Cardiac time intervals derived by magnetocardiography in fetuses exposed to pregnancy hypertension syndromes

OBJECTIVE: To test the hypothesis that fetuses exposed to maternal preeclampsia or chronic hypertension have deranged development of cardiac time intervals. STUDY DESIGN: Pregnancies were divided into three groups: Intrauterine Growth Restricted (IUGR), Hypertensive, and Normal. Each group's mean fetal cardiac time intervals (P, PR, QRS and RR) derived by magnetocardiography were calculated using an analysis of covariance model's regression-adjusted estimates for a gestational age of 35 weeks. RESULTS: We reviewed 141 recordings from 21 IUGR, 46 Hypertensive and 74 Normal patients. The IUGR, Hypertensive and Normal groups, respectively, had adjusted mean intervals in milliseconds of 66.4, 66.8 and 76.2 for P (P = 0.001), 95.9, 101.6 and 109.6 for PR (P = 0.002), 77.2, 78.7 and 78.7 for QRS (P = 0.81) and 429.8, 429.2 and 428.5 for RR (P = 0.97). CONCLUSION: P and PR intervals are abbreviated in normotrophic fetuses exposed to maternal hypertension, suggesting shortened atrioventricular conduction times.