Unconventional electrocardiographic signs of ischemia during exercise testing.

Because of the failure to consider some of the unconventional electrocardiographic signs of ischemia during exercise testing, its sensitivity and specificity are lower than optimum. Two cases are presented to illustrate how precordial peaking of the T waves and lead-strength calculations in patients with low-voltage R waves can be used to improve the diagnostic power of exercise testing. Other rarely used electrocardiographic changes during exercise testing include ST elevation in lead aVR, an increase in P-wave duration, and ST depression in premature ventricular complexes. In conclusion, this experience demonstrates that the routine consideration of these electrocardiographic changes will result in significant increases in the sensitivity and specificity of exercise testing.