I. General treatment
1.For those who are suspected of having unstable angina, relevant tests should be done quickly to evaluate and start anti-ischemic treatment as soon as possible.
2, clinically confirmed as unstable angina pectoris, most of them should be hospitalized.
3.Bed rest, oxygenation and sedation treatment.
4.Actively treat factors that aggravate myocardial oxygen consumption, such as infection, fever, hyperthyroidism, tachycardia, deterioration of cardiac insufficiency, etc. Correct anemia. Zhang Guoliang, Department of Geriatrics, Yuncheng Central Hospital
5. Continuous cardiac monitoring. Perform cardiac enzyme (TnT or CK-MB, etc.) tests to exclude myocardial infarction.
II. Drug treatment
1.Nitrates
(1) Short-acting preparations (such as cardiac pain) should be used, once every six hours.
(2) Take nitroglycerin under the tongue or use nitrate spray during attack.
(3) Nitroglycerin or 5-mononitrate preparations (e.g., isosuggestion) should be used intravenously during acute attacks. Nitroglycerin should be started in small doses (5-10 μg/min) and increased by 10 μg/min in 5-10 minute increments until the symptoms are relieved or side effects occur (headache, blood pressure below 90 mmHg or 30% decrease in mean pressure).
2. β-blockers
If there is no contraindication, it should be used in all patients with unstable angina. The therapeutic goal is to reduce the heart rate to 50-60 beats per minute. Commonly used preparations are metolamide (betalactam) and atenolol (amiloride), etc. If the heart rate needs to be lowered quickly, esmolol can be used intravenously, which can be used even in people with cardiac dysfunction, because its effect disappears 20 minutes after stopping.
3.Calcium antagonist
Short-acting preparations should be used during acute attacks. Commonly used drugs are diltiazem (Tenelheart, thiodiazepine) and nifedipine (cardiac pain). Diltiazem should be used with caution (or not) in patients with bradycardia or conduction block. Cardiac pain relief should be avoided in patients with cardiac dysfunction.
Cardiac pain relief may be preferred in people with high blood pressure and normal cardiac function. It is more effective when combined with beta-blockers and/or nitrates.
Diltiazem is preferred in the absence of slow-onset arrhythmias. Extra caution should be exercised when combining diltiazem with β-blockers, because the two drugs have synergistic effects on slowing down heart rate and blocking conduction, so attention should be paid to ECG monitoring.
After the disease is relatively stable, long-acting dihydropyridine calcium antagonists can be used instead.
To control the symptoms, anti-myocardial ischemic drugs can be selected according to the nature of the angina pectoris attack. If the attack of angina is mainly related to the rise of myocardial oxygen consumption, β-blockers are the main choice. When the attack is mainly coronary artery spasm, then mainly choose nitrates and calcium antagonists.
4.Anti-platelet agents
Most of the unstable angina is due to plaque rupture induced by incomplete occlusion thrombosis. Therefore, effective antiplatelet and anticoagulation treatment during the acute stage of the disease can prevent further development of thrombus and reduce the incidence of acute myocardial infarction. The most commonly used antiplatelet agents are aspirin and clopidogrel (Poliovel). The newest and most powerful antiplatelet agents are IIb/IIIa receptor antagonists.
Aspirin is currently considered to have similar efficacy in the dose range of 80-325 mg/day. Those who are aspirin resistant are ineffective with aspirin. However, there is no routine clinical method for detecting aspirin resistance.
Bolivar, in combination with aspirin in the acute phase, has a synergistic antiplatelet effect. Dosage: 300mg shock once, then 75mg/day. Polivivir alone may be used for those who are allergic or resistant to aspirin.
IIb/IIIa receptor antagonist, currently there are intravenous tirofiban (Xinwenin), which can be used for those who are extremely unstable or have a significant tendency to thrombosis.
5.General heparin and low molecular heparin
Anticoagulation therapy mainly refers to the treatment of antithrombin, and heparin is one of the most effective drugs. Low-molecular-weight heparin has been used as a routine drug for unstable angina.
Normal heparin: In the acute phase, it can be pumped intravenously continuously. Generally, it is maintained at 1000 IU/hour after a shock of 3000 IU, or the dosage is adjusted according to APTT to keep it between 45-70 seconds.
Low molecular heparin: Its efficacy is currently considered similar to or better than that of regular heparin. No need to monitor the APTT time, the clinical application is very convenient. Commonly used drugs are.
(1) Kesai (Eroheparin): 1mg/kg body weight, subcutaneous injection, once every 12 hours.
(2) Fast coagulation avoidance (Fraxiparine): weight ≤ 70kg, 0.4ml subcutaneous injection, once every 12 hours. Weight >70kg, 0.6ml subcutaneous injection every 12 hours.
(3) Fragmin: 120IU/kg body weight, subcutaneous injection every 12 hours. It is appropriate to treat for about one week, and the minimum time should not be less than 48 hours.
Antiplatelet and antithrombin therapy are now used as routine treatment for unstable angina (UA), and the most commonly used clinical regimen to prevent thrombosis is the combination of aspirin or clopidogrel and heparin or low-molecular heparin.
III. Intra-aortic balloon counterpulsation
Intra-aortic balloon counterpulsation (IABP) is often effective in patients with unstable angina who have failed to respond to adequate drug therapy. It also provides an effective bailout for the ensuing hemodialysis treatment.
IV. Thrombolytic therapy
Large-scale clinical trials have demonstrated that thrombolytic therapy is not only ineffective but even harmful (increased bleeding complications) in patients with unstable angina.