Effects of acepromazine and buprenorphine on measured indices of the signal-averaged electrocardiogram in healthy dogs

Abstract

Objectives - To determine values for indices of signal-averaged electrocardiograms (SAECG) in healthy dogs, and to determine whether sedation with acepromazine and buprenorphine would alter these indices. Animals - 15 healthy adult dogs. Procedure - SAECG were recorded from each dog twice: prior to sedation and immediately after sedation with acepromazine (0.01 mg/kg of body weight, IV) and buprenorphine (0.007 mg/kg, IV). Time-domain methods were used to analyze the SAECG. All indices were calculated by use of a computer. Measured indices included QRS duration, duration of low-amplitude signals in the terminal part of the QRS complex, root mean square voltages of the terminal 30 and 40 milliseconds of the QRS complex, heart rate, and high-frequency noise levels. Results - We did not detect significant differences between values measured when dogs were not sedated and values measured when dogs were sedated except in regard to heart rate (P = 0.0001) and high-frequency noise levels (P = 0.0004), which were lower when dogs were sedated. Late potentials were not visually identified in SAECG from any dog in this study. Conclusion and clinical relevance - Sedation facilitated recording of SAECG in dogs without altering the results.