Electrocardiographic variations during three trimesters of normal pregnancy

Venkatachalam Madras, Nagasireesha Challa


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.



Pregnancy, Three trimesters, Electrocardiography.

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Ouzounian JG, Elkayam U. Physiologic changes during normal pregnancy and delivery. Cardiol Clin. 2012;30(3):317-29.

Oppen V, Carla C, Twell IV, Johan GP, Heethaar RM, Bruinse WH. A longitudinal study of maternal hemodynamics during normal pregnancy. J Obstet and Gynaecol. 1996;88(1):40.

Misra J, Dutta B, Ganguly D. Electrocardiographic study in pregnant women in normal and toxemia of pregnancy. J ObstetGynecol India. 1986;36:635-38.

Goloba M, Nelson S, Macfarlane P. The electrocardiogram in pregnancy. Computing in Cardiology. 2010;37:693-96.

Sharad Kole, Jnaneshwara Shenoy, Shivakumar J, Suvarna P, Prasannakumar J. Variations in electrical activity of the heart as the pregnancy progresses. National Journal of Physiology, Pharmacy & Pharmacology. 2014;4(3):187-90.

Hill CC, Pickinpaugh J. Physiologic changes in pregnancy. Surg Clin North Am. 2008;88(2):391-01.

Poppas A, Shroff SG, Korcarz CE, Hibbard JU, Berger DS, Lindheimer MD, et al. Serial assessment of the cardiovascular system in normal pregnancy. Role of arterial compliance and pulsatile arterial load. Circulation. 1997;95(10):2407-15.

Bazett HC. Analysis of the time relations of electrocardiograms. Heart. 1918;7:353-70.

Surawicz B, Knilans TK. In: Chou’s Electrocardiography in Clinical Practice, 5thedn. Philadelphia: Saunders, 2001: 333-617.

Voss A, Malberg H, Schumann A, Wessel N, Walther T, Stepan H, Faber R. Baroreflex sensitivity, heart rate and blood pressure variability in normal pregnancy. Am J Hypertens. 2000;13(11):1218-25.

Julian DG, Wenger NK. Heart disease and heart surgery during pregnancy. In: women and heart disease. United Kingdom: Martin Dunitz; 2000s.

Katz R, Karliner JS, Resnik R. Effects of a natural volume overload state (pregnancy) on left ventricular performance in normal human subjects. Circulation. 1978;58:434-41.

Burwell CS. Circulatory adjustments to pregnancy. Bull Johns Hopkins Hosp. 1954;95(3):115-29.

Stein PK, Hagley MT, Cole PL, Domitrovicn PP, Kieigner RE, Rottman JN. Changes in 24 hours heart rate variability during normal pregnancy. Am J ObstetGynecol. 1999;180(4):978-85.

Akinwusi PO, Oboro VO, Adebayo RA, Akintunde AA, Adeniji AO, Isawumi IA, et al. Cardiovascular and electrocardiographic changes in Nigerians with a normal pregnancy. Cardiovasc J Afr. 2011;22(2):71-5.

Carruth JE, Mirvis SB, Brogan DR, Wenger NK. The electrocardiography in normal pregnancy. Am Heart J. 1981;102:1075-8.

Nandini BN, Shivakumar DG, Manjunath A, GirishBabu M. Shortening of PR- interval in different trimesters of pregnancy-A cross-sectional study. International Journal of Biomedical and Advance Research. 2011;2(11):421-6.

Veille JC, Kitzman DW, Bacevice AE. Effects of pregnancy on the electrocardiogram in healthy subjects during strenuous exercise. Am J Obstet Gynecol. 1996;175(5):1360-4.

Nandini BN, Shivakumar DG, Manjunath A, Sreepadma S. Occurrence of Q wave, QTC interval and QRS frontal axis during different trimesters of Pregnancy-A cross sectional study. Int J Curr Res Aca Rev. 2014;2(7):79-88.

Lechmanova M, Kittnar O, Mleck M, Slavicek J, DohnalovaA, Havranek S, et al. QT Dispersion and T-Loop Morphology in Late Pregnancy and After Delivery. Physiol Res. 2002;51:121-9.

21. Singh AD, Devi L, Singh L, Devi R, Singh J. Electrocardiographic findings at term, labour and immediate postpartum. J Obstet & Gynecol of India. 1986;36:316-9.

Sunitha M, Chandrasekharappa S, Brid SV. Electrocardiographic QRS axis, Q wave and T-wave changes in 2nd and 3rd trimester of normal pregnancy. Journal of Clinical and Diagnostic Research. 2014;8(9):BC17-BC21.

Montanez A, Ruskin JN, Hebert PR, Lamas GA, Hennekens CH. Prolonged QTc interval and risks of total and cardiovascular mortality and sudden death in general population. Arch Intern Med. 2004;164:943-48.