Displaying publications 1 - 20 of 57 in total

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  1. Wan Ab Naim WN, Mokhtarudin MJM, Lim E, Chan BT, Ahmad Bakir A, Nik Mohamed NA
    Int J Numer Method Biomed Eng, 2020 11;36(11):e3398.
    PMID: 32857480 DOI: 10.1002/cnm.3398
    Myocardial infarction (MI) is the most common cause of a heart failure, which occurs due to myocardial ischemia leading to left ventricular (LV) remodeling. LV remodeling particularly occurs at the ischemic area and the region surrounds it, known as the border zone. The role of the border zone in initiating LV remodeling process urges the investigation on the correlation between early border zone changes and remodeling outcome. Thus, this study aims to simulate a preliminary conceptual work of the border zone formation and evolution during onset of MI and its effect towards early LV remodeling processes by incorporating the oxygen concentration effect on the electrophysiology of an idealized three-dimensional LV through electro-chemical coupled mathematical model. The simulation result shows that the region of border zone, represented by the distribution of electrical conductivities, keeps expanding over time. Based on this result, the border zone is also proposed to consist of three sub-regions, namely mildly, moderately, and seriously impaired conductivity regions, which each region categorized depending on its electrical conductivities. This division could be used as a biomarker for classification of reversible and irreversible myocardial injury and will help to identify the different risks for the survival of patient. Larger ischemic size and complete occlusion of the coronary artery can be associated with an increased risk of developing irreversible injury, in particular if the reperfusion treatment is delayed. Increased irreversible injury area can be related with cardiovascular events and will further deteriorate the LV function over time.
    Matched MeSH terms: Ventricular Function, Left
  2. Mahmod M, Pal N, Rayner J, Holloway C, Raman B, Dass S, et al.
    J Cardiovasc Magn Reson, 2018 12 24;20(1):88.
    PMID: 30580760 DOI: 10.1186/s12968-018-0511-6
    BACKGROUND: Heart failure (HF) is characterized by altered myocardial substrate metabolism which can lead to myocardial triglyceride accumulation (steatosis) and lipotoxicity. However its role in mild HF with preserved ejection fraction (HFpEF) is uncertain. We measured myocardial triglyceride content (MTG) in HFpEF and assessed its relationships with diastolic function and exercise capacity.

    METHODS: Twenty seven HFpEF (clinical features of HF, left ventricular EF >50%, evidence of mild diastolic dysfunction and evidence of exercise limitation as assessed by cardiopulmonary exercise test) and 14 controls underwent 1H-cardiovascular magnetic resonance spectroscopy (1H-CMRS) to measure MTG (lipid/water, %), 31P-CMRS to measure myocardial energetics (phosphocreatine-to-adenosine triphosphate - PCr/ATP) and feature-tracking cardiovascular magnetic resonance (CMR) imaging for diastolic strain rate.

    RESULTS: When compared to controls, HFpEF had 2.3 fold higher in MTG (1.45 ± 0.25% vs. 0.64 ± 0.16%, p = 0.009) and reduced PCr/ATP (1.60 ± 0.09 vs. 2.00 ± 0.10, p = 0.005). HFpEF had significantly reduced diastolic strain rate and maximal oxygen consumption (VO2 max), which both correlated significantly with elevated MTG and reduced PCr/ATP. On multivariate analyses, MTG was independently associated with diastolic strain rate while diastolic strain rate was independently associated with VO2 max.

    CONCLUSIONS: Myocardial steatosis is pronounced in mild HFpEF, and is independently associated with impaired diastolic strain rate which is itself related to exercise capacity. Steatosis may adversely affect exercise capacity by indirect effect occurring via impairment in diastolic function. As such, myocardial triglyceride may become a potential therapeutic target to treat the increasing number of patients with HFpEF.

    Matched MeSH terms: Ventricular Function, Left*
  3. Ning F, Luo L, Ahmad S, Valli H, Jeevaratnam K, Wang T, et al.
    Pflugers Arch., 2016 Apr;468(4):655-65.
    PMID: 26545784 DOI: 10.1007/s00424-015-1750-0
    Catecholaminergic polymorphic ventricular tachycardia (CPVT) predisposes to ventricular arrhythmia due to altered Ca(2+) homeostasis and can arise from ryanodine receptor (RyR2) mutations including RyR2-P2328S. Previous reports established that homozygotic murine RyR2-P2328S (RyR2 (S/S)) hearts show an atrial arrhythmic phenotype associated with reduced action potential (AP) conduction velocity and sodium channel (Nav1.5) expression. We now relate ventricular arrhythmogenicity and slowed AP conduction in RyR2 (S/S) hearts to connexin-43 (Cx43) and Nav1.5 expression and Na(+) current (I Na). Stimulation protocols applying extrasystolic S2 stimulation following 8 Hz S1 pacing at progressively decremented S1S2 intervals confirmed an arrhythmic tendency despite unchanged ventricular effective refractory periods (VERPs) in Langendorff-perfused RyR2 (S/S) hearts. Dynamic pacing imposing S1 stimuli then demonstrated that progressive reductions of basic cycle lengths (BCLs) produced greater reductions in conduction velocity at equivalent BCLs and diastolic intervals in RyR2 (S/S) than WT, but comparable changes in AP durations (APD90) and their alternans. Western blot analyses demonstrated that Cx43 protein expression in whole ventricles was similar, but Nav1.5 expression in both whole tissue and membrane fractions were significantly reduced in RyR2 (S/S) compared to wild-type (WT). Loose patch-clamp studies similarly demonstrated reduced I Na in RyR2 (S/S) ventricles. We thus attribute arrhythmogenesis in RyR2 (S/S) ventricles resulting from arrhythmic substrate produced by reduced conduction velocity to downregulated Nav1.5 reducing I Na, despite normal determinants of repolarization and passive conduction. The measured changes were quantitatively compatible with earlier predictions of linear relationships between conduction velocity and the peak I Na of the AP but nonlinear relationships between peak I Na and maximum Na(+) permeability.
    Matched MeSH terms: Ventricular Function*
  4. Tay E, Muda N, Yap J, Muller DW, Santoso T, Walters DL, et al.
    Catheter Cardiovasc Interv, 2016 Jun;87(7):E275-81.
    PMID: 26508564 DOI: 10.1002/ccd.26289
    OBJECTIVES: The objective of this study is to describe and compare the use of the MitraClip therapy in mitral regurgitation (MR) patients with degenerative MR (DMR) and functional MR (FMR).

    INTRODUCTION: Percutaneous edge-to-edge repair of severe MR using the MitraClip device is approved for use in the USA for high risk DMR while European guidelines include its use in FMR patients as well.

    METHODS: The MitraClip in the Asia-Pacific Registry (MARS) is a multicenter retrospective registry, involving eight sites in five Asia-Pacific countries. Clinical and echocardiographic characteristics, procedural outcomes and 1-month outcomes [death and major adverse events (MAE)] were compared between FMR and DMR patients treated with the MitraClip.

    RESULTS: A total of 163 patients were included from 2011 to 2014. The acute procedural success rates for FMR (95.5%, n = 84) and DMR (92%, n = 69) were similar (P = 0.515). 45% of FMR had ≥2 clips inserted compared to 60% of those with DMR (P = 0.064).The 30-day mortality rate for FMR and DMR was similar at 4.5% and 6.7% respectively (P = 0.555). The 30-day MAE rate was 9.2% for FMR and 14.7% for DMR (P = 0.281). Both FMR and DMR patients had significant improvements in the severity of MR and NYHA class after 30 days. There was a significantly greater reduction in left ventricular end-diastolic diameter (P = 0.002) and end systolic diameter (P = 0.017) in DMR than in FMR.

    CONCLUSIONS: The MitraClip therapy is a safe and efficacious treatment option for both FMR and DMR. Although, there is a significantly greater reduction in LV volumes in DMR, patients in both groups report clinical benefit with improvement in functional class. © 2015 Wiley Periodicals, Inc.

    Matched MeSH terms: Ventricular Function, Left
  5. Vyshnevska IR, Storozhenko T, Kopytsya MP, Bila NV, Kis A, Kaaki M
    Wiad Lek, 2023;76(5 pt 1):911-919.
    PMID: 37326070 DOI: 10.36740/WLek202305104
    OBJECTIVE: The aim: To estimate the role of macrophage migration inhibitory factor and soluble ST2 in predicting the left ventricle remodeling six months after ST-segment elevation myocardial infarction.

    PATIENTS AND METHODS: Materials and methods: The study involved 134 ST-segment elevation myocardial infarction patients. Occurrence of post-percutaneous coronary (PCI) intervention epicardial blood flow of TIMI <3 or myocardial blush grade 0-1 along with ST resolution <70% within 2 hours after PCI was qualified as the no-reflow condition. Left ventricle remodeling was defined after 6-months as an increase in left ventricle end-diastolic volume and/or end-systolic volume by more than 10%.

    RESULTS: Results: A logistic regression formula was evaluated. Included biomarkers were macrophage migration inhibitory factor and sST2, left ventricle ejection fraction: Y=exp(-39.06+0.82EF+0.096ST2+0.0028MIF) / (1+exp(-39.06+0.82EF+0.096ST2+0.0028MIF)). The estimated range is from 0 to 1 point. Less than 0.5 determines an adverse outcome, and more than 0.5 is a good prognosis. This equation, with sensitivity of 77 % and specificity of 85%, could predict the development of adverse left ventricle remodeling six months after a coronary event (AUC=0.864, CI 0.673 to 0.966, p<0.05).

    CONCLUSION: Conclusions: A combination of biomarkers gives a significant predicting result in the formation of adverse left ventricular remodeling after ST-segment elevation myocardial infarction.

    Matched MeSH terms: Ventricular Function, Left
  6. Hamad F, Elnour AA, Elamin A, Mohamed S, Yousif I, Don J, et al.
    Curr Diabetes Rev, 2021;17(3):280-292.
    PMID: 32867644 DOI: 10.2174/1573399816999200821164129
    BACKGROUND: The major cardiovascular outcome trials on glucagon-like peptide one-receptor agonists have examined its effect on hospitalization of subjects with heart failure; however, very limited trials have been conducted on subjects with reduced left ventricular ejection fraction (r- LVEF) as a primary outcome.

    OBJECTIVE: We have conducted a systematic review of two major (FIGHT and LIVE) placebo-controlled trials of liraglutide and its clinical effect on the ejection fraction of subjects with heart failure.

    METHODS: Medline data was retrieved for trials involving liraglutide from 2012 to 2020. The inclusion criteria for trials were: subjects with or without type 2 diabetes mellitus (T2DM), subjects with heart failure with rLVEF, major trials (phase II or III) on liraglutide, trials included liraglutide with defined efficacy primary outcome of patients with heart failure with rLVEF. The search was limited to the English language, whereby two trials [FIGHT and LIVE] had been included and two trials were excluded due to different primary outcomes. Participants (541) had been randomized for either liraglutide or placebo for 24 weeks.

    RESULTS: In the FIGHT trial the primary intention-to-treat, sensitivity, and diabetes subgroup analyses have shown no significant between-group difference in the global rank scores (mean rank of 146 in the liraglutide group versus 156 in the placebo group; Wilcoxon rank-sum P=.31), number of deaths, re-hospitalizations for heart failure, or the composite of death or change in NT-pro BNP level (P= .94). In the LIVE trial, the change in the left ventricular ejection fraction (LVEF) from baseline to week 24 was not significantly different between treatment groups. The overall discontinuation rate of liraglutide was high in the FIGHT trial (29%, 86) as compared to that in the LIVE trial (11.6%, 28).

    CONCLUSION: FIGHT and LIVE trials have demonstrated that liraglutide use in subjects with heart failure and rLVEF was implicated with an increased adverse risk of heart failure-related outcomes.

    Matched MeSH terms: Ventricular Function, Left
  7. Chin SP, Maskon O, Tan CS, Anderson JE, Wong CY, Hassan HHC, et al.
    PMID: 33575315 DOI: 10.21037/sci-2020-026
    Background: Ischemic cardiomyopathy (ICM) is a leading cause of cardiovascular mortality worldwide. It is defined as abnormal enlargement of the left ventricular (LV) cavity with poor LV function due to coronary artery disease. Currently available established treatments are palliative whereby blood supply is recovered to ischemic regions but fails to regenerate heart tissues. Mesenchymal stem cells (MSCs) offer a promising treatment for ICM given their regenerative and multipotent characteristics. This study aims to investigate the effect of MSCs infusion with concurrent revascularization in patients with severe ICM compared to receiving only revascularization procedure or MSCs infusion.

    Methods: Twenty-seven patients with history of anterior myocardial infarction (MI) and baseline left ventricular ejection fraction (LVEF) of less than 35% were recruited into this study. Patients who are eligible for revascularization were grouped into group A (MSCs infusion with concurrent revascularization) or group B (revascularization only) while patients who were not eligible for revascularization were allocated in group C to receive intracoronary MSCs infusion. LV function was measured using echocardiography.

    Results: Patients who received MSCs infusion (either with or without revascularization) demonstrated significant LVEF improvements at 3, 6 and 12 months post-infusion when compared to baseline LVEF within its own group. When comparing the groups, the magnitude of change in LVEF from baseline for third visits i.e., 12 months post-infusion was significant for patients who received MSCs infusion plus concurrent revascularization in comparison to patients who only had the revascularization procedure.

    Conclusions: MSCs infusion significantly improves LV function in ICM patients. MSCs infusion plus concurrent revascularization procedure worked synergistically to improve cardiac function in patients with severe ICM.

    Matched MeSH terms: Ventricular Function, Left
  8. Ding CCA, Dokos S, Bakir AA, Zamberi NJ, Liew YM, Chan BT, et al.
    Biomed Eng Online, 2024 Feb 22;23(1):24.
    PMID: 38388416 DOI: 10.1186/s12938-024-01206-2
    Aortic stenosis, hypertension, and left ventricular hypertrophy often coexist in the elderly, causing a detrimental mismatch in coupling between the heart and vasculature known as ventricular-vascular (VA) coupling. Impaired left VA coupling, a critical aspect of cardiovascular dysfunction in aging and disease, poses significant challenges for optimal cardiovascular performance. This systematic review aims to assess the impact of simulating and studying this coupling through computational models. By conducting a comprehensive analysis of 34 relevant articles obtained from esteemed databases such as Web of Science, Scopus, and PubMed until July 14, 2022, we explore various modeling techniques and simulation approaches employed to unravel the complex mechanisms underlying this impairment. Our review highlights the essential role of computational models in providing detailed insights beyond clinical observations, enabling a deeper understanding of the cardiovascular system. By elucidating the existing models of the heart (3D, 2D, and 0D), cardiac valves, and blood vessels (3D, 1D, and 0D), as well as discussing mechanical boundary conditions, model parameterization and validation, coupling approaches, computer resources and diverse applications, we establish a comprehensive overview of the field. The descriptions as well as the pros and cons on the choices of different dimensionality in heart, valve, and circulation are provided. Crucially, we emphasize the significance of evaluating heart-vessel interaction in pathological conditions and propose future research directions, such as the development of fully coupled personalized multidimensional models, integration of deep learning techniques, and comprehensive assessment of confounding effects on biomarkers.
    Matched MeSH terms: Ventricular Function, Left*
  9. Haranal M, Chin HC, Sivalingam S, Raja N, Mohammad Shaffie MS, Namasiwayam TK, et al.
    World J Pediatr Congenit Heart Surg, 2020 Nov;11(6):720-726.
    PMID: 33164692 DOI: 10.1177/2150135120936119
    BACKGROUND: To compare the safety and effectiveness of del Nido cardioplegia with blood-based St Thomas Hospital (BSTH) cardioplegia in myocardial protection in congenital heart surgery.

    METHODS: It is a prospective, open-labeled, randomized controlled study conducted at National Heart Institute, Kuala Lumpur from July 2018 to July 2019. All patients with simple and complex congenital heart diseases (CHD) with good left ventricular function (left ventricular ejection fraction [LVEF] >50%) were included while those with LVEF <50% were excluded. A total of 100 patients were randomized into two groups of 50 each receiving either del Nido or BSTH cardioplegia. Primary end points were the spontaneous return of activity following aortic cross-clamp release and ventricular function between two groups. Secondary end point was myocardial injury as assessed by troponin T levels.

    RESULTS: Cardiopulmonary bypass and aortic cross-clamp time, return of spontaneous cardiac activity following the aortic cross-clamp release, the duration of mechanical ventilation, and intensive care unit stay were comparable between two groups. Statistically significant difference was seen in the amount and number of cardioplegia doses delivered (P < .001). The hemodilution was significantly less in the del Nido complex CHD group compared to BSTH cardioplegia (P = .001) but no difference in blood usage (P = .36). The myocardial injury was lesser (lower troponin T release) with del Nido compared to BSTH cardioplegia (P = .6).

    CONCLUSION: Our study showed that both del Nido and BSTH cardioplegia are comparable in terms of myocardial protection. However, single, less frequent, and lesser volume of del Nido cardioplegia makes it more suitable for complex repair.

    Matched MeSH terms: Ventricular Function; Ventricular Function, Left
  10. Chan BT, Lim E, Chee KH, Abu Osman NA
    Comput Biol Med, 2013 May;43(4):377-85.
    PMID: 23428371 DOI: 10.1016/j.compbiomed.2013.01.013
    The heart is a sophisticated functional organ that plays a crucial role in the blood circulatory system. Hemodynamics within the heart chamber can be indicative of exert cardiac health. Due to the limitations of current cardiac imaging modalities, computational fluid dynamics (CFD) have been widely used for the purposes of cardiac function assessment and heart disease diagnosis, as they provide detailed insights into the cardiac flow field. An understanding of ventricular hemodynamics and pathological severities can be gained through studies that employ the CFD method. In this research the hemodynamics of two common myocardial diseases, dilated cardiomyopathy (DCM) and myocardial infarction (MI) were investigated, during both the filling phase and the whole cardiac cycle, through a prescribed geometry and fluid structure interaction (FSI) approach. The results of the research indicated that early stage disease identification and the improvement of cardiac assisting devices and therapeutic procedures can be facilitated through the use of the CFD method.
    Matched MeSH terms: Ventricular Function, Left/physiology
  11. MacDonald MR, Tay WT, Teng TK, Anand I, Ling LH, Yap J, et al.
    J Am Heart Assoc, 2020 01 07;9(1):e012199.
    PMID: 31852421 DOI: 10.1161/JAHA.119.012199
    Background Data comparing outcomes in heart failure (HF) across Asia are limited. We examined regional variation in mortality among patients with HF enrolled in the ASIAN-HF (Asian Sudden Cardiac Death in Heart Failure) registry with separate analyses for those with reduced ejection fraction (EF; <40%) versus preserved EF (≥50%). Methods and Results The ASIAN-HF registry is a prospective longitudinal study. Participants with symptomatic HF were recruited from 46 secondary care centers in 3 Asian regions: South Asia (India), Southeast Asia (Thailand, Malaysia, Philippines, Indonesia, Singapore), and Northeast Asia (South Korea, Japan, Taiwan, Hong Kong, China). Overall, 6480 patients aged >18 years with symptomatic HF were recruited (mean age: 61.6±13.3 years; 27% women; 81% with HF and reduced rEF). The primary outcome was 1-year all-cause mortality. Striking regional variations in baseline characteristics and outcomes were observed. Regardless of HF type, Southeast Asians had the highest burden of comorbidities, particularly diabetes mellitus and chronic kidney disease, despite being younger than Northeast Asian participants. One-year, crude, all-cause mortality for the whole population was 9.6%, higher in patients with HF and reduced EF (10.6%) than in those with HF and preserved EF (5.4%). One-year, all-cause mortality was significantly higher in Southeast Asian patients (13.0%), compared with South Asian (7.5%) and Northeast Asian patients (7.4%; P<0.001). Well-known predictors of death accounted for only 44.2% of the variation in risk of mortality. Conclusions This first multinational prospective study shows that the outcomes in Asian patients with both HF and reduced or preserved EF are poor overall and worst in Southeast Asian patients. Region-specific risk factors and gaps in guideline-directed therapy should be addressed to potentially improve outcomes. Clinical Trial Registration URL: https://www.clinicaltrials.gov/. Unique identifier: NCT01633398.
    Matched MeSH terms: Ventricular Function, Left*
  12. Tan ESJ, Jin X, Oon YY, Chan SP, Gong L, Lunaria JB, et al.
    J Am Soc Echocardiogr, 2023 Jan;36(1):29-37.e5.
    PMID: 36441088 DOI: 10.1016/j.echo.2022.10.011
    BACKGROUND: The role of left atrial (LA) strain as an imaging biomarker in aortic stenosis is not well established. The aim of this study was to investigate the prognostic performance of phasic LA strain in relation to clinical and echocardiographic variables and N-terminal pro-B-type natriuretic peptide in asymptomatic and minimally symptomatic patients with moderate to severe aortic stenosis and left ventricular ejection fraction > 50%.

    METHODS: LA reservoir strain (LASr), LA conduit strain (LAScd), and LA contractile strain (LASct) were measured using speckle-tracking echocardiography. The primary outcome was a composite of all-cause mortality, heart failure hospitalization, progression to New York Heart Association functional class III or IV, acute coronary syndrome, or syncope. Secondary outcomes 1 and 2 comprised the same end points but excluded acute coronary syndrome and additionally syncope, respectively. The prognostic performance of phasic LA strain cutoffs was evaluated in competing risk analyses, aortic valve replacement being the competing risk.

    RESULTS: Among 173 patients (mean age, 69 ± 11 years; mean peak transaortic velocity, 4.0 ± 0.8 m/sec), median LASr, LAScd, and LASct were 27% (interquartile range [IQR], 22%-32%), 12% (IQR, 8%-15%), and 16% (IQR, 13%-18%), respectively. Over a median of 2.7 years (IQR, 1.4-4.6 years), the primary outcome and secondary outcomes 1 and 2 occurred in 66 (38%), 62 (36%), and 59 (34%) patients, respectively. LASr < 20%, LAScd < 6%, and LASct < 12% were identified as optimal cutoffs of the primary outcome. In competing risk analyses, progressing from echocardiographic to echocardiographic-clinical and combined models incorporating N-terminal pro-B-type natriuretic peptide, LA strain parameters outperformed other key echocardiographic variables and significantly predicted clinical outcomes. LASr < 20% was associated with the primary outcome and secondary outcome 1, LAScd < 6% with all clinical outcomes, and LASct < 12% with secondary outcome 2. LAScd < 6% had the highest specificity (95%) and positive predictive value (82%) for the primary outcome, and competing risk models incorporating LAScd < 6% had the best discriminative value.

    CONCLUSIONS: In well-compensated patients with moderate to severe aortic stenosis and preserved left ventricular ejection fractions, LA strain was superior to other echocardiographic indices and incremental to N-terminal pro-B-type natriuretic peptide for risk stratification. LAScd < 6%, LASr < 20%, and LASct < 12% identified patients at higher risk for adverse outcomes.

    Matched MeSH terms: Ventricular Function, Left
  13. Ota N, Sivalingam S, Pau KK, Hew CC, Dillon J, Latiff HA, et al.
    PMID: 29310554 DOI: 10.1177/2150135117743225
    OBJECTIVE: We introduced primary arterial switch operation for the patient with transposition of great arteries and intact ventricular septum (TGA-IVS) who had more than 3.5 mm of posterior left ventricle (LV) wall thickness.

    METHODS: Between January 2013 and June 2015, a total of 116 patients underwent arterial switch operation. Of the 116 patients, 26 with TGA-IVS underwent primary arterial switch operation at more than 30 days of age.

    RESULTS: The age and body weight (mean ± SD) at the operation were 120.4 ± 93.8 days and 4.1 ±1.0 kg, respectively. There was no hospital mortality. The thickness of posterior LV wall (preoperation vs postoperation; mm) was 4.04 ± 0.71 versus 5.90 ± 1.3; P < .0001; interval: 11.8 ± 6.5 days. The left atrial pressure (mm Hg; postoperative day 0 vs 3) was 20.0 ± 3.2 versus 10.0 ± 2.0; P < .0001; and the maximum blood lactate level (mmol/dL) was 4.7 ± 1.4 versus 1.4 ± 0.3; P < .0001, which showed significant improvement in the postoperative course. All cases had delayed sternal closure. The patients who belonged to the thin LV posterior wall group (<4 mm [preoperative echo]: n = 13) had significantly longer ventilation time (days; 10.6 ± 4.8 vs 4.8 ± 1.7, P = .0039), and the intensive care unit stay (days) was 14 ± 9.2 versus 7.5 ± 3.5; P = .025, compared with thick LV wall group (≥4.0 mm: n = 13).

    CONCLUSIONS: The children older than 30 days with TGA-IVS can benefit from primary arterial switch operation with acceptable results under our indication. However, we need further investigation for LV function.

    Matched MeSH terms: Ventricular Function, Left
  14. Mansouri M, Salamonsen RF, Lim E, Akmeliawati R, Lovell NH
    PLoS One, 2015;10(4):e0121413.
    PMID: 25849979 DOI: 10.1371/journal.pone.0121413
    In this study, we evaluate a preload-based Starling-like controller for implantable rotary blood pumps (IRBPs) using left ventricular end-diastolic pressure (PLVED) as the feedback variable. Simulations are conducted using a validated mathematical model. The controller emulates the response of the natural left ventricle (LV) to changes in PLVED. We report the performance of the preload-based Starling-like controller in comparison with our recently designed pulsatility controller and constant speed operation. In handling the transition from a baseline state to test states, which include vigorous exercise, blood loss and a major reduction in the LV contractility (LVC), the preload controller outperformed pulsatility control and constant speed operation in all three test scenarios. In exercise, preload-control achieved an increase of 54% in mean pump flow ([Formula: see text]) with minimum loading on the LV, while pulsatility control achieved only a 5% increase in flow and a decrease in mean pump speed. In a hemorrhage scenario, the preload control maintained the greatest safety margin against LV suction. PLVED for the preload controller was 4.9 mmHg, compared with 0.4 mmHg for the pulsatility controller and 0.2 mmHg for the constant speed mode. This was associated with an adequate mean arterial pressure (MAP) of 84 mmHg. In transition to low LVC, [Formula: see text] for preload control remained constant at 5.22 L/min with a PLVED of 8.0 mmHg. With regards to pulsatility control, [Formula: see text] fell to the nonviable level of 2.4 L/min with an associated PLVED of 16 mmHg and a MAP of 55 mmHg. Consequently, pulsatility control was deemed inferior to constant speed mode with a PLVED of 11 mmHg and a [Formula: see text] of 5.13 L/min in low LVC scenario. We conclude that pulsatility control imposes a danger to the patient in the severely reduced LVC scenario, which can be overcome by using a preload-based Starling-like control approach.
    Matched MeSH terms: Ventricular Function, Left/physiology*
  15. Mansouri M, Gregory SD, Salamonsen RF, Lovell NH, Stevens MC, Pauls JP, et al.
    PLoS One, 2017;12(2):e0172393.
    PMID: 28212401 DOI: 10.1371/journal.pone.0172393
    Due to a shortage of donor hearts, rotary left ventricular assist devices (LVADs) are used to provide mechanical circulatory support. To address the preload insensitivity of the constant speed controller (CSC) used in conventional LVADs, we developed a preload-based Starling-like controller (SLC). The SLC emulates the Starling law of the heart to maintain mean pump flow ([Formula: see text]) with respect to mean left ventricular end diastolic pressure (PLVEDm) as the feedback signal. The SLC and CSC were compared using a mock circulation loop to assess their capacity to increase cardiac output during mild exercise while avoiding ventricular suction (marked by a negative PLVEDm) and maintaining circulatory stability during blood loss and severe reductions in left ventricular contractility (LVC). The root mean squared hemodynamic deviation (RMSHD) metric was used to assess the clinical acceptability of each controller based on pre-defined hemodynamic limits. We also compared the in-silico results from our previously published paper with our in-vitro outcomes. In the exercise simulation, the SLC increased [Formula: see text] by 37%, compared to only 17% with the CSC. During blood loss, the SLC maintained a better safety margin against left ventricular suction with PLVEDm of 2.7 mmHg compared to -0.1 mmHg for CSC. A transition to reduced LVC resulted in decreased mean arterial pressure (MAP) and [Formula: see text] with CSC, whilst the SLC maintained MAP and [Formula: see text]. The results were associated with a much lower RMSHD value with SLC (70.3%) compared to CSC (225.5%), demonstrating improved capacity of the SLC to compensate for the varying cardiac demand during profound circulatory changes. In-vitro and in-silico results demonstrated similar trends to the simulated changes in patient state however the magnitude of hemodynamic changes were different, thus justifying the progression to in-vitro evaluation.
    Matched MeSH terms: Ventricular Function, Left/physiology*
  16. Sakthiswary R, Das S
    Saudi Med J, 2015 May;36(5):525-9.
    PMID: 25935171 DOI: 10.15537/smj.2015.5.10751
    The main objective was to determine the predictors of diastolic dysfunction in rheumatoid arthritis (RA). Articles pertaining to diastolic dysfunction in RA were retrieved from Scopus, EBSCO, PubMed, Web of Science, and Cochrane Library databases. Keywords such as: diastolic, cardiac, left ventricular function, heart failure, rheumatoid arthritis, and cardiac failure were used. Studies, which examined factors, or predictors of diastolic dysfunction in RA, and those with echocardiographic evaluation of diastolic dysfunction, were included. A total of 8 studies met the eligibility criteria. Most studies (6 out of 7 studies) demonstrated a significant inverse relationship between the E (early)/A (late) ratio and disease duration. The pooled analysis using the random effects model revealed a significant but weak inverse relationship between the ratio of the E to A ventricular filling velocities (E/A) ratio and the disease duration (p less than 0.05, r=-0.385). There was a significant relationship between E/A ratio and disease duration in RA.

    Study site: Hospital Kuala Lumpur (HKL)
    Matched MeSH terms: Ventricular Function, Left
  17. Oo MM, Tan Chung Zhen I, Ng KS, Tan KL, Tan ATB, Vethakkan SR, et al.
    BMJ Open, 2021 01 21;11(1):e039869.
    PMID: 33478961 DOI: 10.1136/bmjopen-2020-039869
    OBJECTIVE: To identify the prevalence of stage B heart failure (SBHF) in patients with type 2 diabetes mellitus (T2DM) with no history of cardiovascular disease (CVD).

    DESIGN: Observational study.

    SETTING: A single-centre study in which eligible patients were recruited from T2DM clinic. Following consent, patients completed a questionnaire and underwent physical examinations. Patients had blood drawn for laboratory investigations and had a transthoracic echocardiography.

    PARTICIPANTS: A total of 305 patients who were not known to have CVD were recruited. Patients with deranged liver function tests and end stage renal failure were excluded.

    MAIN OUTCOME MEASURES: Echocardiographic parameters such as left ventricular ejection fraction, left ventricular mass index (LVMI), left ventricular hypertrophy, left atrial enlargement and diastolic function were examined.

    RESULTS: A total of 305 patients predominantly females (65%), with mean body mass index of 27.5 kg/m2 participated in this study. None of them had either a history or signs and symptoms of CVD. Seventy-seven percent of patients had a history of hypertension and 83% of this study population had T2DM for more than 10 years. Mean HbA1c of 8.3% was recorded. Almost all patients were taking metformin. Approximately, 40% of patients were on newer anti-T2DM agents such as sodium-glucose cotransporter-2 and dipeptidyl peptidase 4 inhibitors. Fifty-seven percent (n=174) of the study population had SBHF at the time of study: diastolic dysfunction, increased LVMI and increased left atrial volume index (LAVI) were noted in 51 patients (17%), 128 patients (42%) and 98 patients (32%), respectively. Thirty-seven patients (12%) had both increase LVMI and LAVI.

    CONCLUSION: Our study has revealed a high prevalence of SBHF in T2DM patients without overt cardiac disease in Malaysia that has one of the highest prevalence of TDM in the world.

    Matched MeSH terms: Ventricular Function, Left
  18. Zhou H, Zainal H, Puntmann VO
    Aging (Albany NY), 2019 03 25;11(6):1609-1610.
    PMID: 30908271 DOI: 10.18632/aging.101890
    Matched MeSH terms: Ventricular Function, Left/physiology*
  19. Izham IN, Zamrin DM, Joanna OS, Ramzisham AR, Hairolfaizi H, Ishamuddin IM, et al.
    Clin Ter, 2011;162(6):521-5.
    PMID: 22262321
    The effect of the duration of ischaemic myocardial time to left ventricular ejection fraction (LVEF) after valve replacement surgery has been attributed. This study aims to look at the correlation between myocardial ischaemic time and changes LVEF post valve replacement surgery up to 6 months period.
    Matched MeSH terms: Ventricular Function, Left*
  20. Petyunina O, Kopytsya M, Kobets A, Berezin A
    Turk Kardiyol Dern Ars, 2023 Mar;51(2):119-128.
    PMID: 36916808 DOI: 10.5543/tkda.2022.31531
    OBJECTIVE: The aim of the study was to investigate whether increased left ventricular mechanical dispersion is an early predictor for adverse cardiac remodeling in ST-segment elevation myocardial infarction patients who had post-percutaneous coronary intervention thrombolysis in myocardial infarction (TIMI) flow grade > 2.

    METHODS: A total of 119 post-percutaneous coronary intervention ST elevation myocardial infarction patients with TIMI flow grade >2 were prospectively included in the study. Left ventricular global longitudinal strain was quantified by 2-dimensional speckletracking echocardiography, and left ventricular mechanical dispersion was determined at baseline and after 1 year to assess adverse cardiac remodeling. The levels of circulating biomarkers were measured at the baseline. TIMI score and the Global Registry of Acute Coronary Events score systems were used to evaluate the prognosis of patients.

    RESULTS: Patients with high quartile versus low quartile of left ventricular mechanical dispersion exerted higher Global Registry of Acute Coronary Events and TIMI score grades, left ventricular endsystolic volume, global longitudinal strain, and levels of the N-terminal fragment of brain natriuretic peptide and lower left ventricular ejection fraction. Multivariate log regression showed that N-terminal fragment of brain natriuretic peptide > 953 pg/mL, global longitudinal strain > -8%, and high quartile of left ventricular mechanical dispersion remained independent predictors for adverse cardiac remodeling. Addition of left ventricular mechanical dispersion to the N-terminal fragment of brain natriuretic peptide improved the discriminative potency of the whole model.

    CONCLUSION: Measurement of left ventricular mechanical dispersion might be useful in determining the risk of adverse cardiac remodeling in post-percutaneous coronary intervention ST elevation myocardial infarction patients.

    Matched MeSH terms: Ventricular Function, Left
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