LAUSR

Abstract Funding Acknowledgements Type of funding sources: None. Background arrhythmias are the most common cardiac complication in pregnant. However, data on pregnancy course and outcomes of women with bradyarrhythmias is limited. Purpose we aimed to determine pregnancy course and both maternal and fetal outcomes in women with complete atrioventricular block. Methods Out of the 122 pregnant with arrhythmias within the study period of January 2015 to December 2021, 11 patients with complete atrioventricular block were included in this prospective study (study group). All pregnant were without structural pathology of the heart. Clinical signs, treatment as well as outcome data were recorded. Results were compared with the control group (other types of arrhythmias). Results The median age was 25.8 (inter-quartile range 3.1) years, the median gestation age was 18.3 (inter-quartile range 2.8) weeks. Unpaced pre-existing congenital heart block were in three cases (27.3%). In eight women atrioventricular block diagnosed for the first time during gestation (72.7%). All patients in study group had varying symptoms of arrhythmia like dizziness, presyncope and syncope. Course of gestation characterized with increased incidences of uterine contractile activity in women with complete atrioventricular block (27.3% vs 2.1%, p<0,001). Implantation of pacemaker was performed in all cases of complete atrioventricular block in pregnant patient. Implantation procedure carried with minimal fluoroscopy with echocardiographic guidance and EnSite NavX mapping system. There were no any procedure related complication and termination of pregnancy. Uterine blood flow violation was numerically lower in study group, although statistically differences not found. In the majority of cases were vaginal delivery at 39,4±1,8 weeks of gestation in both groups (82% vs 85%, p=0.548). All infants were live-born and without malformation. Incidences of placental abruption and preeclampsia were significantly higher in women with complete atrioventricular block (18.2% vs 2.13%, p<0,001). There were no maternal and fetal mortality in both group. Conclusions Complete atrioventricular block is rare in pregnant. Despite increased incidence of uterine contractile activity, placental abruption and preeclampsia in women with complete atrioventricular block, neonatal outcome is benign.