Myocardial ischemia or cardiac ischemia is the decrease of blood flow, and thus oxygen supply, in the heart due to partial or complete blockage of the heart’s arteries. Its effects range from damage of the heart muscle (heart failure), to heart attack (myocardial infarction), and to abnormal heart rhythms (arrhythmia). Symptoms of myocardial ischemia may not appear (silent ischemia), or may be characterized by chest pressure or pain (angina pectoris), neck or jaw pains, shoulder or arm pains, fast heartbeat, shortness of breath, and nausea and vomiting.
Myocardial ischemia may occur slowly as arteries become blocked over time, slowly decreasing the amount of blood flowing through the heart. Conditions that may cause myocardial ischemia include: coronary artery disease (atherosclerosis), the most common cause of myocardial ischemia, which is the accumulation of plaque (cholesterol and other waste products) along on the arterial walls; blood clot, which occurs when the accumulated plaque in atherosclerosis ruptures and leads its formation; and coronary artery spasm, which is a brief, temporary contraction of muscles in the artery wall, decreasing blood flow for a short period of time. Triggers for chest pain associated with myocardial ischemia are physical exertion, emotional stress, cold temperatures, lying down, and cocaine use. Factors that may increase risk of developing myocardial ischemia include tobacco use, diabetes, high blood pressure, high blood cholesterol or triglyceride levels, lack of physical activity, obesity, waist circumference, and family history. Myocardial ischemia may occur even when 5 liters of blood per minute flows through the chambers of the heart because of the restricted blood flow in some of the arteries surrounding the heart.
Testing and diagnosis for myocardial ischemia makes use of quite sophisticated apparatuses such as the electrocardiogram (ECG), echocardiogram, and nuclear scan, among others. Treatment for myocardial ischemia may include medications (aspirin, calcium channel blockers, etc.), surgical procedures for opening blocked arteries or coronary artery bypass surgery. Healthy lifestyle choices would also contribute greatly to the treatment and prevention of myocardial ischemia.
Mayo Clinic. (2014). “Diseases and Conditions: Myocardial Ischemia.” Accessed: http://www.mayoclinic.org/diseases-conditions/myocardial-ischemia/basics/definition/con-20035096.