A 46-year-old man, an office manager, was brought to the emergency room by his colleague2 hours after onset of sub-sternal pressure-like chest pain. He had been well all his life untila month ago when he began to experience chest tightness on climbing stairs and running; thediscomfort went away shortly after rest. Family history revealed that his father diedsuddenly at age 60. His blood pressure was 140/100 mmHg, respiratory rate 28/min, pulserate 98/min. He appeared apprehensive and diaphoretic. A 4th heart sound was audible alongthe left sternal border and apex. Lung revealed no rales or wheezing. The rest of physicalexamination was normal. A 12-lead electrocardiogram was recorded and shown on thefigure. What is your diagnosis? What will you do if you are working in a tertiary referralcenter where invasive therapeutic facility is available, or if you are working in an emergencyroom where invasive therapeutic facility is not available? (20%)