The hyperacute phase of right ventricular infarction.

In summary, the hyperacute phase of RV infarction presents three possible patterns on the surface ECG (Fig. 3): the typical repolarization picture of hyperacute myocardial infarction, with slope elevation of the ST segment and tall T waves; rounded elevation of the ST segment, where the typical changes are "damped" by negative or posterolaterally directed, LV repolarizing forces; and ST elevation concave upward in the right chest leads, where anteriorly directed, underlying left ventricular ST segment and T wave vectors enhance the hyperacute picture.