Effects of Body Temperature on Electrocardiograms of Lizard Eremias multiocellata

Electrocardiograms (ECG) of Eremias multiocellata were studied at 5-35 ℃ in body temperature.Electrocardiogram wave intervals (R-R,P-R,QRS,T-P,and R-T) shortened while heart rate increased with the increasing of body temperature.The average heart rate was 14.6/min at 5 ℃,whereas it was 201/min at 35 ℃.The duration of wave intervals of ECG and the heart rate were related significantly to the body temperature (P<0.001).Among the components of a cardiac cycle the cardiac rest period (TP intervals) and the atria-ventricular conduction time (PR interval) were affected mostly by body temperature.In the other hand the ventricular depolarization and repolarization (QRS and R-T intervals) were relatively less affected by the body temperature.The increasing of heart rate with body temperature was mainly caused by the shortening of ECG wave intervals,and the T-P interval (the cardiac rest period) was shortened more noticeably than other intervals.