Table 3.
Electrocardiogram variables (mean ± SD) in 54 dogs, 30 min after premedication using acepromazine (0.03 mg/kg) and methadone (0.3 mg/kg) intramuscularly and after induction to general anesthesia with alfaxalone or propofol.
| ECG variable | Mean difference alfaxalone group (n = 27) | Mean difference propofol group (n = 27) | p-value |
|---|---|---|---|
| RR interval (ms) | 355.1 (±207.4) | 154.8 (±129.0) | 0.0001 |
| PR interval (ms) | 0.36 (±15.1) | −4.7 (±6.5) | 0.12 |
| QRS interval (ms) | −1.1 (±2.2) | −1.2 (±2.1) | 0.87 |
| ST segment deviation (mV) | 0.02 (±0.06) | 0.01 (±0.05) | 0.43 |
| T wave amplitude +ve (mV) | −0.07 (±0.15) | 0.002 (±0.14) | 0.15 |
| T wave amplitude –ve (mV) | −0.14 (±0.23) | −0.008 (±0.37) | 0.29 |
| QT interval (ms) | 13.2 (±11.9) | −0.19 (±7.8) | < 0.0001 |
| QTc interval (ms) | −17.7 (±17.8) | −13.7 (±9.6) | 0.30 |
| Jt interval (ms) | 14.2 (±11.8) | 0.24 (±7.7) | < 0.0001 |
| Jtc interval (ms) | −16.7 (±17.4) | −13.2 (±11.2) | 0.39 |
| QT dispersion (ms) | −0.24 (±6.4) | 1.04 (±15.8) | 0.70 |
For each variable, results are reported as mean difference before and after induction, with a positive number indicating a decrease post-induction compared to the pre-induction value.