Identification of Patients with Myocardial Infarction

Myocardial infarction (MI) has been long recognized as the main cause of death worldwide [1]. In addition, cardiac ischemia (CI) causes changes in the energy dependent (ATP) pumps located within the cardiac cells sarcolemma, which modifies the transmembrane potential, usually recorded as morphological changes in the ECG and VCG. Moreover, a sudden occlusion in one of the major coronary arteries (in the absence of a coronary collateral flow) results in transmural ischemia, the first step of the so-called ischemic cascade phenomenon. The chain of events usually proceeds in a sequence, that is: 1) ischemia; 2) diastolic dysfunction (poor relaxation); 3) systolic dysfunction (weak contraction); 4) angina pectoris (brought about by accumulation of metabolites); 5) infarction and eventual necrosis [1]. Within the vectorcardiography framework, the momentary cardiac electrical activity is representable by a single vector in the Euclidian space, i.e., the heart vector, and the VCG precisely describes both components, magnitude and direction, as time proceeds. Different studies [1] have demonstrated that ischemia modifies ECG segments and waves of left ventricular depolarization and repolarization (QRS-complex and ST-T segment). Similarly, other researchers have verified that the QRScomplex and the T-wave loops of the VCG also undergo modifications due to total coronary or partial obstructions. Manocha and Singh [2] summarized most of ECG techniques to CI detection and concluded