Electrocardiographic variations during three trimesters of normal pregnancy.

ABSTRACT

Background: Electrocardiography can detect the physiological adaptations in the maternal cardiovascular system, but the results should be interpreted with caution as they mislead to the diagnosis of heart disease. This study is undertaken to highlight the effect of normal pregnancy on the electrocardiographic changes during three trimesters, so that it helps to distinguish the normal from that of pathological. Methods: A total of 150 normal pregnant women, each 50 in three trimesters fulfilling the inclusion criteria were selected for the study. 50 age matched nonpregnant women were selected as control group. A 12 lead ECG was recorded by using ECG machine with special emphasis on mean ECG heart rate, PR interval, frontal plane QRS axis, T wave inversion in lead III & V2, Q waves in LIII & aVF, QTc. All the parameters were analyzed. Results: The ECG changes observed in our study include, significant increase in mean ECG heart rate, decrease in PR interval, deviation of QRS axis towards left with progression of pregnancy, T wave inversion in lead LIII & V2, presence of Q wave in leads LIII & aVF and QTc was significantly prolonged in second and third trimesters of pregnancy compared to non pregnant group. Conclusions: The cardiovascular hemodynamic adaptation to pregnancy is a well established fact which was also apparent in our study. It is necessary to understand the normal physiological changes which help in better management of cardiac diseases