Effect of extension tube length on the damping coefficient and natural frequency in normotensive dogs.

With an increase in ETL, the NF decreased significantly, while the DC demonstrated a less significant change. Therefore, NF had a greater influence on the damping factor of arterial BP measurement. There was no difference between ETLs from 25 to 275 cm lines for measuring BP. An ETL of less than 275 cm is recommended as the damping amount is adequate. Moreover, an ETL less than 275 cm does not meaningfully affect BP measurement in dogs.