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.

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

Humans ; Atrial Fibrillation/surgery* ; Anti-Arrhythmia Agents/therapeutic use* ; Treatment Outcome ; Catheter Ablation ; Recurrence

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

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

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.

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.

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

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

The main areas of emphasis in the Advanced Cardiac Life Support (ACLS) guidelines are: early recognition of cardiac arrest and call for help; good-quality chest compressions; early defibrillation when applicable; early administration of drugs; appropriate airway management ensuring normoventilation; and delivery of appropriate post-resuscitation care to enhance survival. Of note, it is important to monitor the quality of the various care procedures. The resuscitation team needs to reduce unnecessary interruptions to chest compressions in order to maintain adequate coronary perfusion pressure during the ACLS drill. In addition, the team needs to continually look out for reversible causes of the cardiac arrest.