Common Name/Other Name
Ischemic heart disease; cardiac ischemia (Eng.)
Myocardial ischemia is a condition wherein the heart receives a reduced amount of oxygenated blood. This is due to narrowed or blocked coronary arteries which cause a reduction in the blood and oxygen supply of the heart. The heart cannot efficiently pump blood and eventually experiences heart damage. The condition can lead to abnormal heart rhythms, heart attack or heart failure.
Several conditions can cause myocardial ischemia. Atherosclerosis restricts blood flow due to plaques. A ruptured plaque will lead to blood clot formation and result in a sudden, severe myocardial ischemia. An uncommon cause is the spasm of the coronary arteries which briefly decrease blood flow. Chest pain can be triggered by physical exertion, emotional stress, cold temperature and use of illicit drugs.
Diagnosis of myocardial ischemia begins with a physical exam and medical history. Other diagnostic tests that can be done include electrocardiogram, echocardiogram, coronary angiography, cardiac CT scan and stress test. These tests can indicate the presence of a narrowed or blocked coronary artery and presence of heart damage.
Some cases of myocardial ischemia do not present with any symptoms. This is known as silent ischemia. It commonly happens among women, older people, diabetics and people who previously had a heart attack. Silent ischemia can lead to the same complications as myocardial ischemia.
Commonly Prescribed Drugs
- Aspirin is a commonly prescribed drug in preventing blood clot formation. This prevents further blockage of coronary arteries.
- Nitrates dilate the veins and arteries to improve blood flow to the heart. Dilation of the veins decrease the blood volume returning to the heart while dilation of the arteries decrease the pressure against which the heart must pump. Examples of this are isosorbide dinitrate and isosorbide mononitrate. Side effects: headache, lightheadedness, flushing
- Beta blockers improve blood flow to the heart by decreasing heart rate and blood pressure. These agents are considered as first-line treatment because they can block the effects of epinephrine. Examples include atenolol, metoprolol and propranolol. Side effects: fatigue, cold hands and feet, weight gain
- Calcium channel blockers dilate the blood vessels to increase blood flow towards the heart. Common examples include amlodipine, diltiazem and verapamil. Side effects: palpitation, swelling of lower extremities, flushing
- Antihyperlipidemic agents target the substances that cause the narrowing or blockage of the arteries. It decreases the levels of bad cholesterol in the body. An example of this are the HMG-CoA reductase inhibitors or the statins and the fibric acid derivatives such as fenofibrate and gemfibrozil.
- ACE inhibitors are given to patients who have hypertension or diabetes alongside myocardial ischemia. It lowers the blood pressure and allows blood vessels to relax. These agents inhibit the enzyme that produces Angiotensin II, a substance that constricts blood vessels and increases blood pressure. Examples include captopril, enalapril and perindopril. Side effects: dry cough, increase in potassium levels, fatigue
- Ranolazine is an antianginal medication. It works by inhibiting the entry of calcium which relaxes arterial walls. Side effects: dizziness
Treatment and Management
Manage underlying conditions that increase the risk for myocardial ischemia.
Quit or avoid smoking. Avoid exposure to secondhand smoke.
Maintain a healthy lifestyle by eating a healthy diet, exercising regularly and decreasing stress.
Have regular checkups to monitor the health of your heart and its blood vessels. Since its complications rarely present with early symptoms, early detection and treatment are important.
Invasive and Non-Invasive Procedures
- Angioplasty and stenting addresses the most common cause of myocardial ischemia – narrowing or blockage of coronary arteries. A balloon is inflated inside the affected artery to open the artery. A stent or wire mesh tube can be placed to keep the artery open.
- Coronary artery bypass graft (CABG) attaches a new blood vessel to avoid the blocked artery. This diverts the blood flow to supply the heart with oxygenated blood.
- Enhanced external counterpulsation uses cuffs wrapped around the legs to improve blood flow to the heart. The cuffs are gently inflated then deflated to apply pressure on the blood vessels and drive the blood flow.