The myocardium depends on a constant supply of oxygen in order
to work properly. There are a number of situations in which the
oxygen supply can be disrupted resulting in myocardial ischemia.
These include:
Obstruction of an artery caused by:
plaque (fat deposit)
thrombus (clot)
vasospasm
Reduced blood flow associated with conditions
that cause:
Myocardial ischemia is poor oxygen supply to the
heart's muscle tissue. It can be caused by plaque
or a clot inside an artery. Plaque is a deposit of
fatty material on the inner lining of an arterial
wall. An embolus is a fat particle or blood clot
that travels from another location in the cardiovascular
system. In either case, the substance narrows the
inside of the artery and reduces the amount of blood
that can pass.
In addition, myocardial ischemia can be caused by
a vasospasm. Vasospasm is the narrowing of a blood
vessel by tightening or spasm of the muscles within
the vessel's wall. Cocaine or methamphetamine use
can cause vasospasm.
Other causes of myocardial ischemia include symptomatic
hypotension (e.g., blood loss), symptomatic tachycardia,
or symptomatic bradycardia due a medical condition
such as CHF. Severe anemia (lack of sufficient red
blood cells) can be a cause, too.
