Ischaemic or ischemic heart disease (IHD), or myocardial ischaemia, is a disease characterized by ischaemia to the heart muscle, usually due to coronary artery disease. Its risk increases with age, smoking,hypercholesterolaemia, diabetes, and hypertension (high blood pressure), and is more common in men and those who have close relatives with ischaemic heart disease.
Symptoms of stable ischaemic heart disease include angina and decreased exercise tolerance. Unstable IHD presents itself as chest pain or other symptoms at rest, or rapidly worsening angina. Diagnosis of IHD is with anelectrocardiogram, blood tests (cardiac markers), cardiac stress testing or a coronary angiogram. Depending on the symptoms and risk, treatment may be with medication, percutaneous coronary intervention (angioplasty) or coronary artery bypass surgery (CABG).
It is the most common cause of death in most Western countries, and a major cause of hospital admissions. There is limited evidence for population screening, but prevention (with a healthy diet and sometimes medication for diabetes, cholesterol and high blood pressure) is used both to prevent IHD and to decrease the risk of complications.
The medical history distinguishes between various alternative causes for chest pain (such as dyspepsia, musculoskeletal pain, pulmonary embolism). As part of an assessment of the three main presentations of IHD, risk factors are addressed. These are the main causes of atherosclerosis (the disease process underlying IHD): age, male sex, hyperlipidaemia, smoking, hypertension (high blood pressure), diabetes, and the family history.
The disease process underlying most ischaemic heart disease is atherosclerosis of the coronary arteries. The arteries become "furred up" by fat-rich deposits in the vessel wall (plaques).
Stable angina is due to inability to supply the myocardium with sufficient blood in situations of increased demand for oxygen, such as exertion.
Unstable angina, STEMI and NSTEMI are attributed to "plaque rupture", where one of the plaques gets weakened, develops a tear, and forms an adherent blood clot that either obstructs blood flow or floats further down the blood vessel, causing obstruction there.
