The significance of right-sided chest leads in exercise testing for the detection of right ventricular dysfunction post myocardial infarction of the inferior wall.
Michaelides A., Tousoulis D., Liakos C., Aggeli K., Antoniades C., Vyssoulis G., Raftopoulos L., Soulis D., Toutouzas K., Stefanadis C.
BACKGROUND: The incorporation of right-sided chest leads (V(3)R-V(5)R) into the standard exercise testing has been reported to improve its diagnostic accuracy. The purpose of this study was to evaluate the ability of exercise testing in detecting right ventricular (RV) dysfunction post myocardial infarction (MI) of the inferior wall, using additional V(3)R-V(5)R leads. METHODS: We studied 133 patients (59 ± 5 years, 81 males) with a history of inferior MI due to right coronary artery obstruction (affirmed with coronary angiography). All patients underwent an echocardiographic assessment of RV function 4 weeks after discharge and an exercise treadmill test in order to detect possible RV dysfunction. Recordings during exercise were obtained with the standard 12 leads plus V(3)R-V(5)R. RESULTS: From 133 patients, 97 (group A) presented with normal right ventricle according to the echocardiographic study while the rest 36 patients (group B) presented with RV dysfunction. Maximal exercise-induced ST-segment deviation (in mm) was similar in the standard 12 leads for the 2 groups (2.1 ± 0.4 vs 1.8 ± 0.3, p = NS) while in V(3)R-V(5)R it was greater in group B (0.7 ± 0.3 vs 1.4 ± 0.4, p<0.05). Sensitivity, positive prognostic value, negative prognostic value and accuracy of exercise testing in detecting RV dysfunction were all improved using V(3)R-V(5)R (78 vs 47%, 39 vs 29%, 87 vs 75%, 62 vs 55% respectively, p<0.05 for all) while specificity was not deteriorated (56 vs 58%, p = NS). CONCLUSIONS: The addition of right-sided chest leads (V(3)R-V(5)R) improves the diagnostic ability of standard exercise testing in detecting and especially in excluding RV dysfunction post inferior MI.