Prehospital 12-Lead Electrocardiogram within 60 Minutes Differentiates Proximal versus Nonproximal Left Anterior Descending Artery Myocardial Infarction.

Introduction: Acute anterior myocardial infarctions caused by proximal left anterior descending (LAD) artery occlusions are associated with a higher morbidity and mortality. Early identification of high-risk patients via the 12-lead electrocardiogram (ECG) could assist physicians and emergency response teams in providing early and aggressive care for patients with anterior ST-elevation myocardial infarctions (STEMI). Approximately 25% of US hospitals have primary percutaneous coronary intervention (PCI) capability for the treatment of acute myocardial infarctions.

Left ventricular unloading with intra-aortic counter pulsation prior to reperfusion reduces myocardial release of endothelin-1 and decreases infarction size in a porcine ischemia-reperfusion model.

Objectives: We tested the hypothesis that unloading the left ventricle with intra-aortic balloon counter-pulsation just prior to reperfusion provides infarct salvage compared with left ventricular (LV) unloading postreperfusion or reperfusion alone.

Background: Previous reports demonstrated infarct salvage with complete LV unloading with an LVAD prior to reperfusion; however, partial LV unloading using intra-aortic balloon pumps (IABPs) has not been evaluated.

Methods: Twenty-eight Yorkshire pigs were subjected to 1 hr of left anterior descending artery occlusion and 4 hr of reperfusion.