Asymptomatic myocardial ischemia is an objective evidence of myocardial ischemia in patients with coronary heart disease, but is not accompanied by angina or angina pectoris in myocardial ischemia. Evidence of myocardial ischemia includes electrocardiogram (resting, dynamic or load test) with typical ischemic ST segment changes, radionuclide or echocardiography showed perfusion defects and (or) wall motion abnormalities. Asymptomatic myocardial ischemia is a special type of coronary heart disease, also known as occult coronary heart disease, prevalent in the course of various types of coronary heart disease. As the attack is not accompanied by the corresponding symptoms, often by doctors or patients ignored, but not early treatment.However, it and the symptoms of coronary heart disease, can lead to acute myocardial infarction, sudden death and other acute coronary events.
Often appear depressed, fatigue, weakness, after exercise, chest tightness, shortness of breath and palpitations; or nausea, abdominal distension, loss of appetite; or insomnia, night sweats, five upset hot, dry mouth.
Patients with more than middle age, no symptoms of myocardial ischemia, in the physical examination found that ECG (rest, dynamic or load) ST segment depression, T wave inversion and other changes, radionuclide myocardial development (rest or load test ), Or echocardiography showed myocardial ischemia.
1. Dynamic electrocardiogram: arterial electrocardiogram is currently used to detect asymptomatic myocardial ischemia commonly used methods, but which patterns reflect the ischemia, there is no consensus. It is generally considered that the ST-segment descent criterion: the horizontal or sagging depression of 80 ms at point J is greater than 1 mm, and the interval of myocardial ischemia is determined to be 1 mm (1 x 1 x 1 standard).
2. ECG exercise test: one of the following conditions are positive: ⑴ typical angina in exercise; ⑵ exercise and post-exercise level or sagging type (ie, ischemic) ST segment depression ≥ 0.1mV. ⑶ exercise to reduce blood pressure.
3. Radionuclide exercise Myocardial development: clinical commonly used is 201 thallium myocardial development, is the most sensitive non-invasive method of myocardial ischemia detection of myocardial ischemia diagnosis of up to 80% sensitivity, specificity of 90%, and Can measure the extent of exercise myocardial ischemia, severity and infer the location of coronary artery stenosis, degree, and to determine the prognosis are of great significance.
4. Echocardiography: two-dimensional echocardiography technology has been used this year to detect wall activity, especially in the case of load, the determination of local wall motion abnormalities can be indirectly estimated myocardial ischemia.
1. Objective evidence of myocardial ischemia Asymptomatic myocardial ischemia in patients with electrocardiogram (including electrocardiographic load test and dynamic electrocardiogram), radionuclide, echocardiography and other tests, often can occur objective evidence of myocardial ischemia.
2. No clinical manifestations of myocardial ischemia
Although these patients have objective evidence of myocardial ischemia, but the ischemic attack without myocardial ischemia-related symptoms and signs, such as angina.
3. often accompanied by a variety of ischemic heart disease risk factors
4. Asymptomatic myocardial ischemia patients often have a number of ischemic heart disease risk factors, such as hyperlipidemia, hypertension, diabetes, smoking and overweight or obesity can be regarded as asymptomatic myocardial deficiency Blood diagnostic criteria.