Effect Of Acute Stress On Rat ECG

Rat ECG is commonly used parameter for various cardiovascular studies. The rat ECG resembles essentially human ECG with minor differences. Stress is common in day to day life. Stress affect hypothalamus-pituitary-adrenal axis resulting alteration in various physiological functions of body esp cardiovascular system. Studies regarding effect of acute stress on rat ECG are lacking, hence it was planned to study the effect of acute stress on rat ECG. Albino rats (n=15) of either sex weighing 200 to 300 gm were used. Acute stress in the form of 5 hr. immobilization was given to the experimental animals. Pentobarbital in subanesthetic dose (25 mg/kg I.P.) was administered to immobilize the rats in supine posture. Within 45 mts of pentobarbital administration animal regained consciousness and control ECG was recorded. Five hr. after immobilization ECG was again recorded, changes in ECG were noted in respect of HR, PR interval, QRS complex, QT interval and changes in amplitude of waves. Acute stress of 5 hr. immobilization produced changes in atrial and ventricular depolarization and repolarization. CONCLUSION: Acute stress affect atrial and ventricular depolarization – repolarization significantly in albino rats. INTRODUCTION Stress is common in day to day life, and affect HPA axis resulting alteration in various physiological functions of the body. Cardiovascular system is more prone to be affected by stress, directly or indirectly. ECG is commonly used parameter for various cardiovascular studies in human and in animal. Rat ECG resemble essentially to human ECG with minor differences. Studies regarding effect of acute stress on rat ECG are lacking. Hence with the prior approval from Institutional Ethical Committee, the present study was planned to evaluate the effect acute stress on rat ECG.