shannon's Entropy (ShEnt), and Kapur's Entropy (KEnt) features are extracted from textons. These features are ranked using t-test and fuzzy Max-Relevancy and Min-Redundancy (mRMR) ranking methods. Then, combinations of highly ranked features are used in the formulation and development of an integrated MII. This calculated novel MII is used to accurately and quickly detect infarcted myocardium by using one numerical value. Also, the highly ranked features are subjected to classification using different classifiers for the characterization of normal and MI LV ultrasound images using a minimum number of features. Our current technique is able to characterize MI with an average accuracy of 94.37%, sensitivity of 91.25% and specificity of 97.50% with 8 apical four chambers view features extracted from only single frame per patient making this a more reliable and accurate classification.
    Matched MeSH terms: Heart Failure
  12. Sudarshan VK, Acharya UR, Ng EY, Tan RS, Chou SM, Ghista DN
    Comput Biol Med, 2016 Apr 1;71:241-51.
    PMID: 26897481 DOI: 10.1016/j.compbiomed.2016.01.029
    Early expansion of infarcted zone after Acute Myocardial Infarction (AMI) has serious short and long-term consequences and contributes to increased mortality. Thus, identification of moderate and severe phases of AMI before leading to other catastrophic post-MI medical condition is most important for aggressive treatment and management. Advanced image processing techniques together with robust classifier using two-dimensional (2D) echocardiograms may aid for automated classification of the extent of infarcted myocardium. Therefore, this paper proposes novel algorithms namely Curvelet Transform (CT) and Local Configuration Pattern (LCP) for an automated detection of normal, moderately infarcted and severely infarcted myocardium using 2D echocardiograms. The methodology extracts the LCP features from CT coefficients of echocardiograms. The obtained features are subjected to Marginal Fisher Analysis (MFA) dimensionality reduction technique followed by fuzzy entropy based ranking method. Different classifiers are used to differentiate ranked features into three classes normal, moderate and severely infarcted based on the extent of damage to myocardium. The developed algorithm has achieved an accuracy of 98.99%, sensitivity of 98.48% and specificity of 100% for Support Vector Machine (SVM) classifier using only six features. Furthermore, we have developed an integrated index called Myocardial Infarction Risk Index (MIRI) to detect the normal, moderately and severely infarcted myocardium using a single number. The proposed system may aid the clinicians in faster identification and quantification of the extent of infarcted myocardium using 2D echocardiogram. This system may also aid in identifying the person at risk of developing heart failure based on the extent of infarcted myocardium.
    Matched MeSH terms: Heart Failure
  13. Soo KW, Leong MC, Khalid F
    Cardiol Young, 2016 Feb;26(2):371-4.
    PMID: 26095661 DOI: 10.1017/S1047951115001055
    We describe the case of an infant who was a late presenter of transposition of the great arteries where we proceeded with ductal stenting to improve oxygenation and left ventricle training. Stenting improved the infant's saturation while keeping the left ventricle well trained for 4 months after the procedure. This report demonstrates that intermediate-term left ventricle training can be achieved via ductal stenting.
    Matched MeSH terms: Heart Ventricles
  14. Sze TL, Abdul Aziz YF, Abu Bakar N, Mohd Sani F, Oemar H
    Iran J Radiol, 2015 Jan;12(1):e6878.
    PMID: 25793089 DOI: 10.5812/iranjradiol.6878
    Coronary artery fistula (CAF) is a rare anomaly of the coronary artery. Patients with this condition are usually asymptomatic. However, cardiac failure may occur later in life due to progressive enlargement of the fistula. Diagnosis is traditionally made by echocardiogram and conventional angiogram. However with the advantage of new technologies such as computed tomography (CT) coronary angiography, the course and communications of these fistulae can be delineated non-invasively and with greater accuracy. We report a case of a left circumflex artery fistula to the coronary sinus which was suspected on echocardiogram and the diagnosis was clinched on ECG-gated CT.
    Matched MeSH terms: Heart Failure
  15. Kuah KB
    Med J Malaysia, 1974 Mar;28(3):187-90.
    PMID: 4278020
    Matched MeSH terms: Fetal Heart/drug effects; Heart Rate/drug effects
  16. Valli H, Ahmad S, Chadda KR, Al-Hadithi ABAK, Grace AA, Jeevaratnam K, et al.
    Mech Ageing Dev, 2017 Oct;167:30-45.
    PMID: 28919427 DOI: 10.1016/j.mad.2017.09.002
    INTRODUCTION: Ageing and several age-related chronic conditions including obesity, insulin resistance and hypertension are associated with mitochondrial dysfunction and represent independent risk factors for atrial fibrillation (AF).

    MATERIALS AND METHODS: Atrial arrhythmogenesis was investigated in Langendorff-perfused young (3-4 month) and aged (>12 month), wild type (WT) and peroxisome proliferator activated receptor-γ coactivator-1β deficient (Pgc-1β-/-) murine hearts modeling age-dependent chronic mitochondrial dysfunction during regular pacing and programmed electrical stimulation (PES).

    RESULTS AND DISCUSSION: The Pgc-1β-/- genotype was associated with a pro-arrhythmic phenotype progressing with age. Young and aged Pgc-1β-/- hearts showed compromised maximum action potential (AP) depolarization rates, (dV/dt)max, prolonged AP latencies reflecting slowed action potential (AP) conduction, similar effective refractory periods and baseline action potential durations (APD90) but shortened APD90 in APs in response to extrasystolic stimuli at short stimulation intervals. Electrical properties of APs triggering arrhythmia were similar in WT and Pgc-1β-/- hearts. Pgc-1β-/- hearts showed accelerated age-dependent fibrotic change relative to WT, with young Pgc-1β-/- hearts displaying similar fibrotic change as aged WT, and aged Pgc-1β-/- hearts the greatest fibrotic change. Mitochondrial deficits thus result in an arrhythmic substrate, through slowed AP conduction and altered repolarisation characteristics, arising from alterations in electrophysiological properties and accelerated structural change.

    Matched MeSH terms: Heart/physiopathology*; Heart Atria/pathology
  17. Oh SL, Ng EYK, Tan RS, Acharya UR
    Comput Biol Med, 2019 Feb;105:92-101.
    PMID: 30599317 DOI: 10.1016/j.compbiomed.2018.12.012
    Abnormality of the cardiac conduction system can induce arrhythmia - abnormal heart rhythm - that can frequently lead to other cardiac diseases and complications, and are sometimes life-threatening. These conduction system perturbations can manifest as morphological changes on the surface electrocardiographic (ECG) signal. Assessment of these morphological changes can be challenging and time-consuming, as ECG signal features are often low in amplitude and subtle. The main aim of this study is to develop an automated computer aided diagnostic (CAD) system that can expedite the process of arrhythmia diagnosis, as an aid to clinicians to provide appropriate and timely intervention to patients. We propose an autoencoder of ECG signals that can diagnose normal sinus beats, atrial premature beats (APB), premature ventricular contractions (PVC), left bundle branch block (LBBB) and right bundle branch block (RBBB). Apart from the first, the rest are morphological beat-to-beat elements that characterize and constitute complex arrhythmia. The novelty of this work lies in how we modified the U-net model to perform beat-wise analysis on heterogeneously segmented ECGs of variable lengths derived from the MIT-BIH arrhythmia database. The proposed system has demonstrated self-learning ability in generating class activations maps, and these generated maps faithfully reflect the cardiac conditions in each ECG cardiac cycle. It has attained a high classification accuracy of 97.32% in diagnosing cardiac conditions, and 99.3% for R peak detection using a ten-fold cross validation strategy. Our developed model can help physicians to screen ECG accurately, potentially resulting in timely intervention of patients with arrhythmia.
    Matched MeSH terms: Heart Conduction System
  18. Adam Linoby, Jamiaton Kusrin, Muhammad Iskandar Asraff, Muhammad Azamuddin Rodzi, Sufyan Zaki, Hosni Hasan
    Jurnal Inovasi Malaysia, 2020;4(1):193-208.
    MyJurnal
    The conventional heart rate monitor is usually developed with a numeric digital display. This numerical view is obviously not practical to be used during exercise. In this study, the iOS-based mobile application, called Chromozone, was developed to monitor heart rate using the universal color-coding system. The heart rate monitor during the exercise is designed to notify the exercise intensity information to users using the three universal color-coded (i.e. green zone: optimal heart rate; yellow zone: heart rate lower than the optimal zone, and red zone: heart rate higher than the optimal zone). Chromozone is programmed to display uniform colors across the smart phone display, which allows users to easily be informed in regards to the state of exercise intensity. The transfer of heart rate data from the chest transmitter to Chromozone application is designed to use Bluetooth Low Energy (BLE) system technology. The heart rate data is then processed by the application to determine the intensity range of exercise training heart rate based on the user’s personal input (i.e. age, gender, fitness levels and training objective). Preliminary analysis found that Chromozone application is effective in delivering real-time exercise intensity heart rate. Chromozone could potentially help athletes, active individuals and clinical populations to monitor and regulate their workout training regime in a more effective and safer manner.
    Matched MeSH terms: Heart Rate
  19. Kamauzaman THT, Ngu JTH, Arithra A, Noh AYM, Siti-Azrin AH, Nor J
    Med J Malaysia, 2021 03;76(2):171-176.
    PMID: 33742624
    BACKGROUND: Maintaining good quality CPR while transporting out-of-hospital cardiac arrest patients is very challenging. We aim to determine how different ambulance speed can affect the quality of chest compression performed either manually or mechanically.

    METHODS: This was an observational manikin-based study. A total of 96 participants as well as two types of mechanical compression devices: Lucas-2 and AutoPulse, performed one minute of continuous chest compression on BT-CPEA programmed manikin while the ambulance travelled at different speeds, i.e., idle state, 30km/hr and 60km/hr. Seven outcome variables of chest compression were measured. Performance data of different groups of compressor were compared and analysed using repeated measures analysis of variance (ANOVA).

    RESULTS: In manual chest compression, significant variation were noted among different speeds in term of average compression rate (p<0.001), average compression depth (p=0.007), fraction of adequate/insufficient compression depth and fraction of normal hands positioning with p=0.018, 0.022 and 0.034 respectively. Overall, AutoPulse and Lucas-2 were not affected by ambulance speed. Lucas- 2 showed more consistent average compression rate, higher fraction of adequate compression depth and reduced fraction of insufficient compression depth as compared to manual compression with p<0.001, 0.001 and 0.043 respectively.

    CONCLUSION: In this study we found that ambulance speed significantly affected certain aspects of manual chest compression most notably compression depth, rate and hand positioning. AutoPulse and Lucas-2 can improve these aspects by providing more consistent compression rate, depth and fraction of adequate compression depth during transport.

    Matched MeSH terms: Heart Massage
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