It was an ordinary week day and 22-year-old Tesha (not her real name) was preparing for work. She never made it to work that day. She suffered a sudden cardiac arrest and collapsed at home.
Her husband called 995 - Singapore's emergency services number - and received instructions to start cardiopulmonary resuscitation (CPR). When the ambulance paramedics arrived, they found her without a pulse because her heart was stuck in an abnormal rhythm called ventricular fibrillation. Delivering electric shocks with a defibrillator, they managed to restart it.