Displaying publications 1 - 20 of 47 in total

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  1. Pakzad KK, Tan JJ, Anderson S, Board M, Clarke K, Carr CA
    Stem Cell Res, 2021 07;54:102422.
    PMID: 34118565 DOI: 10.1016/j.scr.2021.102422
    Cardiosphere-derived cells (CDCs) can be expanded in vitro and induced to differentiate along the cardiac lineage. To recapitulate the phenotype of an adult cardiomyocyte, differentiating progenitors need to upregulate mitochondrial glucose and fatty acid oxidation. Here we cultured and differentiated CDCs using protocols aimed to maintain stemness or to promote differentiation, including triggering fatty acid oxidation using an agonist of peroxisome proliferator-activated receptor alpha (PPARα). Metabolic changes were characterised in undifferentiated CDCs and during differentiation towards a cardiac phenotype. CDCs from rat atria were expanded on fibronectin or collagen IV via cardiosphere formation. Differentiation was assessed using flow cytometry and qPCR and substrate metabolism was quantified using radiolabelled substrates. Collagen IV promoted proliferation of CDCs whereas fibronectin primed cells for differentiation towards a cardiac phenotype. In both populations, treatment with 5-Azacytidine induced a switch towards oxidative metabolism, as shown by changes in gene expression, decreased glycolytic flux and increased oxidation of glucose and palmitate. Addition of a PPARα agonist during differentiation increased both glucose and fatty acid oxidation and expression of cardiac genes. We conclude that oxidative metabolism and cell differentiation act in partnership with increases in one driving an increase in the other.
    Matched MeSH terms: Heart Atria*
  2. Chodankar, Nagesh N., May, Honey Ohn, D’Souza, Urban John Arnold
    MyJurnal
    Electrocardiogram (ECG) is a record of electrical activity of the heart. PQRST waves represent
    the electrical activities of atria and ventricles. A complete three-dimensional electrical activity is
    possible to be recorded using a 12-lead ECG. The normal and different routinely-met clinical ECG
    are elaborated and discussed. This routine, normal and abnormal ECG, like arrhythmias and heart
    block records as well as their clinical notes shall be educational information for the medical students.
    Matched MeSH terms: Heart Atria
  3. Siew TY, Zambahari R
    Med J Malaysia, 1986 Sep;41(3):229-32.
    PMID: 3670139
    The left atrial myxoma is important not only because of its relative frequency and diagnostic difficulty but because it can be successfully removed by surgery. However, if untreated, it invariably leads to death. We report three cases seen at the Cardiology Department, General Hospital, Kuala Lumpur in 1985.
    Matched MeSH terms: Heart Atria/surgery
  4. Shahbuddin HMA, Hussin SA, W Isa WYH, Mamat AZ, Marzuki A, Yusof Z
    BMJ Case Rep, 2024 Mar 07;17(3).
    PMID: 38453227 DOI: 10.1136/bcr-2024-259675
    Diagnosing atrial myxoma in pregnancy is challenging because patients may present with non-specific symptoms that might be overlooked. The timing of non-obstetric operation usually depends on the nature of the disease, after careful consideration of feto-maternal safety, including the use of cardiopulmonary bypass and placental transfer of anaesthetic drug. A woman in her 30s at 18 weeks of pregnancy presented with recurring dizziness. She underwent successful myxoma excision at 20 weeks under general anaesthesia and cardiopulmonary bypass. The 6×5 cm myxoma was histologically confirmed as myxoma. Early detection of atrial myxoma in pregnancy is crucial, and a clinician has to consider the diagnosis of left atrial myxoma with mitral valve obstruction as a cause of severe dizziness. Optimal outcomes require multidisciplinary management. In this case, surgery during the second trimester of pregnancy enabled a full-term pregnancy with the patient's and foetal well-being and normal postprocedural echocardiography.
    Matched MeSH terms: Heart Atria/surgery
  5. Yeap TB, Teah MK, Thevarajah S, Azerai S
    BMJ Case Rep, 2021 Mar 25;14(3).
    PMID: 33766970 DOI: 10.1136/bcr-2020-241176
    Wolff-Parkinson-White (WPW) syndrome is an extremely rare congenital cardiac conduction disorder. It is due to an aberrant pathway between the atrium and ventricle. This manuscript entails a man with an underlying WPW who was posted for an elective orchidectomy. We discussed the important perioperative precautions to prevent the precipitation of acute cardiac events.
    Matched MeSH terms: Heart Atria
  6. Singham KT, Saw HS, Johnson RO, Ganendran A
    Med J Malaysia, 1978 Jun;32(4):274-7.
    PMID: 732619
    Matched MeSH terms: Heart Atria/abnormalities*; Heart Atria/surgery
  7. Qureshi AU, Latiff HA, Sivalingam S
    Cardiol Young, 2014 Aug;24(4):756-9.
    PMID: 24016801 DOI: 10.1017/S1047951113001200
    Incomplete involution of valve of systemic venous sinus can present across a spectrum of anatomical lesions ranging from eustachian valve to division of right atrium (cor triatriatum dexter) with overlapping features. We present the case of a neonate presenting with cyanosis, having persistent valve of systemic venous sinus with anatomical details of the redundant tissue in right atrium suggesting an intermediate form between Chiari network and division of right atrium.
    Matched MeSH terms: Heart Atria/abnormalities; Heart Atria/ultrasonography
  8. Zainudin AR, Tiong KG, Mokhtar SA
    Ann Pediatr Cardiol, 2012 Jan;5(1):92-4.
    PMID: 22529613 DOI: 10.4103/0974-2069.93725
    Cor triatriatum dexter is a rare congenital heart anomaly where the right atrium is divided into two chambers by a membrane. We report a boy who had persistent mild cyanosis and diagnosed to have cor triatriatum dexter with secundum atrial septal defect by transoesophageal echocardiography. Interestingly, he had persistent mild cyanosis despite insignificant obstruction to the right ventricular inflow and normal pulmonary artery pressure. The pathophysiology, approach to the diagnosis, and mode of treatment are also discussed.
    Matched MeSH terms: Heart Atria
  9. Singham KT, Anuar M
    Med J Malaysia, 1983 Mar;38(1):68-70.
    PMID: 6633342
    A patient with a left atrial myxoma is reported to illustrate the value of two dimensional real time echocardiography in the diagnosis of intracavitary cardiac tumours.
    Matched MeSH terms: Heart Atria
  10. Amran, A.R., Ranganathan, S.
    MyJurnal
    Hepatocellular carcinoma (HCC) presenting with right atrial metastases and pulmonary tumour embolism is rare . Intracavitary cardiac metastasis is uncommon and metastasis to the right atrium is even less common. The majority of such cases are believed to be due to advanced HCC such as Stage III or IV, in which the progression rate is high, and in infiltrative HCC it tends to be associated with vascular invasion. The diagnosis of pulmonary intravascular tumour emboli is difficult to establish both clinically and with conventional radiographic studies. We report a case hepatocellular carcinoma associated with tumour thrombus in the inferior vena cava (IVC), right atrium and pulmonary tumour embolism detected with multidetector helical computerized tomography (MDHCT).
    Matched MeSH terms: Heart Atria
  11. Peter CA, Anand Swaroop U, Wong BS
    Med J Malaysia, 2017 02;72(1):58-59.
    PMID: 28255143
    Intra-cardiac extension of hepatocellular carcinoma (HCC) is an uncommon but serious condition related to poor prognosis. We report a 57-year-old male diagnosed with HCC with intra-cardiac extension into the right atrium at presentation. There were no symptoms related to cardiac involvement and intra-cardiac extension was incidentally noted on radiological imaging. He was offered palliative treatment and succumbed to his disease within 50 days of first diagnosis.
    Matched MeSH terms: Heart Atria
  12. Khalil A, Faisal A, Ng SC, Liew YM, Lai KW
    J Med Imaging (Bellingham), 2017 Jul;4(3):037001.
    PMID: 28840172 DOI: 10.1117/1.JMI.4.3.037001
    A registration method to fuse two-dimensional (2-D) echocardiography images with cardiac computed tomography (CT) volume is presented. The method consists of two major procedures: temporal and spatial registrations. In temporal registration, the echocardiography frames at similar cardiac phases as the CT volume were interpolated based on electrocardiogram signal information, and the noise of the echocardiography image was reduced using the speckle reducing anisotropic diffusion technique. For spatial registration, an intensity-based normalized mutual information method was applied with a pattern search optimization algorithm to produce an interpolated cardiac CT image. The proposed registration framework does not require optical tracking information. Dice coefficient and Hausdorff distance for the left atrium assessments were [Formula: see text] and [Formula: see text], respectively; for left ventricle, they were [Formula: see text] and [Formula: see text], respectively. There was no significant difference in the mitral valve annulus diameter measurement between the manually and automatically registered CT images. The transformation parameters showed small deviations ([Formula: see text] deviation in translation and [Formula: see text] for rotation) between manual and automatic registrations. The proposed method aids the physician in diagnosing mitral valve disease as well as provides surgical guidance during the treatment procedure.
    Matched MeSH terms: Heart Atria
  13. Abrika OS, Yam MF, Asmawi MZ, Sadikun A, Dieng H, Hussain EA
    J Acupunct Meridian Stud, 2013 Aug;6(4):199-207.
    PMID: 23972242 DOI: 10.1016/j.jams.2013.01.020
    There is currently a great deal of research interest in utilizing plant compounds against human diseases, including hypertension. The present study investigated the effects of different extracts and fractions from leaves of Gynura procumbens Merr. on rat atrial contraction in vitro. Isolated left and right atria, mounted in a 20-ml organ bath, were allowed to equilibrate for 15 min before the application of the extracts or fractions. The extracts (petroleum-ether extract (PE) and methanol extract (ME)) and the fractions (chloroform fraction (CHL), ethyl-acetate fraction (EA), n-butanol fraction (NB) and water fraction (WA) of the methanol extract) were tested at three concentrations (0.25, 0.5 and 1.0 mg/ml), with a β-adrenergic agonist (isoprenaline) as a control. All data on contraction responses were log-transformed and analyzed. When exposed to the different extracts, both atria tended to exhibit greater contractive responses with the NB whereas cardiac contractions had a tendency to be reduced with most other extracts. For a given extract, the contraction responses were particularly greater at 0.5 mg/ml for the right atrium and at 1 mg/ml for the left atrium. Further analysis focusing on the NB fraction revealed that positive inotropism was greater in left atria exposed to highly-concentrated F2 and F3 sub-fractions. Taken together, our results suggest that NB extracts and fractions from the G. procumbens-leaf methanol extract have positive inotropic activities and, hence, can be considered as an alternative/traditional medicine against increased blood pressure in humans or can be used in strategies aimed at finding antihypertensive biomolecules from an accessible source.
    Matched MeSH terms: Heart Atria/drug effects*
  14. Lu HT, Chong JL, Othman N, Vendargon S, Omar S
    J Med Case Rep, 2016 May 03;10(1):109.
    PMID: 27142514 DOI: 10.1186/s13256-016-0888-5
    BACKGROUND: Renal cell carcinoma is a potentially lethal cancer with aggressive behavior and it tends to metastasize. Renal cell carcinoma involves the inferior vena cava in approximately 15% of cases and it rarely extends into the right atrium. A majority of renal cell carcinoma are detected as incidental findings on imaging studies obtained for unrelated reasons. At presentation, nearly 25% of patients either have distant metastases or significant local-regional disease with no symptoms that can be attributed to renal cell carcinoma.

    CASE PRESENTATION: A 64-year-old Indian male with a past history of coronary artery bypass graft surgery, congestive heart failure, and diabetes mellitus complained of worsening shortness of breath for 2 weeks. Incidentally, a transthoracic echocardiography showed a "thumb-like" mass in his right atrium extending into his right ventricle through the tricuspid valve with each systole. Abdomen magnetic resonance imaging revealed a heterogenous lobulated mass in the upper and mid-pole of his right kidney with a tumor extending into his inferior vena cava and right atrium, consistent with our diagnosis of advanced renal cell carcinoma which was later confirmed by surgical excision and histology. Radical right nephrectomy, lymph nodes clearance, inferior vena cava cavatomy, and complete tumor thrombectomy were performed successfully. Perioperatively, he did not require cardiopulmonary bypass or deep hypothermic circulatory arrest. He had no recurrence during the follow-up period for more than 2 years after surgery.

    CONCLUSIONS: Advanced extension of renal cell carcinoma can occur with no apparent symptoms and be detected incidentally. In rare circumstances, atypical presentation of renal cell carcinoma should be considered in a patient presenting with right atrial mass detected by echocardiography. Renal cell carcinoma with inferior vena cava and right atrium extension is a complex surgical challenge, but excellent results can be obtained with proper patient selection, meticulous surgical techniques, and close perioperative patient care.

    Matched MeSH terms: Heart Atria/surgery
  15. Nadesan K
    Am J Forensic Med Pathol, 2000 Jun;21(2):107-13.
    PMID: 10871122
    True vehicular homicides are defined as those occurrences in which a motor vehicle is intentionally used as a weapon in taking of a life. A case is presented in which the deceased was traveling in the front passenger seat of a motor car that was deliberately rammed by a heavy jeep that came in the opposite direction, resulting in a serious frontal collision. Immediately after the impact, while the occupants of the car were lying in a dazed condition, the two persons riding in the jeep escaped with a bag containing money that was in the car, leaving the jeep behind. The impact mainly involved the driver's sides of both vehicles. The driver of the car sustained serious injuries but was found to be alive, whereas the front-seat passenger, who did not show any serious external injuries, was found to be in a collapsed state and was pronounced dead on admission to the hospital within 30 minutes of the accident. The autopsy revealed that death was caused by closed hemopericardium from a ruptured right atrium. The evaluation of the external and internal injuries confirmed that the fatal injury and a few serious internal injuries were caused by the seat belt (tertiary-impact injuries). The ruptured right atrium was attributed to blunt abdominal trauma by impacting against the lap belt. The case was a true vehicular homicide in which a motor vehicle had been used as a weapon to kill a person. Various aspects pertaining to road accidents, the safety of the occupants, and the advantage and disadvantage of the safety devices are discussed.
    Matched MeSH terms: Heart Atria/injuries
  16. Awang Y, Sallehuddin A
    Med J Malaysia, 1991 Mar;46(1):28-34.
    PMID: 1836035
    Fifteen patients underwent surgery for cardiac tumours in General Hospital Kuala Lumpur between October 1984 and June 1989. Twelve of the patients had cardiac myxomas and underwent excision under cardiopulmonary bypass. Two patients had sarcoma, of which one was excised. The other was inoperable. Another patient had a metastalic malignant melanoma which was inoperable. Of the patients 10 were female and five male. Their ages ranged from 16 to 60 years. All were symptomatic and the commonest mode of presentation was exertional dyspnoea and palpitations. Two presented with cerebral embolisation. The three patients with malignant tumours had constitutional symptoms at the time of surgery. All patients had echocardiography pre-operatively to confirm the diagnosis of cardiac tumour. Only one patient underwent preoperative cardiac catheterisation and angiography. The surgical approach in all patients was through a median sternotomy and all except one were operated under cardiopulmonary bypass. There was no intraoperative embolisation. There was one perioperative death. Fourteen patients were followed up for periods ranging from one to 44 months. Three patients with malignant cardiac tumours died. One had recurrence of myxoma 21 months after the initial surgery. We conclude that excision of cardiac myxomas carry a very small risk following which patients have good prognosis. Malignant tumours carry a bad prognosis. From our experience, we conclude that echocardiography is an extremely accurate tool in the diagnosis of cardiac tumours.
    Matched MeSH terms: Heart Atria/surgery
  17. Steinwender C, Khelae SK, Garweg C, Chan JYS, Ritter P, Johansen JB, et al.
    JACC Clin Electrophysiol, 2020 01;6(1):94-106.
    PMID: 31709982 DOI: 10.1016/j.jacep.2019.10.017
    OBJECTIVES: This study reports on the performance of a leadless ventricular pacemaker with automated, enhanced accelerometer-based algorithms that provide atrioventricular (AV) synchronous pacing.

    BACKGROUND: Despite many advantages, leadless pacemakers are currently only capable of single-chamber ventricular pacing.

    METHODS: The prospective MARVEL 2 (Micra Atrial tRacking using a Ventricular accELerometer 2) study assessed the performance of an automated, enhanced accelerometer-based algorithm downloaded to the Micra leadless pacemaker for up to 5 h in patients with AV block. The primary efficacy objective was to demonstrate the superiority of the algorithm to provide AV synchronous (VDD) pacing versus VVI-50 pacing in patients with sinus rhythm and complete AV block. The primary safety objective was to demonstrate that the algorithm did not result in pauses or heart rates of >100 beats/min.

    RESULTS: Overall, 75 patients from 12 centers were enrolled; an accelerometer-based algorithm was downloaded to their leadless pacemakers. Among the 40 patients with sinus rhythm and complete AV block included in the primary efficacy objective analysis, the proportion of patients with ≥70% AV synchrony at rest was significantly greater with VDD pacing than with VVI pacing (95% vs. 0%; p 

    Matched MeSH terms: Heart Atria/physiopathology*
  18. Ho YL, Ng PF, Krishinan S, Abdul Kareem BA
    J Cardiothorac Surg, 2021 May 29;16(1):151.
    PMID: 34051789 DOI: 10.1186/s13019-021-01526-7
    BACKGROUND: Papillary fibroelastomas are rare but benign cardiac tumour that are often found on cardiac valvular surfaces. Their clinical manifestations ranging from clinically asymptomatic to substantial complications that are usually secondary to systemic embolism. Multiple theories have been proposed to explain the pathophysiology of its formation.

    CASE PRESENTATION: We reported a rare case of large papillary fibroelastoma in the right atrium of a young gentleman which was complicated with pulmonary embolism. Transthoracic echocardiography identified a large pedunculated mass measuring 3.4cmX3.4cmX2cm in right atrium with stalk attached to interatrial septum. The intracardiac mass was resected surgically, which revealed papillary fibroelastoma in histology examination.

    CONCLUSION: Differential diagnosis of intracardiac masses requires clinical information, laboratory tests and imaging modalities including echocardiography. Incidentally discovered papillary fibroelastomas are treated on the basis of their sizes, site, mobility and potential embolic complications. Due to the embolic risk inherent to intraacardiac masses, surgical resection represents an effective curative protocol in treating both symptomatic and asymptomatic right sided and left sided papillary fibroelastomas, with excellent long term postoperative prognosis.

    Matched MeSH terms: Heart Atria/pathology
  19. Anpalakhan S, Ramasamy D, Fan KS
    Singapore Med J, 2014 Oct;55(10):e156-8.
    PMID: 25631903
    Myxomas are uncommon primary cardiac tumours that usually affect the left atrium. We herein report the case of a patient who presented with right heart failure and proteinuria, leading to the diagnosis of atrial myxoma. Surgical resection resulted in resolution of the patient's symptoms.
    Matched MeSH terms: Heart Atria/surgery
  20. Valli H, Ahmad S, Jiang AY, Smyth R, Jeevaratnam K, Matthews HR, et al.
    Mech Ageing Dev, 2018 01;169:1-9.
    PMID: 29197478 DOI: 10.1016/j.mad.2017.11.016
    INTRODUCTION: Recent studies reported that energetically deficient murine Pgc-1β-/- hearts replicate age-dependent atrial arrhythmic phenotypes associated with their corresponding clinical conditions, implicating action potential (AP) conduction slowing consequent upon reduced AP upstroke rates.

    MATERIALS AND METHODS: We tested a hypothesis implicating Na+ current alterations as a mechanism underlying these electrophysiological phenotypes. We applied loose patch-clamp techniques to intact young and aged, WT and Pgc-1β-/-, atrial cardiomyocyte preparations preserving their in vivo extracellular and intracellular conditions.

    RESULTS AND DISCUSSION: Depolarising steps activated typical voltage-dependent activating and inactivating inward (Na+) currents whose amplitude increased or decreased with the amplitudes of the activating, or preceding inactivating, steps. Maximum values of peak Na+ current were independently influenced by genotype but not age or interacting effects of genotype and age on two-way ANOVA. Neither genotype, nor age, whether independently or interactively, influenced voltages at half-maximal current, or steepness factors, for current activation and inactivation, or time constants for recovery from inactivation following repolarisation. In contrast, delayed outward (K+) currents showed similar activation and rectification properties through all experimental groups. These findings directly demonstrate and implicate reduced Na+ in contrast to unchanged K+ current, as a mechanism for slowed conduction causing atrial arrhythmogenicity in Pgc-1β-/- hearts.

    Matched MeSH terms: Heart Atria/metabolism; Heart Atria/pathology
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