Evolving ST elevation/Q wave inferior-posterior-lateral myocardial infarction

This ECG, from a patient with an acute coronary syndrome, shows sinus rhythm at a rate of about 60/min, with normal PR, QRS, and QT intervals. Pathologic Q waves and ST elevations are seen in II, III, aVF and, more subtly, in V6. The tall R waves (V1-V2) in this context are consistent with loss of postero-lateral forces; the ST depressions in the right-mid precordial leads are consistent with reciprocal changes (opposite to presumed postero-lateral ST elevations). Some degree of primary anterior ischemia is not excluded. The R waves are also tall in V3 and V4 but do not meet left ventricular hypertrophy criteria.