This dataset includes QTc and RR values related to the electrocardiogram of rats exposed to either air or diesel exhaust. This dataset is associated with the following publication: Hazari , M., J. Lancaster, J. Starobin, A. Farraj , and W. Cascio. Diesel exhaust worsens cardiac conduction instability in dobutamine-challenged Wistar-Kyoto and spontaneously hypertensive rats. Cardiovascular Toxicology. Humana Press Incorporated, Totowa, NJ, USA, 17(2): 120-129, (2017).