The Precordial Electrocardiogram during Exercise

Abstract

The precordial ecg continuously monitored in subjects performing the two-step test was rendered free of muscle noise and baseline shift by employing cupped wire mesh electrodes, bentonite electrode paste and a new system of electrode placement. The right arm electrode was placed on the right ear lobe, the left arm electrode over the ensiform process and the left leg electrode at V7 position. Preliminary findings show that in 135 of 150 instances the maximum ecg changes occurred before the termination of exercise and started to revert toward control levels within 5 to 30 seconds after termination of exercise. V3 and V5 leads best showed the changes occurring during exercise. The technic designated as the "ear-ensiform-precordial (E-E-P) system" offers the advantage of safety since exercise can be stopped at the 1st ecg evidence of abnormality or be safely continued beyond any limits previously described. The test can be done with any ecg without additional electronic equipment. The precordial tracings obtained by the E-E-P system are comparable to those obtained with the Wilson central terminal. The technic makes possible detection of relatively transient ecg abnormalities that may be present during but not after exercise.