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

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.