Q: Which leads in EKG are preferred to measure the QT interval?
Answer: Leads II and V5
Lead II and lead V5 is preferred due to the fact that termination of T waves is most clearly visible in these leads, which makes these leads best to measure reliable QT interval.
Cowan JC, Yusoff K, Moore M, et al. Importance of lead selection in QT interval measurement. Am J Cardiol 1988; 61:83.