ASSESSMENT OF THE VALUE OF V4R CHEST LEAD IN RAISING THE DIAGNOSTIC EFFICACY OF EXERCISE TEST

Background- The exercise test remains an important tool for diagnosing ‎cardiovascular disease and determining its prognosis. However, remarkable ‎achievements brought about by coronary angiography have demonstrated that the ‎exercise test is of inadequate sensitivity in diagnosing coronary artery diseases in ‎some patients. Hence, any new methods that can add to the sensitivity and diagnostic ‎efficacy of this test will likely result in improved prognosis determination in affected ‎patients‏.‏‎
‎ Patients and Methods- The exercise test was performed for 218 patients (130 men and ‎‎88 women) aged between 30 and 74 years (mean: 50±7 years), all of whom ultimately ‎underwent coronary angiography. The test was conducted using the V4R instead of ‎V2 chest lead, and the other 11 standard chest leads, and the results of the tests were ‎analyzed.
‎ ‎ Results- 103 of 218 patients (47%) who took the exercise test with the Bruce method ‎using V4R lead had positive exercise test results in standard chest leads. Exercise test ‎electrocardiogram of 25 patients (11.5%) revealed positive findings, both in V4R and ‎in the other 11 standard chest leads. 15 patients (7%) displayed positive exercise test ‎findings solely in V4R. 148 of 218 patients had more than 75% stenosis of one or ‎more coronary arteries. Adding V4R to the other 11 standard chest leads in the ‎exercise test raised its sensitivity from 69.5% to 80%, but adding the results obtained ‎using lead V4R did not result in increased specificity‏.‏‎
‎ Discussion- Using the V4R chest lead in the exercise test results in increased ‎sensitivity of this procedure in diagnosing left circumflex and right coronary artery ‎disease; however, sensitivity remains unchanged in diagnosing disease of other ‎coronary artery branches (Iranian Heart Journal 2003; 4 (2,3): 24-28‎‏).