Can we prolong safe pregnancy in cases of tachyarrhythmia?

Background tachyarrhythmias are relatively common in pregnant, however, the data on their clinical characteristics and impact on obstetric and neonatal outcomes remain limited. Purpose to determine clinical characteristics and pregnancy outcomes associated with tachyarrhythmias. Methods a total of 90 consecutive pregnant women diagnosed with tachyarrhythmia (mean age 27.3±4.3 years, mean gestation age 23.6 ±4.1 weeks) were included. Obstetric and neonatal outcomes were compared across types of arrhythmias and management strategies determined by the multidisciplinary Pregnancy heart team. Results The most frequent type of tachyarrhythmia in pregnant were paroxysmal supraventricular tachycardia (n=46, 51%) and premature contractions (n=36, 40%), while ventricular tachycardia was rare (n=8, 9%). A high risk of adverse maternal cardiac events was identified in 9% (mWHO 2.0 class III) and 44% (CARPEG II score of 3) of pregnant with tachyarrhythmias. Clinical manifestation typically first appeared during the second trimester (mean 16.2±1.3 weeks). The most frequent symptoms were palpitations (60.4%), general weakness (51.6%), while dyspnea (32.9%) and dizziness (27.4%) were less common (p=0.209). Management was individualized: dynamic observation in 15 cases (17%) with benign arrhythmia; antiarrhythmic therapy in 31 pregnant (34%) with severe symptoms and hemodynamic instability; catheter ablation without fluoroscopy in drug refractory and severe cases, performed using CARTO (21 cases; 47.7%) or Ensite Precision systems (23 cases; 52.3%). Further course of gestation was favorable with rare complication such as preeclampsia (4.4%) and impaired uterine blood flow (17.8%, p=0.451). Uterine contractile activity (2.2%) and placental abruption (2.2%) were observed only in pregnant after catheter ablation (p=0,464). Term delivery occurred in 98.9% of pregnancies, while one woman after catheter ablation delivered preterm at 35 weeks (1.1%; p=1.0). Vaginal delivery was predominant across all types of arrhythmias (82.2%). Neonatal outcomes characterized by normal range of fetal birth weight and 5-minute Apgar score regardless of arrhythmia type or management strategy (3316.3±212.1 grams and 8.6±1.3 respectively). There was no incidence of maternal and fetal mortality and arrhythmia recurrence after ablation in follow-up. Conclusion tachyarrhythmias may develop de novo in pregnancy (56%), most frequently in second trimester. Despite differing management approaches, gestation course and outcomes were benign, emphasizing the importance of coordinated multidisciplinary care.