How does heart attack affect tissues?

Answer 1

A heart attack is an obstruction to the blood supply to the heart's own tissues. In the brain this is a stroke and in the lungs it is a pulmonary embolism. Depending on the severity of the blockage, and how long before treated, the tissues without blood supply will die.

Answer 2

The systemic cells will be in immediate peril should the heart stop working or start working improperly. The cells need a constant supply of oxygen to function and stay living. Blood carries this oxygen to the cells, but it cannot move without the heart pumping. In other words, no pumping of the heart, no movement of the blood, no oxygen delivery to the cells, cells start dying.

Some cells, like muscle cells, will be able to withstand a temporary lack of oxygen due to the alternate pathway of respiration, lactic acid fermentation, it can utilize. However, the cells that need the most oxygen are those in the brain; without a supply of oxygen for even a short period of time, temporary or even permanent neurological damage can result.