ST-segment elevation

A reduction of at least 50% of the ST-segment elevation on follow-up ECG obtained 60-90 min after fibrinolytic therapy... 

O Ischemic heart disease results from an imbalance between myocardial oxygen demand and oxygen supply that is most often due to coronary atherosclerosis. Common clinical manifestations of ischemic heart disease include chronic stable angina and the acute coronary syndromes of unstable angina, non-ST-segment elevation myocardial infarction, and ST-segment elevation myocardial infarction. 

Biochemical markers (creatine kinase [CK], CK-MB fraction, troponin I and troponin T) are elevated in Ml (ST-segment elevation Ml and non-ST-segment elevation Ml), but normal in chronic stable angina and unstable angina. 

List key electrocardiographic and clinical features identifying a patient with non-ST-segment elevation acute coronary syndrome who is at high risk of myocardial infarction or death. 

Devise a pharmacotherapy treatment plan for a patient undergoing primary percutaneous coronary intervention in ST-segment elevation myocardial infarction given patient-specific data. 

Formulate a monitoring plan for a patient with ST-segment elevation acute coronary syndrome receiving fibrinolytics, aspirin, unfractionated heparin, intravenous nitroglycerin, intravenous (3-blockers followed by oral P-blockers, an angiotensin-converting enzyme inhibitor, and a statin. 

The American Heart Association and the American College of Cardiology recommend strategies, or guidelines, for acute coronary syndrome patient care for ST-segment and non-ST-segment elevation acute coronary syndrome. 

Early reperfusion therapy with either primary percutaneous coronary intervention or administration of a fibrinolytic agent within 3 hours of symptom onset is the recommended therapy for patients presenting with ST-segment elevation acute coronary syndrome. 

In patients with ST-segment elevation (STE) ACS, in-hospital death rates are approximately 7% for patients who are treated with fibrinolytics and 16% for patients who do not receive reperfusion therapy. In patients with non-ST-segment elevation (NSTE) MI, in-hospital mortality is less than 5%. In-hospital and 1-year mortality rates are higher for women and elderly patients. In the first year following MI, 38% of women and 25% of men will die, most from recurrent infarction.1 At 1 year, rates of mortality and reinfarction are similar between STE and NSTE MI. 

Patients are risk-stratified into two groups ST-segment elevation ACS and suspected non-ST-segment elevation ACS. 

ECG normal sinus rhythm, PR 0.16 s, QRS 0.08 s, QTC 0.38 s, occasional polymorphic premature ventricular contractions, 3 mm ST-segment elevation anterior leads... 

TABLE 5-1. TIMI Risk Score for Non-ST-Segment Elevation Acute Coronary Syndromes2 17... 

Early Pharmacologic Therapy for ST-Segment Elevation Acute Coronary Syndromes... 

Pharmacotherapy for early treatment of ACS is outlined in Fig. 5-3. According to the ACC/AHA ST-segment elevation ACS practice guidelines, in addition to reperfusion therapy, early pharmacotherapy of STE should include intranasal oxygen... 

Pharmacotherapy for Acute Coronary Syndromes (ST-Segment Elevation and Non-ST-Segment Elevation)2 3 20 21 22... 

TABLE 5-3. Indications and Contraindications to Fibrinolytic Therapy per ACC/AHA Guidelines for Management of Patients with ST-Segment Elevation Myocardial Infarction3... 

ST-segment elevation of at least 1 mm in height in two or more contiguous leads, or new or presumed new left bundle-branch block... 

Antman EM, Cohen M, Bernink PJ, et al. The TIMI risk score for unstable angina/non-ST-segment elevation MI a method for prognostication and therapeutic decision-making. JAMA 2000 284 835-842. 

Acute coronary syndromes Ischemic chest discomfort at rest, most often accompanied by ST-segment elevation, ST-segment depression, or T-wave inversion on the 12-lead electrocardiogram. Furthermore, it is caused by plaque rupture and partial or complete occlusion of the coronary artery by thrombus. Acute coronary syndromes include myocardial infarction and unstable angina. Former terms used to describe types of acute coronary syndromes include Q-wave myocardial infarction, non-Q-wave myocardial infarction, and unstable angina. 

Non-ST-segment elevation A type of myocardial infarction (MI) that is limited to the subendocardial myocardium and is smaller and less extensive than an ST-segment MI. There is usually no pathologic Q-wave on the electrocardiogram in non-ST-segment elevation. 

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