Chi Keong Ching

National Heart Centre Singapore, Tumasik, Singapore

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Publications (44)115.63 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Background: Heart failure with preserved ejection fraction (HF-PEF) has been shown to be of better or equivalent prognosis than heart failure with reduced ejection fraction (HF-REF). We aimed to characterize and study the outcome of HF-PEF in a multiethnic South East Asian context. Methods: This is a single-centre retrospective analysis of 312 patients admitted with decompensated heart failure over 1 year from January to December 2009. We evaluated clinical characteristics of patients according to left ventricular ejection fraction at least 50 or less than 50%. Outcomes as defined by 1-year mortality and 90-day re-hospitalization rates for heart failure were compared between the two groups in an in-patient setting. Results: The median age was 68 years and median length of hospitalization was 4 days. Around 21.8% had HF-PEF. Patients with preserved ejection fraction were more often older, female, hypertensive, with atrial fibrillation, had no coronary artery disease and had never smoked before. They were less often prescribed antiplatelets, angiotensin-converting enzyme inhibitor/angiotensin-II receptor blocker, aldosterone-receptor antagonists, digoxin and loop diuretics. After 1 year, mortality was 5.9% in patients with HF-PEF and 11.3% in those with HF-REF, but the difference was nonsignificant (P = 0.195). There was also no difference in 90-day rehospitalization rates between the groups (16.2 vs. 17.6%, respectively, P = 0.780). Poor prognostic factors for the cohort of heart failure patients included increased age, diabetes and renal impairment, but not left ventricular ejection fraction. Conclusion: HF-PEF is associated with distinct risk factors from HF-REF, but has a similar morbidity and mortality to HF-REF. Copyright (C) 2015 Wolters Kluwer Health, Inc. All rights reserved.
    Journal of Cardiovascular Medicine 07/2014; · 1.41 Impact Factor
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    ABSTRACT: The aim of this study was to test the hypothesis that diabetes modifies the risk of mortality in acute heart failure patients, especially in patients with impaired LVEF, and that impaired LVEF in turn modifies the risk of mortality in diabetic patients.
    European Journal of Heart Failure 06/2014; 16(11). · 6.58 Impact Factor
  • Global Heart. 03/2014; 9(1):e168.
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    ABSTRACT: A 48-year-old male patient underwent cardiac resynchronization therapy defibrillator implantation, and he was found to have atresia of the coronary sinus ostium with venous drainage occurring via a persistent left-sided superior vena cava, which was connected to the right-sided superior vena cava by the innominate vein. This is a rare benign cardiac anomaly that can pose problems when the coronary sinus needs to be cannulated. To identify the course of the coronary sinus, a coronary angiogram can be performed with attention directed to the venous phase of the angiogram. Although the technical difficulty of coronary sinus cannulation increases, various catheters, wires, and delivery systems can be utilized and this anomaly does not usually prevent successful left ventricular lead placement in cardiac resynchronization therapy via a left-sided superior vena cava approach. There however needs to be consideration regarding caliber of the left-sided superior vena cava being sufficiently large to avoid compromise of venous drainage after lead insertion.
    International Journal of Angiology 09/2013; 22(3):199-202.
  • Annals of the Academy of Medicine, Singapore 09/2013; 42(9):480-2. · 1.22 Impact Factor
  • Europace 06/2013; · 3.05 Impact Factor
  • Source
    Heart Asia. 01/2013; 5(1):15.
  • Amit Kumar Malik, Chi Keong Ching, Wee Siong Teo
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    ABSTRACT: a b s t r a c t The combineduseofanAmplatzguidingcatheterandsupportcathetercreatesaprogressively supportiverailtoimplanttheleftventricular(LV)leadindifficultcardiacresynchronizationtherapy deviceimplantation.Wedescribethecaseofa32-year-oldmalewithnon-ischaemiccardiomyopathy, left bundle-branchblock,andanLVejectionfractionof30%,whowasreferredtoourcentreforarepeat attemptatanLVleadimplant.Previously,theimplanterhadbeenunabletoadvancedifferentguide cathetersoverthewiretothedesiredtributaryofthecoronarysinus(CS).Atourcentre,theCSwas cannulatedwitha6-FrAL2coronaryguidingcatheter.A135-cmsupportcatheter(SpectraneticsQuick- Cross)wasadvancedviaAL2guidingoverthe0.035in.guidewiretothedistalCS.Theproximalluer fitting ofthesupportcatheterwascutandaninnersheath(MedtronicATTAINSELECTII)advancedover the supportcatheterintotheCS.A4-Frover-the-wireLVleadwasadvancedthroughtheinnersheath over a0.014in.percutaneoustransluminalcoronaryangioplastywireafterremovalofthesupport catheter.Theuseofasupportcatheterservesasrailfortheplacementoftheinnersheathdeepinthe CS andfacilitatesimplantationoftheLVpacinglead.Thistechniqueissafeandeasilyapplied.
    Journal of Arrhythmia 08/2012; 28(4):225-227.
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    ABSTRACT: AIMS: Guidelines from the ESC and ACC/AHA recommend implantable cardioverter defibrillators (ICDs) be implanted in clinically indicated patients with a reasonable expectation of >1 year survival. Our study aimed to assess if selected clinical markers of organ dysfunction were associated with increased 1-year mortality despite ICD therapy.METHODS AND RESULTS: We retrospectively studied 283 patients with de novo ICDs implanted for primary or secondary prevention in ischaemic heart disease and dilated cardiomyopathy. We investigated the association of the following clinical markers of organ dysfunction with 1 year mortality: liver dysfunction (aspartate transaminase/alanine transaminase ≥ 3× upper limit of normal or prothrombin time/international normalized ratio ≥ 1.5 in the absence of anticoagulation), respiratory dysfunction (recent mechanical ventilation within 3 months prior to ICD implant), renal dysfunction (creatinine ≥150 µmol/L or glomerular filtration rate ≤ 30 mL/min/1.73 m(2)), anaemia (Hb ≤ 100 g/L), and prior cerebral vascular injury. With no organ dysfunction, 1 year mortality was 1.9%. In the presence of a single organ dysfunction, mortality was increased to 14.3%. With two or more markers of organ dysfunction mortality was 38.1% at 1 year (log-rank test P < 0.001).CONCLUSIONS: Clinical markers of liver dysfunction, recent mechanical ventilation, and renal impairment were independently associated with increased 1 year mortality. Presence of more than one clinical marker of organ dysfunction was associated with significantly increased risk of mortality in our study.
    Europace 07/2012; · 3.05 Impact Factor
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    ABSTRACT: BACKGROUND: Fragmented QRS complexes (fQRS) correlate with myocardial scar, and may predict arrhythmias in patients with repaired tetralogy of Fallot (TOF). We investigated the relationship between fQRS in operated TOF patients with right ventricular (RV) dysfunction and RV outflow tract (RVOT) aneurysm. METHODS: We studied 56 operated TOF patients with moderate/severe pulmonary regurgitation, referred for cardiac magnetic resonance imaging (MRI) over a 4.5year period. The presence of fQRS (additional notches in the R/S wave in ≥2 contiguous leads on the ECG) was correlated with MRI findings. RESULTS: fQRS was observed in 44 (78.6%) patients. Patients with fQRS had significantly larger RV end diastolic volume index (RVEDVi; 162ml vs 141ml, p=0.028) and RV end systolic volume index (RVESVi; 88ml vs 70ml, p=0.031). Increasing number of leads with fragmentation was independently associated with increasingly lower RV ejection fraction (adjusted co-efficient -0.97, 95%CI -1.83 to -0.12, p=0.026), greater pulmonary regurgitation fraction (1.65, 0.28 to 3.01, p=0.019), larger RVEDVi (6.78, 2.00 to 11.56, p=0.006) and RVESVi (5.41, 1.66 to 9.15, p=0.005). Anterior fragmentation correlated most significantly with RV dysfunction (p<0.05). fQRS had no significant association with LV dysfunction. Presence of any fQRS (OR 17.5, 95%CI 2.1-147.8, p=0.009) and inferior fQRS (OR 9.0, 95%CI 2.7-30.1, p<0.001) were found to be significant predictors for RVOT aneurysm. CONCLUSIONS: The presence of fQRS on the ECG is significantly associated with RV dysfunction and RVOT aneurysms in repaired TOF patients. Increasing burden of fragmentation, especially in the anterior leads, is associated with increasing RV dysfunction.
    International journal of cardiology 04/2012; · 6.18 Impact Factor
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    ABSTRACT: Ablation of sinus node reentrant tachycardia (SNRT) may be difficult with risk of sinus node injury by using conventional catheters. We report successful ablation of SNRT by using remote magnetic navigation system (Stereotaxis).
    Europace 03/2012; 14(3):455-6. · 3.05 Impact Factor
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    ABSTRACT: Resting 12-lead electrocardiograms (ECGs) have been employed in the pre-participation evaluation of young asymptomatic subjects to detect pre-existing heart diseases. Although the incorporation of routine ECG in pre-participation screening remains controversial, there is increasing evidence that cardiomyopathies and ion channelopathies have ECG changes as the initial manifestation. The causes of sudden cardiac death in young people show significant geographical variation. We aim to determine the prevalence and spectrum of ECG abnormalities in a young male South-East Asian population. The Singapore Armed Forces Electrocardiogram and Echocardiogram (SAFE) protocol is an ECG-based pre-participation cardiac screening programme modelled after the Italian system. From October 2008 to May 2009, a total of 18 476 young male conscripts (mean age 19.5 years old, range 16-27) underwent mandatory pre-enlistment medical screening at a single medical facility. Subjects with abnormal ECG findings were classified into two groups: Group A had ECG changes that fulfilled a pre-specified checklist to screen for hypertrophic cardiomyopathy and were referred for transthoracic echocardiogram; Group B had other ECG abnormalities [such as Brugada pattern, Wolff-Parkinson-White (WPW) pattern, long QTc] and were referred for secondary screening at a tertiary institution. Of the 18 476 subjects screened, 7.0% (n= 1285) had ECG abnormalities. Of note, 19 (0.10%) had Brugada pattern, 25 (0.14%) had WPW pattern, and 31 (0.17%) had prolonged QT interval on ECG. The prevalence of ECG abnormalities was significantly higher in Chinese than in South Asians (7.2 vs. 5.7%, P= 0.003). The prevalence of ECG abnormalities in a young, South-East Asian male population was 7.0%. There were significant ethnic differences, with ECG abnormalities more prevalent in Chinese than in South Asians (7.2 vs. 5.7%, P= 0.003). The inclusion of universal ECG, in addition to history and physical examination, may increase the sensitivity of a cardiovascular screening programme. Knowledge of the spectrum and prevalence of ECG abnormalities and disease conditions would be pivotal in designing customized screening programmes.
    Europace 02/2012; 14(7):1018-24. · 3.05 Impact Factor
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    ABSTRACT: Hypertrophic cardiomyopathy is a leading cause of sudden cardiac death (SCD) in young people in the USA. Pre-participation screening for athletes might reduce the incidence of SCD. In Singapore, military service is compulsory for all young able-bodied male citizens. The Singapore Armed Forces Electrocardiogram and Echocardiogram (SAFE) pre-participation screening protocol based on the Italian programme was introduced. This study evaluates the prevalence of hypertrophic cardiomyopathy (HCM) in a young male South-East Asian population. From October 2008 to May 2009, all male military conscripts underwent pre-participation screening. For all conscripts whose electrocardiogram (ECG) findings fulfilled any of these pre-specified criteria (Group A), direct referral for a transthoracic echocardiogram was mandatory. Conscripts with ECG findings other than pre-specified criteria (e.g. T-wave inversions, repolarization abnormalities) were referred for secondary screening by cardiologists (Group B), which could include echocardiography. Out of 18 476 subjects screened during the study period, 988 (5.3%) subjects were fast tracked for echocardiogram (Group A). Of them, there were three (0.3%) cases with severe abnormalities; there was one case each of HCM, bicuspid aortic valve with significant aortic valve regurgitation, and atrial septal defect with right ventricular systolic dysfunction. The patient with HCM had left axis deviation on ECG. None of the 215 patients who underwent echocardiography following cardiology consult (Group B) had HCM. The prevalence of HCM in our young male population (mean age 19.5, range 16-27) using an ECG-based screening protocol was 0.005%; this appeared lower than published data from other geographical cohorts. Possible explanations include a later age of phenotypic manifestation in our population, limitations of the ECG criteria for screening, or a truly lower prevalence of HCM. More population-based longitudinal studies would be needed to ascertain the true prevalence of HCM in our South-East Asian population.
    Europace 06/2011; 13(6):883-8. · 3.05 Impact Factor
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    ABSTRACT: Cardiac electric therapies effectively terminate tachyarrhythmias. Recent data suggest a possible increase in long-term mortality associated with implantable cardioverter-defibrillator shocks. Little is known about the association between external cardioversion episodes (ECVe) and long-term mortality. We sought to assess the safety of repeated ECVe with regard to cardiovascular mortality and morbidity. We analyzed the data of the 4060 patients from the AFFIRM (Atrial Fibrillation Follow-up Investigation of Rhythm Management) trial. In particular, associations of ECVe with all-cause mortality, cardiovascular mortality, and hospitalizations after ECVe were studied. Over an average follow-up of 3.5 years, 660 (16.3%) patients died, 331 (8.2%) from cardiovascular causes. A total of 207 (5.1%) and 1697 (41.8%) patients had low ejection fraction and nonparoxysmal atrial fibrillation, respectively; 2460 patients received no ECVe, whereas 1600 experienced ≥ 1 ECVe. Death occurred in 412 (16.7%), 196 (16.5%), 39 (13.5%), and 13 (10.4%) of patients with 0, 1, 2, and ≥ 3 ECVe, respectively. There was no significant association between ECVe and mortality within any of the 4 subgroups defined by ejection fraction and atrial fibrillation type, although myocardial infarction, coronary artery bypass graft, and digoxin were significantly associated with death (estimated hazard ratios, 1.65, 1.59, and 1.62, respectively; P < 0.0001). ECVe were associated with increased cardiac hospitalization reported at the next follow-up visit (39.3% versus 5.8%; estimated odds ratio, 1.39; P < 0.0001). In the AFFIRM study, there was no significant association between ECVe and long-term mortality, even though ECVe were associated with increased hospitalizations from cardiac causes. Digoxin, myocardial infarction, and coronary artery bypass graft were significantly associated with mortality.
    Circulation Arrhythmia and Electrophysiology 04/2011; 4(4):465-9. · 5.95 Impact Factor
  • Journal of Arrhythmia 01/2011; 27(Supplement):OP63_4.
  • Journal of Arrhythmia 01/2011; 27(Supplement):PE3_011.
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    ABSTRACT: Introduction: We report two cases of recurrent VT, successfully controlled by EndoEpicardial ablation using Stereotaxis System. Case 1: 65 year female had ICD, PTCA and Mitral valve replacement, presented with recurrent monomorphic VT (CL 430 ms, LBBB superior axis), LVEF 20%. Mapping done with CARTO and Stereotaxis. RF ablation at earliest endocardial activation and low voltage areas unable to terminate VT. Epicardial approach was attempted via pericardial window. Earliest activation and presystolic potentials noted in mid posterior septal LV, RF ablation at this site terminated the VT. Subsequently slower VT 2 (CL 520 ms) was induced with earliest activation more laterally. RF ablations in mid posterior LV from lateral LV to near the septum terminated VT. Case 2: 43 year male case of dialated cardiomyopathy, LV dysfunction (EF 25%) previously failed endocardial RF ablation for VT. Percutaneous subxiphiod epicardial access was obtained. VT1 (CL 610 ms, right inferior axis, RBBB pattern) was spontaneously induced during epicardial instrumentation. Scar and area of double potentials mapped epicardially at basal anterolateral LV. Ablation at this site terminated VT. PES subsequently induced VT2 (CL 340 ms) and VT3 (CL 210 ms). Both VT mapped and ablated endocardially. Conclusion: Enhanced maneuverability of catheter by using Stereotaxis permits accurate mapping of difficult reach areas, with minimal trauma to cardiac tissue and radiation exposure.
    Journal of Arrhythmia 01/2011; 27(Supplement):OP66_5.
  • Journal of Arrhythmia 01/2011; 27(Supplement):PE3_038.
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    ABSTRACT: Background: In secondary prevention patients, ICD detection zones are often tailored individually. We aim to determine whether patients initial presenting VT tachycardia cycle length (TCL) prior to ICD implant predicts subsequent VT TCL.Methods: All secondary prevention ICD patients on follow up with available records of appropriate ICD therapy for VT within a 3-year period were studied.Results: 249 VT events in 20 patients were analysed. Mean age 55.8 years, median 5-years follow up. All had sustained VT on 12-lead ECG prior to ICD implant. Mean presenting VT TCL was 313±46 (SD) ms. In majority, post implant VT TCL increased by 20–50 ms compared to at presentation (R=0.52, p=0.02). In the entire group, mean TCL of VTs post implant was 350±43 (SD) ms. Reasons for the increased TCL include medications, ischaemia, scar size changes and different VT circuits.Conclusion: In our population, VT cycle lengths post implant are on average longer, but remain correlated to presenting TCL. Detection cycle lengths 50 ms longer than the TCL of the presenting VT should be programmed if under-detection of subsequent VTs is to be minimised.
    Journal of Arrhythmia 01/2011; 27(Supplement):PE4_083.
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    ABSTRACT: Permanent cardiac pacing is the treatment of choice in patients with symptomatic bradyarrhythmias. The SCDB is a prospective registry of interventional cardiac procedures done in Singapore since July 2000. This report looks at the data from NHC during the period from 2000–2010. There were 1724 pacemakers implanted during the 10 year with almost yearly increase in the number of pacemakers implanted at this single centre. The mean age of the patients was 69.86 years+12.2 old (median 71 years old, range 11–98 years). Over the 10 year period, there were more females (54.2% females vs 45.8% males). Sick sinus syndrome remains the most common indication for pacemaker implantation (60.7%) and the second most common indication was AV block (35.3%). This trend was consistently seen over the decade. The number of females was higher in the sick sinus syndrome group (59.8% females vs 40.2% males) whereas the proportion of males was higher in the complete heart block group (46.5% females vs 53.5% males). In conclusion, there is an increase in the number of pacemakers implanted likely due to an aging population. Females remain consistently higher and sick sinus syndrome remains the most important indication for pacing. With the rapidly aging population, it would be expected that this trend would continue to increase over the next decade.
    Journal of Arrhythmia 01/2011; 27(Supplement):PE4_043.

Publication Stats

502 Citations
115.63 Total Impact Points


  • 2010–2014
    • National Heart Centre Singapore
      Tumasik, Singapore
  • 2006–2014
    • National Heart Centre Singapore
      • Cardiology
      Tumasik, Singapore
  • 2009
    • St. David's North Austin Medical Center
      Austin, Texas, United States
  • 2007–2009
    • Cleveland Clinic
      • Center for Atrial Fibrillation
      Cleveland, Ohio, United States
  • 2008
    • Case Western Reserve University
      Cleveland, Ohio, United States
    • Clinique Ambroise Paré
      Tolosa de Llenguadoc, Midi-Pyrénées, France