The Effects of Acute Blood Loss on Electrocardiogram in Male and Female Swiss Albino Mice

Abstract

The aim of the present study is to investigate the possible effects of acute blood loss (1% of body weight) on electrocardiogram (ECG) in male and female Swiss albino mice. Anesthesia was maintained with the ketamine-xylazine combination. The tail was cut using a scalpel blade and blood at a ratio of 1% body weight was collected in capillary tubes. ECG recording was done by using the standard lead II. P and T waves, intervals of PQ, QT, and RR, and QRS complex were measured after all ECG was recorded. The amplitude of P and QRS waves were significantly higher in males than that of females (P<0.005, P<0.05 respectively). PR intervals were also longer in male mice than those of females (P<0,001). Neither blood removal nor anesthesia affected the amplitude of the QRS complex in any gender. The duration of the QRS complex was longer in males than females in both groups (P<0,01). Blood removal led to a reduction in the duration of the QRS complex in male mice (P<0.01). Anesthesia caused the prolongation of the QT and QTc in all groups (P<0,001, P<0,05 respectively). Females had longer QT interval compared to male groups (P<0,05) and blood removal caused prolongation of the QT period in females (P<0,05). An acute blood loss of 1% of body weight in male mice led to a reduction in heart rate, whereas prolongation of the QT interval in female mice. It was concluded that gender is an important factor in terms of blood-loss associated ECG alterations.