EXERCISE TEST . CORONARY ARTERY ANGIOGRAPHY . V4R CHEST LEAD
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).