① Risk factors and age over 40;

② Typical symptoms and signs and nitroglycerin are effective;

③ Ischemic ST-T changes in ECG during the attack;

④ ECG exercise test or dynamic ECG is positive;

⑤ The diagnosis can be made if radionuclide myocardial perfusion imaging is positive and coronary angiography is positive.

The location and nature of chest pain in unstable angina pectoris are similar to those in stable angina pectoris, but it has one of the following characteristics:

① The original stable angina pectoris, the pain attack frequency increased, the degree increased, the time limit prolonged, the inducing factors changed, and the relief effect of nitrate drugs weakened within 1 month;

② The new angina pectoris occurred within 1 month and was induced by light load;

③ It can be induced by angina pectoris or slight activity at rest, and variant angina pectoris with elevated st segment during attack also belongs to this category.

2. Differential diagnosis

(1) Acute myocardial infarction: The position of chest pain is similar to angina pectoris, but the pain is severe and lasts for several hours or more, often accompanied by shock, arrhythmia or heart failure and fever. The pain can't be relieved after taking nitroglycerin. ST segment of ECG leads facing the infarct site is elevated, with abnormal Q wave. Laboratory examination showed that white blood cell count and serum myocardial necrosis markers increased, and erythrocyte sedimentation rate increased.

(2) Cardiac neurosis: more common in middle-aged or menopausal women. Pain is located under the left breast or near the apex of the heart, mostly short-term tingling or persistent chest tightness and chest pain. Patients often like to take a deep breath or sigh from time to time. It has nothing to do with physical activity. Often accompanied by anxiety, palpitations, numbness of hands and feet and other neurasthenia symptoms. Nitroglycerin is invalid.

(3) Other diseases that can cause angina pectoris: such as severe stenosis or insufficiency of aortic valve, rheumatic and syphilitic Takayasu arteritis (causing coronary artery stenosis), hypertrophic cardiomyopathy, and syndrome X (found in Kemp 1973, mostly female, with positive ECG stress test, but negative coronary angiography and no coronary artery spasm, with good prognosis, which is caused by poor capillary function of coronary artery system).

The treatment principle is to improve coronary blood supply, reduce myocardial oxygen consumption and treat atherosclerosis at the same time.

1. Treatment during the attack

(1) Rest: When angina attacks, you should rest immediately. Generally, the symptoms will disappear after stopping activities.

(2) Drug therapy: For severe attack, nitrate ester preparation with quick effect can be used.

(1) nitroglycerin:

0.3 ~ 0.6 mg, taken sublingually.

② isosorbide dinitrate (isosorbide dinitrate): 5 ~ 10 mg taken sublingually, taking effect in 2 ~ 5 minutes or inhaled by spray.

Unstable angina pectoris should be treated with oxygen inhalation, analgesia (morphine 5 ~ 10 mg, subcutaneous injection), nitroglycerin or isosorbide dinitrate continuous intravenous drip or micropump infusion, if necessary, under close ECG monitoring. B blockers and anticoagulants (aspirin and heparin) should be used as soon as possible.

2. In remission, actively control the risk factors of coronary heart disease and treat hypertension, hyperlipidemia and hyperglycemia. Adjust your diet, ban alcohol and smoking, maintain proper physical activity, remain optimistic, and try to avoid all kinds of known inducing factors.

Drug treatment: use long-acting anti-angina drugs to prevent angina pectoris. The following drugs can be used alone or alternately or in combination:

(1) nitrate preparation. Isosorbide nitrate 5 ~ 10 mg, 3 times a day, or sustained-release tablets 1 tablet, 2 times a day; Isosorbide mononitrate 20mg, twice a day, and can be increased to three times a day if necessary; 5 isosorbide mononitrate 20 ~ 40 mg, twice a day; Long-acting nitroglycerin preparation,

2.5mg, 8h 1 time; 2% nitroglycerin ointment or patch medicine (containing 5 ~ 10 mg) is applied to chest and upper arm skin, and the effect can last 12 ~ 24 hours. It is suitable for preventing angina pectoris at night.

(2)p receptor blocker: metoprolol 25 ~ 50mg, twice a day; Atenolol 25 ~ 50mg, twice a day; Bisolol

2.5~5mg， 1/d； Carvedilol 25mg, twice a day, has the effect of blocking α receptor. Contraindications should be paid attention to when using this kind of preparation.

(3) Calcium channel blockers: especially suitable for patients with hypertension. Commonly used preparations are: nifedipine, its sustained release agent is 20 ~ 40 mg, twice a day, and its controlled release agent is 30mg, 1 time a day; Nisoldipine 10 ~ 30 mg,1/d; Amlodipine 5 ~ 10 mg,1/d; Diltiazem 30 ~ 60 mg, 3 times a day; Verapamil 40 ~ 80 mg, 3 times a day, the side effects are headache, dizziness and blood pressure drop, and the P-R interval of the latter two is prolonged.

3. Vascular recanalization surgery can be selected according to the situation, such as percutaneous transluminal coronary angioplasty, coronary stenting, laser coronary angioplasty, coronary plaque rotation or coronary plaque rotation.

4. TCM syndrome differentiation and treatment refers to the common TCM syndrome "chest obstruction".

Most patients with angina pectoris can survive for many years, but they are at risk of acute myocardial infarction or sudden death at any time, especially unstable angina pectoris. The prognosis of patients with ventricular arrhythmia and conduction block is poor, but the main factors that determine the prognosis are the range of coronary artery lesions and cardiac function. The prognosis of left main coronary artery disease is poor, and the left anterior descending branch disease is more serious than the other two branches.