Electrocardiographic indices and pregnancy: A focus on changes between first and third trimesters

Pregnancy can affect the cardiac conduction system, causing changes to the electrocardiographic indices that may mimic pathologic ones. The aim of this study was to discover these changes in normal pregnant women.

We included 103 healthy pregnant women, aged between 18-35 years. Standard 12-lead electrocardiogram was performed in the first and third trimester and electrocardiographic indices were calculated. The patients were classified in two age categories.

The mean PR interval in trimester one (T1) was 133.36±20.9 ms and in third trimester (T3) was 125.03±22.6ms (p=0.046). The mean QT in T1 and T3 was 314.21±18.99 ms and 324.02±19.4 ms, respectively (p<0.001). QRS duration in T1 and T3 was 90.24±28.91 ms and 94.97±10.79 ms, respectively (p=0.027). Mean of QTc (corrected QT interval) was 384.03±23.2 in T1 and 393.20±42.48 ms in T3 (p 0.023). The difference in electrocardiogram indices between T1 and T3 was not significant within the two age groups.

When comparing results between T1 and T3, mean parameters of electrocardiogram indices showed significant statistical differences. This will contribute insight on the approach to a number of pregnant women who complain of palpitations and visit a cardiologist. Although not statistically significant, the QT dispersion was 2% higher in participants over 30 years of age.