AbstractIntroduction: Pregnancy is a normal physiological phenomenon causing major hemodynamic changes. Aim: To measure various cardiovascular changes that occurs during various trimesters of pregnancy. Objective: To record the pulse rate, heart rate, blood pressure (BP) and electrocardiographic (ECG) changes to see any variations in different trimesters of pregnancy. To determine if underlying physiological changes predispose the pregnant women to any cardiovascular risk. Method: Eighty healthy pregnant women in the age group 20-35years were included in the study. The following cardiovascular parameters were recorded pulse, BP, heart rate (HR) and ECG were thoroughly studied. In ECG- RR interval, P wave duration , PR interval, QRS complex, QT interval, QTC interval, P axis, QSR axis, Taxis, P(II)volt, S(V1)volt, R(V5)volt were noted Results: A significant increase in the pulse rate, heart rate was seen as the pregnancy progressed. Other changes in the BP and ECG found were positive however not statistically significant. QT interval shortened and the Taxis was altered. Dominance of the sympathetic nervous system (SNS) over the parasympathetic nervous system (PNS) has been shown to be a strong risk factor for cardiovascular disease. Sympathetic dominance is the cause of cardiovascular changes seen during pregnancy. Conclusion: Pregnancy has an effect on heart so as to attenuate the vagal dominance in the form of increase in the pulse and heart rate and shortening of QT interval which may be concern in patients with cardiovascular disease during pregnancy.

Key words: Normal pregnancy, cardiovascular changes, ECG.