Patterns of acute inferior wall myocardial infarction caused by hyperkalemia

This is one of the first published articles dealing with two patients with hyperkalemia showing, not only a pattern of acute anteroseptal myocardial i nfarction, but of inferior myocardial infarction as well. This was attribut ed to uneven effects of high potassium in different regions of the heart. M arked reduction of resting potential of a large group of cells from the mos t affected regions could produce areas of inexcitability, capable of genera ting abnormal q waves. Likewise, ST-segment elevation could be attributed t o a hyperkalemic diastolic current of injury (due to depolarization of rest ing potential) and to a combination of diastolic and systolic current of in jury (due to a reduction of action potential amplitude). In addition, curre nt flowing down voltage gradients on either side (epicardial and endocardia l) of the IM cell region could be responsible for the T wave, and even, to some extent, to the ST-segment changes. However, it cannot be excluded that the previously described changes may have resulted from coronary spasm wit hout chest pain. In fact, an intriguing possibility, namely that hyperkalem ia could trigger coronary spasm has to be considered also.