EVALUATION OF THE FRONTAL-PLANE QRS-T ANGLE IN PREGNANCY

Abstract

Objective: Our aim in this study was to evaluate changes in the frontal QRS–T (fQRS-T) angle, which is an important indicator of repolarisation defects and arrhythmogenic predisposition, in pregnant women relative to non-pregnant women and between trimester groups. Material and Methods: One hundred fifty-seven pregnant women with no history of cardiac or chronic disease and 150 healthy non-pregnant women as a control group were included in this study. PR, QRS, QT, corrected QT and fQRS-T angles were calculated manually. Subgroup analysis was performed to investigate the effects of changes in trimester on ECG of 58 pregnant women, whose ECG data of all three trimesters could be accessed. Result: The mean age of study participants was 31±7 years. The heart rates of pregnant women and the control group were 83±12 bpm and 76±14 bpm respectively (p<0.001), while fQRS–T angles measured 27.6°±17.7° and 20.7°±6.6° respectively (p<0.001). The frontal QRS-T angle was also detected significantly decrease in the progression from the first trimester (34.4±15.4) to the second (26.5±14.8) and third (23.3±20.3) trimesters (p=0.003). Gestational week had a statistically significant negative correlation with fQRS-T angle (r = −0.233; p=0.003). Conclusion: The fQRS-T angle, even if remained within the normal range was larger in pregnant women than in non-pregnant women and also larger in first trimester pregnant women relative to those in the second or third trimester.