Fetal conduction abnormalities: retrospective analysis of 40 cases from a South Indian tertiary care centre with management insights and brief review

Introduction:
Fetal cardiac rhythm disruptions pose significant challenges to prenatal and postnatal well-being. These disruptions, encompassing various arrhythmias, necessitate timely diagnosis and precise management. Transabdominal fetal echocardiography has become a crucial diagnostic tool for evaluating fetal arrhythmias, enabling tailored interventions.

Aim:
This retrospective study aims to examine 40 cases of fetal arrhythmias at our institution, shedding light on common abnormalities, diagnostic intricacies, and therapeutic strategies.

Material and methods:
A seven-year retrospective analysis was conducted at a tertiary-level hospital in South India. Cases with sustained fetal arrhythmias were reviewed, considering gestational age, types of arrhythmias, associated anomalies, and maternal factors. The diagnostic process involved transabdominal fetal echocardiography, emphasising M-mode and pulsed wave Doppler measurements.

Results:
Fetal bradyarrhythmias were predominant (57.5%, 23/40), with complete heart blocks being a primary cause. Hydrops was observed in 20% (8/40) of cases. Structural cardiac anomalies were present in 27.5% (11/40) of cases, with maternal antibody positivity noted in 22.5% (9/40). Management varied, including intrauterine and postnatal interventions based on the gestational period, severity of rhythm disturbance, and structural abnormalities. Few ectopic cases exhibited spontaneous regression. Fetal tachyarrhythmias (20%, 8/40) included supraventricular tachycardia (62.5%; 5/8), atrial flutter (12.5%, 1/8), junctional ectopic tachycardia (12.5%, 1/8), and ventricular tachycardia (12.5%, 1/8). Combined digoxin and flecainide showed success, especially in hydrops-associated cases.

Conclusions:
This study provides insights into the diverse presentations, diagnostic challenges, and therapeutic approaches in managing fetal arrhythmias. The findings underscore the critical role of accurate prenatal diagnosis for tailored therapeutic interventions. While advancements have been made, persistent challenges necessitate ongoing innovation. Call for further research to refine treatment strategies and collaboration among multidisciplinary teams remains paramount for these uncommon conditions.