CHARACTERIZATION OF THE ELECTROCARDIOGRAM OF THE AMERICAN ALLIGATOR (ALLIGATOR-MISSISSIPPIENSIS)

Electrocardiograms (ECGs) were evaluated for time and amplitude charac teristics and mean electrical axis (MEA) in 10 clinically healthy Amer ican alligators (Alligator mississippiensis) in two separate recording s. The ECG characteristics evaluated (($) over bar x +/- SD) were R-R intervals (1.56 +/- 0.18 sec, 1.71 +/- 0.30 sec), QRS complex duration (0.106 +/- 0.021 sec, 0.100 +/- 0.015 sec), Q-T intervals(1.19 +/- 0. 13 sec, 1.18 +/- 0.19 sec), T wave duration (0.35 +/- 0.10 sec, 0.33 /- 0.08 sec), and Q wave (0.08 +/- 0.03 mV, 0.09 +/- 0.04 mV), R wave (0.23 +/- 0.10 mV, 0.25 +/- 0.12 mV), S wave (0.12 +/- 0.07 mV, 0.16 /- 0.07 mV), and T wave (0.12 +/- 0.03 mV, 0.13 +/- 0.03 mV) amplitude s. The P-R intervals and P wave duration and amplitude were inconsiste ntly recorded and not evaluated. Core body temperatures (23.24 +/- 1.1 7 degrees C, 25.38 +/- 2.78 degrees C) and heart rates (38.6 +/- 4.01 bpm, 37.6 +/- 4.79 bpm) were measured during each recording. Statistic al analysis revealed no significant difference (P > 0.05) in heart rat es or R-R intervals between the two recordings. Mean electrical axis ( 83.83 +/- 9.72 degrees, 82.95 +/- 13.85 degrees) is reported for the f irst time in the American alligator.