A 78-year-old woman with a long-standing history of ischaemic heart

disease develops a sudden thrombotic occlusion of her left coronary

artery whilst shopping. She is observed by staff clutching her chest

before collapsing on the floor. When assessed by the shop’s trained

First Aid officer, the woman is unresponsive, not breathing and has no

detectable pulse. The ambulance is called but despite best efforts,

resuscitation proves unsuccessful, and she is pronounced dead by the

paramedics 45 minutes later. Which ONE of the following is the MOST

LIKELY cause of this woman’s death?