First Records of Heartbeats via ECG in a Stingless Bee, Melipona flavolineata (Apidae, Meliponini), during Contention Stress, Using Isoflurane as an Anesthetic

The hemodynamic activity of Melipona flavolineata workers was evaluated during restraint stress for a period of 30 minutes. The observed parameters were power variation in the elapsed time, and subsequently six periods of one second were divided and called: A, B, C, D, E and F; in each period the electrocardiographic parameters were evaluated: Heart rate, Amplitude, R-R Interval, Duration of QRS and Q-T interval. The experiment was carried out with 8 worker bees of M. flavolineata, for which electrodes with nickel-chromium alloy were made. The bees were previously anesthetized with isoflurane and properly contained and fixed in a base for stereotaxis in which the electrode was implanted. All these procedures were performed inside a Faraday cage. The results showed power oscillations during the recording with the highest energy level between 300 and 600 s. Heart rate, QRS amplitude and QRS duration parameters underwent changes recorded during the restraint stress period. However, for the Q-T interval there was no difference during the recordings. Thus, the cardiac activity of M. flavolineata can be used as a biomarker and being used to clarify physiological issues or alterations caused by toxic agents and indicate risk factors for these animals.