945-66 Combination of Left and Right Precordial Leads: A New Technique in Exercise Testing with the Highest Diagnostic Ability for the Detection of Coronary Artery Disease

It is known that right precordial leads RV 3 , RV 4 , RV 5 could detect Rightcoronary (RC) artery stenosis. The common exercise test (ET) has a low ability to detect RC disease especially as a single vessel disease (VD). The aim of this study was to improve the diagnostic accuracy of the ET for the detection of coronary artery disease (CAD) using a combination of Left (L) and Right (R) precordial leads. We studied 133 patients (pts) aged 32–73 (mean 48 ± 7) years (122 males and 11 females) who underwent treadmill ET using the Bruce protocol and coronary arteriography. We used two Exercise systems. The pts were walking on the treadmill of the one system. In the monitor of the first system the usual 12-lead ECG and in the monitor of the second system the additional R precordial leads (RV 3 , RV 4 , RV 5 ) were simultaneously recording. The start and the end of the ET in both systems were done at the same time by two of the investigators. Thirty-four pts had normal coronary arteries, whereas 54 pts had l-VD, 27 2-VD and 18 3-VD. Of the pts with 1VD, 25 had Left Anterior Descending (LAD) disease, 16 had RC artery disease and 13 Left Circumflex (LC) artery disease. The sensitivies of the usual 12- lead ET and of the combination of Land R precordial leads (new technique) for the detection of LAD disease were found respectively 76% (19/25) vs 92% (23/25), for RC disease 25% (4/16) vs 88% (14/16), for LC diseese 47% (6/13) vs 85% (11/13), for the detection of l-VD were 54% (29/54) vs 89% (48/54), for 2-VD 63% (17/27) vs 96% (26/271. for 3-VD 83% (15/18) vs 100% (18/18) and for the detection of CAD 61% (61/99) vs 93% (92/99), P l 0.001, while the specificities were found the same 91% (31/34) Conclusion It is concluded that this new technique based on two Exercise Systems has the highest diagnostic ability for the detection of CAD and it evokes the need for the creation of a new exercise system with 15 leads