Standardization of electrocardiographic examination in corn snakes (Pantherophis guttatus)

Introduction: Corn snakes are a very common pet reptile species, yet
there is an absence of evidence-based literature standardising collection
of electrocardiographs (ECG) or detailing ECG deflection morphology in
the normal animal. We describe a well-tolerated, reproducible technique
and detail the cardiac cycle in terms of lead 2 equivalent waveforms and
intervals.
Animals: 29 adult corn snakes.
Materials and methods: This prospective study evaluated under speciesappropriate, standardised conditions, a technique for producing standard
six-lead ECG tracings. Lead 2 equivalent cardiac cycles were described in
detail and statistically analysed for gender, weight, length, heart rate
and mean electrical axis.
Results: High-quality tracings demonstrated common ECG characteristics
for this species, including: no Q, S or SV waves, prolonged PR and RT
intervals, rhythmic oscillation of the baseline, short TP segments and a
right displaced mean electrical axis. An influence of gender, weight or
length on heart rate and mean electrical axis was not identified.
Conclusions: To the authors’ knowledge, this is the first study to describe
a standardised technique for recording ECG in significant numbers of
normal corn snakes. Ranges have been provided that may be of
diagnostic value or form the basis for future development of reference
intervals for this species