[1] Tan Tock Seng Hosp, Dept Cardiol, Cardiac Intens Care Unit, 11 Jalan Tan Tock Seng, Singapore 308433, Singapore
[2] Natl Univ Singapore Hosp, Natl Univ Heart Ctr Singapore, Dept Cardiol, Singapore, Singapore
[3] Natl Heart Ctr Singapore, Dept Cardiol, Cardiac Intens Care Unit, Singapore, Singapore
[4] Natl Univ Singapore Hosp, Dept Emergency Med, Singapore, Singapore
[5] Singapore Gen Hosp, Dept Emergency Med, Singapore, Singapore
[6] Duke NUS Med Sch, Singapore, Singapore