Optimal lead selection for detection of ST segment shifts

A comparison was made to determine the ability of optimal sets of 2-6 unipolar leads and a normal Holter lead set to estimate ST potential distributions changes induced by balloon inflation during angioplasty. The performance of these lead sets was compared to measurements observed in recorded 32-lead body surface maps. Unipolar lead potentials were estimated using a linear, least mean squared error estimator of the total body surface map. The correlation between maximum ST potential change in the body surface map and that predicted by the unipolar lead sets ranged from 0.84-0.93. The correlation between maximum ST segment change measured from the body surface map and measured from the Holter leads was 0.29. Therefore, shifts in ST segment potentials can accurately be estimated from a small number of unipolar leads. In contrast, current bipolar ambulatory recording techniques may introduce significant bias to such estimates.