1.Rate or Rhythm Control of Atrial Fibrillation - Pearls for the Internist.
Weiting HUANG ; Felix Yj KENG ; Chi Keong CHING
Annals of the Academy of Medicine, Singapore 2017;46(11):433-438
Atrial fibrillation is an epidemic in Asia that is increasingly prevalent. Apart from stroke risk stratification and management of anticoagulation, physicians managing this group of patients also need to determine an optimal strategy in terms of rate or rhythm control. With new techniques of catheter ablation to maintain patients in sinus rhythm, patients with atrial fibrillation now have more options for treatment, on top of pharmacological methods. This paper aims to review the current evidence for rate and rhythm control in both general patients and subgroups of interest commonly encountered in clinical practices such as obesity, heart failure and thyroid disease.
2.Implantation of lumenless pacing leads at the inter-atrial septum and right ventricular outflow tract with deflectable catheter-sheath.
Rong, BAI ; Ruth, KAM ; Chi Keong, CHING ; Li Fern, HSU ; Wee Siong, TEO
Journal of Huazhong University of Science and Technology (Medical Sciences) 2008;28(6):639-44
Current permanent right ventricular and right atrial endocardial pacing leads are implanted utilizing a central lumen stylet. Right ventricular apex pacing initiates an abnormal asynchronous electrical activation pattern, which results in asynchronous ventricular contraction and relaxation. When pacing from right atrial appendage, the conduction time between two atria will be prolonged, which results in heterogeneity for both depolarization and repolarization. Six patients with Class I indication for permanent pacing were implanted with either single chamber or dual chamber pacemaker. The SelectSecure 3830 4-French (Fr) lumenless lead and the SelectSite C304 8.5-Fr steerable catheter-sheath (Medtronic Inc., USA) were used. Pre-selected pacing sites included inter-atrial septum and right ventricular outflow tract, which were defined by ECG and fluoroscopic criteria. All the implanting procedures were successful without complication. Testing results (mean atrial pacing threshold: 0.87 V; mean P wave amplitude: 2.28 mV; mean ventricular pacing threshold: 0.53V; mean R wave amplitude: 8.75 mV) were satisfactory. It is concluded that implantation of a 4-Fr lumenless pacing lead by using a streerable catheter-sheath to achieve inter-atrial septum or right ventricular outflow tract pacing is safe and feasible.
Cardiac Pacing, Artificial/*methods
;
Electrodes, Implanted
;
Equipment Safety
;
Pacemaker, Artificial
;
Prosthesis Implantation/methods
;
Sick Sinus Syndrome/*therapy
4.Mutation screening in KCNQ1, HERG, KCNE1, KCNE2 and SCN5A genes in a long QT syndrome family.
Seok-Hwee KOO ; Wee-Siong TEO ; Chi-Keong CHING ; Soh-Ha CHAN ; Edmund J D LEE
Annals of the Academy of Medicine, Singapore 2007;36(6):394-398
INTRODUCTIONLong QT syndrome (LQTS), an inherited cardiac arrhythmia, is a disorder of ventricular repolarisation characterised by electrocardiographic abnormalities and the onset of torsades de pointes leading to syncope and sudden death. Genetic polymorphisms in 5 well-characterised cardiac ion channel genes have been identified to be responsible for the disorder. The aim of this study is to identify disease-causing mutations in these candidate genes in a LQTS family.
MATERIALS AND METHODSThe present study systematically screens the coding region of the LQTS-associated genes (KCNQ1, HERG, KCNE1, KCNE2 and SCN5A) for mutations using DNA sequencing analysis.
RESULTSThe mutational analysis revealed 7 synonymous and 2 non-synonymous polymorphisms in the 5 ion channel genes screened.
CONCLUSIONWe did not identify any clear identifiable genetic marker causative of LQTS, suggesting the existence of LQTS-associated genes awaiting discovery.
Adolescent ; Adult ; Child ; DNA Mutational Analysis ; ERG1 Potassium Channel ; Ether-A-Go-Go Potassium Channels ; analysis ; genetics ; Female ; Frameshift Mutation ; Humans ; KCNQ1 Potassium Channel ; analysis ; genetics ; Long QT Syndrome ; genetics ; Male ; Middle Aged ; Muscle Proteins ; analysis ; genetics ; NAV1.5 Voltage-Gated Sodium Channel ; Polymorphism, Genetic ; genetics ; Potassium Channels, Voltage-Gated ; analysis ; genetics ; Sodium Channels ; analysis ; genetics ; Trans-Activators
5.Trends amongst implantable cardioverter defibrillator patients in a tertiary cardiac centre in Singapore from 2002 to 2011.
Daniel T T CHONG ; Boon Yew TAN ; Kah Leng HO ; Wee Siong TEO ; Chi Keong CHING
Annals of the Academy of Medicine, Singapore 2013;42(9):480-482
Aged
;
Cardiac Care Facilities
;
trends
;
Cardiac Resynchronization Therapy
;
trends
;
utilization
;
Cardiac Resynchronization Therapy Devices
;
trends
;
utilization
;
Death, Sudden, Cardiac
;
prevention & control
;
Defibrillators, Implantable
;
trends
;
utilization
;
Electric Countershock
;
trends
;
utilization
;
Female
;
Heart Failure
;
therapy
;
Humans
;
Male
;
Middle Aged
;
Retrospective Studies
;
Singapore
;
Stroke Volume
;
Tachycardia, Ventricular
;
therapy
;
Tertiary Care Centers
6.Implantation of Lumenless Pacing Leads at the Inter-atrial Septum and Right Ventricular Outflow Tract with Deflectable Catheter-sheath
BAI RONG ; KAM RUTH ; CHING Keong CHI ; HSU Fern LI ; TEO Siong WEE
Journal of Huazhong University of Science and Technology (Medical Sciences) 2008;28(6):639-644
Current permanent fight ventricular and fight atrial endocardial pacing leads are implanted utilizing a central lumen stylet. Right ventricular apex pacing initiates an abnormal asyno chronous electrical activation pattern, which results in asynchronous ventricular contraction and re-laxation. When pacing from right atrial appendage, the conduction time between two atria will be prolonged, which results in heterogeneity for both depolarization and repolarization. Six patients with Class Ⅰ indication for permanent pacing were implanted with either single chamber or dual chamber pacemaker. The SelectSecure 3830 4-French (Fr) lumenless lead and the SelectSite C304 8.5-Fr steerable catheter-sheath (Medtronic Inc., USA) were used. Pre-selected pacing sites included inter-atrial septum and right ventricular outflow tract, which were defined by ECG and fluoroscopic criteria. All the implanting procedures were successful without complication. Testing results (mean atrial pacing threshold: 0.87 V; mean P wave amplitude: 2.28 mV; mean ventricular pacing threshold:0.53V; mean R wave amplitude: 8.75 mV) were satisfactory. It is concluded that implantation of a 4-Fr lumenless pacing lead by using a streerable catheter-sheath to achieve inter-atrial septum or right ventricular outflow tract pacing is safe and feasible.
7.The Singapore Heart Failure Risk Score: Prediction of Survival in Southeast Asian Patients.
Jonathan YAP ; Shaw Yang CHIA ; Fang Yi LIM ; John C ALLEN ; Louis TEO ; David SIM ; Yun Yun GO ; Fazlur Rehman JAUFEERALLY ; Matthew SEOW ; Bernard KWOK ; Reginald LIEW ; Carolyn Sp LAM ; Chi Keong CHING
Annals of the Academy of Medicine, Singapore 2019;48(3):86-94
INTRODUCTION:
Numerous heart failure risk scores have been developed but there is none for Asians. We aimed to develop a risk calculator, the Singapore Heart Failure Risk Score, to predict 1- and 2-year survival in Southeast Asian patients hospitalised for heart failure.
MATERIALS AND METHODS:
Consecutive patients admitted for heart failure were identified from the Singapore Cardiac Databank Heart Failure registry. The follow-up was 2 to 4 years and mortality was obtained from national registries.
RESULTS:
The derivation (2008-2009) and 2 validation cohorts (2008-2009, 2013) included 1392, 729 and 804 patients, respectively. Ten variables were ultimately included in the risk model: age, prior myocardial infarction, prior stroke, atrial fibrillation, peripheral vascular disease, systolic blood pressure, QRS duration, ejection fraction and creatinine and sodium levels. In the derivation cohort, predicted 1- and 2-year survival was 79.1% and 68.1% compared to actual 1- and 2-year survival of 78.2% and 67.9%. There was good agreement between the predicted and observed mortality rates (Hosmer-Lemeshow statistic = 14.36, = 0.073). C-statistics for 2-year mortality in the derivation and validation cohorts were 0.73 (95% CI, 0.70-0.75) and 0.68 (95% CI, 0.64-0.72), respectively.
CONCLUSION
We provided a risk score based on readily available clinical characteristics to predict 1- and 2-year survival in Southeast Asian patients hospitalised for heart failure via a simple online risk calculator, the Singapore Heart Failure Risk Score.
8.Prevalence and Risk Factors of Atrial Fibrillation in Chinese Elderly: Results from the Chinese Longitudinal Healthy Longevity Survey.
Choy-Lye CHEI ; Prassanna RAMAN ; Chi Keong CHING ; Zhao-Xue YIN ; Xiao-Ming SHI ; Yi ZENG ; David B MATCHAR ;
Chinese Medical Journal 2015;128(18):2426-2432
BACKGROUNDPrevalence of atrial fibrillation (AF) is increasing as the world ages. AF is associated with higher risk of mortality and disease, including stroke, hypertension, heart failure, and dementia. Prevalence of AF differs with each population studied, and research on non-Western populations and the oldest old is scarce.
METHODSWe used data from the 2012 wave of the Chinese Longitudinal Healthy Longevity Survey, a community-based study in eight longevity areas in China, to estimate AF prevalence in an elderly Chinese population (n = 1418, mean age = 85.6 years) and to identify risk factors. We determined the presence of AF in our participants using single-lead electrocardiograms. The weighted prevalence of AF was estimated in subjects stratified according to age groups (65-74, 75-84, 85-94, 95 years and above) and gender. We used logistic regressions to determine the potential risk factors of AF.
RESULTSThe overall prevalence of AF was 3.5%; 2.4% of men and 4.5% of women had AF (P < 0.05). AF was associated with weight extremes of being underweight or overweight/obese. Finally, advanced age (85-94 years), history of stroke or heart disease, low high-density lipoprotein levels, low triglyceride levels, and lack of regular physical activity were associated with AF.
CONCLUSIONSIn urban elderly, AF prevalence increased with age (P < 0.05), and in rural elderly, women had higher AF prevalence (P < 0.05). Further exploration of population-specific risk factors is needed to address the AF epidemic.
Aged ; Aged, 80 and over ; Atrial Fibrillation ; epidemiology ; China ; epidemiology ; Female ; Humans ; Longitudinal Studies ; Male ; Prevalence ; Risk Factors
9.Initial experience of subcutaneous implantable cardioverter defibrillators in Singapore: a case series and review of the literature.
Tien Siang Eric LIM ; Boon Yew TAN ; Kah Leng HO ; Chuh Yih Paul LIM ; Wee Siong TEO ; Chi-Keong CHING
Singapore medical journal 2015;56(10):580-585
Transvenous implantable cardioverter defibrillators are a type of implantable cardiac device. They are effective at reducing total and arrhythmic mortality in patients at risk of sudden cardiac death. Subcutaneous implantable cardioverter defibrillators (S-ICDs) are a new alternative that avoids the disadvantages of transvenous lead placement. In this case series, we report on the initial feasibility and safety of S-ICD implantation in Singapore.
Adult
;
Death, Sudden, Cardiac
;
prevention & control
;
Defibrillators, Implantable
;
statistics & numerical data
;
Electrophysiology
;
Follow-Up Studies
;
Humans
;
Male
;
Middle Aged
;
Patient Safety
;
Prosthesis Implantation
;
Singapore
;
Tachycardia, Ventricular
;
Ventricular Fibrillation
10.Patient barriers to implantable cardioverter defibrillator implantation for the primary prevention of sudden cardiac death in patients with heart failure and reduced ejection fraction.
Laura Lihua CHAN ; Choon Pin LIM ; Soe Tin AUNG ; Paul QUETUA ; Kah Leng HO ; Daniel CHONG ; Wee Siong TEO ; David SIM ; Chi Keong CHING
Singapore medical journal 2016;57(4):182-187
INTRODUCTIONDevice therapy is efficacious in preventing sudden cardiac death (SCD) in patients with reduced ejection fraction. However, few who need the device eventually opt to undergo implantation and even fewer reconsider their decisions after deliberation. This is due to many factors, including unresolved patient barriers. This study identified the factors that influenced patients' decision to decline implantable cardioverter defibrillator (ICD) implantation, and those that influenced patients who initially declined an implant to reconsider having one.
METHODSA single-centre survey was conducted among 240 patients who had heart failure with reduced ejection fraction and met the ICD implantation criteria, but had declined ICD implantation.
RESULTSParticipants who refused ICD implantation were mostly male (84%), Chinese (71%), married (72%), currently employed (54%), and had up to primary or secondary education (78%) and monthly income of < SGD 3,000 (51%). Those who were more likely to reconsider their decision were aware that SCD was a consequence of heart failure with reduced ejection fraction, knowledgeable of the preventive role of ICDs, currently employed and aware that their doctor strongly recommended the implant. Based on multivariate analysis, knowledge of the role of ICDs for primary prophylaxis was the most important factor influencing patient decision.
CONCLUSIONThis study identified the demographic and social factors of patients who refused ICD therapy. Knowledge of the role of ICDs in preventing SCD was found to be the strongest marker for reconsidering ICD implantation. Measures to address this information gap may lead to higher rates of ICD implantation.
Cross-Sectional Studies ; Death, Sudden, Cardiac ; prevention & control ; Defibrillators, Implantable ; Female ; Heart Failure ; mortality ; physiopathology ; therapy ; Humans ; Male ; Middle Aged ; Primary Prevention ; methods ; Risk Factors ; Singapore ; epidemiology ; Stroke Volume ; physiology ; Survival Rate ; trends