The death of muscle cells within the heart muscle.
Stedman's defines a myocardial infarction as follows:
"Infarction of a segment of the heart muscle, usually as a result of occlusion of a coronary artery.
"Myocardial infarction is the most commoncause of death in the United States."
The Merck Manual states that mycardial infarction:
"... usually resulting from abrupt reduction in coronary blood flow to a segment of the myocardium....
"The ability of the heart to continue to function as a pump relates directly to the extent of myocardial damage. Patients who die of cardiogenic shock usually have an infarct, or a combination of scar and new infarct, of (greater than or equal to) 50% of (left ventricle) mass."
Similarly, this, from the Attorney's Dictionary of Medicine:
"Myocardial infarction: Infarction (infarct formation) involving the muscular wall of the heart, usually as a result of an occulsion (blockage) of a coronary artery."
In Green, Justice Ayles of the New Brunswick Court of Appeal noted these words:
"[M]yocardial infarction is caused by a blockage by blood clots of a coronary artery at the site of a fatty deposit...."
Justice Ayles also quoted an expert that noted that myocardial infarction can result from gradual or sudden events:
"If he had gradual progression of arteriosclerotic disease he would have had gradual anginal symptoms and even if this were the case than the fight would certainly have been a aprecipitating factor. As it was it appears most likely that the sudden catastrophic appearance of his disease is as the result of a plaque rupture which is well associated in association with severe physical and emotional stress."
The following expert evidence was put to the Court in Dillon:
"Myocardial infarction is usually the beginnings of permanent damage to the heart caused by a blockage and because it's permanent, because there is no replacement part for the heart, it is a very serious diagnosis and may be very serious in terms of a person's life expectancy and what they can expect to do."
In Zazelenchuk, Justice Ross of the Court of Queen's Bench of Alberta wrote of:
".... complete occlusion or myocardial infarction. A blockage is typically caused by the rupture of a plaque deposit in an artery, and blood platelet adhesion and aggregation around the rupture. Untreated, a partial occlusion may go on to develop into a complete occlusion or clot in the artery. However, with treatments that interfere with adhesion and aggregation, the process can often be stopped before a complete blockage is formed. These treatments include Aspirin, a platelet inhibitor, and Heparin, an anticoagulant."
REFERENCES:
- Beers, M. and Berkow, R., editors, The Merck Manual of Diagnosis and Therapy, 17th Ed. (Whitehouse Station, New Jersey: Merck Research Laboratories, 1999), page 1668.
- Dillon v Leroux, 89 B.C.L.R. (2d) 376 (1994)
- Duhaime, Lloyd, Legal Definition of Infarction
- Duhaime, Lloyd, Legal Definition of Myocardium
- Green v New Brunswick, 201 N.B.R. (2d) 93 (1998)
- Pugh, M., Stedman's Medical Dictionary, 27th Ed. (Philadelphia: Lippincott Williams & Wilkins, 2000), page 1173.
- Schmidt, J.E., Attorney's Dictionary of Medicine and Word Finder, Volume 4 (LexisNexis, 2001)
- Zazelenchuk v. Kumleben, 2007 ABQB 650