Page 13 - Coronary hemodynamics in acute myocardial infarction - Matthijs Bax

General introduction and outline of the thesis
General introduction 1
Irreversible damage to the heart muscle cell occurs due to a lack of delivery of oxygenated blood within 20 minutes after the blockage of a coronary artery. The wavefront phenomenon describes how ischemic cell death due to coronary occlusion in dogs develops over time from the subendocardium to the epicardium leading to an increase in infarct size and a decrease in left ventricular function.1 After the first myocardial infarction, the risk of re- infarction or another cardiovascular event is considerably enhanced even above 50% in the next ten years in high-risk patients,2, 3 This patients face an annual death rate of six times that in people of the same age who do not have coronary heart disease.4, 5
The purpose of the initial treatment of the acute myocardial infarction is to limit the infarct size, maintain the left ventricle function and to reduce the associated risk of mortality.
In the sixties of the previous century the risk of dying in the acute phase of the myocardial infarction was reduced by almost 30% by installment of acute Coronary Care Units with ECG monitoring and the possibility of direct defibrillation.6 The in-hospital mortality could be further reduced in the 80s and 90s from around 20% to 10% through early treatment with aspirin, thrombolysis and other medication interfering with coagulation.7, 8
In the following years, mechanical reperfusion by percutaneous transluminal coronary angioplasty (PTCA) or percutaneous coronary intervention (PCI), initially with balloon only and later on with stent implantation, was the therapy of first choice due to its effectiveness and sustainable result.9, 10 With current treatment methods, the in-hospital mortality is now below 4%.
The duration between coronary blockage and definite reperfusion is of great importance to maintain left ventricular function and improve clinical outcome. 11
ST-elevation myocardial infarction
The myocardial infarction with ST segment elevation on the ECG generally occurs on the basis of (sub) acute thrombosis on a destabilized, ruptured or eroded atherosclerotic plaque.12, 13 The endothelium of the coronary vessels
11