Lead systems: sensitivity and specificity.

In this article, the modified 12-lead system and the bipolar lead systems are discussed, both of which may provide adequate sensitivity and specificity of stress tests for clinical purposes. A single lead V5 or, preferably, bipolar modification of lead V5 may be adequate in certain situations in which cost or the type of population being tested legitimizes such a choice. However, the modified 12-lead system is far more popular for the diagnosis and follow-up of patients with ischemic heart disease. The final choice of lead system for monitoring stress tests will ultimately depend on the needs and resources of a given laboratory.