[Anti-ischemic therapy in patients with STEMI or NSTEMI treated at county and university hospitals].Acta Med Croatica. 2009 Feb; 63(1):53-8.AM
The objective of prehospital care of patients with acute coronary syndrom (ACS) [acute ST segment elevation myocardial infarction (STEMI), acute non-ST segment elevation myocardial infarction (NSTEMI), and unstable angina (UA)], is prompt diagnosis of the acute myocardial infarction, patient's risk assessment, drug administration in order to reduce patient's pain and fear, and prevention or treatment of heart failure. In hospital treatment therapeutic procedures include reperfusion therapy, limitation of infarction zone, treatment of complications (heart failure, life-threatening arrhythmias), prevention of reinfarction, heart failure and eventually prevention of sudden cardiac death. Acute therapeutic procedures include revascularization, anti-ischemic and antithrombolytic treatment, possible surgical revascularization and treatment of complications (arrhythmias, heart failure). The patients with STEMI that present within 3-12 hours from the onset of chest pain should undergo primary percutaneous coronary intervention (PCI). In case of presentation within 3 hours from the occurrence of chest pain, the administration of thrombolytic therapy in this period is equally efficient as PCI. Regardless of reperfusion regimen, the anti-ischemics administered including nitrates (nitroglycerin); intravenous analgesics (morphine-sulfate); O2 2-4 L/min; beta-adrenergic blockers; calcium channel blockers; angiotensin converting enzyme inhibitors (ACE-I); magnesium and glucose-insulin-potassium have proved to be efficient as shown by study results and clinical experience. The mechanism of action of anti-ischemics includes reduction in myocardial oxygen consumption achieved by a decrease of heart frequency, reduction of systemic blood pressure and reduction in myocardial contractility by vasodilatation and consequent better myocardial oxygen supply. The outstanding results of major clinical studies are presented, and main guidelines for anti-ischemic therapy of ACS adopted by the international professional associations are set forth.