Acute Anterior Transmural Myocardial Ischemia

Presence of transient ST segment deviations is the most commonly used noninvasive indicator of acute myocardial ischemia. Changes in R- and S-wave amplitudes have been proposed as additional electro­cardiographic (ECG) markers of ischemia. These amplitude changes have been primarily described during subendocardial ischemia and ST depres­sions, but they have also been seen with transmural ischemia and ST elevations. While some investiga­tors have found that the behavior of these QRS wave forms is consistent and a valuable aid in assessing presence of myocardial ischemia and dysfunction,others have reported that these changes are variable and not reliable. Whether the growth or the dimi­nution of the QRS amplitudes is a reflection of myocardial ischemia is, by itself, not totally clear and appears to be dependent on several factors.

The purpose of our investigation was to (1) deter­mine R- and S-wave amplitude changes during acute left anterior descending artery (LAD) occlusion and anterior transmural ischemia, (2) define the relation­ship between changes in R and S waves and magnitude of ST elevations, and (3) evaluate the relationship between R- and S-wave changes and ST elevations and the changes in pulmonary capillary wedge pressures (PW). Coronary angioplasty served as the model of acute coronary occlusion and transmural ischemia. Viagra Soft Tabs