Heart attack

Health encyclopaedia - Alphabetical Topic List

| A |

| B |

| C |

| D |

| E |

| F |

| G |

| H |

| I |

| J |

| K |

| L |

| M |

| N |

| O |

| P |

| Q |

| R |

| S |

| T |

| U |

| V |

| W |

| X |

| Y |

The phrase â€˜heart attackâ€™ is commonly used to describe a blockage in a heart artery. A more accurate name is myocardial infarction (MI). An MI is the sudden death of part of the heart muscle cells (myocardium) from a blockage of the blood supply to that part of the heart (coronary artery thrombosis).

This is the final result of disease of the two coronary arteries that supply the heart muscle with blood and is one of the major killers in the UK. Layers (plaques) of cholesterol build up inside the coronary arteries (atherosclerosis). These can rupture, blocking the artery through the sudden formation of a blood clot on the ruptured plaque.

Occasionally the blockage is brought on by spasm of the muscle walls of the coronary arteries. It can also be the result of an abnormal, very fast heart rate, where the heart muscle demands more oxygen than the blood supply can provide.

MI occurs in 5 per 1000 people in the UK each year. It occurs more often in men than in women, and mostly in people over 40 years old.

The process of infarction causes severe pain, and the immediate reduction in heart efficiency causes a range of other symptoms. Half of those who die from a particular attack do so from heart stoppage (cardiac arrest) within 3 or 4 hours of onset, so anyone suspected of having a heart attack should receive urgent medical attention.