1.Catheter ablation of ventricular fibrillation storm in a long QT syndrome genotype carrier with normal QT interval.
Jonathan YAP ; Vern Hsen TAN ; Li Fern HSU ; Reginald LIEW
Singapore medical journal 2013;54(1):e1-4
Patients with long QT syndrome can sometimes present with a ventricular fibrillation (VF) storm. Catheter ablation of culprit premature ventricular complexes responsible for the triggering of the VF episodes may be required in rare cases of electrical storm that do not respond to conventional measures, and this can be life-saving. We describe a case of emergency catheter ablation in a young woman with a normal corrected QT interval, who presented with malignant VF storm for the first time. We also discuss the diagnostic and management challenges involved, as well as the value of genetic testing in refining the diagnosis.
Cardiology
;
Catheter Ablation
;
methods
;
Electrocardiography
;
methods
;
Female
;
Heart Arrest
;
genetics
;
therapy
;
Heterozygote
;
Humans
;
Long QT Syndrome
;
genetics
;
Tachycardia, Ventricular
;
therapy
;
Treatment Outcome
;
Ventricular Fibrillation
;
therapy
;
Ventricular Premature Complexes
;
genetics
;
therapy
;
Young Adult
2.Gender Differences in Knowledge, Attitudes and Practices towards Cardiovascular Disease and its Treatment among Asian Patients.
Tong SHEN ; Tse Yean TEO ; Jonathan Jl YAP ; Khung Keong YEO
Annals of the Academy of Medicine, Singapore 2017;46(1):20-28
: Knowledge, attitudes and practices (KAP) impact on cardiac disease outcomes, with noted cultural and gender differences. In this Asian cohort, we aimed to analyse the KAP of patients towards cardiac diseases and pertinent factors that influence such behaviour, focusing on gender differences.: A cross-sectional survey was performed among consecutive outpatients from a cardiac clinic over 2 months in 2014.: Of 1406 patients approached, 1000 (71.1%) responded (mean age 57.0 ± 12.7 years, 713 [71.3%] males). There was significant correlation between knowledge and attitude scores (r = 0.224,<0.001), and knowledge and practice scores (r = 0.114,<0.001). There was no correlation between attitude and practice scores. Multivariate predictors of higher knowledge scores included female sex, higher education, higher attitude and practice scores and prior coronary artery disease. Multivariate predictors of higher attitude scores included higher education, higher knowledge scores and non-Indian ethnicity. Multivariate predictors of higher practice scores included male sex, Indian ethnicity, older age, higher knowledge score and hypertension. Males had lower knowledge scores (85.8 ± 8.0% vs 88.0 ± 8.2%,<0.001), lower attitude scores (91.4 ± 9.4% vs 93.2 ± 8.3%,= 0.005) and higher practice scores (58.4 ± 18.7% vs 55.1 ± 19.3%,= 0.013) than females.: In our Asian cohort, knowledge of cardiovascular health plays a significant role in influencing attitudes and practices. There exists significant gender differences in KAP. Adopting gender-specific strategies for future public health campaigns could address the above gender differences.
Adult
;
Aged
;
Asian Continental Ancestry Group
;
Cardiovascular Diseases
;
Coronary Artery Disease
;
Cross-Sectional Studies
;
Educational Status
;
Ethnic Groups
;
European Continental Ancestry Group
;
Female
;
Health Knowledge, Attitudes, Practice
;
Health Promotion
;
Humans
;
India
;
Male
;
Middle Aged
;
Multivariate Analysis
;
Public Health
;
Sex Factors
;
Singapore
;
Surveys and Questionnaires
3.Outbreak of acute norovirus gastroenteritis in a military facility in Singapore: a public health perspective.
Jonathan YAP ; Abdul QADIR ; Isaac LIU ; Jimmy LOH ; Boon Huan TAN ; Vernon J LEE
Singapore medical journal 2012;53(4):249-254
INTRODUCTIONNorovirus gastrointestinal disease (GID) outbreaks occur frequently in closed settings, with high attack rates. On October 16, 2008, a norovirus GID outbreak occurred at a Singapore military camp. This study describes the epidemiological investigations conducted to determine the cause of outbreak and the efficacy of the public health measures implemented.
METHODSEpidemiologic investigations included a case-control study of exposure to different food items and an environmental exposure survey. Stool samplings of patients and food handlers for common pathogens, and microbiologic testing of food and water samples were performed. Inspection of dining facilities and health screening of all food-handlers were also conducted.
RESULTSA total of 156 GID cases were reported on October 15-31, 2008. 24 (15.4%) personnel were positive for norovirus. The predominant symptoms were diarrhoea (76.3%) and abdominal pain (69.2%). There was no clinical correlation between any food item and the affected personnel. Testing of food and water samples, dining facility inspections and health screening of food handlers showed satisfactory results. The environmental exposure survey indicated possible transmission due to environmental contamination by vomitus in common areas. Comprehensive environmental decontamination was performed with hypochlorite solution, and personal hygiene measures were enforced. The outbreak lasted 17 days, with a decline in cases post intervention.
CONCLUSIONTimely notification and prompt response can curtail disease transmission. Swift implementation of public health measures, such as emphasis on personal hygiene, isolation of affected cases and comprehensive disinfection of the environment, effectively stopped norovirus transmission and may be adapted for future GID outbreaks.
Acute Disease ; Adolescent ; Caliciviridae Infections ; diagnosis ; epidemiology ; Case-Control Studies ; Communicable Disease Control ; methods ; Diarrhea ; virology ; Disease Outbreaks ; statistics & numerical data ; Feces ; virology ; Food Handling ; Gastroenteritis ; epidemiology ; virology ; Humans ; Male ; Military Facilities ; Norovirus ; isolation & purification ; Singapore ; epidemiology ; Water Microbiology ; Young Adult
4.Triaging Primary Care Patients Referred for Chest Pain to Specialist Cardiology Centres: Efficacy of an Optimised Protocol.
Francine Cl TAN ; Jonathan YAP ; John C ALLEN ; Olivia TAN ; Swee Yaw TAN ; David B MATCHAR ; Terrance Sj CHUA
Annals of the Academy of Medicine, Singapore 2018;47(2):56-62
INTRODUCTION:
Patients referred for chest pain from primary care have increased, along with demand for outpatient cardiology consultations. We evaluated 'Triage Protocol' that implements standardised diagnostic testing prior to patients' first cardiology consultation.
MATERIALS AND METHODS:
Under the 'Triage Protocol', patients referred for chest pain were pretriaged using a standardised algorithm and subsequently referred for relevant functional diagnostic cardiology tests before their initial cardiology consultation. At the initial cardiology consultation scheduled by the primary care provider, test results were reviewed. A total of 522 triage patients (mean age 55 ± 13, male 53%) were frequency-matched by age, gender and risk cohort to 289 control patients (mean age: 56 ± 11, male: 52%). Pretest risk of coronary artery disease was defined according to a Modified Duke Clinical Score (MDCS) as low (<10), intermediate (10-20) and high (>20). The primary outcome was time from referral to diagnosis (days). Secondary outcomes were total visits, discharge rate at first consultation, patient cost and adverse cardiac outcomes.
RESULTS:
The 'Triage Protocol' resulted in shorter times from referral to diagnosis (46 vs 131 days; <0.0001) and fewer total visits (2.4 vs 3.0; <0.0001). However, triage patients in low-risk groups experienced higher costs due to increased testing (S$421 vs S$357, = 0.003). Adverse cardiac event rates under the 'Triage Protocol' indicated no compromise to patient safety (triage vs control: 0.57% vs 0.35%; = 1.000).
CONCLUSION
By implementing diagnostic cardiac testing prior to patients' first specialist consultation, the 'Triage Protocol' expedited diagnosis and reduced subsequent visits across all risk groups in ambulatory chest pain patients.
Algorithms
;
Cardiology Service, Hospital
;
Chest Pain
;
therapy
;
Clinical Protocols
;
Female
;
Humans
;
Male
;
Middle Aged
;
Primary Health Care
;
Treatment Outcome
;
Triage
;
methods
6.Interaction of sex and diabetes in Asian patients with heart failure with mildly reduced left ventricular ejection fraction.
Julian C K TAY ; Shaw Yang CHIA ; David K L SIM ; Ping CHAI ; Seet Yoong LOH ; Aland K L SHUM ; Sheldon S G LEE ; Patrick Z Y LIM ; Jonathan YAP
Annals of the Academy of Medicine, Singapore 2022;51(8):473-482
INTRODUCTION:
The impact of sex and diabetes mellitus (DM) on patients with heart failure with mildly reduced ejection fraction (HFmrEF) is not well elucidated. This study aims to evaluate sex differences in the clinical profile and outcomes in Asian HFmrEF patients with and without DM.
METHODS:
Patients admitted nationally for HFmrEF (ejection fraction 40-49%) between 2008 and 2014 were included and followed up until December 2016. The primary outcome was all-cause mortality. Secondary outcomes included cardiovascular (CV) death and/or heart failure (HF) rehospitalisations.
RESULTS:
A total of 2,272 HFmrEF patients (56% male) were included. More women had DM than men (60% versus 55%, P=0.013). Regardless of DM status, HFmrEF females were older, less likely to smoke, had less coronary artery disease, narrower QRS and lower haemoglobin compared to men. The odds of having DM decreases in smokers who are women as opposed to men (Pinteraction =0.017). In multivariate analysis, DM reached statistical analysis for all-cause mortality and combined CV mortality or HF rehospitalisation in both men and women. However, the results suggest that there may be sex differences in terms of outcomes. DM (vs non-DM) was less strongly associated with increased all-cause mortality (adjusted hazards ratio [adj HR] 1.234 vs adj HR 1.290, Pinteraction <0.001] but more strongly associated with the combined CV death/HF rehospitalisation (adj HR 1.429 vs adj HR 1.317, Pinteraction =0.027) in women (vs men).
CONCLUSION
Asian women with HFmrEF had a higher prevalence of DM, with differences in clinical characteristics, compared to men. While diabetes conferred poor outcomes regardless of sex, there were distinct sex differences. These highlight the need for sex-specific management strategies.
Diabetes Mellitus/epidemiology*
;
Female
;
Heart Failure
;
Humans
;
Male
;
Prognosis
;
Stroke Volume
;
Ventricular Dysfunction, Left/epidemiology*
;
Ventricular Function, Left
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.Impact of Chronic Kidney Disease on Outcomes in Transcatheter Aortic Valve Implantation.
Jonathan Jl YAP ; Julian Ck TAY ; See Hooi EWE ; Nishanth THIAGARAJAN ; Shaw Yang CHIA ; Mohammed Rizwan AMANULLAH ; Soo Teik LIM ; Victor Tt CHAO ; Kay Woon HO
Annals of the Academy of Medicine, Singapore 2020;49(5):273-284
INTRODUCTION:
Chronic kidney disease (CKD) is a significant comorbidity in aortic stenosis (AS) patients. We examined the impact of baseline CKD, postoperative acute kidney injury (AKI) and CKD progression on clinical outcomes in patients who underwent transcatheter aortic valve implantation (TAVI).
MATERIALS AND METHODS:
Consecutive patients with severe AS who underwent TAVI were classified into CKD stages 1-2 (≥60 mL/min/1.72m), 3 (30-59 mL/min/1.73m) and 4-5 (<30 mL/min/1.73m or dialysis) based on estimated glomerular filtration rate (eGFR). Primary outcome was mortality and secondary outcomes included 1-year echocardiographic data on aortic valve area (AVA), mean pressure gradient (MPG) and aortic regurgitation (AR).
RESULTS:
A total of 216 patients were included. Higher eGFR was associated with lower overall mortality (adjusted hazards ratio [AHR] 0.981, 95% confidence interval [CI] 0.968-0.993, = 0.002). CKD 4-5 were associated with significantly higher mortality from non-cardiovascular causes ( <0.05). Patients with CKD 3-5 had higher incidence of moderate AR than those with CKD 1-2 ( = 0.010); no difference in AVA and MPG was seen. AKI patients had higher mortality ( = 0.008), but the effect was attenuated on multivariate analysis (AHR 1.823, 95% CI 0.977-3.403, = 0.059). Patients with CKD progression also had significantly higher mortality (AHR 2.969, 95% CI 1.373-6.420, = 0.006).
CONCLUSION
CKD in severe AS patients undergoing TAVI portends significantly higher mortality and morbidity. Renal disease progression impacts negatively on outcomes and identifies a challenging subgroup of patients for optimal management.
9.Pulmonary endarterectomy and balloon pulmonary angioplasty in chronic thromboembolic pulmonary hypertension: The Singapore experience.
Wen RUAN ; Jonathan YAP ; Kevin QUAH ; Foong Koon CHEAH ; Ghee Chee PHUA ; Duu Wen SEWA ; Aidila Binte ISMAIL ; Alicia CHIA ; David JENKINS ; Ju Le TAN ; Victor CHAO ; Soo Teik LIM
Annals of the Academy of Medicine, Singapore 2021;50(3):270-273
10.Pericarditis and myocarditis after COVID-19 mRNA vaccination in a nationwide setting.
Jonathan YAP ; Mun Yee THAM ; Jalene POH ; Dorothy TOH ; Cheng Leng CHAN ; Toon Wei LIM ; Shir Lynn LIM ; Yew Woon CHIA ; Yean Teng LIM ; Jonathan CHOO ; Zee Pin DING ; Ling Li FOO ; Simin KUO ; Yee How LAU ; Annie LEE ; Khung Keong YEO
Annals of the Academy of Medicine, Singapore 2022;51(2):96-100
INTRODUCTION:
Despite reports suggesting an association between COVID-19 mRNA vaccination and pericarditis and myocarditis, detailed nationwide population-based data are sparsely available. We describe the incidence of pericarditis and myocarditis by age categories and sex after COVID-19 mRNA vaccination from a nationwide mass vaccination programme in Singapore.
METHODS:
The incidence of adjudicated cases of pericarditis and myocarditis following COVID-19 mRNA vaccination that were reported to the vaccine safety committee between January to July 2021 was compared with the background incidence of myocarditis in Singapore.
RESULTS:
As of end July 2021, a total of 34 cases were reported (9 pericarditis only, 14 myocarditis only, and 11 concomitant pericarditis and myocarditis) with 7,183,889 doses of COVID-19 mRNA vaccine administered. Of the 9 cases of pericarditis only, all were male except one. The highest incidence of pericarditis was in males aged 12-19 years with an incidence of 1.11 cases per 100,000 doses. Of the 25 cases of myocarditis, 80% (20 cases) were male and the median age was 23 years (range 12-55 years) with 16 cases after the second dose. A higher-than-expected number of cases were seen in males aged 12-19 and 20-29 years, with incidence rates of 3.72 and 0.98 case per 100,000 doses, respectively.
CONCLUSION
Data from the national registry in Singapore indicate an increased incidence of pericarditis and myocarditis in younger men after COVID-19 mRNA vaccination.
Adolescent
;
Adult
;
COVID-19/prevention & control*
;
COVID-19 Vaccines/adverse effects*
;
Child
;
Female
;
Humans
;
Male
;
Middle Aged
;
Myocarditis/etiology*
;
Pericarditis/etiology*
;
RNA, Messenger
;
SARS-CoV-2
;
Vaccination/adverse effects*
;
Vaccines, Synthetic
;
Young Adult
;
mRNA Vaccines