Novel methodology for the detection of exercise-induced myocardial wall motion abnormalities by surface electrocardiogram during exercise test.
Michaelides AP., Massias S., Antoniades C., Tsiachris D., Dilaveris P., Aggelis A., Liakos C., Marinou K., Raftopoulos L., Soulis D., Stefanadis C.
BACKGROUND: We investigated whether ischemia-induced wall motion abnormalities during exercise test modify electrical vector variation. METHODS: We performed treadmill exercise test and thallium 201 scintigraphy in 150 normotensives. Beat-to-beat change of direction of S wave in V(1) (reference lead) was compared with that of R wave in V(5) and aVF, representative of anterior and inferior walls, respectively. The percentage of neighboring QRS couples where S wave in V(1) and R wave in V(5) or aVF change toward the same direction (increase or decrease) constitutes V1-V5 and V1-aVF indexes. RESULTS: V1-V5 and V1-aVF indexes were significantly decreased in subjects with reversible anterior or inferior ischemia, respectively. A decrease in V1-V5 index ≥0.14 defines those with anterior wall ischemia (sensitivity, 100%; specificity, 75.5%), whereas a decrease in V1-aVF index ≥0.05 defines those with inferior wall ischemia (sensitivity, 92.3%; specificity, 61.5%). CONCLUSIONS: These novel electrocardiographic exercise test indexes improved significantly their sensitivities.