Myocardial ischemia, or cardiac ischemia, occurs when there is a reduction in blood flow to the heart, according to Mayo Clinic. The decrease in blood flow prevents the heart muscle from receiving adequate oxygen.
Cardiac ischemia can cause damage to the heart muscle, notes Mayo Clinic. The damage can lead to a reduction in the heart's ability to pump blood efficiently. Severe, sudden coronary artery blockage can cause heart attacks and may cause serious and abnormal heart rhythms.
A common symptom of myocardial ischemia is chest pressure or pain, usually on the left side of the body, explains Mayo Clinic. Myocardial ischemia chest pain is caused by emotional stress, physical exertion, cocaine use and cold temperatures. Additional symptoms may include shoulder or arm pain, sweating, accelerated heartbeat, neck pain and jaw pain. Shortness of breath during physical activity, nausea, vomiting and fatigue are also symptoms of myocardial ischemia.
Coronary artery disease, or atherosclerosis, is usually the cause of myocardial ischemia, states Mayo Clinic. Atherosclerosis causes plaque of mostly cholesterol to build on artery walls, restricting the flow of blood. The plaque can also rupture, which, in turn, creates blood clots. Severe, sudden myocardial ischemia may develop if a blood clot blocks an artery. A coronary artery spasm may also cause myocardial ischemia, though it is uncommon.