Acute Coronary Syndrome



Acute Coronary Syndrome

Question 1: Summarize the Australian evidence based guidelines for the management of ACS?

Answer 1: Myocardial ischemia is dynamic and unpredictable which, if not identified and treated promptly, can lead to devastating outcomes. Coronary heart disease (CHD) is the leading cause of death in many parts of the world and nearly 17 million persons in the U.S. are currently diagnosed with it. The incidence of cardiovascular disease in the U.S. increased rapidly during the last century and currently claims the lives of nearly one million people annually. CHD caused one of every five deaths in many developed countries such as Australia, UK and USA (Barrett, 1998). It is the most important cardiovascular disorder in number of persons affected each year. Coronary atherosclerosis is the most common cause of CHD and is a chronic disease characterized by stable and unstable periods. Unstable periods manifest themselves in acute coronary syndrome (ACS), the spectrum of clinical syndromes that reflect progression of occlusion in a coronary artery (Armstrong, 1999).

In adults above 35 years of age, coronary atherosclerotic disease (CAD) can lead to sudden death in exercising individuals. Over time, susceptible individuals will build up fatty plaque within the arteries, which causes significant narrowing. As exertion increases, as during exercise, the heart requires more oxygen; the narrowed artery can limit the amount of blood flow that can get to the heart. The oxygen demand can outpace the supply, causing heart muscle ischemia; this in turn can disrupt the electrical signal, throwing the heart into a lethal rhythm, as in ventricular fibrillation. The atherosclerotic plaques may also break off, especially during times of high demand or stress on the heart; the plaque can then limit or cut off blood flow distal to the blockage, causing heart muscle ischemia and tissue death. Diagnosis of CAD can be supported indirectly with a variety of cardiac stress tests and directly with invasive cardiac catheterization. Of note, changes of CAD have been found in people in their 20s and younger and so may contribute to some cases of SCD in this age-group as well (Kiecolt, 1995).

Each year, five million ED visits and one and a half million admissions are related to acute coronary syndrome. The most important goal in the management of ACS is identifying the problem early and initiating prompt intervention. This recommendation is based on the premise that longer delays are associated with worse outcomes. The presence of acute ischemic changes on the initial ECG, often conducted at presentation to the ED, is associated with a higher risk of cardiac events. Moreover, these acute ischemic changes are unpredictable and dynamic in nature, which suggests that a single snap-shot 12 lead ECG is inadequate and continuous or serial ECG monitoring may be diagnostically superior (Gamberino, 1999). In the case of William who has suffered chest pain and has also been diagnosed with Acute Coronary Syndrome, he would need to go through all the necessary steps that will enable him to take care ...